Convert to unix line endings

Sorry about the huge diff, but it is just line-ending changes so you can skip it

36 files changed, 7731 insertions, 7731 deletions

diff --git a/src/mongo/db/commands/document_source_cursor.cpp b/src/mongo/db/commands/document_source_cursor.cpp
index 5ac0e460b14..3fc2e4d4228 100755
--- a/src/mongo/db/commands/document_source_cursor.cpp
+++ b/src/mongo/db/commands/document_source_cursor.cpp
@@ -1,186 +1,186 @@
-/**

- * Copyright 2011 (c) 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "mongo/pch.h"

-

-#include "mongo/db/pipeline/document_source.h"

-

-#include "mongo/client/dbclientcursor.h"

-#include "mongo/db/clientcursor.h"

-#include "mongo/db/cursor.h"

-#include "mongo/db/instance.h"

-#include "mongo/db/pipeline/document.h"

-

-namespace mongo {

-

-    DocumentSourceCursor::~DocumentSourceCursor() {

-    }

-

-    void DocumentSourceCursor::releaseCursor() {

-        // note the order here; the cursor holder has to go first

-        pClientCursor.reset();

-        pCursor.reset();

-    }

-

-    bool DocumentSourceCursor::eof() {

-        /* if we haven't gotten the first one yet, do so now */

-        if (!pCurrent.get())

-            findNext();

-

-        return (pCurrent.get() == NULL);

-    }

-

-    bool DocumentSourceCursor::advance() {

-        DocumentSource::advance(); // check for interrupts

-

-        /* if we haven't gotten the first one yet, do so now */

-        if (!pCurrent.get())

-            findNext();

-

-        findNext();

-        return (pCurrent.get() != NULL);

-    }

-

-    intrusive_ptr<Document> DocumentSourceCursor::getCurrent() {

-        /* if we haven't gotten the first one yet, do so now */

-        if (!pCurrent.get())

-            findNext();

-

-        return pCurrent;

-    }

-

-    void DocumentSourceCursor::advanceAndYield() {

-        pCursor->advance();

-        /*

-          TODO ask for index key pattern in order to determine which index

-          was used for this particular document; that will allow us to

-          sometimes use ClientCursor::MaybeCovered.

-          See https://jira.mongodb.org/browse/SERVER-5224 .

-        */

-        bool cursorOk = pClientCursor->yieldSometimes(ClientCursor::WillNeed);

-        if (!cursorOk) {

-            uassert(16028,

-                    "collection or database disappeared when cursor yielded",

-                    false);

-        }

-    }

-

-    void DocumentSourceCursor::findNext() {

-        /* standard cursor usage pattern */

-        while(pCursor->ok()) {

-            CoveredIndexMatcher *pCIM; // save intermediate result

-            if ((!(pCIM = pCursor->matcher()) ||

-                 pCIM->matchesCurrent(pCursor.get())) &&

-                !pCursor->getsetdup(pCursor->currLoc())) {

-

-                /* grab the matching document */

-                BSONObj documentObj(pCursor->current());

-                pCurrent = Document::createFromBsonObj(

-                    &documentObj, NULL /* LATER pDependencies.get()*/);

-                advanceAndYield();

-                return;

-            }

-

-            advanceAndYield();

-        }

-

-        /* if we got here, there aren't any more documents */

-        pCurrent.reset();

-    }

-

-    void DocumentSourceCursor::setSource(DocumentSource *pSource) {

-        /* this doesn't take a source */

-        verify(false);

-    }

-

-    void DocumentSourceCursor::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-

-        /* this has no analog in the BSON world, so only allow it for explain */

-        if (explain)

-        {

-            BSONObj bsonObj;

-            

-            pBuilder->append("query", *pQuery);

-

-            if (pSort.get())

-            {

-                pBuilder->append("sort", *pSort);

-            }

-

-            // construct query for explain

-            BSONObjBuilder queryBuilder;

-            queryBuilder.append("$query", *pQuery);

-            if (pSort.get())

-                queryBuilder.append("$orderby", *pSort);

-            queryBuilder.append("$explain", 1);

-            Query query(queryBuilder.obj());

-

-            DBDirectClient directClient;

-            BSONObj explainResult(directClient.findOne(ns, query));

-

-            pBuilder->append("cursor", explainResult);

-        }

-    }

-

-    DocumentSourceCursor::DocumentSourceCursor(

-        const shared_ptr<Cursor> &pTheCursor,

-        const string &ns,

-        const intrusive_ptr<ExpressionContext> &pCtx):

-        DocumentSource(pCtx),

-        pCurrent(),

-        bsonDependencies(),

-        pCursor(pTheCursor),

-        pClientCursor(),

-        pDependencies() {

-        pClientCursor.reset(

-            new ClientCursor(QueryOption_NoCursorTimeout, pTheCursor, ns));

-    }

-

-    intrusive_ptr<DocumentSourceCursor> DocumentSourceCursor::create(

-        const shared_ptr<Cursor> &pCursor,

-        const string &ns,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        verify(pCursor.get());

-        intrusive_ptr<DocumentSourceCursor> pSource(

-            new DocumentSourceCursor(pCursor, ns, pExpCtx));

-            return pSource;

-    }

-

-    void DocumentSourceCursor::setNamespace(const string &n) {

-        ns = n;

-    }

-

-    void DocumentSourceCursor::setQuery(const shared_ptr<BSONObj> &pBsonObj) {

-        pQuery = pBsonObj;

-    }

-

-    void DocumentSourceCursor::setSort(const shared_ptr<BSONObj> &pBsonObj) {

-        pSort = pBsonObj;

-    }

-

-    void DocumentSourceCursor::addBsonDependency(

-        const shared_ptr<BSONObj> &pBsonObj) {

-        bsonDependencies.push_back(pBsonObj);

-    }

-

-    void DocumentSourceCursor::manageDependencies(

-        const intrusive_ptr<DependencyTracker> &pTracker) {

-        /* hang on to the tracker */

-        pDependencies = pTracker;

-    }

-

-}

+/**
+ * Copyright 2011 (c) 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "mongo/pch.h"
+
+#include "mongo/db/pipeline/document_source.h"
+
+#include "mongo/client/dbclientcursor.h"
+#include "mongo/db/clientcursor.h"
+#include "mongo/db/cursor.h"
+#include "mongo/db/instance.h"
+#include "mongo/db/pipeline/document.h"
+
+namespace mongo {
+
+    DocumentSourceCursor::~DocumentSourceCursor() {
+    }
+
+    void DocumentSourceCursor::releaseCursor() {
+        // note the order here; the cursor holder has to go first
+        pClientCursor.reset();
+        pCursor.reset();
+    }
+
+    bool DocumentSourceCursor::eof() {
+        /* if we haven't gotten the first one yet, do so now */
+        if (!pCurrent.get())
+            findNext();
+
+        return (pCurrent.get() == NULL);
+    }
+
+    bool DocumentSourceCursor::advance() {
+        DocumentSource::advance(); // check for interrupts
+
+        /* if we haven't gotten the first one yet, do so now */
+        if (!pCurrent.get())
+            findNext();
+
+        findNext();
+        return (pCurrent.get() != NULL);
+    }
+
+    intrusive_ptr<Document> DocumentSourceCursor::getCurrent() {
+        /* if we haven't gotten the first one yet, do so now */
+        if (!pCurrent.get())
+            findNext();
+
+        return pCurrent;
+    }
+
+    void DocumentSourceCursor::advanceAndYield() {
+        pCursor->advance();
+        /*
+          TODO ask for index key pattern in order to determine which index
+          was used for this particular document; that will allow us to
+          sometimes use ClientCursor::MaybeCovered.
+          See https://jira.mongodb.org/browse/SERVER-5224 .
+        */
+        bool cursorOk = pClientCursor->yieldSometimes(ClientCursor::WillNeed);
+        if (!cursorOk) {
+            uassert(16028,
+                    "collection or database disappeared when cursor yielded",
+                    false);
+        }
+    }
+
+    void DocumentSourceCursor::findNext() {
+        /* standard cursor usage pattern */
+        while(pCursor->ok()) {
+            CoveredIndexMatcher *pCIM; // save intermediate result
+            if ((!(pCIM = pCursor->matcher()) ||
+                 pCIM->matchesCurrent(pCursor.get())) &&
+                !pCursor->getsetdup(pCursor->currLoc())) {
+
+                /* grab the matching document */
+                BSONObj documentObj(pCursor->current());
+                pCurrent = Document::createFromBsonObj(
+                    &documentObj, NULL /* LATER pDependencies.get()*/);
+                advanceAndYield();
+                return;
+            }
+
+            advanceAndYield();
+        }
+
+        /* if we got here, there aren't any more documents */
+        pCurrent.reset();
+    }
+
+    void DocumentSourceCursor::setSource(DocumentSource *pSource) {
+        /* this doesn't take a source */
+        verify(false);
+    }
+
+    void DocumentSourceCursor::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+
+        /* this has no analog in the BSON world, so only allow it for explain */
+        if (explain)
+        {
+            BSONObj bsonObj;
+            
+            pBuilder->append("query", *pQuery);
+
+            if (pSort.get())
+            {
+                pBuilder->append("sort", *pSort);
+            }
+
+            // construct query for explain
+            BSONObjBuilder queryBuilder;
+            queryBuilder.append("$query", *pQuery);
+            if (pSort.get())
+                queryBuilder.append("$orderby", *pSort);
+            queryBuilder.append("$explain", 1);
+            Query query(queryBuilder.obj());
+
+            DBDirectClient directClient;
+            BSONObj explainResult(directClient.findOne(ns, query));
+
+            pBuilder->append("cursor", explainResult);
+        }
+    }
+
+    DocumentSourceCursor::DocumentSourceCursor(
+        const shared_ptr<Cursor> &pTheCursor,
+        const string &ns,
+        const intrusive_ptr<ExpressionContext> &pCtx):
+        DocumentSource(pCtx),
+        pCurrent(),
+        bsonDependencies(),
+        pCursor(pTheCursor),
+        pClientCursor(),
+        pDependencies() {
+        pClientCursor.reset(
+            new ClientCursor(QueryOption_NoCursorTimeout, pTheCursor, ns));
+    }
+
+    intrusive_ptr<DocumentSourceCursor> DocumentSourceCursor::create(
+        const shared_ptr<Cursor> &pCursor,
+        const string &ns,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        verify(pCursor.get());
+        intrusive_ptr<DocumentSourceCursor> pSource(
+            new DocumentSourceCursor(pCursor, ns, pExpCtx));
+            return pSource;
+    }
+
+    void DocumentSourceCursor::setNamespace(const string &n) {
+        ns = n;
+    }
+
+    void DocumentSourceCursor::setQuery(const shared_ptr<BSONObj> &pBsonObj) {
+        pQuery = pBsonObj;
+    }
+
+    void DocumentSourceCursor::setSort(const shared_ptr<BSONObj> &pBsonObj) {
+        pSort = pBsonObj;
+    }
+
+    void DocumentSourceCursor::addBsonDependency(
+        const shared_ptr<BSONObj> &pBsonObj) {
+        bsonDependencies.push_back(pBsonObj);
+    }
+
+    void DocumentSourceCursor::manageDependencies(
+        const intrusive_ptr<DependencyTracker> &pTracker) {
+        /* hang on to the tracker */
+        pDependencies = pTracker;
+    }
+
+}
diff --git a/src/mongo/db/commands/pipeline.cpp b/src/mongo/db/commands/pipeline.cpp
index 3ee80c42d7a..951c642162d 100755
--- a/src/mongo/db/commands/pipeline.cpp
+++ b/src/mongo/db/commands/pipeline.cpp
@@ -1,500 +1,500 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "db/commands/pipeline.h"

-

-#include "db/cursor.h"

-#include "db/pipeline/accumulator.h"

-#include "db/pipeline/dependency_tracker.h"

-#include "db/pipeline/document.h"

-#include "db/pipeline/document_source.h"

-#include "db/pipeline/expression.h"

-#include "db/pipeline/expression_context.h"

-#include "db/pdfile.h"

-#include "util/mongoutils/str.h"

-

-namespace mongo {

-

-    const char Pipeline::commandName[] = "aggregate";

-    const char Pipeline::pipelineName[] = "pipeline";

-    const char Pipeline::explainName[] = "explain";

-    const char Pipeline::fromRouterName[] = "fromRouter";

-    const char Pipeline::splitMongodPipelineName[] = "splitMongodPipeline";

-    const char Pipeline::serverPipelineName[] = "serverPipeline";

-    const char Pipeline::mongosPipelineName[] = "mongosPipeline";

-

-    Pipeline::~Pipeline() {

-    }

-

-    Pipeline::Pipeline(const intrusive_ptr<ExpressionContext> &pTheCtx):

-        collectionName(),

-        sourceVector(),

-        explain(false),

-        splitMongodPipeline(false),

-        pCtx(pTheCtx) {

-    }

-

-

-    /* this structure is used to make a lookup table of operators */

-    struct StageDesc {

-        const char *pName;

-        intrusive_ptr<DocumentSource> (*pFactory)(

-            BSONElement *, const intrusive_ptr<ExpressionContext> &);

-    };

-

-    /* this table must be in alphabetical order by name for bsearch() */

-    static const StageDesc stageDesc[] = {

-#ifdef NEVER /* disabled for now in favor of $match */

-        {DocumentSourceFilter::filterName,

-         DocumentSourceFilter::createFromBson},

-#endif

-        {DocumentSourceGroup::groupName,

-         DocumentSourceGroup::createFromBson},

-        {DocumentSourceLimit::limitName,

-         DocumentSourceLimit::createFromBson},

-        {DocumentSourceMatch::matchName,

-         DocumentSourceMatch::createFromBson},

-#ifdef LATER /* https://jira.mongodb.org/browse/SERVER-3253 */

-        {DocumentSourceOut::outName,

-         DocumentSourceOut::createFromBson},

-#endif

-        {DocumentSourceProject::projectName,

-         DocumentSourceProject::createFromBson},

-        {DocumentSourceSkip::skipName,

-         DocumentSourceSkip::createFromBson},

-        {DocumentSourceSort::sortName,

-         DocumentSourceSort::createFromBson},

-        {DocumentSourceUnwind::unwindName,

-         DocumentSourceUnwind::createFromBson},

-    };

-    static const size_t nStageDesc = sizeof(stageDesc) / sizeof(StageDesc);

-

-    static int stageDescCmp(const void *pL, const void *pR) {

-        return strcmp(((const StageDesc *)pL)->pName,

-                      ((const StageDesc *)pR)->pName);

-    }

-

-    intrusive_ptr<Pipeline> Pipeline::parseCommand(

-        string &errmsg, BSONObj &cmdObj,

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        intrusive_ptr<Pipeline> pPipeline(new Pipeline(pCtx));

-        vector<BSONElement> pipeline;

-

-        /* gather the specification for the aggregation */

-        for(BSONObj::iterator cmdIterator = cmdObj.begin();

-                cmdIterator.more(); ) {

-            BSONElement cmdElement(cmdIterator.next());

-            const char *pFieldName = cmdElement.fieldName();

-

-            /* look for the aggregation command */

-            if (!strcmp(pFieldName, commandName)) {

-                pPipeline->collectionName = cmdElement.String();

-                continue;

-            }

-

-            /* check for the collection name */

-            if (!strcmp(pFieldName, pipelineName)) {

-                pipeline = cmdElement.Array();

-                continue;

-            }

-

-            /* check for explain option */

-            if (!strcmp(pFieldName, explainName)) {

-                pPipeline->explain = cmdElement.Bool();

-                continue;

-            }

-

-            /* if the request came from the router, we're in a shard */

-            if (!strcmp(pFieldName, fromRouterName)) {

-                pCtx->setInShard(cmdElement.Bool());

-                continue;

-            }

-

-            /* check for debug options */

-            if (!strcmp(pFieldName, splitMongodPipelineName)) {

-                pPipeline->splitMongodPipeline = true;

-                continue;

-            }

-

-            /* we didn't recognize a field in the command */

-            ostringstream sb;

-            sb <<

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "db/commands/pipeline.h"
+
+#include "db/cursor.h"
+#include "db/pipeline/accumulator.h"
+#include "db/pipeline/dependency_tracker.h"
+#include "db/pipeline/document.h"
+#include "db/pipeline/document_source.h"
+#include "db/pipeline/expression.h"
+#include "db/pipeline/expression_context.h"
+#include "db/pdfile.h"
+#include "util/mongoutils/str.h"
+
+namespace mongo {
+
+    const char Pipeline::commandName[] = "aggregate";
+    const char Pipeline::pipelineName[] = "pipeline";
+    const char Pipeline::explainName[] = "explain";
+    const char Pipeline::fromRouterName[] = "fromRouter";
+    const char Pipeline::splitMongodPipelineName[] = "splitMongodPipeline";
+    const char Pipeline::serverPipelineName[] = "serverPipeline";
+    const char Pipeline::mongosPipelineName[] = "mongosPipeline";
+
+    Pipeline::~Pipeline() {
+    }
+
+    Pipeline::Pipeline(const intrusive_ptr<ExpressionContext> &pTheCtx):
+        collectionName(),
+        sourceVector(),
+        explain(false),
+        splitMongodPipeline(false),
+        pCtx(pTheCtx) {
+    }
+
+
+    /* this structure is used to make a lookup table of operators */
+    struct StageDesc {
+        const char *pName;
+        intrusive_ptr<DocumentSource> (*pFactory)(
+            BSONElement *, const intrusive_ptr<ExpressionContext> &);
+    };
+
+    /* this table must be in alphabetical order by name for bsearch() */
+    static const StageDesc stageDesc[] = {
+#ifdef NEVER /* disabled for now in favor of $match */
+        {DocumentSourceFilter::filterName,
+         DocumentSourceFilter::createFromBson},
+#endif
+        {DocumentSourceGroup::groupName,
+         DocumentSourceGroup::createFromBson},
+        {DocumentSourceLimit::limitName,
+         DocumentSourceLimit::createFromBson},
+        {DocumentSourceMatch::matchName,
+         DocumentSourceMatch::createFromBson},
+#ifdef LATER /* https://jira.mongodb.org/browse/SERVER-3253 */
+        {DocumentSourceOut::outName,
+         DocumentSourceOut::createFromBson},
+#endif
+        {DocumentSourceProject::projectName,
+         DocumentSourceProject::createFromBson},
+        {DocumentSourceSkip::skipName,
+         DocumentSourceSkip::createFromBson},
+        {DocumentSourceSort::sortName,
+         DocumentSourceSort::createFromBson},
+        {DocumentSourceUnwind::unwindName,
+         DocumentSourceUnwind::createFromBson},
+    };
+    static const size_t nStageDesc = sizeof(stageDesc) / sizeof(StageDesc);
+
+    static int stageDescCmp(const void *pL, const void *pR) {
+        return strcmp(((const StageDesc *)pL)->pName,
+                      ((const StageDesc *)pR)->pName);
+    }
+
+    intrusive_ptr<Pipeline> Pipeline::parseCommand(
+        string &errmsg, BSONObj &cmdObj,
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<Pipeline> pPipeline(new Pipeline(pCtx));
+        vector<BSONElement> pipeline;
+
+        /* gather the specification for the aggregation */
+        for(BSONObj::iterator cmdIterator = cmdObj.begin();
+                cmdIterator.more(); ) {
+            BSONElement cmdElement(cmdIterator.next());
+            const char *pFieldName = cmdElement.fieldName();
+
+            /* look for the aggregation command */
+            if (!strcmp(pFieldName, commandName)) {
+                pPipeline->collectionName = cmdElement.String();
+                continue;
+            }
+
+            /* check for the collection name */
+            if (!strcmp(pFieldName, pipelineName)) {
+                pipeline = cmdElement.Array();
+                continue;
+            }
+
+            /* check for explain option */
+            if (!strcmp(pFieldName, explainName)) {
+                pPipeline->explain = cmdElement.Bool();
+                continue;
+            }
+
+            /* if the request came from the router, we're in a shard */
+            if (!strcmp(pFieldName, fromRouterName)) {
+                pCtx->setInShard(cmdElement.Bool());
+                continue;
+            }
+
+            /* check for debug options */
+            if (!strcmp(pFieldName, splitMongodPipelineName)) {
+                pPipeline->splitMongodPipeline = true;
+                continue;
+            }
+
+            /* we didn't recognize a field in the command */
+            ostringstream sb;
+            sb <<
                "unrecognized field \"" <<
-               cmdElement.fieldName();

-            errmsg = sb.str();

-            return intrusive_ptr<Pipeline>();

-        }

-

-        /*

-          If we get here, we've harvested the fields we expect for a pipeline.

-

-          Set up the specified document source pipeline.

-        */

-        SourceVector *pSourceVector = &pPipeline->sourceVector; // shorthand

-

-        /* iterate over the steps in the pipeline */

-        const size_t nSteps = pipeline.size();

-        for(size_t iStep = 0; iStep < nSteps; ++iStep) {

-            /* pull out the pipeline element as an object */

-            BSONElement pipeElement(pipeline[iStep]);

-            uassert(15942, str::stream() << "pipeline element " <<

-                    iStep << " is not an object",

-                    pipeElement.type() == Object);

-            BSONObj bsonObj(pipeElement.Obj());

-

-            intrusive_ptr<DocumentSource> pSource;

-

-            /* use the object to add a DocumentSource to the processing chain */

-            BSONObjIterator bsonIterator(bsonObj);

-            while(bsonIterator.more()) {

-                BSONElement bsonElement(bsonIterator.next());

-                const char *pFieldName = bsonElement.fieldName();

-

-                /* select the appropriate operation and instantiate */

-                StageDesc key;

-                key.pName = pFieldName;

-                const StageDesc *pDesc = (const StageDesc *)

-                    bsearch(&key, stageDesc, nStageDesc, sizeof(StageDesc),

-                            stageDescCmp);

-                if (pDesc) {

-                    pSource = (*pDesc->pFactory)(&bsonElement, pCtx);

-                    pSource->setPipelineStep(iStep);

-                }

-                else {

-                    ostringstream sb;

-                    sb <<

-                       "Pipeline::run(): unrecognized pipeline op \"" <<

-                       pFieldName;

-                    errmsg = sb.str();

-                    return intrusive_ptr<Pipeline>();

-                }

-            }

-

-            pSourceVector->push_back(pSource);

-        }

-

-        /* if there aren't any pipeline stages, there's nothing more to do */

-        if (!pSourceVector->size())

-            return pPipeline;

-

-        /*

-          Move filters up where possible.

-

-          CW TODO -- move filter past projections where possible, and noting

-          corresponding field renaming.

-        */

-

-        /*

-          Wherever there is a match immediately following a sort, swap them.

-          This means we sort fewer items.  Neither changes the documents in

-          the stream, so this transformation shouldn't affect the result.

-

-          We do this first, because then when we coalesce operators below,

-          any adjacent matches will be combined.

-         */

-        for(size_t srcn = pSourceVector->size(), srci = 1;

-            srci < srcn; ++srci) {

-            intrusive_ptr<DocumentSource> &pSource = pSourceVector->at(srci);

-            if (dynamic_cast<DocumentSourceMatch *>(pSource.get())) {

-                intrusive_ptr<DocumentSource> &pPrevious =

-                    pSourceVector->at(srci - 1);

-                if (dynamic_cast<DocumentSourceSort *>(pPrevious.get())) {

-                    /* swap this item with the previous */

-                    intrusive_ptr<DocumentSource> pTemp(pPrevious);

-                    pPrevious = pSource;

-                    pSource = pTemp;

-                }

-            }

-        }

-

-        /*

-          Coalesce adjacent filters where possible.  Two adjacent filters

-          are equivalent to one filter whose predicate is the conjunction of

-          the two original filters' predicates.  For now, capture this by

-          giving any DocumentSource the option to absorb it's successor; this

-          will also allow adjacent projections to coalesce when possible.

-

-          Run through the DocumentSources, and give each one the opportunity

-          to coalesce with its successor.  If successful, remove the

-          successor.

-

-          Move all document sources to a temporary list.

-        */

-        SourceVector tempVector(*pSourceVector);

-        pSourceVector->clear();

-

-        /* move the first one to the final list */

-        pSourceVector->push_back(tempVector[0]);

-

-        /* run through the sources, coalescing them or keeping them */

-        for(size_t tempn = tempVector.size(), tempi = 1;

-            tempi < tempn; ++tempi) {

-            /*

-              If we can't coalesce the source with the last, then move it

-              to the final list, and make it the new last.  (If we succeeded,

-              then we're still on the same last, and there's no need to move

-              or do anything with the source -- the destruction of tempVector

-              will take care of the rest.)

-            */

-            intrusive_ptr<DocumentSource> &pLastSource = pSourceVector->back();

-            intrusive_ptr<DocumentSource> &pTemp = tempVector.at(tempi);

+               cmdElement.fieldName();
+            errmsg = sb.str();
+            return intrusive_ptr<Pipeline>();
+        }
+
+        /*
+          If we get here, we've harvested the fields we expect for a pipeline.
+
+          Set up the specified document source pipeline.
+        */
+        SourceVector *pSourceVector = &pPipeline->sourceVector; // shorthand
+
+        /* iterate over the steps in the pipeline */
+        const size_t nSteps = pipeline.size();
+        for(size_t iStep = 0; iStep < nSteps; ++iStep) {
+            /* pull out the pipeline element as an object */
+            BSONElement pipeElement(pipeline[iStep]);
+            uassert(15942, str::stream() << "pipeline element " <<
+                    iStep << " is not an object",
+                    pipeElement.type() == Object);
+            BSONObj bsonObj(pipeElement.Obj());
+
+            intrusive_ptr<DocumentSource> pSource;
+
+            /* use the object to add a DocumentSource to the processing chain */
+            BSONObjIterator bsonIterator(bsonObj);
+            while(bsonIterator.more()) {
+                BSONElement bsonElement(bsonIterator.next());
+                const char *pFieldName = bsonElement.fieldName();
+
+                /* select the appropriate operation and instantiate */
+                StageDesc key;
+                key.pName = pFieldName;
+                const StageDesc *pDesc = (const StageDesc *)
+                    bsearch(&key, stageDesc, nStageDesc, sizeof(StageDesc),
+                            stageDescCmp);
+                if (pDesc) {
+                    pSource = (*pDesc->pFactory)(&bsonElement, pCtx);
+                    pSource->setPipelineStep(iStep);
+                }
+                else {
+                    ostringstream sb;
+                    sb <<
+                       "Pipeline::run(): unrecognized pipeline op \"" <<
+                       pFieldName;
+                    errmsg = sb.str();
+                    return intrusive_ptr<Pipeline>();
+                }
+            }
+
+            pSourceVector->push_back(pSource);
+        }
+
+        /* if there aren't any pipeline stages, there's nothing more to do */
+        if (!pSourceVector->size())
+            return pPipeline;
+
+        /*
+          Move filters up where possible.
+
+          CW TODO -- move filter past projections where possible, and noting
+          corresponding field renaming.
+        */
+
+        /*
+          Wherever there is a match immediately following a sort, swap them.
+          This means we sort fewer items.  Neither changes the documents in
+          the stream, so this transformation shouldn't affect the result.
+
+          We do this first, because then when we coalesce operators below,
+          any adjacent matches will be combined.
+         */
+        for(size_t srcn = pSourceVector->size(), srci = 1;
+            srci < srcn; ++srci) {
+            intrusive_ptr<DocumentSource> &pSource = pSourceVector->at(srci);
+            if (dynamic_cast<DocumentSourceMatch *>(pSource.get())) {
+                intrusive_ptr<DocumentSource> &pPrevious =
+                    pSourceVector->at(srci - 1);
+                if (dynamic_cast<DocumentSourceSort *>(pPrevious.get())) {
+                    /* swap this item with the previous */
+                    intrusive_ptr<DocumentSource> pTemp(pPrevious);
+                    pPrevious = pSource;
+                    pSource = pTemp;
+                }
+            }
+        }
+
+        /*
+          Coalesce adjacent filters where possible.  Two adjacent filters
+          are equivalent to one filter whose predicate is the conjunction of
+          the two original filters' predicates.  For now, capture this by
+          giving any DocumentSource the option to absorb it's successor; this
+          will also allow adjacent projections to coalesce when possible.
+
+          Run through the DocumentSources, and give each one the opportunity
+          to coalesce with its successor.  If successful, remove the
+          successor.
+
+          Move all document sources to a temporary list.
+        */
+        SourceVector tempVector(*pSourceVector);
+        pSourceVector->clear();
+
+        /* move the first one to the final list */
+        pSourceVector->push_back(tempVector[0]);
+
+        /* run through the sources, coalescing them or keeping them */
+        for(size_t tempn = tempVector.size(), tempi = 1;
+            tempi < tempn; ++tempi) {
+            /*
+              If we can't coalesce the source with the last, then move it
+              to the final list, and make it the new last.  (If we succeeded,
+              then we're still on the same last, and there's no need to move
+              or do anything with the source -- the destruction of tempVector
+              will take care of the rest.)
+            */
+            intrusive_ptr<DocumentSource> &pLastSource = pSourceVector->back();
+            intrusive_ptr<DocumentSource> &pTemp = tempVector.at(tempi);
             if (!pTemp || !pLastSource) {
                 errmsg = "Pipeline received empty document as argument";
                 return intrusive_ptr<Pipeline>();
             }
-            if (!pLastSource->coalesce(pTemp))

-                pSourceVector->push_back(pTemp);

-        }

-

-        /* optimize the elements in the pipeline */

-        for(SourceVector::iterator iter(pSourceVector->begin()),

+            if (!pLastSource->coalesce(pTemp))
+                pSourceVector->push_back(pTemp);
+        }
+
+        /* optimize the elements in the pipeline */
+        for(SourceVector::iterator iter(pSourceVector->begin()),
                 listEnd(pSourceVector->end()); iter != listEnd; ++iter) {
             if (!*iter) {
                 errmsg = "Pipeline received empty document as argument";
                 return intrusive_ptr<Pipeline>();
             }
 
-            (*iter)->optimize();

+            (*iter)->optimize();
         }
-

-        return pPipeline;

-    }

-

-    intrusive_ptr<Pipeline> Pipeline::splitForSharded() {

-        /* create an initialize the shard spec we'll return */

-        intrusive_ptr<Pipeline> pShardPipeline(new Pipeline(pCtx));

-        pShardPipeline->collectionName = collectionName;

-        pShardPipeline->explain = explain;

-

-        /* put the source list aside */

-        SourceVector tempVector(sourceVector);

-        sourceVector.clear();

-

-        /*

-          Run through the pipeline, looking for points to split it into

-          shard pipelines, and the rest.

-         */

-        while(!tempVector.empty()) {

-            intrusive_ptr<DocumentSource> &pSource = tempVector.front();

-

-            /* hang on to this in advance, in case it is a group */

-            DocumentSourceGroup *pGroup =

-                dynamic_cast<DocumentSourceGroup *>(pSource.get());

-

-            /* move the source from the tempVector to the shard sourceVector */

-            pShardPipeline->sourceVector.push_back(pSource);

-            tempVector.erase(tempVector.begin());

-

-            /*

-              If we found a group, that's a split point.

-             */

-            if (pGroup) {

-                /* start this pipeline with the group merger */

-                sourceVector.push_back(pGroup->createMerger());

-

-                /* and then add everything that remains and quit */

-                for(size_t tempn = tempVector.size(), tempi = 0;

-                    tempi < tempn; ++tempi)

-                    sourceVector.push_back(tempVector[tempi]);

-                break;

-            }

-        }

-

-        return pShardPipeline;

-    }

-

-    bool Pipeline::getInitialQuery(BSONObjBuilder *pQueryBuilder) const

-    {

-        if (!sourceVector.size())

-            return false;

-

-        /* look for an initial $match */

-        const intrusive_ptr<DocumentSource> &pMC = sourceVector.front();

-        const DocumentSourceMatch *pMatch =

-            dynamic_cast<DocumentSourceMatch *>(pMC.get());

-

-        if (!pMatch)

-            return false;

-

-        /* build the query */

-        pMatch->toMatcherBson(pQueryBuilder);

-

-        return true;

-    }

-

-    void Pipeline::toBson(BSONObjBuilder *pBuilder) const {

-        /* create an array out of the pipeline operations */

-        BSONArrayBuilder arrayBuilder;

-        for(SourceVector::const_iterator iter(sourceVector.begin()),

-                listEnd(sourceVector.end()); iter != listEnd; ++iter) {

-            intrusive_ptr<DocumentSource> pSource(*iter);

-            pSource->addToBsonArray(&arrayBuilder);

-        }

-

-        /* add the top-level items to the command */

-        pBuilder->append(commandName, getCollectionName());

-        pBuilder->append(pipelineName, arrayBuilder.arr());

-

-        if (explain) {

-            pBuilder->append(explainName, explain);

-        }

-

-        bool btemp;

-        if ((btemp = getSplitMongodPipeline())) {

-            pBuilder->append(splitMongodPipelineName, btemp);

-        }

-

-        if ((btemp = pCtx->getInRouter())) {

-            pBuilder->append(fromRouterName, btemp);

-        }

-    }

-

-    bool Pipeline::run(BSONObjBuilder &result, string &errmsg,

-                       const intrusive_ptr<DocumentSource> &pInputSource) {

-        /*

-          Analyze dependency information.

-

-          This pushes dependencies from the end of the pipeline back to the

-          front of it, and finally passes that to the input source before we

-          execute the pipeline.

-        */

-        intrusive_ptr<DependencyTracker> pTracker(new DependencyTracker());

-        for(SourceVector::reverse_iterator iter(sourceVector.rbegin()),

-                listBeg(sourceVector.rend()); iter != listBeg; ++iter) {

-            intrusive_ptr<DocumentSource> pTemp(*iter);

-            pTemp->manageDependencies(pTracker);

-        }

-

-        pInputSource->manageDependencies(pTracker);

-        

-        /* chain together the sources we found */

-        DocumentSource *pSource = pInputSource.get();

-        for(SourceVector::iterator iter(sourceVector.begin()),

-                listEnd(sourceVector.end()); iter != listEnd; ++iter) {

-            intrusive_ptr<DocumentSource> pTemp(*iter);

-            pTemp->setSource(pSource);

-            pSource = pTemp.get();

-        }

-        /* pSource is left pointing at the last source in the chain */

-

-        /*

-          Iterate through the resulting documents, and add them to the result.

-          We do this even if we're doing an explain, in order to capture

-          the document counts and other stats.  However, we don't capture

-          the result documents for explain.

-

-          We wrap all the BSONObjBuilder calls with a try/catch in case the

-          objects get too large and cause an exception.

-        */

-        try {

-            if (explain) {

-                if (!pCtx->getInRouter())

-                    writeExplainShard(result, pInputSource);

-                else {

-                    writeExplainMongos(result, pInputSource);

-                }

-            }

-            else

-            {

-                BSONArrayBuilder resultArray; // where we'll stash the results

-                for(bool hasDocument = !pSource->eof(); hasDocument;

-                    hasDocument = pSource->advance()) {

-                    intrusive_ptr<Document> pDocument(pSource->getCurrent());

-

-                    /* add the document to the result set */

-                    BSONObjBuilder documentBuilder;

-                    pDocument->toBson(&documentBuilder);

-                    resultArray.append(documentBuilder.done());

-                }

-

-                result.appendArray("result", resultArray.arr());

-            }

-         } catch(AssertionException &ae) {

-            /* 

-               If its not the "object too large" error, rethrow.

-               At time of writing, that error code comes from

-               mongo/src/mongo/bson/util/builder.h

-            */

-            if (ae.getCode() != 13548)

-                throw;

-

-            /* throw the nicer human-readable error */

-            uassert(16029, str::stream() <<

-                    "aggregation result exceeds maximum document size limit ("

-                    << (BSONObjMaxUserSize / (1024 * 1024)) << "MB)",

-                    false);

-         }

-

-        return true;

-    }

-

-    void Pipeline::writeExplainOps(BSONArrayBuilder *pArrayBuilder) const {

-        for(SourceVector::const_iterator iter(sourceVector.begin()),

-                listEnd(sourceVector.end()); iter != listEnd; ++iter) {

-            intrusive_ptr<DocumentSource> pSource(*iter);

-

-            pSource->addToBsonArray(pArrayBuilder, true);

-        }

-    }

-

-    void Pipeline::writeExplainShard(

-        BSONObjBuilder &result,

-        const intrusive_ptr<DocumentSource> &pInputSource) const {

-        BSONArrayBuilder opArray; // where we'll put the pipeline ops

-

-        // first the cursor, which isn't in the opArray

-        pInputSource->addToBsonArray(&opArray, true);

-

-        // next, add the pipeline operators

-        writeExplainOps(&opArray);

-

-        result.appendArray(serverPipelineName, opArray.arr());

-    }

-

-    void Pipeline::writeExplainMongos(

-        BSONObjBuilder &result,

-        const intrusive_ptr<DocumentSource> &pInputSource) const {

-

-        /*

-          For now, this should be a BSON source array.

-          In future, we might have a more clever way of getting this, when

-          we have more interleaved fetching between shards.  The DocumentSource

-          interface will have to change to accomodate that.

-         */

-        DocumentSourceBsonArray *pSourceBsonArray =

-            dynamic_cast<DocumentSourceBsonArray *>(pInputSource.get());

-        verify(pSourceBsonArray);

-

-        BSONArrayBuilder shardOpArray; // where we'll put the pipeline ops

-        for(bool hasDocument = !pSourceBsonArray->eof(); hasDocument;

-            hasDocument = pSourceBsonArray->advance()) {

-            intrusive_ptr<Document> pDocument(

-                pSourceBsonArray->getCurrent());

-            BSONObjBuilder opBuilder;

-            pDocument->toBson(&opBuilder);

-            shardOpArray.append(opBuilder.obj());

-        }

-

-        BSONArrayBuilder mongosOpArray; // where we'll put the pipeline ops

-        writeExplainOps(&mongosOpArray);

-

-        // now we combine the shard pipelines with the one here

-        result.append(serverPipelineName, shardOpArray.arr());

-        result.append(mongosPipelineName, mongosOpArray.arr());

-    }

-

-} // namespace mongo

+
+        return pPipeline;
+    }
+
+    intrusive_ptr<Pipeline> Pipeline::splitForSharded() {
+        /* create an initialize the shard spec we'll return */
+        intrusive_ptr<Pipeline> pShardPipeline(new Pipeline(pCtx));
+        pShardPipeline->collectionName = collectionName;
+        pShardPipeline->explain = explain;
+
+        /* put the source list aside */
+        SourceVector tempVector(sourceVector);
+        sourceVector.clear();
+
+        /*
+          Run through the pipeline, looking for points to split it into
+          shard pipelines, and the rest.
+         */
+        while(!tempVector.empty()) {
+            intrusive_ptr<DocumentSource> &pSource = tempVector.front();
+
+            /* hang on to this in advance, in case it is a group */
+            DocumentSourceGroup *pGroup =
+                dynamic_cast<DocumentSourceGroup *>(pSource.get());
+
+            /* move the source from the tempVector to the shard sourceVector */
+            pShardPipeline->sourceVector.push_back(pSource);
+            tempVector.erase(tempVector.begin());
+
+            /*
+              If we found a group, that's a split point.
+             */
+            if (pGroup) {
+                /* start this pipeline with the group merger */
+                sourceVector.push_back(pGroup->createMerger());
+
+                /* and then add everything that remains and quit */
+                for(size_t tempn = tempVector.size(), tempi = 0;
+                    tempi < tempn; ++tempi)
+                    sourceVector.push_back(tempVector[tempi]);
+                break;
+            }
+        }
+
+        return pShardPipeline;
+    }
+
+    bool Pipeline::getInitialQuery(BSONObjBuilder *pQueryBuilder) const
+    {
+        if (!sourceVector.size())
+            return false;
+
+        /* look for an initial $match */
+        const intrusive_ptr<DocumentSource> &pMC = sourceVector.front();
+        const DocumentSourceMatch *pMatch =
+            dynamic_cast<DocumentSourceMatch *>(pMC.get());
+
+        if (!pMatch)
+            return false;
+
+        /* build the query */
+        pMatch->toMatcherBson(pQueryBuilder);
+
+        return true;
+    }
+
+    void Pipeline::toBson(BSONObjBuilder *pBuilder) const {
+        /* create an array out of the pipeline operations */
+        BSONArrayBuilder arrayBuilder;
+        for(SourceVector::const_iterator iter(sourceVector.begin()),
+                listEnd(sourceVector.end()); iter != listEnd; ++iter) {
+            intrusive_ptr<DocumentSource> pSource(*iter);
+            pSource->addToBsonArray(&arrayBuilder);
+        }
+
+        /* add the top-level items to the command */
+        pBuilder->append(commandName, getCollectionName());
+        pBuilder->append(pipelineName, arrayBuilder.arr());
+
+        if (explain) {
+            pBuilder->append(explainName, explain);
+        }
+
+        bool btemp;
+        if ((btemp = getSplitMongodPipeline())) {
+            pBuilder->append(splitMongodPipelineName, btemp);
+        }
+
+        if ((btemp = pCtx->getInRouter())) {
+            pBuilder->append(fromRouterName, btemp);
+        }
+    }
+
+    bool Pipeline::run(BSONObjBuilder &result, string &errmsg,
+                       const intrusive_ptr<DocumentSource> &pInputSource) {
+        /*
+          Analyze dependency information.
+
+          This pushes dependencies from the end of the pipeline back to the
+          front of it, and finally passes that to the input source before we
+          execute the pipeline.
+        */
+        intrusive_ptr<DependencyTracker> pTracker(new DependencyTracker());
+        for(SourceVector::reverse_iterator iter(sourceVector.rbegin()),
+                listBeg(sourceVector.rend()); iter != listBeg; ++iter) {
+            intrusive_ptr<DocumentSource> pTemp(*iter);
+            pTemp->manageDependencies(pTracker);
+        }
+
+        pInputSource->manageDependencies(pTracker);
+        
+        /* chain together the sources we found */
+        DocumentSource *pSource = pInputSource.get();
+        for(SourceVector::iterator iter(sourceVector.begin()),
+                listEnd(sourceVector.end()); iter != listEnd; ++iter) {
+            intrusive_ptr<DocumentSource> pTemp(*iter);
+            pTemp->setSource(pSource);
+            pSource = pTemp.get();
+        }
+        /* pSource is left pointing at the last source in the chain */
+
+        /*
+          Iterate through the resulting documents, and add them to the result.
+          We do this even if we're doing an explain, in order to capture
+          the document counts and other stats.  However, we don't capture
+          the result documents for explain.
+
+          We wrap all the BSONObjBuilder calls with a try/catch in case the
+          objects get too large and cause an exception.
+        */
+        try {
+            if (explain) {
+                if (!pCtx->getInRouter())
+                    writeExplainShard(result, pInputSource);
+                else {
+                    writeExplainMongos(result, pInputSource);
+                }
+            }
+            else
+            {
+                BSONArrayBuilder resultArray; // where we'll stash the results
+                for(bool hasDocument = !pSource->eof(); hasDocument;
+                    hasDocument = pSource->advance()) {
+                    intrusive_ptr<Document> pDocument(pSource->getCurrent());
+
+                    /* add the document to the result set */
+                    BSONObjBuilder documentBuilder;
+                    pDocument->toBson(&documentBuilder);
+                    resultArray.append(documentBuilder.done());
+                }
+
+                result.appendArray("result", resultArray.arr());
+            }
+         } catch(AssertionException &ae) {
+            /* 
+               If its not the "object too large" error, rethrow.
+               At time of writing, that error code comes from
+               mongo/src/mongo/bson/util/builder.h
+            */
+            if (ae.getCode() != 13548)
+                throw;
+
+            /* throw the nicer human-readable error */
+            uassert(16029, str::stream() <<
+                    "aggregation result exceeds maximum document size limit ("
+                    << (BSONObjMaxUserSize / (1024 * 1024)) << "MB)",
+                    false);
+         }
+
+        return true;
+    }
+
+    void Pipeline::writeExplainOps(BSONArrayBuilder *pArrayBuilder) const {
+        for(SourceVector::const_iterator iter(sourceVector.begin()),
+                listEnd(sourceVector.end()); iter != listEnd; ++iter) {
+            intrusive_ptr<DocumentSource> pSource(*iter);
+
+            pSource->addToBsonArray(pArrayBuilder, true);
+        }
+    }
+
+    void Pipeline::writeExplainShard(
+        BSONObjBuilder &result,
+        const intrusive_ptr<DocumentSource> &pInputSource) const {
+        BSONArrayBuilder opArray; // where we'll put the pipeline ops
+
+        // first the cursor, which isn't in the opArray
+        pInputSource->addToBsonArray(&opArray, true);
+
+        // next, add the pipeline operators
+        writeExplainOps(&opArray);
+
+        result.appendArray(serverPipelineName, opArray.arr());
+    }
+
+    void Pipeline::writeExplainMongos(
+        BSONObjBuilder &result,
+        const intrusive_ptr<DocumentSource> &pInputSource) const {
+
+        /*
+          For now, this should be a BSON source array.
+          In future, we might have a more clever way of getting this, when
+          we have more interleaved fetching between shards.  The DocumentSource
+          interface will have to change to accomodate that.
+         */
+        DocumentSourceBsonArray *pSourceBsonArray =
+            dynamic_cast<DocumentSourceBsonArray *>(pInputSource.get());
+        verify(pSourceBsonArray);
+
+        BSONArrayBuilder shardOpArray; // where we'll put the pipeline ops
+        for(bool hasDocument = !pSourceBsonArray->eof(); hasDocument;
+            hasDocument = pSourceBsonArray->advance()) {
+            intrusive_ptr<Document> pDocument(
+                pSourceBsonArray->getCurrent());
+            BSONObjBuilder opBuilder;
+            pDocument->toBson(&opBuilder);
+            shardOpArray.append(opBuilder.obj());
+        }
+
+        BSONArrayBuilder mongosOpArray; // where we'll put the pipeline ops
+        writeExplainOps(&mongosOpArray);
+
+        // now we combine the shard pipelines with the one here
+        result.append(serverPipelineName, shardOpArray.arr());
+        result.append(mongosPipelineName, mongosOpArray.arr());
+    }
+
+} // namespace mongo
diff --git a/src/mongo/db/commands/pipeline_command.cpp b/src/mongo/db/commands/pipeline_command.cpp
index 71449ea53c3..e79bf75fe68 100755
--- a/src/mongo/db/commands/pipeline_command.cpp
+++ b/src/mongo/db/commands/pipeline_command.cpp
@@ -1,301 +1,301 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-

-#include "db/commands/pipeline.h"

-#include "db/commands/pipeline_d.h"

-#include "db/cursor.h"

-#include "db/interrupt_status_mongod.h"

-#include "db/pdfile.h"

-#include "db/pipeline/accumulator.h"

-#include "db/pipeline/document.h"

-#include "db/pipeline/document_source.h"

-#include "db/pipeline/expression.h"

-#include "db/pipeline/expression_context.h"

-

-namespace mongo {

-

-    /** mongodb "commands" (sent via db.$cmd.findOne(...))

-        subclass to make a command.  define a singleton object for it.

-        */

-    class PipelineCommand :

-        public Command {

-    public:

-        // virtuals from Command

-        virtual ~PipelineCommand();

-        virtual bool run(const string &db, BSONObj &cmdObj, int options,

-                         string &errmsg, BSONObjBuilder &result, bool fromRepl);

-        virtual LockType locktype() const;

-        virtual bool slaveOk() const;

-        virtual void help(stringstream &help) const;

-

-        PipelineCommand();

-

-    private:

-        /*

-          For the case of explain, we don't want to hold any lock at all,

-          because it generates warnings about recursive locks.  However,

-          the getting the explain information for the underlying cursor uses

-          the direct client cursor, and that gets a lock.  Therefore, we need

-          to take steps to avoid holding a lock while we use that.  On the

-          other hand, we need to have a READ lock for normal explain execution.

-          Therefore, the lock is managed manually, and not through the virtual

-          locktype() above.

-

-          In order to achieve this, locktype() returns NONE, but the lock that

-          would be managed for reading (for executing the pipeline in the

-          regular way),  will be managed manually here.  This code came from

-          dbcommands.cpp, where objects are constructed to hold the lock

-          and automatically release it on destruction.  The use of this

-          pattern requires extra functions to hold the lock scope and from

-          within which to execute the other steps of the explain.

-

-          The arguments for these are all the same, and come from run(), but

-          are passed in so that new blocks can be created to hold the

-          automatic locking objects.

-         */

-

-        /*

-          Execute the pipeline for the explain.  This is common to both the

-          locked and unlocked code path.  However, the results are different.

-          For an explain, with no lock, it really outputs the pipeline

-          chain rather than fetching the data.

-         */

-        bool executePipeline(

-            BSONObjBuilder &result, string &errmsg, const string &ns,

-            intrusive_ptr<Pipeline> &pPipeline,

-            intrusive_ptr<DocumentSourceCursor> &pSource,

-            intrusive_ptr<ExpressionContext> &pCtx);

-

-        /*

-          The explain code path holds a lock while the original cursor is

-          parsed; we still need to take that step, because that is how we

-          determine whether or not indexes will allow the optimization of

-          early $match and/or $sort.

-

-          Once the Cursor is identified, it is released, and then the lock

-          is released (automatically, via end of a block), and then the

-          pipeline is executed.

-         */

-        bool runExplain(

-            BSONObjBuilder &result, string &errmsg,

-            const string &ns, const string &db,

-            intrusive_ptr<Pipeline> &pPipeline,

-            intrusive_ptr<ExpressionContext> &pCtx);

-

-        /*

-          The execute code path holds a READ lock for its entire duration.

-          The Cursor is created, and then documents are pulled out of it until

-          they are exhausted (or some other error occurs).

-         */

-        bool runExecute(

-            BSONObjBuilder &result, string &errmsg,

-            const string &ns, const string &db,

-            intrusive_ptr<Pipeline> &pPipeline,

-            intrusive_ptr<ExpressionContext> &pCtx);

-    };

-

-    // self-registering singleton static instance

-    static PipelineCommand pipelineCommand;

-

-    PipelineCommand::PipelineCommand():

-        Command(Pipeline::commandName) {

-    }

-

-    Command::LockType PipelineCommand::locktype() const {

-        /*

-          The locks for this are managed manually.  The problem is that the

-          explain execution uses the direct client interface, and this

-          causes recursive lock warnings if the lock is already held.  As

-          a result, there are two code paths for this.  See the comments in

-          the private section of PipelineCommand for more details.

-         */

-        return NONE;

-    }

-

-    bool PipelineCommand::slaveOk() const {

-        return true;

-    }

-

-    void PipelineCommand::help(stringstream &help) const {

-        help << "{ pipeline : [ { <data-pipe-op>: {...}}, ... ] }";

-    }

-

-    PipelineCommand::~PipelineCommand() {

-    }

-

-    bool PipelineCommand::runExplain(

-        BSONObjBuilder &result, string &errmsg,

-        const string &ns, const string &db,

-        intrusive_ptr<Pipeline> &pPipeline,

-        intrusive_ptr<ExpressionContext> &pCtx) {

-

-        intrusive_ptr<DocumentSourceCursor> pSource;

-        

-        /*

-          For EXPLAIN:

-

-          This block is here to contain the scope of the lock.  We need the lock

-          while we prepare the cursor, but we need to have released it by the

-          time the recursive call is made to get the explain information using

-          the direct client interface under the execution phase.

-         */

-        {

-            scoped_ptr<Lock::GlobalRead> lk;

-            if(lockGlobally())

-                lk.reset(new Lock::GlobalRead());

-            Client::ReadContext ctx(ns, dbpath, requiresAuth()); // read lock

-

-            pSource = PipelineD::prepareCursorSource(pPipeline, db, pCtx);

-

-            /* release the Cursor before the lock gets released */

-            pSource->releaseCursor();

-        }

-

-        /*

-          For EXPLAIN this just uses the direct client to do an explain on

-          what the underlying Cursor was, based on its query and sort

-          settings, and then wraps it with JSON from the pipeline definition.

-          That does not require the lock or cursor, both of which were

-          released above.

-         */

-        return executePipeline(result, errmsg, ns, pPipeline, pSource, pCtx);

-    }

-

-    bool PipelineCommand::runExecute(

-        BSONObjBuilder &result, string &errmsg,

-        const string &ns, const string &db,

-        intrusive_ptr<Pipeline> &pPipeline,

-        intrusive_ptr<ExpressionContext> &pCtx) {

-

-        scoped_ptr<Lock::GlobalRead> lk;

-        if(lockGlobally())

-            lk.reset(new Lock::GlobalRead());

-        Client::ReadContext ctx(ns, dbpath, requiresAuth()); // read lock

-

-        intrusive_ptr<DocumentSourceCursor> pSource(

-            PipelineD::prepareCursorSource(pPipeline, db, pCtx));

-        return executePipeline(result, errmsg, ns, pPipeline, pSource, pCtx);

-    }

-

-    bool PipelineCommand::executePipeline(

-        BSONObjBuilder &result, string &errmsg, const string &ns,

-        intrusive_ptr<Pipeline> &pPipeline,

-        intrusive_ptr<DocumentSourceCursor> &pSource,

-        intrusive_ptr<ExpressionContext> &pCtx) {

-

-        /* this is the normal non-debug path */

-        if (!pPipeline->getSplitMongodPipeline())

-            return pPipeline->run(result, errmsg, pSource);

-

-        /* setup as if we're in the router */

-        pCtx->setInRouter(true);

-

-        /*

-          Here, we'll split the pipeline in the same way we would for sharding,

-          for testing purposes.

-

-          Run the shard pipeline first, then feed the results into the remains

-          of the existing pipeline.

-

-          Start by splitting the pipeline.

-         */

-        intrusive_ptr<Pipeline> pShardSplit(

-            pPipeline->splitForSharded());

-

-        /*

-          Write the split pipeline as we would in order to transmit it to

-          the shard servers.

-        */

-        BSONObjBuilder shardBuilder;

-        pShardSplit->toBson(&shardBuilder);

-        BSONObj shardBson(shardBuilder.done());

-

-        DEV (log() << "\n---- shardBson\n" <<

-             shardBson.jsonString(Strict, 1) << "\n----\n").flush();

-

-        /* for debugging purposes, show what the pipeline now looks like */

-        DEV {

-            BSONObjBuilder pipelineBuilder;

-            pPipeline->toBson(&pipelineBuilder);

-            BSONObj pipelineBson(pipelineBuilder.done());

-            (log() << "\n---- pipelineBson\n" <<

-             pipelineBson.jsonString(Strict, 1) << "\n----\n").flush();

-        }

-

-        /* on the shard servers, create the local pipeline */

-        intrusive_ptr<ExpressionContext> pShardCtx(

-            ExpressionContext::create(&InterruptStatusMongod::status));

-        intrusive_ptr<Pipeline> pShardPipeline(

-            Pipeline::parseCommand(errmsg, shardBson, pShardCtx));

-        if (!pShardPipeline.get()) {

-            return false;

-        }

-

-        /* run the shard pipeline */

-        BSONObjBuilder shardResultBuilder;

-        string shardErrmsg;

-        pShardPipeline->run(shardResultBuilder, shardErrmsg, pSource);

-        BSONObj shardResult(shardResultBuilder.done());

-

-        /* pick out the shard result, and prepare to read it */

-        intrusive_ptr<DocumentSourceBsonArray> pShardSource;

-        BSONObjIterator shardIter(shardResult);

-        while(shardIter.more()) {

-            BSONElement shardElement(shardIter.next());

-            const char *pFieldName = shardElement.fieldName();

-

-            if ((strcmp(pFieldName, "result") == 0) ||

-                (strcmp(pFieldName, "serverPipeline") == 0)) {

-                pShardSource = DocumentSourceBsonArray::create(

-                    &shardElement, pCtx);

-

-                /*

-                  Connect the output of the shard pipeline with the mongos

-                  pipeline that will merge the results.

-                */

-                return pPipeline->run(result, errmsg, pShardSource);

-            }

-        }

-

-        /* NOTREACHED */

-        verify(false);

-        return false;

-    }

-

-    bool PipelineCommand::run(const string &db, BSONObj &cmdObj,

-                              int options, string &errmsg,

-                              BSONObjBuilder &result, bool fromRepl) {

-

-        intrusive_ptr<ExpressionContext> pCtx(

-            ExpressionContext::create(&InterruptStatusMongod::status));

-

-        /* try to parse the command; if this fails, then we didn't run */

-        intrusive_ptr<Pipeline> pPipeline(

-            Pipeline::parseCommand(errmsg, cmdObj, pCtx));

-        if (!pPipeline.get())

-            return false;

-

-        string ns(parseNs(db, cmdObj));

-

-        if (pPipeline->isExplain())

-            return runExplain(result, errmsg, ns, db, pPipeline, pCtx);

-        else

-            return runExecute(result, errmsg, ns, db, pPipeline, pCtx);

-    }

-

-} // namespace mongo

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+
+#include "db/commands/pipeline.h"
+#include "db/commands/pipeline_d.h"
+#include "db/cursor.h"
+#include "db/interrupt_status_mongod.h"
+#include "db/pdfile.h"
+#include "db/pipeline/accumulator.h"
+#include "db/pipeline/document.h"
+#include "db/pipeline/document_source.h"
+#include "db/pipeline/expression.h"
+#include "db/pipeline/expression_context.h"
+
+namespace mongo {
+
+    /** mongodb "commands" (sent via db.$cmd.findOne(...))
+        subclass to make a command.  define a singleton object for it.
+        */
+    class PipelineCommand :
+        public Command {
+    public:
+        // virtuals from Command
+        virtual ~PipelineCommand();
+        virtual bool run(const string &db, BSONObj &cmdObj, int options,
+                         string &errmsg, BSONObjBuilder &result, bool fromRepl);
+        virtual LockType locktype() const;
+        virtual bool slaveOk() const;
+        virtual void help(stringstream &help) const;
+
+        PipelineCommand();
+
+    private:
+        /*
+          For the case of explain, we don't want to hold any lock at all,
+          because it generates warnings about recursive locks.  However,
+          the getting the explain information for the underlying cursor uses
+          the direct client cursor, and that gets a lock.  Therefore, we need
+          to take steps to avoid holding a lock while we use that.  On the
+          other hand, we need to have a READ lock for normal explain execution.
+          Therefore, the lock is managed manually, and not through the virtual
+          locktype() above.
+
+          In order to achieve this, locktype() returns NONE, but the lock that
+          would be managed for reading (for executing the pipeline in the
+          regular way),  will be managed manually here.  This code came from
+          dbcommands.cpp, where objects are constructed to hold the lock
+          and automatically release it on destruction.  The use of this
+          pattern requires extra functions to hold the lock scope and from
+          within which to execute the other steps of the explain.
+
+          The arguments for these are all the same, and come from run(), but
+          are passed in so that new blocks can be created to hold the
+          automatic locking objects.
+         */
+
+        /*
+          Execute the pipeline for the explain.  This is common to both the
+          locked and unlocked code path.  However, the results are different.
+          For an explain, with no lock, it really outputs the pipeline
+          chain rather than fetching the data.
+         */
+        bool executePipeline(
+            BSONObjBuilder &result, string &errmsg, const string &ns,
+            intrusive_ptr<Pipeline> &pPipeline,
+            intrusive_ptr<DocumentSourceCursor> &pSource,
+            intrusive_ptr<ExpressionContext> &pCtx);
+
+        /*
+          The explain code path holds a lock while the original cursor is
+          parsed; we still need to take that step, because that is how we
+          determine whether or not indexes will allow the optimization of
+          early $match and/or $sort.
+
+          Once the Cursor is identified, it is released, and then the lock
+          is released (automatically, via end of a block), and then the
+          pipeline is executed.
+         */
+        bool runExplain(
+            BSONObjBuilder &result, string &errmsg,
+            const string &ns, const string &db,
+            intrusive_ptr<Pipeline> &pPipeline,
+            intrusive_ptr<ExpressionContext> &pCtx);
+
+        /*
+          The execute code path holds a READ lock for its entire duration.
+          The Cursor is created, and then documents are pulled out of it until
+          they are exhausted (or some other error occurs).
+         */
+        bool runExecute(
+            BSONObjBuilder &result, string &errmsg,
+            const string &ns, const string &db,
+            intrusive_ptr<Pipeline> &pPipeline,
+            intrusive_ptr<ExpressionContext> &pCtx);
+    };
+
+    // self-registering singleton static instance
+    static PipelineCommand pipelineCommand;
+
+    PipelineCommand::PipelineCommand():
+        Command(Pipeline::commandName) {
+    }
+
+    Command::LockType PipelineCommand::locktype() const {
+        /*
+          The locks for this are managed manually.  The problem is that the
+          explain execution uses the direct client interface, and this
+          causes recursive lock warnings if the lock is already held.  As
+          a result, there are two code paths for this.  See the comments in
+          the private section of PipelineCommand for more details.
+         */
+        return NONE;
+    }
+
+    bool PipelineCommand::slaveOk() const {
+        return true;
+    }
+
+    void PipelineCommand::help(stringstream &help) const {
+        help << "{ pipeline : [ { <data-pipe-op>: {...}}, ... ] }";
+    }
+
+    PipelineCommand::~PipelineCommand() {
+    }
+
+    bool PipelineCommand::runExplain(
+        BSONObjBuilder &result, string &errmsg,
+        const string &ns, const string &db,
+        intrusive_ptr<Pipeline> &pPipeline,
+        intrusive_ptr<ExpressionContext> &pCtx) {
+
+        intrusive_ptr<DocumentSourceCursor> pSource;
+        
+        /*
+          For EXPLAIN:
+
+          This block is here to contain the scope of the lock.  We need the lock
+          while we prepare the cursor, but we need to have released it by the
+          time the recursive call is made to get the explain information using
+          the direct client interface under the execution phase.
+         */
+        {
+            scoped_ptr<Lock::GlobalRead> lk;
+            if(lockGlobally())
+                lk.reset(new Lock::GlobalRead());
+            Client::ReadContext ctx(ns, dbpath, requiresAuth()); // read lock
+
+            pSource = PipelineD::prepareCursorSource(pPipeline, db, pCtx);
+
+            /* release the Cursor before the lock gets released */
+            pSource->releaseCursor();
+        }
+
+        /*
+          For EXPLAIN this just uses the direct client to do an explain on
+          what the underlying Cursor was, based on its query and sort
+          settings, and then wraps it with JSON from the pipeline definition.
+          That does not require the lock or cursor, both of which were
+          released above.
+         */
+        return executePipeline(result, errmsg, ns, pPipeline, pSource, pCtx);
+    }
+
+    bool PipelineCommand::runExecute(
+        BSONObjBuilder &result, string &errmsg,
+        const string &ns, const string &db,
+        intrusive_ptr<Pipeline> &pPipeline,
+        intrusive_ptr<ExpressionContext> &pCtx) {
+
+        scoped_ptr<Lock::GlobalRead> lk;
+        if(lockGlobally())
+            lk.reset(new Lock::GlobalRead());
+        Client::ReadContext ctx(ns, dbpath, requiresAuth()); // read lock
+
+        intrusive_ptr<DocumentSourceCursor> pSource(
+            PipelineD::prepareCursorSource(pPipeline, db, pCtx));
+        return executePipeline(result, errmsg, ns, pPipeline, pSource, pCtx);
+    }
+
+    bool PipelineCommand::executePipeline(
+        BSONObjBuilder &result, string &errmsg, const string &ns,
+        intrusive_ptr<Pipeline> &pPipeline,
+        intrusive_ptr<DocumentSourceCursor> &pSource,
+        intrusive_ptr<ExpressionContext> &pCtx) {
+
+        /* this is the normal non-debug path */
+        if (!pPipeline->getSplitMongodPipeline())
+            return pPipeline->run(result, errmsg, pSource);
+
+        /* setup as if we're in the router */
+        pCtx->setInRouter(true);
+
+        /*
+          Here, we'll split the pipeline in the same way we would for sharding,
+          for testing purposes.
+
+          Run the shard pipeline first, then feed the results into the remains
+          of the existing pipeline.
+
+          Start by splitting the pipeline.
+         */
+        intrusive_ptr<Pipeline> pShardSplit(
+            pPipeline->splitForSharded());
+
+        /*
+          Write the split pipeline as we would in order to transmit it to
+          the shard servers.
+        */
+        BSONObjBuilder shardBuilder;
+        pShardSplit->toBson(&shardBuilder);
+        BSONObj shardBson(shardBuilder.done());
+
+        DEV (log() << "\n---- shardBson\n" <<
+             shardBson.jsonString(Strict, 1) << "\n----\n").flush();
+
+        /* for debugging purposes, show what the pipeline now looks like */
+        DEV {
+            BSONObjBuilder pipelineBuilder;
+            pPipeline->toBson(&pipelineBuilder);
+            BSONObj pipelineBson(pipelineBuilder.done());
+            (log() << "\n---- pipelineBson\n" <<
+             pipelineBson.jsonString(Strict, 1) << "\n----\n").flush();
+        }
+
+        /* on the shard servers, create the local pipeline */
+        intrusive_ptr<ExpressionContext> pShardCtx(
+            ExpressionContext::create(&InterruptStatusMongod::status));
+        intrusive_ptr<Pipeline> pShardPipeline(
+            Pipeline::parseCommand(errmsg, shardBson, pShardCtx));
+        if (!pShardPipeline.get()) {
+            return false;
+        }
+
+        /* run the shard pipeline */
+        BSONObjBuilder shardResultBuilder;
+        string shardErrmsg;
+        pShardPipeline->run(shardResultBuilder, shardErrmsg, pSource);
+        BSONObj shardResult(shardResultBuilder.done());
+
+        /* pick out the shard result, and prepare to read it */
+        intrusive_ptr<DocumentSourceBsonArray> pShardSource;
+        BSONObjIterator shardIter(shardResult);
+        while(shardIter.more()) {
+            BSONElement shardElement(shardIter.next());
+            const char *pFieldName = shardElement.fieldName();
+
+            if ((strcmp(pFieldName, "result") == 0) ||
+                (strcmp(pFieldName, "serverPipeline") == 0)) {
+                pShardSource = DocumentSourceBsonArray::create(
+                    &shardElement, pCtx);
+
+                /*
+                  Connect the output of the shard pipeline with the mongos
+                  pipeline that will merge the results.
+                */
+                return pPipeline->run(result, errmsg, pShardSource);
+            }
+        }
+
+        /* NOTREACHED */
+        verify(false);
+        return false;
+    }
+
+    bool PipelineCommand::run(const string &db, BSONObj &cmdObj,
+                              int options, string &errmsg,
+                              BSONObjBuilder &result, bool fromRepl) {
+
+        intrusive_ptr<ExpressionContext> pCtx(
+            ExpressionContext::create(&InterruptStatusMongod::status));
+
+        /* try to parse the command; if this fails, then we didn't run */
+        intrusive_ptr<Pipeline> pPipeline(
+            Pipeline::parseCommand(errmsg, cmdObj, pCtx));
+        if (!pPipeline.get())
+            return false;
+
+        string ns(parseNs(db, cmdObj));
+
+        if (pPipeline->isExplain())
+            return runExplain(result, errmsg, ns, db, pPipeline, pCtx);
+        else
+            return runExecute(result, errmsg, ns, db, pPipeline, pCtx);
+    }
+
+} // namespace mongo
diff --git a/src/mongo/db/pipeline/accumulator.cpp b/src/mongo/db/pipeline/accumulator.cpp
index 0f6b2253ffc..da605eda6e3 100755
--- a/src/mongo/db/pipeline/accumulator.cpp
+++ b/src/mongo/db/pipeline/accumulator.cpp
@@ -1,79 +1,79 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "db/pipeline/accumulator.h"

-

-#include "db/jsobj.h"

-#include "util/mongoutils/str.h"

-

-namespace mongo {

-    using namespace mongoutils;

-

-    void Accumulator::addOperand(

-        const intrusive_ptr<Expression> &pExpression) {

-        uassert(15943, str::stream() << "group accumulator " <<

-                getOpName() << " only accepts one operand",

-                vpOperand.size() < 1);

-        

-        ExpressionNary::addOperand(pExpression);

-    }

-

-    Accumulator::Accumulator():

-        ExpressionNary() {

-    }

-

-    void Accumulator::opToBson(

-        BSONObjBuilder *pBuilder, string opName,

-        string fieldName) const {

-        verify(vpOperand.size() == 1);

-        BSONObjBuilder builder;

-        vpOperand[0]->addToBsonObj(&builder, opName, false);

-        pBuilder->append(fieldName, builder.done());

-    }

-

-    void Accumulator::addToBsonObj(

-        BSONObjBuilder *pBuilder, string fieldName,

-        bool requireExpression) const {

-        opToBson(pBuilder, getOpName(), fieldName);

-    }

-

-    void Accumulator::addToBsonArray(BSONArrayBuilder *pBuilder) const {

-        verify(false); // these can't appear in arrays

-    }

-

-    void agg_framework_reservedErrors() {

-        uassert(16030, "reserved error", false);

-        uassert(16031, "reserved error", false);

-        uassert(16032, "reserved error", false);

-        uassert(16033, "reserved error", false);

-

-        uassert(16036, "reserved error", false);

-        uassert(16037, "reserved error", false);

-        uassert(16038, "reserved error", false);

-        uassert(16039, "reserved error", false);

-        uassert(16040, "reserved error", false);

-        uassert(16041, "reserved error", false);

-        uassert(16042, "reserved error", false);

-        uassert(16043, "reserved error", false);

-        uassert(16044, "reserved error", false);

-        uassert(16045, "reserved error", false);

-        uassert(16046, "reserved error", false);

-        uassert(16047, "reserved error", false);

-        uassert(16048, "reserved error", false);

-        uassert(16049, "reserved error", false);

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "db/pipeline/accumulator.h"
+
+#include "db/jsobj.h"
+#include "util/mongoutils/str.h"
+
+namespace mongo {
+    using namespace mongoutils;
+
+    void Accumulator::addOperand(
+        const intrusive_ptr<Expression> &pExpression) {
+        uassert(15943, str::stream() << "group accumulator " <<
+                getOpName() << " only accepts one operand",
+                vpOperand.size() < 1);
+        
+        ExpressionNary::addOperand(pExpression);
+    }
+
+    Accumulator::Accumulator():
+        ExpressionNary() {
+    }
+
+    void Accumulator::opToBson(
+        BSONObjBuilder *pBuilder, string opName,
+        string fieldName) const {
+        verify(vpOperand.size() == 1);
+        BSONObjBuilder builder;
+        vpOperand[0]->addToBsonObj(&builder, opName, false);
+        pBuilder->append(fieldName, builder.done());
+    }
+
+    void Accumulator::addToBsonObj(
+        BSONObjBuilder *pBuilder, string fieldName,
+        bool requireExpression) const {
+        opToBson(pBuilder, getOpName(), fieldName);
+    }
+
+    void Accumulator::addToBsonArray(BSONArrayBuilder *pBuilder) const {
+        verify(false); // these can't appear in arrays
+    }
+
+    void agg_framework_reservedErrors() {
+        uassert(16030, "reserved error", false);
+        uassert(16031, "reserved error", false);
+        uassert(16032, "reserved error", false);
+        uassert(16033, "reserved error", false);
+
+        uassert(16036, "reserved error", false);
+        uassert(16037, "reserved error", false);
+        uassert(16038, "reserved error", false);
+        uassert(16039, "reserved error", false);
+        uassert(16040, "reserved error", false);
+        uassert(16041, "reserved error", false);
+        uassert(16042, "reserved error", false);
+        uassert(16043, "reserved error", false);
+        uassert(16044, "reserved error", false);
+        uassert(16045, "reserved error", false);
+        uassert(16046, "reserved error", false);
+        uassert(16047, "reserved error", false);
+        uassert(16048, "reserved error", false);
+        uassert(16049, "reserved error", false);
+    }
+}
diff --git a/src/mongo/db/pipeline/accumulator.h b/src/mongo/db/pipeline/accumulator.h
index 74dcd403e65..f53682c957c 100755
--- a/src/mongo/db/pipeline/accumulator.h
+++ b/src/mongo/db/pipeline/accumulator.h
@@ -1,258 +1,258 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#pragma once

-

-#include "pch.h"

-

-#include <boost/unordered_set.hpp>

-#include "db/pipeline/value.h"

-#include "db/pipeline/expression.h"

-#include "bson/bsontypes.h"

-

-namespace mongo {

-    class ExpressionContext;

-

-    class Accumulator :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-        virtual void addToBsonObj(

-            BSONObjBuilder *pBuilder, string fieldName,

-            bool requireExpression) const;

-        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;

-

-        /*

-          Get the accumulated value.

-

-          @returns the accumulated value

-         */

-        virtual intrusive_ptr<const Value> getValue() const = 0;

-

-    protected:

-        Accumulator();

-

-        /*

-          Convenience method for doing this for accumulators.  The pattern

-          is always the same, so a common implementation works, but requires

-          knowing the operator name.

-

-          @param pBuilder the builder to add to

-          @param fieldName the projected name

-          @param opName the operator name

-         */

-        void opToBson(

-            BSONObjBuilder *pBuilder, string fieldName, string opName) const;

-    };

-

-

-    class AccumulatorAddToSet :

-        public Accumulator {

-    public:

-        // virtuals from Expression

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual intrusive_ptr<const Value> getValue() const;

-        virtual const char *getOpName() const;

-

-        /*

-          Create an appending accumulator.

-

-          @param pCtx the expression context

-          @returns the created accumulator

-         */

-        static intrusive_ptr<Accumulator> create(

-            const intrusive_ptr<ExpressionContext> &pCtx);

-

-    private:

-        AccumulatorAddToSet(const intrusive_ptr<ExpressionContext> &pTheCtx);

-        typedef boost::unordered_set<intrusive_ptr<const Value>, Value::Hash > SetType;

-        mutable SetType set;

-        mutable SetType::iterator itr; 

-        intrusive_ptr<ExpressionContext> pCtx;

-    };

-

-

-    /*

-      This isn't a finished accumulator, but rather a convenient base class

-      for others such as $first, $last, $max, $min, and similar.  It just

-      provides a holder for a single Value, and the getter for that.  The

-      holder is protected so derived classes can manipulate it.

-     */

-    class AccumulatorSingleValue :

-        public Accumulator {

-    public:

-        // virtuals from Expression

-        virtual intrusive_ptr<const Value> getValue() const;

-

-    protected:

-        AccumulatorSingleValue();

-

-        mutable intrusive_ptr<const Value> pValue; /* current min/max */

-    };

-

-

-    class AccumulatorFirst :

-        public AccumulatorSingleValue {

-    public:

-        // virtuals from Expression

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-

-        /*

-          Create the accumulator.

-

-          @returns the created accumulator

-         */

-        static intrusive_ptr<Accumulator> create(

-            const intrusive_ptr<ExpressionContext> &pCtx);

-

-    private:

-        AccumulatorFirst();

-    };

-

-

-    class AccumulatorLast :

-        public AccumulatorSingleValue {

-    public:

-        // virtuals from Expression

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-

-        /*

-          Create the accumulator.

-

-          @returns the created accumulator

-         */

-        static intrusive_ptr<Accumulator> create(

-            const intrusive_ptr<ExpressionContext> &pCtx);

-

-    private:

-        AccumulatorLast();

-    };

-

-

-    class AccumulatorSum :

-        public Accumulator {

-    public:

-        // virtuals from Accumulator

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual intrusive_ptr<const Value> getValue() const;

-        virtual const char *getOpName() const;

-

-        /*

-          Create a summing accumulator.

-

-          @param pCtx the expression context

-          @returns the created accumulator

-         */

-        static intrusive_ptr<Accumulator> create(

-            const intrusive_ptr<ExpressionContext> &pCtx);

-

-    protected: /* reused by AccumulatorAvg */

-        AccumulatorSum();

-

-        mutable BSONType totalType;

-        mutable long long longTotal;

-        mutable double doubleTotal;

-    };

-

-

-    class AccumulatorMinMax :

-        public AccumulatorSingleValue {

-    public:

-        // virtuals from Expression

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-

-        /*

-          Create either the max or min accumulator.

-

-          @returns the created accumulator

-         */

-        static intrusive_ptr<Accumulator> createMin(

-            const intrusive_ptr<ExpressionContext> &pCtx);

-        static intrusive_ptr<Accumulator> createMax(

-            const intrusive_ptr<ExpressionContext> &pCtx);

-

-    private:

-        AccumulatorMinMax(int theSense);

-

-        int sense; /* 1 for min, -1 for max; used to "scale" comparison */

-    };

-

-

-    class AccumulatorPush :

-        public Accumulator {

-    public:

-        // virtuals from Expression

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual intrusive_ptr<const Value> getValue() const;

-        virtual const char *getOpName() const;

-

-        /*

-          Create an appending accumulator.

-

-          @param pCtx the expression context

-          @returns the created accumulator

-         */

-        static intrusive_ptr<Accumulator> create(

-            const intrusive_ptr<ExpressionContext> &pCtx);

-

-    private:

-        AccumulatorPush(const intrusive_ptr<ExpressionContext> &pTheCtx);

-

-        mutable vector<intrusive_ptr<const Value> > vpValue;

-        intrusive_ptr<ExpressionContext> pCtx;

-    };

-

-

-    class AccumulatorAvg :

-        public AccumulatorSum {

-        typedef AccumulatorSum Super;

-    public:

-        // virtuals from Accumulator

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual intrusive_ptr<const Value> getValue() const;

-        virtual const char *getOpName() const;

-

-        /*

-          Create an averaging accumulator.

-

-          @param pCtx the expression context

-          @returns the created accumulator

-         */

-        static intrusive_ptr<Accumulator> create(

-            const intrusive_ptr<ExpressionContext> &pCtx);

-

-    private:

-        static const char subTotalName[];

-        static const char countName[];

-

-        AccumulatorAvg(const intrusive_ptr<ExpressionContext> &pCtx);

-

-        mutable long long count;

-        intrusive_ptr<ExpressionContext> pCtx;

-    };

-

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "pch.h"
+
+#include <boost/unordered_set.hpp>
+#include "db/pipeline/value.h"
+#include "db/pipeline/expression.h"
+#include "bson/bsontypes.h"
+
+namespace mongo {
+    class ExpressionContext;
+
+    class Accumulator :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+        virtual void addToBsonObj(
+            BSONObjBuilder *pBuilder, string fieldName,
+            bool requireExpression) const;
+        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;
+
+        /*
+          Get the accumulated value.
+
+          @returns the accumulated value
+         */
+        virtual intrusive_ptr<const Value> getValue() const = 0;
+
+    protected:
+        Accumulator();
+
+        /*
+          Convenience method for doing this for accumulators.  The pattern
+          is always the same, so a common implementation works, but requires
+          knowing the operator name.
+
+          @param pBuilder the builder to add to
+          @param fieldName the projected name
+          @param opName the operator name
+         */
+        void opToBson(
+            BSONObjBuilder *pBuilder, string fieldName, string opName) const;
+    };
+
+
+    class AccumulatorAddToSet :
+        public Accumulator {
+    public:
+        // virtuals from Expression
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual intrusive_ptr<const Value> getValue() const;
+        virtual const char *getOpName() const;
+
+        /*
+          Create an appending accumulator.
+
+          @param pCtx the expression context
+          @returns the created accumulator
+         */
+        static intrusive_ptr<Accumulator> create(
+            const intrusive_ptr<ExpressionContext> &pCtx);
+
+    private:
+        AccumulatorAddToSet(const intrusive_ptr<ExpressionContext> &pTheCtx);
+        typedef boost::unordered_set<intrusive_ptr<const Value>, Value::Hash > SetType;
+        mutable SetType set;
+        mutable SetType::iterator itr; 
+        intrusive_ptr<ExpressionContext> pCtx;
+    };
+
+
+    /*
+      This isn't a finished accumulator, but rather a convenient base class
+      for others such as $first, $last, $max, $min, and similar.  It just
+      provides a holder for a single Value, and the getter for that.  The
+      holder is protected so derived classes can manipulate it.
+     */
+    class AccumulatorSingleValue :
+        public Accumulator {
+    public:
+        // virtuals from Expression
+        virtual intrusive_ptr<const Value> getValue() const;
+
+    protected:
+        AccumulatorSingleValue();
+
+        mutable intrusive_ptr<const Value> pValue; /* current min/max */
+    };
+
+
+    class AccumulatorFirst :
+        public AccumulatorSingleValue {
+    public:
+        // virtuals from Expression
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+
+        /*
+          Create the accumulator.
+
+          @returns the created accumulator
+         */
+        static intrusive_ptr<Accumulator> create(
+            const intrusive_ptr<ExpressionContext> &pCtx);
+
+    private:
+        AccumulatorFirst();
+    };
+
+
+    class AccumulatorLast :
+        public AccumulatorSingleValue {
+    public:
+        // virtuals from Expression
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+
+        /*
+          Create the accumulator.
+
+          @returns the created accumulator
+         */
+        static intrusive_ptr<Accumulator> create(
+            const intrusive_ptr<ExpressionContext> &pCtx);
+
+    private:
+        AccumulatorLast();
+    };
+
+
+    class AccumulatorSum :
+        public Accumulator {
+    public:
+        // virtuals from Accumulator
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual intrusive_ptr<const Value> getValue() const;
+        virtual const char *getOpName() const;
+
+        /*
+          Create a summing accumulator.
+
+          @param pCtx the expression context
+          @returns the created accumulator
+         */
+        static intrusive_ptr<Accumulator> create(
+            const intrusive_ptr<ExpressionContext> &pCtx);
+
+    protected: /* reused by AccumulatorAvg */
+        AccumulatorSum();
+
+        mutable BSONType totalType;
+        mutable long long longTotal;
+        mutable double doubleTotal;
+    };
+
+
+    class AccumulatorMinMax :
+        public AccumulatorSingleValue {
+    public:
+        // virtuals from Expression
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+
+        /*
+          Create either the max or min accumulator.
+
+          @returns the created accumulator
+         */
+        static intrusive_ptr<Accumulator> createMin(
+            const intrusive_ptr<ExpressionContext> &pCtx);
+        static intrusive_ptr<Accumulator> createMax(
+            const intrusive_ptr<ExpressionContext> &pCtx);
+
+    private:
+        AccumulatorMinMax(int theSense);
+
+        int sense; /* 1 for min, -1 for max; used to "scale" comparison */
+    };
+
+
+    class AccumulatorPush :
+        public Accumulator {
+    public:
+        // virtuals from Expression
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual intrusive_ptr<const Value> getValue() const;
+        virtual const char *getOpName() const;
+
+        /*
+          Create an appending accumulator.
+
+          @param pCtx the expression context
+          @returns the created accumulator
+         */
+        static intrusive_ptr<Accumulator> create(
+            const intrusive_ptr<ExpressionContext> &pCtx);
+
+    private:
+        AccumulatorPush(const intrusive_ptr<ExpressionContext> &pTheCtx);
+
+        mutable vector<intrusive_ptr<const Value> > vpValue;
+        intrusive_ptr<ExpressionContext> pCtx;
+    };
+
+
+    class AccumulatorAvg :
+        public AccumulatorSum {
+        typedef AccumulatorSum Super;
+    public:
+        // virtuals from Accumulator
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual intrusive_ptr<const Value> getValue() const;
+        virtual const char *getOpName() const;
+
+        /*
+          Create an averaging accumulator.
+
+          @param pCtx the expression context
+          @returns the created accumulator
+         */
+        static intrusive_ptr<Accumulator> create(
+            const intrusive_ptr<ExpressionContext> &pCtx);
+
+    private:
+        static const char subTotalName[];
+        static const char countName[];
+
+        AccumulatorAvg(const intrusive_ptr<ExpressionContext> &pCtx);
+
+        mutable long long count;
+        intrusive_ptr<ExpressionContext> pCtx;
+    };
+
+}
diff --git a/src/mongo/db/pipeline/accumulator_add_to_set.cpp b/src/mongo/db/pipeline/accumulator_add_to_set.cpp
index 61a0ca5a39b..e91726345a1 100755
--- a/src/mongo/db/pipeline/accumulator_add_to_set.cpp
+++ b/src/mongo/db/pipeline/accumulator_add_to_set.cpp
@@ -1,79 +1,79 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "accumulator.h"

-

-#include "db/pipeline/expression_context.h"

-#include "db/pipeline/value.h"

-

-namespace mongo {

-    intrusive_ptr<const Value> AccumulatorAddToSet::evaluate(

-        const intrusive_ptr<Document> &pDocument) const {

-        verify(vpOperand.size() == 1);

-        intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));

-

-        if (prhs->getType() == Undefined)

-            ; /* nothing to add to the array */

-        else if (!pCtx->getInRouter())

-            set.insert(prhs);

-        else {

-            /*

-              If we're in the router, we need to take apart the arrays we

-              receive and put their elements into the array we are collecting.

-              If we didn't, then we'd get an array of arrays, with one array

-              from each shard that responds.

-             */

-            verify(prhs->getType() == Array);

-            

-            intrusive_ptr<ValueIterator> pvi(prhs->getArray());

-            while(pvi->more()) {

-                intrusive_ptr<const Value> pElement(pvi->next());

-                set.insert(pElement);

-            }

-        }

-

-        return Value::getNull();

-    }

-

-    intrusive_ptr<const Value> AccumulatorAddToSet::getValue() const {

-        vector<intrusive_ptr<const Value> > valVec;

-

-        for (itr = set.begin(); itr != set.end(); ++itr) {

-            valVec.push_back(*itr);

-        }

-        /* there is no issue of scope since createArray copy constructs */

-        return Value::createArray(valVec);

-    }

-

-    AccumulatorAddToSet::AccumulatorAddToSet(

-        const intrusive_ptr<ExpressionContext> &pTheCtx):

-        Accumulator(),

-        set(),

-        pCtx(pTheCtx) {

-    }

-

-    intrusive_ptr<Accumulator> AccumulatorAddToSet::create(

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        intrusive_ptr<AccumulatorAddToSet> pAccumulator(

-            new AccumulatorAddToSet(pCtx));

-        return pAccumulator;

-    }

-

-    const char *AccumulatorAddToSet::getOpName() const {

-        return "$addToSet";

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "accumulator.h"
+
+#include "db/pipeline/expression_context.h"
+#include "db/pipeline/value.h"
+
+namespace mongo {
+    intrusive_ptr<const Value> AccumulatorAddToSet::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        verify(vpOperand.size() == 1);
+        intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));
+
+        if (prhs->getType() == Undefined)
+            ; /* nothing to add to the array */
+        else if (!pCtx->getInRouter())
+            set.insert(prhs);
+        else {
+            /*
+              If we're in the router, we need to take apart the arrays we
+              receive and put their elements into the array we are collecting.
+              If we didn't, then we'd get an array of arrays, with one array
+              from each shard that responds.
+             */
+            verify(prhs->getType() == Array);
+            
+            intrusive_ptr<ValueIterator> pvi(prhs->getArray());
+            while(pvi->more()) {
+                intrusive_ptr<const Value> pElement(pvi->next());
+                set.insert(pElement);
+            }
+        }
+
+        return Value::getNull();
+    }
+
+    intrusive_ptr<const Value> AccumulatorAddToSet::getValue() const {
+        vector<intrusive_ptr<const Value> > valVec;
+
+        for (itr = set.begin(); itr != set.end(); ++itr) {
+            valVec.push_back(*itr);
+        }
+        /* there is no issue of scope since createArray copy constructs */
+        return Value::createArray(valVec);
+    }
+
+    AccumulatorAddToSet::AccumulatorAddToSet(
+        const intrusive_ptr<ExpressionContext> &pTheCtx):
+        Accumulator(),
+        set(),
+        pCtx(pTheCtx) {
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorAddToSet::create(
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<AccumulatorAddToSet> pAccumulator(
+            new AccumulatorAddToSet(pCtx));
+        return pAccumulator;
+    }
+
+    const char *AccumulatorAddToSet::getOpName() const {
+        return "$addToSet";
+    }
+}
diff --git a/src/mongo/db/pipeline/accumulator_avg.cpp b/src/mongo/db/pipeline/accumulator_avg.cpp
index f166c185f9a..7217de163d6 100755
--- a/src/mongo/db/pipeline/accumulator_avg.cpp
+++ b/src/mongo/db/pipeline/accumulator_avg.cpp
@@ -1,123 +1,123 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "accumulator.h"

-

-#include "db/pipeline/document.h"

-#include "db/pipeline/expression_context.h"

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    const char AccumulatorAvg::subTotalName[] = "subTotal";

-    const char AccumulatorAvg::countName[] = "count";

-

-    intrusive_ptr<const Value> AccumulatorAvg::evaluate(

-        const intrusive_ptr<Document> &pDocument) const {

-        if (!pCtx->getInRouter()) {

-            Super::evaluate(pDocument);

-            ++count;

-        }

-        else {

-            /*

-              If we're in the router, we expect an object that contains

-              both a subtotal and a count.  This is what getValue() produced

-              below.

-             */

-            intrusive_ptr<const Value> prhs(

-                vpOperand[0]->evaluate(pDocument));

-            verify(prhs->getType() == Object);

-            intrusive_ptr<Document> pShardDoc(prhs->getDocument());

-

-            intrusive_ptr<const Value> pSubTotal(

-                pShardDoc->getValue(subTotalName));

-            verify(pSubTotal.get());

-            BSONType subTotalType = pSubTotal->getType();

-            if ((totalType == NumberLong) || (subTotalType == NumberLong))

-                totalType = NumberLong;

-            if ((totalType == NumberDouble) || (subTotalType == NumberDouble))

-                totalType = NumberDouble;

-

-            if (subTotalType == NumberInt) {

-                int v = pSubTotal->getInt();

-                longTotal += v;

-                doubleTotal += v;

-            }

-            else if (subTotalType == NumberLong) {

-                long long v = pSubTotal->getLong();

-                longTotal += v;

-                doubleTotal += v;

-            }

-            else {

-                double v = pSubTotal->getDouble();

-                doubleTotal += v;

-            }

-                

-            intrusive_ptr<const Value> pCount(pShardDoc->getValue(countName));

-            count += pCount->getLong();

-        }

-

-        return Value::getZero();

-    }

-

-    intrusive_ptr<Accumulator> AccumulatorAvg::create(

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        intrusive_ptr<AccumulatorAvg> pA(new AccumulatorAvg(pCtx));

-        return pA;

-    }

-

-    intrusive_ptr<const Value> AccumulatorAvg::getValue() const {

-        if (!pCtx->getInShard()) {

-            double avg = 0;

-            if (count) {

-                if (totalType != NumberDouble)

-                    avg = static_cast<double>(longTotal / count);

-                else

-                    avg = doubleTotal / count;

-            }

-

-            return Value::createDouble(avg);

-        }

-

-        intrusive_ptr<Document> pDocument(Document::create());

-

-        intrusive_ptr<const Value> pSubTotal;

-        if (totalType == NumberInt)

-            pSubTotal = Value::createInt((int)longTotal);

-        else if (totalType == NumberLong)

-            pSubTotal = Value::createLong(longTotal);

-        else

-            pSubTotal = Value::createDouble(doubleTotal);

-        pDocument->addField(subTotalName, pSubTotal);

-

-        intrusive_ptr<const Value> pCount(Value::createLong(count));

-        pDocument->addField(countName, pCount);

-

-        return Value::createDocument(pDocument);

-    }

-

-    AccumulatorAvg::AccumulatorAvg(

-        const intrusive_ptr<ExpressionContext> &pTheCtx):

-        AccumulatorSum(),

-        count(0),

-        pCtx(pTheCtx) {

-    }

-

-    const char *AccumulatorAvg::getOpName() const {

-        return "$avg";

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "accumulator.h"
+
+#include "db/pipeline/document.h"
+#include "db/pipeline/expression_context.h"
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    const char AccumulatorAvg::subTotalName[] = "subTotal";
+    const char AccumulatorAvg::countName[] = "count";
+
+    intrusive_ptr<const Value> AccumulatorAvg::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        if (!pCtx->getInRouter()) {
+            Super::evaluate(pDocument);
+            ++count;
+        }
+        else {
+            /*
+              If we're in the router, we expect an object that contains
+              both a subtotal and a count.  This is what getValue() produced
+              below.
+             */
+            intrusive_ptr<const Value> prhs(
+                vpOperand[0]->evaluate(pDocument));
+            verify(prhs->getType() == Object);
+            intrusive_ptr<Document> pShardDoc(prhs->getDocument());
+
+            intrusive_ptr<const Value> pSubTotal(
+                pShardDoc->getValue(subTotalName));
+            verify(pSubTotal.get());
+            BSONType subTotalType = pSubTotal->getType();
+            if ((totalType == NumberLong) || (subTotalType == NumberLong))
+                totalType = NumberLong;
+            if ((totalType == NumberDouble) || (subTotalType == NumberDouble))
+                totalType = NumberDouble;
+
+            if (subTotalType == NumberInt) {
+                int v = pSubTotal->getInt();
+                longTotal += v;
+                doubleTotal += v;
+            }
+            else if (subTotalType == NumberLong) {
+                long long v = pSubTotal->getLong();
+                longTotal += v;
+                doubleTotal += v;
+            }
+            else {
+                double v = pSubTotal->getDouble();
+                doubleTotal += v;
+            }
+                
+            intrusive_ptr<const Value> pCount(pShardDoc->getValue(countName));
+            count += pCount->getLong();
+        }
+
+        return Value::getZero();
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorAvg::create(
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<AccumulatorAvg> pA(new AccumulatorAvg(pCtx));
+        return pA;
+    }
+
+    intrusive_ptr<const Value> AccumulatorAvg::getValue() const {
+        if (!pCtx->getInShard()) {
+            double avg = 0;
+            if (count) {
+                if (totalType != NumberDouble)
+                    avg = static_cast<double>(longTotal / count);
+                else
+                    avg = doubleTotal / count;
+            }
+
+            return Value::createDouble(avg);
+        }
+
+        intrusive_ptr<Document> pDocument(Document::create());
+
+        intrusive_ptr<const Value> pSubTotal;
+        if (totalType == NumberInt)
+            pSubTotal = Value::createInt((int)longTotal);
+        else if (totalType == NumberLong)
+            pSubTotal = Value::createLong(longTotal);
+        else
+            pSubTotal = Value::createDouble(doubleTotal);
+        pDocument->addField(subTotalName, pSubTotal);
+
+        intrusive_ptr<const Value> pCount(Value::createLong(count));
+        pDocument->addField(countName, pCount);
+
+        return Value::createDocument(pDocument);
+    }
+
+    AccumulatorAvg::AccumulatorAvg(
+        const intrusive_ptr<ExpressionContext> &pTheCtx):
+        AccumulatorSum(),
+        count(0),
+        pCtx(pTheCtx) {
+    }
+
+    const char *AccumulatorAvg::getOpName() const {
+        return "$avg";
+    }
+}
diff --git a/src/mongo/db/pipeline/accumulator_first.cpp b/src/mongo/db/pipeline/accumulator_first.cpp
index 937b260f136..53d8f9595e9 100755
--- a/src/mongo/db/pipeline/accumulator_first.cpp
+++ b/src/mongo/db/pipeline/accumulator_first.cpp
@@ -1,49 +1,49 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "accumulator.h"

-

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    intrusive_ptr<const Value> AccumulatorFirst::evaluate(

-        const intrusive_ptr<Document> &pDocument) const {

-        verify(vpOperand.size() == 1);

-

-        /* only remember the first value seen */

-        if (!pValue.get())

-            pValue = vpOperand[0]->evaluate(pDocument);

-

-        return pValue;

-    }

-

-    AccumulatorFirst::AccumulatorFirst():

-        AccumulatorSingleValue() {

-    }

-

-    intrusive_ptr<Accumulator> AccumulatorFirst::create(

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        intrusive_ptr<AccumulatorFirst> pAccumulator(

-            new AccumulatorFirst());

-        return pAccumulator;

-    }

-

-    const char *AccumulatorFirst::getOpName() const {

-        return "$first";

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "accumulator.h"
+
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    intrusive_ptr<const Value> AccumulatorFirst::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        verify(vpOperand.size() == 1);
+
+        /* only remember the first value seen */
+        if (!pValue.get())
+            pValue = vpOperand[0]->evaluate(pDocument);
+
+        return pValue;
+    }
+
+    AccumulatorFirst::AccumulatorFirst():
+        AccumulatorSingleValue() {
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorFirst::create(
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<AccumulatorFirst> pAccumulator(
+            new AccumulatorFirst());
+        return pAccumulator;
+    }
+
+    const char *AccumulatorFirst::getOpName() const {
+        return "$first";
+    }
+}
diff --git a/src/mongo/db/pipeline/accumulator_last.cpp b/src/mongo/db/pipeline/accumulator_last.cpp
index 820907a1151..d934e64111b 100755
--- a/src/mongo/db/pipeline/accumulator_last.cpp
+++ b/src/mongo/db/pipeline/accumulator_last.cpp
@@ -1,48 +1,48 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "accumulator.h"

-

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    intrusive_ptr<const Value> AccumulatorLast::evaluate(

-        const intrusive_ptr<Document> &pDocument) const {

-        verify(vpOperand.size() == 1);

-

-        /* always remember the last value seen */

-        pValue = vpOperand[0]->evaluate(pDocument);

-

-        return pValue;

-    }

-

-    AccumulatorLast::AccumulatorLast():

-        AccumulatorSingleValue() {

-    }

-

-    intrusive_ptr<Accumulator> AccumulatorLast::create(

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        intrusive_ptr<AccumulatorLast> pAccumulator(

-            new AccumulatorLast());

-        return pAccumulator;

-    }

-

-    const char *AccumulatorLast::getOpName() const {

-        return "$last";

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "accumulator.h"
+
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    intrusive_ptr<const Value> AccumulatorLast::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        verify(vpOperand.size() == 1);
+
+        /* always remember the last value seen */
+        pValue = vpOperand[0]->evaluate(pDocument);
+
+        return pValue;
+    }
+
+    AccumulatorLast::AccumulatorLast():
+        AccumulatorSingleValue() {
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorLast::create(
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<AccumulatorLast> pAccumulator(
+            new AccumulatorLast());
+        return pAccumulator;
+    }
+
+    const char *AccumulatorLast::getOpName() const {
+        return "$last";
+    }
+}
diff --git a/src/mongo/db/pipeline/accumulator_min_max.cpp b/src/mongo/db/pipeline/accumulator_min_max.cpp
index 902f910dcb8..aec461bab02 100755
--- a/src/mongo/db/pipeline/accumulator_min_max.cpp
+++ b/src/mongo/db/pipeline/accumulator_min_max.cpp
@@ -1,67 +1,67 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "accumulator.h"

-

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    intrusive_ptr<const Value> AccumulatorMinMax::evaluate(

-        const intrusive_ptr<Document> &pDocument) const {

-        verify(vpOperand.size() == 1);

-        intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));

-

-        /* if this is the first value, just use it */

-        if (!pValue.get())

-            pValue = prhs;

-        else {

-            /* compare with the current value; swap if appropriate */

-            int cmp = Value::compare(pValue, prhs) * sense;

-            if (cmp > 0)

-                pValue = prhs;

-        }

-

-        return pValue;

-    }

-

-    AccumulatorMinMax::AccumulatorMinMax(int theSense):

-        AccumulatorSingleValue(),

-        sense(theSense) {

-        verify((sense == 1) || (sense == -1));

-    }

-

-    intrusive_ptr<Accumulator> AccumulatorMinMax::createMin(

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        intrusive_ptr<AccumulatorMinMax> pAccumulator(

-            new AccumulatorMinMax(1));

-        return pAccumulator;

-    }

-

-    intrusive_ptr<Accumulator> AccumulatorMinMax::createMax(

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        intrusive_ptr<AccumulatorMinMax> pAccumulator(

-            new AccumulatorMinMax(-1));

-        return pAccumulator;

-    }

-

-    const char *AccumulatorMinMax::getOpName() const {

-        if (sense == 1)

-            return "$min";

-        return "$max";

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "accumulator.h"
+
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    intrusive_ptr<const Value> AccumulatorMinMax::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        verify(vpOperand.size() == 1);
+        intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));
+
+        /* if this is the first value, just use it */
+        if (!pValue.get())
+            pValue = prhs;
+        else {
+            /* compare with the current value; swap if appropriate */
+            int cmp = Value::compare(pValue, prhs) * sense;
+            if (cmp > 0)
+                pValue = prhs;
+        }
+
+        return pValue;
+    }
+
+    AccumulatorMinMax::AccumulatorMinMax(int theSense):
+        AccumulatorSingleValue(),
+        sense(theSense) {
+        verify((sense == 1) || (sense == -1));
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorMinMax::createMin(
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<AccumulatorMinMax> pAccumulator(
+            new AccumulatorMinMax(1));
+        return pAccumulator;
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorMinMax::createMax(
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<AccumulatorMinMax> pAccumulator(
+            new AccumulatorMinMax(-1));
+        return pAccumulator;
+    }
+
+    const char *AccumulatorMinMax::getOpName() const {
+        if (sense == 1)
+            return "$min";
+        return "$max";
+    }
+}
diff --git a/src/mongo/db/pipeline/accumulator_push.cpp b/src/mongo/db/pipeline/accumulator_push.cpp
index 932ca6361cd..b097894cb4e 100755
--- a/src/mongo/db/pipeline/accumulator_push.cpp
+++ b/src/mongo/db/pipeline/accumulator_push.cpp
@@ -1,73 +1,73 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "accumulator.h"

-

-#include "db/pipeline/expression_context.h"

-#include "db/pipeline/value.h"

-

-namespace mongo {

-    intrusive_ptr<const Value> AccumulatorPush::evaluate(

-        const intrusive_ptr<Document> &pDocument) const {

-        verify(vpOperand.size() == 1);

-        intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));

-

-        if (prhs->getType() == Undefined)

-            ; /* nothing to add to the array */

-        else if (!pCtx->getInRouter())

-            vpValue.push_back(prhs);

-        else {

-            /*

-              If we're in the router, we need to take apart the arrays we

-              receive and put their elements into the array we are collecting.

-              If we didn't, then we'd get an array of arrays, with one array

-              from each shard that responds.

-             */

-            verify(prhs->getType() == Array);

-            

-            intrusive_ptr<ValueIterator> pvi(prhs->getArray());

-            while(pvi->more()) {

-                intrusive_ptr<const Value> pElement(pvi->next());

-                vpValue.push_back(pElement);

-            }

-        }

-

-        return Value::getNull();

-    }

-

-    intrusive_ptr<const Value> AccumulatorPush::getValue() const {

-        return Value::createArray(vpValue);

-    }

-

-    AccumulatorPush::AccumulatorPush(

-        const intrusive_ptr<ExpressionContext> &pTheCtx):

-        Accumulator(),

-        vpValue(),

-        pCtx(pTheCtx) {

-    }

-

-    intrusive_ptr<Accumulator> AccumulatorPush::create(

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        intrusive_ptr<AccumulatorPush> pAccumulator(

-            new AccumulatorPush(pCtx));

-        return pAccumulator;

-    }

-

-    const char *AccumulatorPush::getOpName() const {

-        return "$push";

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "accumulator.h"
+
+#include "db/pipeline/expression_context.h"
+#include "db/pipeline/value.h"
+
+namespace mongo {
+    intrusive_ptr<const Value> AccumulatorPush::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        verify(vpOperand.size() == 1);
+        intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));
+
+        if (prhs->getType() == Undefined)
+            ; /* nothing to add to the array */
+        else if (!pCtx->getInRouter())
+            vpValue.push_back(prhs);
+        else {
+            /*
+              If we're in the router, we need to take apart the arrays we
+              receive and put their elements into the array we are collecting.
+              If we didn't, then we'd get an array of arrays, with one array
+              from each shard that responds.
+             */
+            verify(prhs->getType() == Array);
+            
+            intrusive_ptr<ValueIterator> pvi(prhs->getArray());
+            while(pvi->more()) {
+                intrusive_ptr<const Value> pElement(pvi->next());
+                vpValue.push_back(pElement);
+            }
+        }
+
+        return Value::getNull();
+    }
+
+    intrusive_ptr<const Value> AccumulatorPush::getValue() const {
+        return Value::createArray(vpValue);
+    }
+
+    AccumulatorPush::AccumulatorPush(
+        const intrusive_ptr<ExpressionContext> &pTheCtx):
+        Accumulator(),
+        vpValue(),
+        pCtx(pTheCtx) {
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorPush::create(
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<AccumulatorPush> pAccumulator(
+            new AccumulatorPush(pCtx));
+        return pAccumulator;
+    }
+
+    const char *AccumulatorPush::getOpName() const {
+        return "$push";
+    }
+}
diff --git a/src/mongo/db/pipeline/accumulator_single_value.cpp b/src/mongo/db/pipeline/accumulator_single_value.cpp
index 7e2491d121f..ea12ee333a2 100755
--- a/src/mongo/db/pipeline/accumulator_single_value.cpp
+++ b/src/mongo/db/pipeline/accumulator_single_value.cpp
@@ -1,32 +1,32 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "accumulator.h"

-

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    intrusive_ptr<const Value> AccumulatorSingleValue::getValue() const {

-        return pValue;

-    }

-

-    AccumulatorSingleValue::AccumulatorSingleValue():

-        pValue(intrusive_ptr<const Value>()) {

-    }

-

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "accumulator.h"
+
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    intrusive_ptr<const Value> AccumulatorSingleValue::getValue() const {
+        return pValue;
+    }
+
+    AccumulatorSingleValue::AccumulatorSingleValue():
+        pValue(intrusive_ptr<const Value>()) {
+    }
+
+}
diff --git a/src/mongo/db/pipeline/accumulator_sum.cpp b/src/mongo/db/pipeline/accumulator_sum.cpp
index 26258c2f19a..f0a3c1a7ba3 100755
--- a/src/mongo/db/pipeline/accumulator_sum.cpp
+++ b/src/mongo/db/pipeline/accumulator_sum.cpp
@@ -1,74 +1,74 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "accumulator.h"

-

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    intrusive_ptr<const Value> AccumulatorSum::evaluate(

-        const intrusive_ptr<Document> &pDocument) const {

-        verify(vpOperand.size() == 1);

-        intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));

-

-        /* upgrade to the widest type required to hold the result */

-        totalType = Value::getWidestNumeric(totalType, prhs->getType());

-

-        if (totalType == NumberInt) {

-            int v = prhs->coerceToInt();

-            longTotal += v;

-            doubleTotal += v;

-        }

-        else if (totalType == NumberLong) {

-            long long v = prhs->coerceToLong();

-            longTotal += v;

-            doubleTotal += v;

-        }

-        else { /* (totalType == NumberDouble) */

-            double v = prhs->coerceToDouble();

-            doubleTotal += v;

-        }

-

-        return Value::getZero();

-    }

-

-    intrusive_ptr<Accumulator> AccumulatorSum::create(

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        intrusive_ptr<AccumulatorSum> pSummer(new AccumulatorSum());

-        return pSummer;

-    }

-

-    intrusive_ptr<const Value> AccumulatorSum::getValue() const {

-        if (totalType == NumberInt)

-            return Value::createInt((int)longTotal);

-        if (totalType == NumberLong)

-            return Value::createLong(longTotal);

-        return Value::createDouble(doubleTotal);

-    }

-

-    AccumulatorSum::AccumulatorSum():

-        Accumulator(),

-        totalType(NumberInt),

-        longTotal(0),

-        doubleTotal(0) {

-    }

-

-    const char *AccumulatorSum::getOpName() const {

-        return "$sum";

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "accumulator.h"
+
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    intrusive_ptr<const Value> AccumulatorSum::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        verify(vpOperand.size() == 1);
+        intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));
+
+        /* upgrade to the widest type required to hold the result */
+        totalType = Value::getWidestNumeric(totalType, prhs->getType());
+
+        if (totalType == NumberInt) {
+            int v = prhs->coerceToInt();
+            longTotal += v;
+            doubleTotal += v;
+        }
+        else if (totalType == NumberLong) {
+            long long v = prhs->coerceToLong();
+            longTotal += v;
+            doubleTotal += v;
+        }
+        else { /* (totalType == NumberDouble) */
+            double v = prhs->coerceToDouble();
+            doubleTotal += v;
+        }
+
+        return Value::getZero();
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorSum::create(
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<AccumulatorSum> pSummer(new AccumulatorSum());
+        return pSummer;
+    }
+
+    intrusive_ptr<const Value> AccumulatorSum::getValue() const {
+        if (totalType == NumberInt)
+            return Value::createInt((int)longTotal);
+        if (totalType == NumberLong)
+            return Value::createLong(longTotal);
+        return Value::createDouble(doubleTotal);
+    }
+
+    AccumulatorSum::AccumulatorSum():
+        Accumulator(),
+        totalType(NumberInt),
+        longTotal(0),
+        doubleTotal(0) {
+    }
+
+    const char *AccumulatorSum::getOpName() const {
+        return "$sum";
+    }
+}
diff --git a/src/mongo/db/pipeline/builder.cpp b/src/mongo/db/pipeline/builder.cpp
index b3f7872ef94..6b7673a20d3 100755
--- a/src/mongo/db/pipeline/builder.cpp
+++ b/src/mongo/db/pipeline/builder.cpp
@@ -1,117 +1,117 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-

-#include "db/jsobj.h"

-#include "db/pipeline/builder.h"

-

-

-namespace mongo {

-

-    void BuilderObj::append() {

-        pBuilder->appendNull(fieldName);

-    }

-

-    void BuilderObj::append(bool b) {

-        pBuilder->append(fieldName, b);

-    }

-

-    void BuilderObj::append(int i) {

-        pBuilder->append(fieldName, i);

-    }

-

-    void BuilderObj::append(long long ll) {

-        pBuilder->append(fieldName, ll);

-    }

-

-    void BuilderObj::append(double d) {

-        pBuilder->append(fieldName, d);

-    }

-

-    void BuilderObj::append(string s) {

-        pBuilder->append(fieldName, s);

-    }

-

-    void BuilderObj::append(const OID &o) {

-        pBuilder->append(fieldName, o);

-    }

-

-    void BuilderObj::append(const Date_t &d) {

-        pBuilder->append(fieldName, d);

-    }

-

-    void BuilderObj::append(BSONObjBuilder *pDone) {

-        pBuilder->append(fieldName, pDone->done());

-    }

-

-    void BuilderObj::append(BSONArrayBuilder *pDone) {

-        pBuilder->append(fieldName, pDone->arr());

-    }

-

-    BuilderObj::BuilderObj(

-        BSONObjBuilder *pObjBuilder, string theFieldName):

-        pBuilder(pObjBuilder),

-        fieldName(theFieldName) {

-    }

-

-

-    void BuilderArray::append() {

-        pBuilder->appendNull();

-    }

-

-    void BuilderArray::append(bool b) {

-        pBuilder->append(b);

-    }

-

-    void BuilderArray::append(int i) {

-        pBuilder->append(i);

-    }

-

-    void BuilderArray::append(long long ll) {

-        pBuilder->append(ll);

-    }

-

-    void BuilderArray::append(double d) {

-        pBuilder->append(d);

-    }

-

-    void BuilderArray::append(string s) {

-        pBuilder->append(s);

-    }

-

-    void BuilderArray::append(const OID &o) {

-        pBuilder->append(o);

-    }

-

-    void BuilderArray::append(const Date_t &d) {

-        pBuilder->append(d);

-    }

-

-    void BuilderArray::append(BSONObjBuilder *pDone) {

-        pBuilder->append(pDone->done());

-    }

-

-    void BuilderArray::append(BSONArrayBuilder *pDone) {

-        pBuilder->append(pDone->arr());

-    }

-

-    BuilderArray::BuilderArray(

-        BSONArrayBuilder *pArrayBuilder):

-        pBuilder(pArrayBuilder) {

-    }

-

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+
+#include "db/jsobj.h"
+#include "db/pipeline/builder.h"
+
+
+namespace mongo {
+
+    void BuilderObj::append() {
+        pBuilder->appendNull(fieldName);
+    }
+
+    void BuilderObj::append(bool b) {
+        pBuilder->append(fieldName, b);
+    }
+
+    void BuilderObj::append(int i) {
+        pBuilder->append(fieldName, i);
+    }
+
+    void BuilderObj::append(long long ll) {
+        pBuilder->append(fieldName, ll);
+    }
+
+    void BuilderObj::append(double d) {
+        pBuilder->append(fieldName, d);
+    }
+
+    void BuilderObj::append(string s) {
+        pBuilder->append(fieldName, s);
+    }
+
+    void BuilderObj::append(const OID &o) {
+        pBuilder->append(fieldName, o);
+    }
+
+    void BuilderObj::append(const Date_t &d) {
+        pBuilder->append(fieldName, d);
+    }
+
+    void BuilderObj::append(BSONObjBuilder *pDone) {
+        pBuilder->append(fieldName, pDone->done());
+    }
+
+    void BuilderObj::append(BSONArrayBuilder *pDone) {
+        pBuilder->append(fieldName, pDone->arr());
+    }
+
+    BuilderObj::BuilderObj(
+        BSONObjBuilder *pObjBuilder, string theFieldName):
+        pBuilder(pObjBuilder),
+        fieldName(theFieldName) {
+    }
+
+
+    void BuilderArray::append() {
+        pBuilder->appendNull();
+    }
+
+    void BuilderArray::append(bool b) {
+        pBuilder->append(b);
+    }
+
+    void BuilderArray::append(int i) {
+        pBuilder->append(i);
+    }
+
+    void BuilderArray::append(long long ll) {
+        pBuilder->append(ll);
+    }
+
+    void BuilderArray::append(double d) {
+        pBuilder->append(d);
+    }
+
+    void BuilderArray::append(string s) {
+        pBuilder->append(s);
+    }
+
+    void BuilderArray::append(const OID &o) {
+        pBuilder->append(o);
+    }
+
+    void BuilderArray::append(const Date_t &d) {
+        pBuilder->append(d);
+    }
+
+    void BuilderArray::append(BSONObjBuilder *pDone) {
+        pBuilder->append(pDone->done());
+    }
+
+    void BuilderArray::append(BSONArrayBuilder *pDone) {
+        pBuilder->append(pDone->arr());
+    }
+
+    BuilderArray::BuilderArray(
+        BSONArrayBuilder *pArrayBuilder):
+        pBuilder(pArrayBuilder) {
+    }
+
+}
diff --git a/src/mongo/db/pipeline/builder.h b/src/mongo/db/pipeline/builder.h
index fc37a72236f..5456a9c5efb 100755
--- a/src/mongo/db/pipeline/builder.h
+++ b/src/mongo/db/pipeline/builder.h
@@ -1,95 +1,95 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#pragma once

-

-#include "pch.h"

-

-namespace mongo {

-

-    class BSONArrayBuilder;

-    class BSONObjBuilder;

-

-    /*

-      Generic Builder.

-

-      The methods to append items to an object (on BSONObjBuilder) and an array

-      (on BSONArrayBuilder) differ only by their inclusion of a field name. 

-      For more complicated implementations of addToBsonObj() and

-      addToBsonArray(), it makes sense to abstract that out and use

-      this generic builder that always looks the same, and then implement

-      addToBsonObj() and addToBsonArray() by using a common method.

-    */

-    class Builder :

-        boost::noncopyable {

-    public:

-        virtual ~Builder() {};

-

-        virtual void append() = 0; // append a null

-        virtual void append(bool b) = 0;

-        virtual void append(int i) = 0;

-        virtual void append(long long ll) = 0;

-        virtual void append(double d) = 0;

-        virtual void append(string s) = 0;

-        virtual void append(const OID &o) = 0;

-        virtual void append(const Date_t &d) = 0;

-        virtual void append(BSONObjBuilder *pDone) = 0;

-        virtual void append(BSONArrayBuilder *pDone) = 0;

-    };

-

-    class BuilderObj :

-        public Builder {

-    public:

-        // virtuals from Builder

-        virtual void append();

-        virtual void append(bool b);

-        virtual void append(int i);

-        virtual void append(long long ll);

-        virtual void append(double d);

-        virtual void append(string s);

-        virtual void append(const OID &o);

-        virtual void append(const Date_t &d);

-        virtual void append(BSONObjBuilder *pDone);

-        virtual void append(BSONArrayBuilder *pDone);

-

-        BuilderObj(BSONObjBuilder *pBuilder, string fieldName);

-

-    private:

-        BSONObjBuilder *pBuilder;

-        string fieldName;

-    };

-

-    class BuilderArray :

-        public Builder {

-    public:

-        // virtuals from Builder

-        virtual void append();

-        virtual void append(bool b);

-        virtual void append(int i);

-        virtual void append(long long ll);

-        virtual void append(double d);

-        virtual void append(string s);

-        virtual void append(const OID &o);

-        virtual void append(const Date_t &d);

-        virtual void append(BSONObjBuilder *pDone);

-        virtual void append(BSONArrayBuilder *pDone);

-

-        BuilderArray(BSONArrayBuilder *pBuilder);

-

-    private:

-        BSONArrayBuilder *pBuilder;

-    };

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "pch.h"
+
+namespace mongo {
+
+    class BSONArrayBuilder;
+    class BSONObjBuilder;
+
+    /*
+      Generic Builder.
+
+      The methods to append items to an object (on BSONObjBuilder) and an array
+      (on BSONArrayBuilder) differ only by their inclusion of a field name. 
+      For more complicated implementations of addToBsonObj() and
+      addToBsonArray(), it makes sense to abstract that out and use
+      this generic builder that always looks the same, and then implement
+      addToBsonObj() and addToBsonArray() by using a common method.
+    */
+    class Builder :
+        boost::noncopyable {
+    public:
+        virtual ~Builder() {};
+
+        virtual void append() = 0; // append a null
+        virtual void append(bool b) = 0;
+        virtual void append(int i) = 0;
+        virtual void append(long long ll) = 0;
+        virtual void append(double d) = 0;
+        virtual void append(string s) = 0;
+        virtual void append(const OID &o) = 0;
+        virtual void append(const Date_t &d) = 0;
+        virtual void append(BSONObjBuilder *pDone) = 0;
+        virtual void append(BSONArrayBuilder *pDone) = 0;
+    };
+
+    class BuilderObj :
+        public Builder {
+    public:
+        // virtuals from Builder
+        virtual void append();
+        virtual void append(bool b);
+        virtual void append(int i);
+        virtual void append(long long ll);
+        virtual void append(double d);
+        virtual void append(string s);
+        virtual void append(const OID &o);
+        virtual void append(const Date_t &d);
+        virtual void append(BSONObjBuilder *pDone);
+        virtual void append(BSONArrayBuilder *pDone);
+
+        BuilderObj(BSONObjBuilder *pBuilder, string fieldName);
+
+    private:
+        BSONObjBuilder *pBuilder;
+        string fieldName;
+    };
+
+    class BuilderArray :
+        public Builder {
+    public:
+        // virtuals from Builder
+        virtual void append();
+        virtual void append(bool b);
+        virtual void append(int i);
+        virtual void append(long long ll);
+        virtual void append(double d);
+        virtual void append(string s);
+        virtual void append(const OID &o);
+        virtual void append(const Date_t &d);
+        virtual void append(BSONObjBuilder *pDone);
+        virtual void append(BSONArrayBuilder *pDone);
+
+        BuilderArray(BSONArrayBuilder *pBuilder);
+
+    private:
+        BSONArrayBuilder *pBuilder;
+    };
+}
diff --git a/src/mongo/db/pipeline/doc_mem_monitor.cpp b/src/mongo/db/pipeline/doc_mem_monitor.cpp
index e4e8323cf96..3cbe14e8f40 100755
--- a/src/mongo/db/pipeline/doc_mem_monitor.cpp
+++ b/src/mongo/db/pipeline/doc_mem_monitor.cpp
@@ -1,68 +1,68 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "db/pipeline/doc_mem_monitor.h"

-#include "util/systeminfo.h"

-

-namespace mongo {

-

-    DocMemMonitor::DocMemMonitor(StringWriter *pW) {

-        /*

-          Use the default values.

-

-          Currently, we warn in log at 5%, and assert at 10%.

-        */

-        size_t errorRam = SystemInfo::getPhysicalRam() / 10;

-        size_t warnRam = errorRam / 2;

-

-        init(pW, warnRam, errorRam);

-    }

-

-    DocMemMonitor::DocMemMonitor(StringWriter *pW,

-                                 size_t warnLimit, size_t errorLimit) {

-        init(pW, warnLimit, errorLimit);

-    }

-

-    void DocMemMonitor::addToTotal(size_t amount) {

-        totalUsed += amount;

-

-        if (!warned) {

-            if (warnLimit && (totalUsed > warnLimit)) {

-                stringstream ss;

-                ss << "warning, 5% of physical RAM used for ";

-                pWriter->writeString(ss);

-                ss << endl;

-                warning() << ss.str();

-                warned = true;

-            }

-        }

-        

-        if (errorLimit) {

-            uassert(15944, "terminating request:  request heap use exceeded 10% of physical RAM", (totalUsed <= errorLimit));

-        }

-    }

-

-    void DocMemMonitor::init(StringWriter *pW,

-                             size_t warnLimit, size_t errorLimit) {

-        this->pWriter = pW;

-        this->warnLimit = warnLimit;

-        this->errorLimit = errorLimit;

-

-        warned = false;

-        totalUsed = 0;

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "db/pipeline/doc_mem_monitor.h"
+#include "util/systeminfo.h"
+
+namespace mongo {
+
+    DocMemMonitor::DocMemMonitor(StringWriter *pW) {
+        /*
+          Use the default values.
+
+          Currently, we warn in log at 5%, and assert at 10%.
+        */
+        size_t errorRam = SystemInfo::getPhysicalRam() / 10;
+        size_t warnRam = errorRam / 2;
+
+        init(pW, warnRam, errorRam);
+    }
+
+    DocMemMonitor::DocMemMonitor(StringWriter *pW,
+                                 size_t warnLimit, size_t errorLimit) {
+        init(pW, warnLimit, errorLimit);
+    }
+
+    void DocMemMonitor::addToTotal(size_t amount) {
+        totalUsed += amount;
+
+        if (!warned) {
+            if (warnLimit && (totalUsed > warnLimit)) {
+                stringstream ss;
+                ss << "warning, 5% of physical RAM used for ";
+                pWriter->writeString(ss);
+                ss << endl;
+                warning() << ss.str();
+                warned = true;
+            }
+        }
+        
+        if (errorLimit) {
+            uassert(15944, "terminating request:  request heap use exceeded 10% of physical RAM", (totalUsed <= errorLimit));
+        }
+    }
+
+    void DocMemMonitor::init(StringWriter *pW,
+                             size_t warnLimit, size_t errorLimit) {
+        this->pWriter = pW;
+        this->warnLimit = warnLimit;
+        this->errorLimit = errorLimit;
+
+        warned = false;
+        totalUsed = 0;
+    }
+}
diff --git a/src/mongo/db/pipeline/doc_mem_monitor.h b/src/mongo/db/pipeline/doc_mem_monitor.h
index ca5ac23e16b..7a3f0062bfb 100755
--- a/src/mongo/db/pipeline/doc_mem_monitor.h
+++ b/src/mongo/db/pipeline/doc_mem_monitor.h
@@ -1,94 +1,94 @@
-/**

- * Copyright 2011 (c) 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#pragma once

-

-#include "pch.h"

-#include "util/string_writer.h"

-

-

-namespace mongo {

-

-    /*

-      This utility class provides an easy way to total up, monitor, warn, and

-      signal an error when the amount of memory used for an operation exceeds

-      given thresholds.

-

-      Create a local instance of this class, and then inform it of any memory

-      that you consume using addToTotal().

-

-      Warnings or errors are issued as usage exceeds certain fractions of

-      physical memory on the host, as determined by SystemInfo.

-

-      This class is not guaranteed to warn or signal errors if the host system

-      does not support the ability to report its memory, as per the warnings

-      for SystemInfo in systeminfo.h.

-     */

-    class DocMemMonitor {

-    public:

-        /*

-          Constructor.

-

-          Uses default limits for warnings and errors.

-

-          The StringWriter parameter must outlive the DocMemMonitor instance.

-

-          @param pWriter string writer that provides information about the

-              operation being monitored

-         */

-        DocMemMonitor(StringWriter *pWriter);

-

-        /*

-          Constructor.

-

-          This variant allows explicit selection of the limits.  Note that

-          limits of zero are treated as infinite.

-

-          The StringWriter parameter must outlive the DocMemMonitor instance.

-

-          @param pWriter string writer that provides information about the

-              operation being monitored

-          @param warnLimit the amount of ram to issue (log) a warning for

-          @param errorLimit the amount of ram to throw an error for

-         */

-        DocMemMonitor(StringWriter *pWriter, size_t warnLimit,

-                      size_t errorLimit);

-

-        /*

-          Increment the total amount of memory used by the given amount.  If

-          the warning threshold is exceeded, a warning will be logged.  If the

-          error threshold is exceeded, an error will be thrown.

-

-          @param amount the amount of memory to add to the current total

-         */

-        void addToTotal(size_t amount);

-

-    private:

-        /*

-          Real constructor body.

-

-          Provides common construction for all the variant constructors.

-         */

-        void init(StringWriter *pW, size_t warnLimit, size_t errorLimit);

-

-        bool warned;

-        size_t totalUsed;

-        size_t warnLimit;

-        size_t errorLimit;

-        StringWriter *pWriter;

-    };

-

-}

+/**
+ * Copyright 2011 (c) 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "pch.h"
+#include "util/string_writer.h"
+
+
+namespace mongo {
+
+    /*
+      This utility class provides an easy way to total up, monitor, warn, and
+      signal an error when the amount of memory used for an operation exceeds
+      given thresholds.
+
+      Create a local instance of this class, and then inform it of any memory
+      that you consume using addToTotal().
+
+      Warnings or errors are issued as usage exceeds certain fractions of
+      physical memory on the host, as determined by SystemInfo.
+
+      This class is not guaranteed to warn or signal errors if the host system
+      does not support the ability to report its memory, as per the warnings
+      for SystemInfo in systeminfo.h.
+     */
+    class DocMemMonitor {
+    public:
+        /*
+          Constructor.
+
+          Uses default limits for warnings and errors.
+
+          The StringWriter parameter must outlive the DocMemMonitor instance.
+
+          @param pWriter string writer that provides information about the
+              operation being monitored
+         */
+        DocMemMonitor(StringWriter *pWriter);
+
+        /*
+          Constructor.
+
+          This variant allows explicit selection of the limits.  Note that
+          limits of zero are treated as infinite.
+
+          The StringWriter parameter must outlive the DocMemMonitor instance.
+
+          @param pWriter string writer that provides information about the
+              operation being monitored
+          @param warnLimit the amount of ram to issue (log) a warning for
+          @param errorLimit the amount of ram to throw an error for
+         */
+        DocMemMonitor(StringWriter *pWriter, size_t warnLimit,
+                      size_t errorLimit);
+
+        /*
+          Increment the total amount of memory used by the given amount.  If
+          the warning threshold is exceeded, a warning will be logged.  If the
+          error threshold is exceeded, an error will be thrown.
+
+          @param amount the amount of memory to add to the current total
+         */
+        void addToTotal(size_t amount);
+
+    private:
+        /*
+          Real constructor body.
+
+          Provides common construction for all the variant constructors.
+         */
+        void init(StringWriter *pW, size_t warnLimit, size_t errorLimit);
+
+        bool warned;
+        size_t totalUsed;
+        size_t warnLimit;
+        size_t errorLimit;
+        StringWriter *pWriter;
+    };
+
+}
diff --git a/src/mongo/db/pipeline/document.cpp b/src/mongo/db/pipeline/document.cpp
index a224f56eacb..3242dec4c4a 100755
--- a/src/mongo/db/pipeline/document.cpp
+++ b/src/mongo/db/pipeline/document.cpp
@@ -1,227 +1,227 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include <boost/functional/hash.hpp>

-#include "db/jsobj.h"

-#include "db/pipeline/dependency_tracker.h"

-#include "db/pipeline/document.h"

-#include "db/pipeline/value.h"

-#include "util/mongoutils/str.h"

-

-namespace mongo {

-    using namespace mongoutils;

-

-    string Document::idName("_id");

-

-    intrusive_ptr<Document> Document::createFromBsonObj(

-        BSONObj *pBsonObj, const DependencyTracker *pDependencies) {

-        intrusive_ptr<Document> pDocument(

-            new Document(pBsonObj, pDependencies));

-        return pDocument;

-    }

-

-    Document::Document(BSONObj *pBsonObj,

-                       const DependencyTracker *pDependencies):

-        vFieldName(),

-        vpValue() {

-        BSONObjIterator bsonIterator(pBsonObj->begin());

-        while(bsonIterator.more()) {

-            BSONElement bsonElement(bsonIterator.next());

-            string fieldName(bsonElement.fieldName());

-

-            // LATER check pDependencies

-            // LATER grovel through structures???

-            intrusive_ptr<const Value> pValue(

-                Value::createFromBsonElement(&bsonElement));

-

-            vFieldName.push_back(fieldName);

-            vpValue.push_back(pValue);

-        }

-    }

-

-    void Document::toBson(BSONObjBuilder *pBuilder) {

-        const size_t n = vFieldName.size();

-        for(size_t i = 0; i < n; ++i)

-            vpValue[i]->addToBsonObj(pBuilder, vFieldName[i]);

-    }

-

-    intrusive_ptr<Document> Document::create(size_t sizeHint) {

-        intrusive_ptr<Document> pDocument(new Document(sizeHint));

-        return pDocument;

-    }

-

-    Document::Document(size_t sizeHint):

-        vFieldName(),

-        vpValue() {

-        if (sizeHint) {

-            vFieldName.reserve(sizeHint);

-            vpValue.reserve(sizeHint);

-        }

-    }

-

-    intrusive_ptr<Document> Document::clone() {

-        const size_t n = vFieldName.size();

-        intrusive_ptr<Document> pNew(Document::create(n));

-        for(size_t i = 0; i < n; ++i)

-            pNew->addField(vFieldName[i], vpValue[i]);

-

-        return pNew;

-    }

-

-    Document::~Document() {

-    }

-

-    FieldIterator *Document::createFieldIterator() {

-        return new FieldIterator(intrusive_ptr<Document>(this));

-    }

-

-    intrusive_ptr<const Value> Document::getValue(const string &fieldName) {

-        /*

-          For now, assume the number of fields is small enough that iteration

-          is ok.  Later, if this gets large, we can create a map into the

-          vector for these lookups.

-

-          Note that because of the schema-less nature of this data, we always

-          have to look, and can't assume that the requested field is always

-          in a particular place as we would with a statically compilable

-          reference.

-        */

-        const size_t n = vFieldName.size();

-        for(size_t i = 0; i < n; ++i) {

-            if (fieldName.compare(vFieldName[i]) == 0)

-                return vpValue[i];

-        }

-

-        return(intrusive_ptr<const Value>());

-    }

-

-    void Document::addField(const string &fieldName,

-                            const intrusive_ptr<const Value> &pValue) {

-        uassert(15945, str::stream() << "cannot add undefined field " <<

-                fieldName << " to document", pValue->getType() != Undefined);

-

-        vFieldName.push_back(fieldName);

-        vpValue.push_back(pValue);

-    }

-

-    void Document::setField(size_t index,

-                            const string &fieldName,

-                            const intrusive_ptr<const Value> &pValue) {

-        /* special case:  should this field be removed? */

-        if (!pValue.get()) {

-            vFieldName.erase(vFieldName.begin() + index);

-            vpValue.erase(vpValue.begin() + index);

-            return;

-        }

-

-        /* make sure we have a valid value */

-        uassert(15968, str::stream() << "cannot set undefined field " <<

-                fieldName << " to document", pValue->getType() != Undefined);

-

-        /* set the indicated field */

-        vFieldName[index] = fieldName;

-        vpValue[index] = pValue;

-    }

-

-    intrusive_ptr<const Value> Document::getField(const string &fieldName) const {

-        const size_t n = vFieldName.size();

-        for(size_t i = 0; i < n; ++i) {

-            if (fieldName.compare(vFieldName[i]) == 0)

-                return vpValue[i];

-        }

-

-        /* if we got here, there's no such field */

-        return intrusive_ptr<const Value>();

-    }

-

-    size_t Document::getApproximateSize() const {

-        size_t size = sizeof(Document);

-        const size_t n = vpValue.size();

-        for(size_t i = 0; i < n; ++i)

-            size += vpValue[i]->getApproximateSize();

-

-        return size;

-    }

-

-    size_t Document::getFieldIndex(const string &fieldName) const {

-        const size_t n = vFieldName.size();

-        size_t i = 0;

-        for(; i < n; ++i) {

-            if (fieldName.compare(vFieldName[i]) == 0)

-                break;

-        }

-

-        return i;

-    }

-

-    void Document::hash_combine(size_t &seed) const {

-        const size_t n = vFieldName.size();

-        for(size_t i = 0; i < n; ++i) {

-            boost::hash_combine(seed, vFieldName[i]);

-            vpValue[i]->hash_combine(seed);

-        }

-    }

-

-    int Document::compare(const intrusive_ptr<Document> &rL,

-                          const intrusive_ptr<Document> &rR) {

-        const size_t lSize = rL->vFieldName.size();

-        const size_t rSize = rR->vFieldName.size();

-

-        for(size_t i = 0; true; ++i) {

-            if (i >= lSize) {

-                if (i >= rSize)

-                    return 0; // documents are the same length

-

-                return -1; // left document is shorter

-            }

-

-            if (i >= rSize)

-                return 1; // right document is shorter

-

-            const int nameCmp = rL->vFieldName[i].compare(rR->vFieldName[i]);

-            if (nameCmp)

-                return nameCmp; // field names are unequal

-

-            const int valueCmp = Value::compare(rL->vpValue[i], rR->vpValue[i]);

-            if (valueCmp)

-                return valueCmp; // fields are unequal

-        }

-

-        /* NOTREACHED */

-        verify(false);

-        return 0;

-    }

-

-    /* ----------------------- FieldIterator ------------------------------- */

-

-    FieldIterator::FieldIterator(const intrusive_ptr<Document> &pTheDocument):

-        pDocument(pTheDocument),

-        index(0) {

-    }

-

-    bool FieldIterator::more() const {

-        return (index < pDocument->vFieldName.size());

-    }

-

-    pair<string, intrusive_ptr<const Value> > FieldIterator::next() {

-        verify(more());

-        pair<string, intrusive_ptr<const Value> > result(

-            pDocument->vFieldName[index], pDocument->vpValue[index]);

-        ++index;

-        return result;

-    }

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include <boost/functional/hash.hpp>
+#include "db/jsobj.h"
+#include "db/pipeline/dependency_tracker.h"
+#include "db/pipeline/document.h"
+#include "db/pipeline/value.h"
+#include "util/mongoutils/str.h"
+
+namespace mongo {
+    using namespace mongoutils;
+
+    string Document::idName("_id");
+
+    intrusive_ptr<Document> Document::createFromBsonObj(
+        BSONObj *pBsonObj, const DependencyTracker *pDependencies) {
+        intrusive_ptr<Document> pDocument(
+            new Document(pBsonObj, pDependencies));
+        return pDocument;
+    }
+
+    Document::Document(BSONObj *pBsonObj,
+                       const DependencyTracker *pDependencies):
+        vFieldName(),
+        vpValue() {
+        BSONObjIterator bsonIterator(pBsonObj->begin());
+        while(bsonIterator.more()) {
+            BSONElement bsonElement(bsonIterator.next());
+            string fieldName(bsonElement.fieldName());
+
+            // LATER check pDependencies
+            // LATER grovel through structures???
+            intrusive_ptr<const Value> pValue(
+                Value::createFromBsonElement(&bsonElement));
+
+            vFieldName.push_back(fieldName);
+            vpValue.push_back(pValue);
+        }
+    }
+
+    void Document::toBson(BSONObjBuilder *pBuilder) {
+        const size_t n = vFieldName.size();
+        for(size_t i = 0; i < n; ++i)
+            vpValue[i]->addToBsonObj(pBuilder, vFieldName[i]);
+    }
+
+    intrusive_ptr<Document> Document::create(size_t sizeHint) {
+        intrusive_ptr<Document> pDocument(new Document(sizeHint));
+        return pDocument;
+    }
+
+    Document::Document(size_t sizeHint):
+        vFieldName(),
+        vpValue() {
+        if (sizeHint) {
+            vFieldName.reserve(sizeHint);
+            vpValue.reserve(sizeHint);
+        }
+    }
+
+    intrusive_ptr<Document> Document::clone() {
+        const size_t n = vFieldName.size();
+        intrusive_ptr<Document> pNew(Document::create(n));
+        for(size_t i = 0; i < n; ++i)
+            pNew->addField(vFieldName[i], vpValue[i]);
+
+        return pNew;
+    }
+
+    Document::~Document() {
+    }
+
+    FieldIterator *Document::createFieldIterator() {
+        return new FieldIterator(intrusive_ptr<Document>(this));
+    }
+
+    intrusive_ptr<const Value> Document::getValue(const string &fieldName) {
+        /*
+          For now, assume the number of fields is small enough that iteration
+          is ok.  Later, if this gets large, we can create a map into the
+          vector for these lookups.
+
+          Note that because of the schema-less nature of this data, we always
+          have to look, and can't assume that the requested field is always
+          in a particular place as we would with a statically compilable
+          reference.
+        */
+        const size_t n = vFieldName.size();
+        for(size_t i = 0; i < n; ++i) {
+            if (fieldName.compare(vFieldName[i]) == 0)
+                return vpValue[i];
+        }
+
+        return(intrusive_ptr<const Value>());
+    }
+
+    void Document::addField(const string &fieldName,
+                            const intrusive_ptr<const Value> &pValue) {
+        uassert(15945, str::stream() << "cannot add undefined field " <<
+                fieldName << " to document", pValue->getType() != Undefined);
+
+        vFieldName.push_back(fieldName);
+        vpValue.push_back(pValue);
+    }
+
+    void Document::setField(size_t index,
+                            const string &fieldName,
+                            const intrusive_ptr<const Value> &pValue) {
+        /* special case:  should this field be removed? */
+        if (!pValue.get()) {
+            vFieldName.erase(vFieldName.begin() + index);
+            vpValue.erase(vpValue.begin() + index);
+            return;
+        }
+
+        /* make sure we have a valid value */
+        uassert(15968, str::stream() << "cannot set undefined field " <<
+                fieldName << " to document", pValue->getType() != Undefined);
+
+        /* set the indicated field */
+        vFieldName[index] = fieldName;
+        vpValue[index] = pValue;
+    }
+
+    intrusive_ptr<const Value> Document::getField(const string &fieldName) const {
+        const size_t n = vFieldName.size();
+        for(size_t i = 0; i < n; ++i) {
+            if (fieldName.compare(vFieldName[i]) == 0)
+                return vpValue[i];
+        }
+
+        /* if we got here, there's no such field */
+        return intrusive_ptr<const Value>();
+    }
+
+    size_t Document::getApproximateSize() const {
+        size_t size = sizeof(Document);
+        const size_t n = vpValue.size();
+        for(size_t i = 0; i < n; ++i)
+            size += vpValue[i]->getApproximateSize();
+
+        return size;
+    }
+
+    size_t Document::getFieldIndex(const string &fieldName) const {
+        const size_t n = vFieldName.size();
+        size_t i = 0;
+        for(; i < n; ++i) {
+            if (fieldName.compare(vFieldName[i]) == 0)
+                break;
+        }
+
+        return i;
+    }
+
+    void Document::hash_combine(size_t &seed) const {
+        const size_t n = vFieldName.size();
+        for(size_t i = 0; i < n; ++i) {
+            boost::hash_combine(seed, vFieldName[i]);
+            vpValue[i]->hash_combine(seed);
+        }
+    }
+
+    int Document::compare(const intrusive_ptr<Document> &rL,
+                          const intrusive_ptr<Document> &rR) {
+        const size_t lSize = rL->vFieldName.size();
+        const size_t rSize = rR->vFieldName.size();
+
+        for(size_t i = 0; true; ++i) {
+            if (i >= lSize) {
+                if (i >= rSize)
+                    return 0; // documents are the same length
+
+                return -1; // left document is shorter
+            }
+
+            if (i >= rSize)
+                return 1; // right document is shorter
+
+            const int nameCmp = rL->vFieldName[i].compare(rR->vFieldName[i]);
+            if (nameCmp)
+                return nameCmp; // field names are unequal
+
+            const int valueCmp = Value::compare(rL->vpValue[i], rR->vpValue[i]);
+            if (valueCmp)
+                return valueCmp; // fields are unequal
+        }
+
+        /* NOTREACHED */
+        verify(false);
+        return 0;
+    }
+
+    /* ----------------------- FieldIterator ------------------------------- */
+
+    FieldIterator::FieldIterator(const intrusive_ptr<Document> &pTheDocument):
+        pDocument(pTheDocument),
+        index(0) {
+    }
+
+    bool FieldIterator::more() const {
+        return (index < pDocument->vFieldName.size());
+    }
+
+    pair<string, intrusive_ptr<const Value> > FieldIterator::next() {
+        verify(more());
+        pair<string, intrusive_ptr<const Value> > result(
+            pDocument->vFieldName[index], pDocument->vpValue[index]);
+        ++index;
+        return result;
+    }
+}
diff --git a/src/mongo/db/pipeline/document_source.cpp b/src/mongo/db/pipeline/document_source.cpp
index 7d5f8355dfa..0f77a90730d 100755
--- a/src/mongo/db/pipeline/document_source.cpp
+++ b/src/mongo/db/pipeline/document_source.cpp
@@ -1,86 +1,86 @@
-/**

-*    Copyright (C) 2011 10gen Inc.

-*

-*    This program is free software: you can redistribute it and/or  modify

-*    it under the terms of the GNU Affero General Public License, version 3,

-*    as published by the Free Software Foundation.

-*

-*    This program is distributed in the hope that it will be useful,

-*    but WITHOUT ANY WARRANTY; without even the implied warranty of

-*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

-*    GNU Affero General Public License for more details.

-*

-*    You should have received a copy of the GNU Affero General Public License

-*    along with this program.  If not, see <http://www.gnu.org/licenses/>.

-*/

-

-#include "pch.h"

-

-#include "db/pipeline/document_source.h"

-#include "db/pipeline/expression_context.h"

-

-namespace mongo {

-

-    DocumentSource::DocumentSource(

-        const intrusive_ptr<ExpressionContext> &pCtx):

-        pSource(NULL),

-        step(-1),

-        pExpCtx(pCtx),

-        nRowsOut(0) {

-    }

-

-    DocumentSource::~DocumentSource() {

-    }

-

-    const char *DocumentSource::getSourceName() const {

-        static const char unknown[] = "[UNKNOWN]";

-        return unknown;

-    }

-

-    void DocumentSource::setSource(DocumentSource *pTheSource) {

-        verify(!pSource);

-        pSource = pTheSource;

-    }

-

-    bool DocumentSource::coalesce(

-        const intrusive_ptr<DocumentSource> &pNextSource) {

-        return false;

-    }

-

-    void DocumentSource::optimize() {

-    }

-

-    void DocumentSource::manageDependencies(

-        const intrusive_ptr<DependencyTracker> &pTracker) {

-#ifdef MONGO_LATER_SERVER_4644

-        verify(false); // identify any sources that need this but don't have it

-#endif /* MONGO_LATER_SERVER_4644 */

-    }

-

-    bool DocumentSource::advance() {

-        pExpCtx->checkForInterrupt(); // might not return

-        return false;

-    }

-

-    void DocumentSource::addToBsonArray(

-        BSONArrayBuilder *pBuilder, bool explain) const {

-        BSONObjBuilder insides;

-        sourceToBson(&insides, explain);

-

-/* No statistics at this time

-        if (explain) {

-            insides.append("nOut", nOut);

-        }

-*/

-

-        pBuilder->append(insides.done());

-    }

-

-    void DocumentSource::writeString(stringstream &ss) const {

-        BSONArrayBuilder bab;

-        addToBsonArray(&bab);

-        BSONArray ba(bab.arr());

-        ss << ba.toString(/* isArray */true); 

-            // our toString should use standard string types.....

-    }

-}

+/**
+*    Copyright (C) 2011 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "pch.h"
+
+#include "db/pipeline/document_source.h"
+#include "db/pipeline/expression_context.h"
+
+namespace mongo {
+
+    DocumentSource::DocumentSource(
+        const intrusive_ptr<ExpressionContext> &pCtx):
+        pSource(NULL),
+        step(-1),
+        pExpCtx(pCtx),
+        nRowsOut(0) {
+    }
+
+    DocumentSource::~DocumentSource() {
+    }
+
+    const char *DocumentSource::getSourceName() const {
+        static const char unknown[] = "[UNKNOWN]";
+        return unknown;
+    }
+
+    void DocumentSource::setSource(DocumentSource *pTheSource) {
+        verify(!pSource);
+        pSource = pTheSource;
+    }
+
+    bool DocumentSource::coalesce(
+        const intrusive_ptr<DocumentSource> &pNextSource) {
+        return false;
+    }
+
+    void DocumentSource::optimize() {
+    }
+
+    void DocumentSource::manageDependencies(
+        const intrusive_ptr<DependencyTracker> &pTracker) {
+#ifdef MONGO_LATER_SERVER_4644
+        verify(false); // identify any sources that need this but don't have it
+#endif /* MONGO_LATER_SERVER_4644 */
+    }
+
+    bool DocumentSource::advance() {
+        pExpCtx->checkForInterrupt(); // might not return
+        return false;
+    }
+
+    void DocumentSource::addToBsonArray(
+        BSONArrayBuilder *pBuilder, bool explain) const {
+        BSONObjBuilder insides;
+        sourceToBson(&insides, explain);
+
+/* No statistics at this time
+        if (explain) {
+            insides.append("nOut", nOut);
+        }
+*/
+
+        pBuilder->append(insides.done());
+    }
+
+    void DocumentSource::writeString(stringstream &ss) const {
+        BSONArrayBuilder bab;
+        addToBsonArray(&bab);
+        BSONArray ba(bab.arr());
+        ss << ba.toString(/* isArray */true); 
+            // our toString should use standard string types.....
+    }
+}
diff --git a/src/mongo/db/pipeline/document_source.h b/src/mongo/db/pipeline/document_source.h
index 24b7c84704b..2d9d0f10d5b 100755
--- a/src/mongo/db/pipeline/document_source.h
+++ b/src/mongo/db/pipeline/document_source.h
@@ -1,1264 +1,1264 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#pragma once

-

-#include "pch.h"

-

-#include <boost/unordered_map.hpp>

-#include "util/intrusive_counter.h"

-#include "client/parallel.h"

-#include "db/clientcursor.h"

-#include "db/jsobj.h"

-#include "db/pipeline/dependency_tracker.h"

-#include "db/pipeline/document.h"

-#include "db/pipeline/expression.h"

-#include "db/pipeline/value.h"

-#include "util/string_writer.h"

-

-namespace mongo {

-    class Accumulator;

-    class Cursor;

-    class DependencyTracker;

-    class Document;

-    class Expression;

-    class ExpressionContext;

-    class ExpressionFieldPath;

-    class ExpressionObject;

-    class Matcher;

-

-    class DocumentSource :

-        public IntrusiveCounterUnsigned,

-        public StringWriter {

-    public:

-        virtual ~DocumentSource();

-

-        // virtuals from StringWriter

-        virtual void writeString(stringstream &ss) const;

-

-        /**

-           Set the step for a user-specified pipeline step.

-

-           The step is used for diagnostics.

-

-           @param step step number 0 to n.

-        */

-        void setPipelineStep(int step);

-

-        /**

-           Get the user-specified pipeline step.

-

-           @returns the step number, or -1 if it has never been set

-        */

-        int getPipelineStep() const;

-

-        /**

-          Is the source at EOF?

-

-          @returns true if the source has no more Documents to return.

-        */

-        virtual bool eof() = 0;

-

-        /**

-          Advance the state of the DocumentSource so that it will return the

-          next Document.

-

-          The default implementation returns false, after checking for

-          interrupts.  Derived classes can call the default implementation

-          in their own implementations in order to check for interrupts.

-

-          @returns whether there is another document to fetch, i.e., whether or

-            not getCurrent() will succeed.  This default implementation always

-            returns false.

-        */

-        virtual bool advance();

-

-        /**

-          Advance the source, and return the next Expression.

-

-          @returns the current Document

-          TODO throws an exception if there are no more expressions to return.

-        */

-        virtual intrusive_ptr<Document> getCurrent() = 0;

-

-        /**

-           Get the source's name.

-

-           @returns the string name of the source as a constant string;

-             this is static, and there's no need to worry about adopting it

-         */

-        virtual const char *getSourceName() const;

-

-        /**

-          Set the underlying source this source should use to get Documents

-          from.

-

-          It is an error to set the source more than once.  This is to

-          prevent changing sources once the original source has been started;

-          this could break the state maintained by the DocumentSource.

-

-          This pointer is not reference counted because that has led to

-          some circular references.  As a result, this doesn't keep

-          sources alive, and is only intended to be used temporarily for

-          the lifetime of a Pipeline::run().

-

-          @param pSource the underlying source to use

-         */

-        virtual void setSource(DocumentSource *pSource);

-

-        /**

-          Attempt to coalesce this DocumentSource with its successor in the

-          document processing pipeline.  If successful, the successor

-          DocumentSource should be removed from the pipeline and discarded.

-

-          If successful, this operation can be applied repeatedly, in an

-          attempt to coalesce several sources together.

-

-          The default implementation is to do nothing, and return false.

-

-          @param pNextSource the next source in the document processing chain.

-          @returns whether or not the attempt to coalesce was successful or not;

-            if the attempt was not successful, nothing has been changed

-         */

-        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);

-

-        /**

-          Optimize the pipeline operation, if possible.  This is a local

-          optimization that only looks within this DocumentSource.  For best

-          results, first coalesce compatible sources using coalesce().

-

-          This is intended for any operations that include expressions, and

-          provides a hook for those to optimize those operations.

-

-          The default implementation is to do nothing.

-         */

-        virtual void optimize();

-

-        /**

-           Adjust dependencies according to the needs of this source.

-

-           $$$ MONGO_LATER_SERVER_4644

-           @param pTracker the dependency tracker

-         */

-        virtual void manageDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker);

-

-        /**

-          Add the DocumentSource to the array builder.

-

-          The default implementation calls sourceToBson() in order to

-          convert the inner part of the object which will be added to the

-          array being built here.

-

-          @param pBuilder the array builder to add the operation to.

-          @param explain create explain output

-         */

-        virtual void addToBsonArray(BSONArrayBuilder *pBuilder,

-            bool explain = false) const;

-        

-    protected:

-        /**

-           Base constructor.

-         */

-        DocumentSource(const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Create an object that represents the document source.  The object

-          will have a single field whose name is the source's name.  This

-          will be used by the default implementation of addToBsonArray()

-          to add this object to a pipeline being represented in BSON.

-

-          @param pBuilder a blank object builder to write to

-          @param explain create explain output

-         */

-        virtual void sourceToBson(BSONObjBuilder *pBuilder,

-                                  bool explain) const = 0;

-

-        /*

-          Most DocumentSources have an underlying source they get their data

-          from.  This is a convenience for them.

-

-          The default implementation of setSource() sets this; if you don't

-          need a source, override that to verify().  The default is to

-          verify() if this has already been set.

-        */

-        DocumentSource *pSource;

-

-        /*

-          The zero-based user-specified pipeline step.  Used for diagnostics.

-          Will be set to -1 for artificial pipeline steps that were not part

-          of the original user specification.

-         */

-        int step;

-

-        intrusive_ptr<ExpressionContext> pExpCtx;

-

-        /*

-          for explain: # of rows returned by this source

-

-          This is *not* unsigned so it can be passed to BSONObjBuilder.append().

-         */

-        long long nRowsOut;

-    };

-

-

-    class DocumentSourceBsonArray :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceBsonArray();

-        virtual bool eof();

-        virtual bool advance();

-        virtual intrusive_ptr<Document> getCurrent();

-        virtual void setSource(DocumentSource *pSource);

-

-        /**

-          Create a document source based on a BSON array.

-

-          This is usually put at the beginning of a chain of document sources

-          in order to fetch data from the database.

-

-          CAUTION:  the BSON is not read until the source is used.  Any

-          elements that appear after these documents must not be read until

-          this source is exhausted.

-

-          @param pBsonElement the BSON array to treat as a document source

-          @param pExpCtx the expression context for the pipeline

-          @returns the newly created document source

-        */

-        static intrusive_ptr<DocumentSourceBsonArray> create(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceBsonArray(BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        BSONObj embeddedObject;

-        BSONObjIterator arrayIterator;

-        BSONElement currentElement;

-        bool haveCurrent;

-    };

-

-    

-    class DocumentSourceCommandFutures :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceCommandFutures();

-        virtual bool eof();

-        virtual bool advance();

-        virtual intrusive_ptr<Document> getCurrent();

-        virtual void setSource(DocumentSource *pSource);

-

-        /* convenient shorthand for a commonly used type */

-        typedef list<shared_ptr<Future::CommandResult> > FuturesList;

-

-        /**

-          Create a DocumentSource that wraps a list of Command::Futures.

-

-          @param errmsg place to write error messages to; must exist for the

-            lifetime of the created DocumentSourceCommandFutures

-          @param pList the list of futures

-          @param pExpCtx the expression context for the pipeline

-          @returns the newly created DocumentSource

-         */

-        static intrusive_ptr<DocumentSourceCommandFutures> create(

-            string &errmsg, FuturesList *pList,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceCommandFutures(string &errmsg, FuturesList *pList,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Advance to the next document, setting pCurrent appropriately.

-

-          Adjusts pCurrent, pBsonSource, and iterator, as needed.  On exit,

-          pCurrent is the Document to return, or NULL.  If NULL, this

-          indicates there is nothing more to return.

-         */

-        void getNextDocument();

-

-        bool newSource; // set to true for the first item of a new source

-        intrusive_ptr<DocumentSourceBsonArray> pBsonSource;

-        intrusive_ptr<Document> pCurrent;

-        FuturesList::iterator iterator;

-        FuturesList::iterator listEnd;

-        string &errmsg;

-    };

-

-

-    class DocumentSourceCursor :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceCursor();

-        virtual bool eof();

-        virtual bool advance();

-        virtual intrusive_ptr<Document> getCurrent();

-        virtual void setSource(DocumentSource *pSource);

-        virtual void manageDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker);

-

-        /**

-          Create a document source based on a cursor.

-

-          This is usually put at the beginning of a chain of document sources

-          in order to fetch data from the database.

-

-          @param pCursor the cursor to use to fetch data

-          @param pExpCtx the expression context for the pipeline

-        */

-        static intrusive_ptr<DocumentSourceCursor> create(

-            const shared_ptr<Cursor> &pCursor,

-            const string &ns,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /*

-          Record the namespace.  Required for explain.

-

-          @param namespace the namespace

-        */

-        void setNamespace(const string &ns);

-

-        /*

-          Record the query that was specified for the cursor this wraps, if

-          any.

-

-          This should be captured after any optimizations are applied to

-          the pipeline so that it reflects what is really used.

-

-          This gets used for explain output.

-

-          @param pBsonObj the query to record

-         */

-        void setQuery(const shared_ptr<BSONObj> &pBsonObj);

-

-        /*

-          Record the sort that was specified for the cursor this wraps, if

-          any.

-

-          This should be captured after any optimizations are applied to

-          the pipeline so that it reflects what is really used.

-

-          This gets used for explain output.

-

-          @param pBsonObj the sort to record

-         */

-        void setSort(const shared_ptr<BSONObj> &pBsonObj);

-

-        /**

-           Release the cursor, but without changing the other data.  This

-           is used for the explain version of pipeline execution.

-         */

-        void releaseCursor();

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceCursor(

-            const shared_ptr<Cursor> &pTheCursor, const string &ns,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        void findNext();

-        intrusive_ptr<Document> pCurrent;

-

-        string ns; // namespace

-

-        /*

-          The bsonDependencies must outlive the Cursor wrapped by this

-          source.  Therefore, bsonDependencies must appear before pCursor

-          in order cause its destructor to be called *after* pCursor's.

-         */

-        shared_ptr<BSONObj> pQuery;

-        shared_ptr<BSONObj> pSort;

-        vector<shared_ptr<BSONObj> > bsonDependencies;

-        shared_ptr<Cursor> pCursor;

-

-        /*

-          In order to yield, we need a ClientCursor.

-         */

-        ClientCursor::Holder pClientCursor;

-

-        /*

-          Advance the cursor, and yield sometimes.

-

-          If the state of the world changed during the yield such that we

-          are unable to continue execution of the query, this will release the

-          client cursor, and throw an error.

-         */

-        void advanceAndYield();

-

-        /*

-          This document source hangs on to the dependency tracker when it

-          gets it so that it can be used for selective reification of

-          fields in order to avoid fields that are not required through the

-          pipeline.

-         */

-        intrusive_ptr<DependencyTracker> pDependencies;

-

-        /**

-           (5/14/12 - moved this to private because it's not used atm)

-           Add a BSONObj dependency.

-

-           Some Cursor creation functions rely on BSON objects to specify

-           their query predicate or sort.  These often take a BSONObj

-           by reference for these, but do not copy it.  As a result, the

-           BSONObjs specified must outlive the Cursor.  In order to ensure

-           that, use this to preserve a pointer to the BSONObj here.

-

-           From the outside, you must also make sure the BSONObjBuilder

-           creates a lasting copy of the data, otherwise it will go away

-           when the builder goes out of scope.  Therefore, the typical usage

-           pattern for this is 

-           {

-               BSONObjBuilder builder;

-               // do stuff to the builder

-               shared_ptr<BSONObj> pBsonObj(new BSONObj(builder.obj()));

-               pDocumentSourceCursor->addBsonDependency(pBsonObj);

-           }

-

-           @param pBsonObj pointer to the BSON object to preserve

-         */

-        void addBsonDependency(const shared_ptr<BSONObj> &pBsonObj);

-    };

-

-

-    /*

-      This contains all the basic mechanics for filtering a stream of

-      Documents, except for the actual predicate evaluation itself.  This was

-      factored out so we could create DocumentSources that use both Matcher

-      style predicates as well as full Expressions.

-     */

-    class DocumentSourceFilterBase :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceFilterBase();

-        virtual bool eof();

-        virtual bool advance();

-        virtual intrusive_ptr<Document> getCurrent();

-

-        /**

-          Create a BSONObj suitable for Matcher construction.

-

-          This is used after filter analysis has moved as many filters to

-          as early a point as possible in the document processing pipeline.

-          See db/Matcher.h and the associated wiki documentation for the

-          format.  This conversion is used to move back to the low-level

-          find() Cursor mechanism.

-

-          @param pBuilder the builder to write to

-         */

-        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const = 0;

-

-    protected:

-        DocumentSourceFilterBase(

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Test the given document against the predicate and report if it

-          should be accepted or not.

-

-          @param pDocument the document to test

-          @returns true if the document matches the filter, false otherwise

-         */

-        virtual bool accept(const intrusive_ptr<Document> &pDocument) const = 0;

-

-    private:

-

-        void findNext();

-

-        bool unstarted;

-        bool hasNext;

-        intrusive_ptr<Document> pCurrent;

-    };

-

-

-    class DocumentSourceFilter :

-        public DocumentSourceFilterBase {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceFilter();

-        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);

-        virtual void optimize();

-        virtual const char *getSourceName() const;

-

-        /**

-          Create a filter.

-

-          @param pBsonElement the raw BSON specification for the filter

-          @param pExpCtx the expression context for the pipeline

-          @returns the filter

-         */

-        static intrusive_ptr<DocumentSource> createFromBson(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Create a filter.

-

-          @param pFilter the expression to use to filter

-          @param pExpCtx the expression context for the pipeline

-          @returns the filter

-         */

-        static intrusive_ptr<DocumentSourceFilter> create(

-            const intrusive_ptr<Expression> &pFilter,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Create a BSONObj suitable for Matcher construction.

-

-          This is used after filter analysis has moved as many filters to

-          as early a point as possible in the document processing pipeline.

-          See db/Matcher.h and the associated wiki documentation for the

-          format.  This conversion is used to move back to the low-level

-          find() Cursor mechanism.

-

-          @param pBuilder the builder to write to

-         */

-        void toMatcherBson(BSONObjBuilder *pBuilder) const;

-

-        static const char filterName[];

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-        // virtuals from DocumentSourceFilterBase

-        virtual bool accept(const intrusive_ptr<Document> &pDocument) const;

-

-    private:

-        DocumentSourceFilter(const intrusive_ptr<Expression> &pFilter,

-                             const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        intrusive_ptr<Expression> pFilter;

-    };

-

-

-    class DocumentSourceGroup :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceGroup();

-        virtual bool eof();

-        virtual bool advance();

-        virtual const char *getSourceName() const;

-        virtual intrusive_ptr<Document> getCurrent();

-

-        /**

-          Create a new grouping DocumentSource.

-          

-          @param pExpCtx the expression context for the pipeline

-          @returns the DocumentSource

-         */

-        static intrusive_ptr<DocumentSourceGroup> create(

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Set the Id Expression.

-

-          Documents that pass through the grouping Document are grouped

-          according to this key.  This will generate the id_ field in the

-          result documents.

-

-          @param pExpression the group key

-         */

-        void setIdExpression(const intrusive_ptr<Expression> &pExpression);

-

-        /**

-          Add an accumulator.

-

-          Accumulators become fields in the Documents that result from

-          grouping.  Each unique group document must have it's own

-          accumulator; the accumulator factory is used to create that.

-

-          @param fieldName the name the accumulator result will have in the

-                result documents

-          @param pAccumulatorFactory used to create the accumulator for the

-                group field

-         */

-        void addAccumulator(string fieldName,

-                            intrusive_ptr<Accumulator> (*pAccumulatorFactory)(

-                            const intrusive_ptr<ExpressionContext> &),

-                            const intrusive_ptr<Expression> &pExpression);

-

-        /**

-          Create a grouping DocumentSource from BSON.

-

-          This is a convenience method that uses the above, and operates on

-          a BSONElement that has been deteremined to be an Object with an

-          element named $group.

-

-          @param pBsonElement the BSONELement that defines the group

-          @param pExpCtx the expression context

-          @returns the grouping DocumentSource

-         */

-        static intrusive_ptr<DocumentSource> createFromBson(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-

-        /**

-          Create a unifying group that can be used to combine group results

-          from shards.

-

-          @returns the grouping DocumentSource

-        */

-        intrusive_ptr<DocumentSource> createMerger();

-

-        static const char groupName[];

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceGroup(const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /*

-          Before returning anything, this source must fetch everything from

-          the underlying source and group it.  populate() is used to do that

-          on the first call to any method on this source.  The populated

-          boolean indicates that this has been done.

-         */

-        void populate();

-        bool populated;

-

-        intrusive_ptr<Expression> pIdExpression;

-

-        typedef boost::unordered_map<intrusive_ptr<const Value>,

-            vector<intrusive_ptr<Accumulator> >, Value::Hash> GroupsType;

-        GroupsType groups;

-

-        /*

-          The field names for the result documents and the accumulator

-          factories for the result documents.  The Expressions are the

-          common expressions used by each instance of each accumulator

-          in order to find the right-hand side of what gets added to the

-          accumulator.  Note that each of those is the same for each group,

-          so we can share them across all groups by adding them to the

-          accumulators after we use the factories to make a new set of

-          accumulators for each new group.

-

-          These three vectors parallel each other.

-        */

-        vector<string> vFieldName;

-        vector<intrusive_ptr<Accumulator> (*)(

-            const intrusive_ptr<ExpressionContext> &)> vpAccumulatorFactory;

-        vector<intrusive_ptr<Expression> > vpExpression;

-

-

-        intrusive_ptr<Document> makeDocument(

-            const GroupsType::iterator &rIter);

-

-        GroupsType::iterator groupsIterator;

-        intrusive_ptr<Document> pCurrent;

-    };

-

-

-    class DocumentSourceMatch :

-        public DocumentSourceFilterBase {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceMatch();

-        virtual const char *getSourceName() const;

-        virtual void manageDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker);

-

-        /**

-          Create a filter.

-

-          @param pBsonElement the raw BSON specification for the filter

-          @returns the filter

-         */

-        static intrusive_ptr<DocumentSource> createFromBson(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pCtx);

-

-        /**

-          Create a BSONObj suitable for Matcher construction.

-

-          This is used after filter analysis has moved as many filters to

-          as early a point as possible in the document processing pipeline.

-          See db/Matcher.h and the associated wiki documentation for the

-          format.  This conversion is used to move back to the low-level

-          find() Cursor mechanism.

-

-          @param pBuilder the builder to write to

-         */

-        void toMatcherBson(BSONObjBuilder *pBuilder) const;

-

-        static const char matchName[];

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-        // virtuals from DocumentSourceFilterBase

-        virtual bool accept(const intrusive_ptr<Document> &pDocument) const;

-

-    private:

-        DocumentSourceMatch(const BSONObj &query,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        Matcher matcher;

-    };

-

-

-    class DocumentSourceOut :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceOut();

-        virtual bool eof();

-        virtual bool advance();

-        virtual const char *getSourceName() const;

-        virtual intrusive_ptr<Document> getCurrent();

-

-        /**

-          Create a document source for output and pass-through.

-

-          This can be put anywhere in a pipeline and will store content as

-          well as pass it on.

-

-          @param pBsonElement the raw BSON specification for the source

-          @param pExpCtx the expression context for the pipeline

-          @returns the newly created document source

-        */

-        static intrusive_ptr<DocumentSourceOut> createFromBson(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        static const char outName[];

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceOut(BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-    };

-

-    

-    class DocumentSourceProject :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceProject();

-        virtual bool eof();

-        virtual bool advance();

-        virtual const char *getSourceName() const;

-        virtual intrusive_ptr<Document> getCurrent();

-        virtual void optimize();

-        virtual void manageDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker);

-

-        /**

-          Create a new DocumentSource that can implement projection.

-

-          @param pExpCtx the expression context for the pipeline

-          @returns the projection DocumentSource

-        */

-        static intrusive_ptr<DocumentSourceProject> create(

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Include a field path in a projection.

-

-          @param fieldPath the path of the field to include

-        */

-        void includePath(const string &fieldPath);

-

-        /**

-          Exclude a field path from the projection.

-

-          @param fieldPath the path of the field to exclude

-         */

-        void excludePath(const string &fieldPath);

-

-        /**

-          Add an output Expression in the projection.

-

-          BSON document fields are ordered, so the new field will be

-          appended to the existing set.

-

-          @param fieldName the name of the field as it will appear

-          @param pExpression the expression used to compute the field

-        */

-        void addField(const string &fieldName,

-                      const intrusive_ptr<Expression> &pExpression);

-

-        /**

-          Create a new projection DocumentSource from BSON.

-

-          This is a convenience for directly handling BSON, and relies on the

-          above methods.

-

-          @param pBsonElement the BSONElement with an object named $project

-          @param pExpCtx the expression context for the pipeline

-          @returns the created projection

-         */

-        static intrusive_ptr<DocumentSource> createFromBson(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        static const char projectName[];

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceProject(const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        // configuration state

-        bool excludeId;

-        intrusive_ptr<ExpressionObject> pEO;

-

-        /*

-          Utility object used by manageDependencies().

-

-          Removes dependencies from a DependencyTracker.

-         */

-        class DependencyRemover :

-            public ExpressionObject::PathSink {

-        public:

-            // virtuals from PathSink

-            virtual void path(const string &path, bool include);

-

-            /*

-              Constructor.

-

-              Captures a reference to the smart pointer to the DependencyTracker

-              that this will remove dependencies from via

-              ExpressionObject::emitPaths().

-

-              @param pTracker reference to the smart pointer to the

-                DependencyTracker

-             */

-            DependencyRemover(const intrusive_ptr<DependencyTracker> &pTracker);

-

-        private:

-            const intrusive_ptr<DependencyTracker> &pTracker;

-        };

-

-        /*

-          Utility object used by manageDependencies().

-

-          Checks dependencies to see if they are present.  If not, then

-          throws a user error.

-         */

-        class DependencyChecker :

-            public ExpressionObject::PathSink {

-        public:

-            // virtuals from PathSink

-            virtual void path(const string &path, bool include);

-

-            /*

-              Constructor.

-

-              Captures a reference to the smart pointer to the DependencyTracker

-              that this will check dependencies from from

-              ExpressionObject::emitPaths() to see if they are required.

-

-              @param pTracker reference to the smart pointer to the

-                DependencyTracker

-              @param pThis the projection that is making this request

-             */

-            DependencyChecker(

-                const intrusive_ptr<DependencyTracker> &pTracker,

-                const DocumentSourceProject *pThis);

-

-        private:

-            const intrusive_ptr<DependencyTracker> &pTracker;

-            const DocumentSourceProject *pThis;

-        };

-    };

-

-

-    class DocumentSourceSort :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceSort();

-        virtual bool eof();

-        virtual bool advance();

-        virtual const char *getSourceName() const;

-        virtual intrusive_ptr<Document> getCurrent();

-        virtual void manageDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker);

-        /*

-          TODO

-          Adjacent sorts should reduce to the last sort.

-        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);

-        */

-

-        /**

-          Create a new sorting DocumentSource.

-          

-          @param pExpCtx the expression context for the pipeline

-          @returns the DocumentSource

-         */

-        static intrusive_ptr<DocumentSourceSort> create(

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Add sort key field.

-

-          Adds a sort key field to the key being built up.  A concatenated

-          key is built up by calling this repeatedly.

-

-          @param fieldPath the field path to the key component

-          @param ascending if true, use the key for an ascending sort,

-            otherwise, use it for descending

-        */

-        void addKey(const string &fieldPath, bool ascending);

-

-        /**

-          Write out an object whose contents are the sort key.

-

-          @param pBuilder initialized object builder.

-          @param fieldPrefix specify whether or not to include the field prefix

-         */

-        void sortKeyToBson(BSONObjBuilder *pBuilder, bool usePrefix) const;

-

-        /**

-          Create a sorting DocumentSource from BSON.

-

-          This is a convenience method that uses the above, and operates on

-          a BSONElement that has been deteremined to be an Object with an

-          element named $group.

-

-          @param pBsonElement the BSONELement that defines the group

-          @param pExpCtx the expression context for the pipeline

-          @returns the grouping DocumentSource

-         */

-        static intrusive_ptr<DocumentSource> createFromBson(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-

-        static const char sortName[];

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceSort(const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /*

-          Before returning anything, this source must fetch everything from

-          the underlying source and group it.  populate() is used to do that

-          on the first call to any method on this source.  The populated

-          boolean indicates that this has been done.

-         */

-        void populate();

-        bool populated;

-        long long count;

-

-        /* these two parallel each other */

-        typedef vector<intrusive_ptr<ExpressionFieldPath> > SortPaths;

-        SortPaths vSortKey;

-        vector<bool> vAscending;

-

-        /*

-          Compare two documents according to the specified sort key.

-

-          @param rL reference to the left document

-          @param rR reference to the right document

-          @returns a number less than, equal to, or greater than zero,

-            indicating pL < pR, pL == pR, or pL > pR, respectively

-         */

-        int compare(const intrusive_ptr<Document> &pL,

-                    const intrusive_ptr<Document> &pR);

-

-        /*

-          This is a utility class just for the STL sort that is done

-          inside.

-         */

-        class Comparator {

-        public:

-            bool operator()(

-                const intrusive_ptr<Document> &pL,

-                const intrusive_ptr<Document> &pR) {

-                return (pSort->compare(pL, pR) < 0);

-            }

-

-            inline Comparator(DocumentSourceSort *pS):

-                pSort(pS) {

-            }

-

-        private:

-            DocumentSourceSort *pSort;

-        };

-

-        typedef vector<intrusive_ptr<Document> > VectorType;

-        VectorType documents;

-

-        VectorType::iterator docIterator;

-        intrusive_ptr<Document> pCurrent;

-    };

-

-

-    class DocumentSourceLimit :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceLimit();

-        virtual bool eof();

-        virtual bool advance();

-        virtual intrusive_ptr<Document> getCurrent();

-        virtual const char *getSourceName() const;

-        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);

-

-        /**

-          Create a new limiting DocumentSource.

-

-          @param pExpCtx the expression context for the pipeline

-          @returns the DocumentSource

-         */

-        static intrusive_ptr<DocumentSourceLimit> create(

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Create a limiting DocumentSource from BSON.

-

-          This is a convenience method that uses the above, and operates on

-          a BSONElement that has been deteremined to be an Object with an

-          element named $limit.

-

-          @param pBsonElement the BSONELement that defines the limit

-          @param pExpCtx the expression context

-          @returns the grouping DocumentSource

-         */

-        static intrusive_ptr<DocumentSource> createFromBson(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-

-        static const char limitName[];

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceLimit(

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        long long limit;

-        long long count;

-        intrusive_ptr<Document> pCurrent;

-    };

-

-    class DocumentSourceSkip :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceSkip();

-        virtual bool eof();

-        virtual bool advance();

-        virtual intrusive_ptr<Document> getCurrent();

-        virtual const char *getSourceName() const;

-        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);

-

-        /**

-          Create a new skipping DocumentSource.

-

-          @param pExpCtx the expression context

-          @returns the DocumentSource

-         */

-        static intrusive_ptr<DocumentSourceSkip> create(

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Create a skipping DocumentSource from BSON.

-

-          This is a convenience method that uses the above, and operates on

-          a BSONElement that has been deteremined to be an Object with an

-          element named $skip.

-

-          @param pBsonElement the BSONELement that defines the skip

-          @param pExpCtx the expression context

-          @returns the grouping DocumentSource

-         */

-        static intrusive_ptr<DocumentSource> createFromBson(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-

-        static const char skipName[];

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceSkip(const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /*

-          Skips initial documents.

-         */

-        void skipper();

-

-        long long skip;

-        long long count;

-        intrusive_ptr<Document> pCurrent;

-    };

-

-

-    class DocumentSourceUnwind :

-        public DocumentSource {

-    public:

-        // virtuals from DocumentSource

-        virtual ~DocumentSourceUnwind();

-        virtual bool eof();

-        virtual bool advance();

-        virtual const char *getSourceName() const;

-        virtual intrusive_ptr<Document> getCurrent();

-        virtual void manageDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker);

-

-        /**

-          Create a new DocumentSource that can implement unwind.

-

-          @param pExpCtx the expression context for the pipeline

-          @returns the projection DocumentSource

-        */

-        static intrusive_ptr<DocumentSourceUnwind> create(

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        /**

-          Specify the field to unwind.  There must be exactly one before

-          the pipeline begins execution.

-

-          @param rFieldPath - path to the field to unwind

-        */

-        void unwindField(const FieldPath &rFieldPath);

-

-        /**

-          Create a new projection DocumentSource from BSON.

-

-          This is a convenience for directly handling BSON, and relies on the

-          above methods.

-

-          @param pBsonElement the BSONElement with an object named $project

-          @param pExpCtx the expression context for the pipeline

-          @returns the created projection

-         */

-        static intrusive_ptr<DocumentSource> createFromBson(

-            BSONElement *pBsonElement,

-            const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        static const char unwindName[];

-

-    protected:

-        // virtuals from DocumentSource

-        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;

-

-    private:

-        DocumentSourceUnwind(const intrusive_ptr<ExpressionContext> &pExpCtx);

-

-        // configuration state

-        FieldPath unwindPath;

-

-        vector<int> fieldIndex; /* for the current document, the indices

-                                   leading down to the field being unwound */

-

-        // iteration state

-        intrusive_ptr<Document> pNoUnwindDocument;

-                                              // document to return, pre-unwind

-        intrusive_ptr<const Value> pUnwindArray; // field being unwound

-        intrusive_ptr<ValueIterator> pUnwinder; // iterator used for unwinding

-        intrusive_ptr<const Value> pUnwindValue; // current value

-

-        /*

-          Clear all the state related to unwinding an array.

-         */

-        void resetArray();

-

-        /*

-          Clone the current document being unwound.

-

-          This is a partial deep clone.  Because we're going to replace the

-          value at the end, we have to replace everything along the path

-          leading to that in order to not share that change with any other

-          clones (or the original) that we've made.

-

-          This expects pUnwindValue to have been set by a prior call to

-          advance().  However, pUnwindValue may also be NULL, in which case

-          the field will be removed -- this is the action for an empty

-          array.

-

-          @returns a partial deep clone of pNoUnwindDocument

-         */

-        intrusive_ptr<Document> clonePath() const;

-    };

-

-}

-

-

-/* ======================= INLINED IMPLEMENTATIONS ========================== */

-

-namespace mongo {

-

-    inline void DocumentSource::setPipelineStep(int s) {

-        step = s;

-    }

-

-    inline int DocumentSource::getPipelineStep() const {

-        return step;

-    }

-    

-    inline void DocumentSourceGroup::setIdExpression(

-        const intrusive_ptr<Expression> &pExpression) {

-        pIdExpression = pExpression;

-    }

-

-    inline DocumentSourceProject::DependencyRemover::DependencyRemover(

-        const intrusive_ptr<DependencyTracker> &pT):

-        pTracker(pT) {

-    }

-

-    inline DocumentSourceProject::DependencyChecker::DependencyChecker(

-        const intrusive_ptr<DependencyTracker> &pTrack,

-        const DocumentSourceProject *pT):

-        pTracker(pTrack),

-        pThis(pT) {

-    }

-

-    inline void DocumentSourceUnwind::resetArray() {

-        pNoUnwindDocument.reset();

-        pUnwindArray.reset();

-        pUnwinder.reset();

-        pUnwindValue.reset();

-    }

-

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "pch.h"
+
+#include <boost/unordered_map.hpp>
+#include "util/intrusive_counter.h"
+#include "client/parallel.h"
+#include "db/clientcursor.h"
+#include "db/jsobj.h"
+#include "db/pipeline/dependency_tracker.h"
+#include "db/pipeline/document.h"
+#include "db/pipeline/expression.h"
+#include "db/pipeline/value.h"
+#include "util/string_writer.h"
+
+namespace mongo {
+    class Accumulator;
+    class Cursor;
+    class DependencyTracker;
+    class Document;
+    class Expression;
+    class ExpressionContext;
+    class ExpressionFieldPath;
+    class ExpressionObject;
+    class Matcher;
+
+    class DocumentSource :
+        public IntrusiveCounterUnsigned,
+        public StringWriter {
+    public:
+        virtual ~DocumentSource();
+
+        // virtuals from StringWriter
+        virtual void writeString(stringstream &ss) const;
+
+        /**
+           Set the step for a user-specified pipeline step.
+
+           The step is used for diagnostics.
+
+           @param step step number 0 to n.
+        */
+        void setPipelineStep(int step);
+
+        /**
+           Get the user-specified pipeline step.
+
+           @returns the step number, or -1 if it has never been set
+        */
+        int getPipelineStep() const;
+
+        /**
+          Is the source at EOF?
+
+          @returns true if the source has no more Documents to return.
+        */
+        virtual bool eof() = 0;
+
+        /**
+          Advance the state of the DocumentSource so that it will return the
+          next Document.
+
+          The default implementation returns false, after checking for
+          interrupts.  Derived classes can call the default implementation
+          in their own implementations in order to check for interrupts.
+
+          @returns whether there is another document to fetch, i.e., whether or
+            not getCurrent() will succeed.  This default implementation always
+            returns false.
+        */
+        virtual bool advance();
+
+        /**
+          Advance the source, and return the next Expression.
+
+          @returns the current Document
+          TODO throws an exception if there are no more expressions to return.
+        */
+        virtual intrusive_ptr<Document> getCurrent() = 0;
+
+        /**
+           Get the source's name.
+
+           @returns the string name of the source as a constant string;
+             this is static, and there's no need to worry about adopting it
+         */
+        virtual const char *getSourceName() const;
+
+        /**
+          Set the underlying source this source should use to get Documents
+          from.
+
+          It is an error to set the source more than once.  This is to
+          prevent changing sources once the original source has been started;
+          this could break the state maintained by the DocumentSource.
+
+          This pointer is not reference counted because that has led to
+          some circular references.  As a result, this doesn't keep
+          sources alive, and is only intended to be used temporarily for
+          the lifetime of a Pipeline::run().
+
+          @param pSource the underlying source to use
+         */
+        virtual void setSource(DocumentSource *pSource);
+
+        /**
+          Attempt to coalesce this DocumentSource with its successor in the
+          document processing pipeline.  If successful, the successor
+          DocumentSource should be removed from the pipeline and discarded.
+
+          If successful, this operation can be applied repeatedly, in an
+          attempt to coalesce several sources together.
+
+          The default implementation is to do nothing, and return false.
+
+          @param pNextSource the next source in the document processing chain.
+          @returns whether or not the attempt to coalesce was successful or not;
+            if the attempt was not successful, nothing has been changed
+         */
+        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);
+
+        /**
+          Optimize the pipeline operation, if possible.  This is a local
+          optimization that only looks within this DocumentSource.  For best
+          results, first coalesce compatible sources using coalesce().
+
+          This is intended for any operations that include expressions, and
+          provides a hook for those to optimize those operations.
+
+          The default implementation is to do nothing.
+         */
+        virtual void optimize();
+
+        /**
+           Adjust dependencies according to the needs of this source.
+
+           $$$ MONGO_LATER_SERVER_4644
+           @param pTracker the dependency tracker
+         */
+        virtual void manageDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker);
+
+        /**
+          Add the DocumentSource to the array builder.
+
+          The default implementation calls sourceToBson() in order to
+          convert the inner part of the object which will be added to the
+          array being built here.
+
+          @param pBuilder the array builder to add the operation to.
+          @param explain create explain output
+         */
+        virtual void addToBsonArray(BSONArrayBuilder *pBuilder,
+            bool explain = false) const;
+        
+    protected:
+        /**
+           Base constructor.
+         */
+        DocumentSource(const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Create an object that represents the document source.  The object
+          will have a single field whose name is the source's name.  This
+          will be used by the default implementation of addToBsonArray()
+          to add this object to a pipeline being represented in BSON.
+
+          @param pBuilder a blank object builder to write to
+          @param explain create explain output
+         */
+        virtual void sourceToBson(BSONObjBuilder *pBuilder,
+                                  bool explain) const = 0;
+
+        /*
+          Most DocumentSources have an underlying source they get their data
+          from.  This is a convenience for them.
+
+          The default implementation of setSource() sets this; if you don't
+          need a source, override that to verify().  The default is to
+          verify() if this has already been set.
+        */
+        DocumentSource *pSource;
+
+        /*
+          The zero-based user-specified pipeline step.  Used for diagnostics.
+          Will be set to -1 for artificial pipeline steps that were not part
+          of the original user specification.
+         */
+        int step;
+
+        intrusive_ptr<ExpressionContext> pExpCtx;
+
+        /*
+          for explain: # of rows returned by this source
+
+          This is *not* unsigned so it can be passed to BSONObjBuilder.append().
+         */
+        long long nRowsOut;
+    };
+
+
+    class DocumentSourceBsonArray :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceBsonArray();
+        virtual bool eof();
+        virtual bool advance();
+        virtual intrusive_ptr<Document> getCurrent();
+        virtual void setSource(DocumentSource *pSource);
+
+        /**
+          Create a document source based on a BSON array.
+
+          This is usually put at the beginning of a chain of document sources
+          in order to fetch data from the database.
+
+          CAUTION:  the BSON is not read until the source is used.  Any
+          elements that appear after these documents must not be read until
+          this source is exhausted.
+
+          @param pBsonElement the BSON array to treat as a document source
+          @param pExpCtx the expression context for the pipeline
+          @returns the newly created document source
+        */
+        static intrusive_ptr<DocumentSourceBsonArray> create(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceBsonArray(BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        BSONObj embeddedObject;
+        BSONObjIterator arrayIterator;
+        BSONElement currentElement;
+        bool haveCurrent;
+    };
+
+    
+    class DocumentSourceCommandFutures :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceCommandFutures();
+        virtual bool eof();
+        virtual bool advance();
+        virtual intrusive_ptr<Document> getCurrent();
+        virtual void setSource(DocumentSource *pSource);
+
+        /* convenient shorthand for a commonly used type */
+        typedef list<shared_ptr<Future::CommandResult> > FuturesList;
+
+        /**
+          Create a DocumentSource that wraps a list of Command::Futures.
+
+          @param errmsg place to write error messages to; must exist for the
+            lifetime of the created DocumentSourceCommandFutures
+          @param pList the list of futures
+          @param pExpCtx the expression context for the pipeline
+          @returns the newly created DocumentSource
+         */
+        static intrusive_ptr<DocumentSourceCommandFutures> create(
+            string &errmsg, FuturesList *pList,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceCommandFutures(string &errmsg, FuturesList *pList,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Advance to the next document, setting pCurrent appropriately.
+
+          Adjusts pCurrent, pBsonSource, and iterator, as needed.  On exit,
+          pCurrent is the Document to return, or NULL.  If NULL, this
+          indicates there is nothing more to return.
+         */
+        void getNextDocument();
+
+        bool newSource; // set to true for the first item of a new source
+        intrusive_ptr<DocumentSourceBsonArray> pBsonSource;
+        intrusive_ptr<Document> pCurrent;
+        FuturesList::iterator iterator;
+        FuturesList::iterator listEnd;
+        string &errmsg;
+    };
+
+
+    class DocumentSourceCursor :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceCursor();
+        virtual bool eof();
+        virtual bool advance();
+        virtual intrusive_ptr<Document> getCurrent();
+        virtual void setSource(DocumentSource *pSource);
+        virtual void manageDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker);
+
+        /**
+          Create a document source based on a cursor.
+
+          This is usually put at the beginning of a chain of document sources
+          in order to fetch data from the database.
+
+          @param pCursor the cursor to use to fetch data
+          @param pExpCtx the expression context for the pipeline
+        */
+        static intrusive_ptr<DocumentSourceCursor> create(
+            const shared_ptr<Cursor> &pCursor,
+            const string &ns,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /*
+          Record the namespace.  Required for explain.
+
+          @param namespace the namespace
+        */
+        void setNamespace(const string &ns);
+
+        /*
+          Record the query that was specified for the cursor this wraps, if
+          any.
+
+          This should be captured after any optimizations are applied to
+          the pipeline so that it reflects what is really used.
+
+          This gets used for explain output.
+
+          @param pBsonObj the query to record
+         */
+        void setQuery(const shared_ptr<BSONObj> &pBsonObj);
+
+        /*
+          Record the sort that was specified for the cursor this wraps, if
+          any.
+
+          This should be captured after any optimizations are applied to
+          the pipeline so that it reflects what is really used.
+
+          This gets used for explain output.
+
+          @param pBsonObj the sort to record
+         */
+        void setSort(const shared_ptr<BSONObj> &pBsonObj);
+
+        /**
+           Release the cursor, but without changing the other data.  This
+           is used for the explain version of pipeline execution.
+         */
+        void releaseCursor();
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceCursor(
+            const shared_ptr<Cursor> &pTheCursor, const string &ns,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        void findNext();
+        intrusive_ptr<Document> pCurrent;
+
+        string ns; // namespace
+
+        /*
+          The bsonDependencies must outlive the Cursor wrapped by this
+          source.  Therefore, bsonDependencies must appear before pCursor
+          in order cause its destructor to be called *after* pCursor's.
+         */
+        shared_ptr<BSONObj> pQuery;
+        shared_ptr<BSONObj> pSort;
+        vector<shared_ptr<BSONObj> > bsonDependencies;
+        shared_ptr<Cursor> pCursor;
+
+        /*
+          In order to yield, we need a ClientCursor.
+         */
+        ClientCursor::Holder pClientCursor;
+
+        /*
+          Advance the cursor, and yield sometimes.
+
+          If the state of the world changed during the yield such that we
+          are unable to continue execution of the query, this will release the
+          client cursor, and throw an error.
+         */
+        void advanceAndYield();
+
+        /*
+          This document source hangs on to the dependency tracker when it
+          gets it so that it can be used for selective reification of
+          fields in order to avoid fields that are not required through the
+          pipeline.
+         */
+        intrusive_ptr<DependencyTracker> pDependencies;
+
+        /**
+           (5/14/12 - moved this to private because it's not used atm)
+           Add a BSONObj dependency.
+
+           Some Cursor creation functions rely on BSON objects to specify
+           their query predicate or sort.  These often take a BSONObj
+           by reference for these, but do not copy it.  As a result, the
+           BSONObjs specified must outlive the Cursor.  In order to ensure
+           that, use this to preserve a pointer to the BSONObj here.
+
+           From the outside, you must also make sure the BSONObjBuilder
+           creates a lasting copy of the data, otherwise it will go away
+           when the builder goes out of scope.  Therefore, the typical usage
+           pattern for this is 
+           {
+               BSONObjBuilder builder;
+               // do stuff to the builder
+               shared_ptr<BSONObj> pBsonObj(new BSONObj(builder.obj()));
+               pDocumentSourceCursor->addBsonDependency(pBsonObj);
+           }
+
+           @param pBsonObj pointer to the BSON object to preserve
+         */
+        void addBsonDependency(const shared_ptr<BSONObj> &pBsonObj);
+    };
+
+
+    /*
+      This contains all the basic mechanics for filtering a stream of
+      Documents, except for the actual predicate evaluation itself.  This was
+      factored out so we could create DocumentSources that use both Matcher
+      style predicates as well as full Expressions.
+     */
+    class DocumentSourceFilterBase :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceFilterBase();
+        virtual bool eof();
+        virtual bool advance();
+        virtual intrusive_ptr<Document> getCurrent();
+
+        /**
+          Create a BSONObj suitable for Matcher construction.
+
+          This is used after filter analysis has moved as many filters to
+          as early a point as possible in the document processing pipeline.
+          See db/Matcher.h and the associated wiki documentation for the
+          format.  This conversion is used to move back to the low-level
+          find() Cursor mechanism.
+
+          @param pBuilder the builder to write to
+         */
+        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const = 0;
+
+    protected:
+        DocumentSourceFilterBase(
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Test the given document against the predicate and report if it
+          should be accepted or not.
+
+          @param pDocument the document to test
+          @returns true if the document matches the filter, false otherwise
+         */
+        virtual bool accept(const intrusive_ptr<Document> &pDocument) const = 0;
+
+    private:
+
+        void findNext();
+
+        bool unstarted;
+        bool hasNext;
+        intrusive_ptr<Document> pCurrent;
+    };
+
+
+    class DocumentSourceFilter :
+        public DocumentSourceFilterBase {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceFilter();
+        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);
+        virtual void optimize();
+        virtual const char *getSourceName() const;
+
+        /**
+          Create a filter.
+
+          @param pBsonElement the raw BSON specification for the filter
+          @param pExpCtx the expression context for the pipeline
+          @returns the filter
+         */
+        static intrusive_ptr<DocumentSource> createFromBson(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Create a filter.
+
+          @param pFilter the expression to use to filter
+          @param pExpCtx the expression context for the pipeline
+          @returns the filter
+         */
+        static intrusive_ptr<DocumentSourceFilter> create(
+            const intrusive_ptr<Expression> &pFilter,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Create a BSONObj suitable for Matcher construction.
+
+          This is used after filter analysis has moved as many filters to
+          as early a point as possible in the document processing pipeline.
+          See db/Matcher.h and the associated wiki documentation for the
+          format.  This conversion is used to move back to the low-level
+          find() Cursor mechanism.
+
+          @param pBuilder the builder to write to
+         */
+        void toMatcherBson(BSONObjBuilder *pBuilder) const;
+
+        static const char filterName[];
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+        // virtuals from DocumentSourceFilterBase
+        virtual bool accept(const intrusive_ptr<Document> &pDocument) const;
+
+    private:
+        DocumentSourceFilter(const intrusive_ptr<Expression> &pFilter,
+                             const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        intrusive_ptr<Expression> pFilter;
+    };
+
+
+    class DocumentSourceGroup :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceGroup();
+        virtual bool eof();
+        virtual bool advance();
+        virtual const char *getSourceName() const;
+        virtual intrusive_ptr<Document> getCurrent();
+
+        /**
+          Create a new grouping DocumentSource.
+          
+          @param pExpCtx the expression context for the pipeline
+          @returns the DocumentSource
+         */
+        static intrusive_ptr<DocumentSourceGroup> create(
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Set the Id Expression.
+
+          Documents that pass through the grouping Document are grouped
+          according to this key.  This will generate the id_ field in the
+          result documents.
+
+          @param pExpression the group key
+         */
+        void setIdExpression(const intrusive_ptr<Expression> &pExpression);
+
+        /**
+          Add an accumulator.
+
+          Accumulators become fields in the Documents that result from
+          grouping.  Each unique group document must have it's own
+          accumulator; the accumulator factory is used to create that.
+
+          @param fieldName the name the accumulator result will have in the
+                result documents
+          @param pAccumulatorFactory used to create the accumulator for the
+                group field
+         */
+        void addAccumulator(string fieldName,
+                            intrusive_ptr<Accumulator> (*pAccumulatorFactory)(
+                            const intrusive_ptr<ExpressionContext> &),
+                            const intrusive_ptr<Expression> &pExpression);
+
+        /**
+          Create a grouping DocumentSource from BSON.
+
+          This is a convenience method that uses the above, and operates on
+          a BSONElement that has been deteremined to be an Object with an
+          element named $group.
+
+          @param pBsonElement the BSONELement that defines the group
+          @param pExpCtx the expression context
+          @returns the grouping DocumentSource
+         */
+        static intrusive_ptr<DocumentSource> createFromBson(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+
+        /**
+          Create a unifying group that can be used to combine group results
+          from shards.
+
+          @returns the grouping DocumentSource
+        */
+        intrusive_ptr<DocumentSource> createMerger();
+
+        static const char groupName[];
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceGroup(const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /*
+          Before returning anything, this source must fetch everything from
+          the underlying source and group it.  populate() is used to do that
+          on the first call to any method on this source.  The populated
+          boolean indicates that this has been done.
+         */
+        void populate();
+        bool populated;
+
+        intrusive_ptr<Expression> pIdExpression;
+
+        typedef boost::unordered_map<intrusive_ptr<const Value>,
+            vector<intrusive_ptr<Accumulator> >, Value::Hash> GroupsType;
+        GroupsType groups;
+
+        /*
+          The field names for the result documents and the accumulator
+          factories for the result documents.  The Expressions are the
+          common expressions used by each instance of each accumulator
+          in order to find the right-hand side of what gets added to the
+          accumulator.  Note that each of those is the same for each group,
+          so we can share them across all groups by adding them to the
+          accumulators after we use the factories to make a new set of
+          accumulators for each new group.
+
+          These three vectors parallel each other.
+        */
+        vector<string> vFieldName;
+        vector<intrusive_ptr<Accumulator> (*)(
+            const intrusive_ptr<ExpressionContext> &)> vpAccumulatorFactory;
+        vector<intrusive_ptr<Expression> > vpExpression;
+
+
+        intrusive_ptr<Document> makeDocument(
+            const GroupsType::iterator &rIter);
+
+        GroupsType::iterator groupsIterator;
+        intrusive_ptr<Document> pCurrent;
+    };
+
+
+    class DocumentSourceMatch :
+        public DocumentSourceFilterBase {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceMatch();
+        virtual const char *getSourceName() const;
+        virtual void manageDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker);
+
+        /**
+          Create a filter.
+
+          @param pBsonElement the raw BSON specification for the filter
+          @returns the filter
+         */
+        static intrusive_ptr<DocumentSource> createFromBson(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pCtx);
+
+        /**
+          Create a BSONObj suitable for Matcher construction.
+
+          This is used after filter analysis has moved as many filters to
+          as early a point as possible in the document processing pipeline.
+          See db/Matcher.h and the associated wiki documentation for the
+          format.  This conversion is used to move back to the low-level
+          find() Cursor mechanism.
+
+          @param pBuilder the builder to write to
+         */
+        void toMatcherBson(BSONObjBuilder *pBuilder) const;
+
+        static const char matchName[];
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+        // virtuals from DocumentSourceFilterBase
+        virtual bool accept(const intrusive_ptr<Document> &pDocument) const;
+
+    private:
+        DocumentSourceMatch(const BSONObj &query,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        Matcher matcher;
+    };
+
+
+    class DocumentSourceOut :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceOut();
+        virtual bool eof();
+        virtual bool advance();
+        virtual const char *getSourceName() const;
+        virtual intrusive_ptr<Document> getCurrent();
+
+        /**
+          Create a document source for output and pass-through.
+
+          This can be put anywhere in a pipeline and will store content as
+          well as pass it on.
+
+          @param pBsonElement the raw BSON specification for the source
+          @param pExpCtx the expression context for the pipeline
+          @returns the newly created document source
+        */
+        static intrusive_ptr<DocumentSourceOut> createFromBson(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        static const char outName[];
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceOut(BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+    };
+
+    
+    class DocumentSourceProject :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceProject();
+        virtual bool eof();
+        virtual bool advance();
+        virtual const char *getSourceName() const;
+        virtual intrusive_ptr<Document> getCurrent();
+        virtual void optimize();
+        virtual void manageDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker);
+
+        /**
+          Create a new DocumentSource that can implement projection.
+
+          @param pExpCtx the expression context for the pipeline
+          @returns the projection DocumentSource
+        */
+        static intrusive_ptr<DocumentSourceProject> create(
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Include a field path in a projection.
+
+          @param fieldPath the path of the field to include
+        */
+        void includePath(const string &fieldPath);
+
+        /**
+          Exclude a field path from the projection.
+
+          @param fieldPath the path of the field to exclude
+         */
+        void excludePath(const string &fieldPath);
+
+        /**
+          Add an output Expression in the projection.
+
+          BSON document fields are ordered, so the new field will be
+          appended to the existing set.
+
+          @param fieldName the name of the field as it will appear
+          @param pExpression the expression used to compute the field
+        */
+        void addField(const string &fieldName,
+                      const intrusive_ptr<Expression> &pExpression);
+
+        /**
+          Create a new projection DocumentSource from BSON.
+
+          This is a convenience for directly handling BSON, and relies on the
+          above methods.
+
+          @param pBsonElement the BSONElement with an object named $project
+          @param pExpCtx the expression context for the pipeline
+          @returns the created projection
+         */
+        static intrusive_ptr<DocumentSource> createFromBson(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        static const char projectName[];
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceProject(const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        // configuration state
+        bool excludeId;
+        intrusive_ptr<ExpressionObject> pEO;
+
+        /*
+          Utility object used by manageDependencies().
+
+          Removes dependencies from a DependencyTracker.
+         */
+        class DependencyRemover :
+            public ExpressionObject::PathSink {
+        public:
+            // virtuals from PathSink
+            virtual void path(const string &path, bool include);
+
+            /*
+              Constructor.
+
+              Captures a reference to the smart pointer to the DependencyTracker
+              that this will remove dependencies from via
+              ExpressionObject::emitPaths().
+
+              @param pTracker reference to the smart pointer to the
+                DependencyTracker
+             */
+            DependencyRemover(const intrusive_ptr<DependencyTracker> &pTracker);
+
+        private:
+            const intrusive_ptr<DependencyTracker> &pTracker;
+        };
+
+        /*
+          Utility object used by manageDependencies().
+
+          Checks dependencies to see if they are present.  If not, then
+          throws a user error.
+         */
+        class DependencyChecker :
+            public ExpressionObject::PathSink {
+        public:
+            // virtuals from PathSink
+            virtual void path(const string &path, bool include);
+
+            /*
+              Constructor.
+
+              Captures a reference to the smart pointer to the DependencyTracker
+              that this will check dependencies from from
+              ExpressionObject::emitPaths() to see if they are required.
+
+              @param pTracker reference to the smart pointer to the
+                DependencyTracker
+              @param pThis the projection that is making this request
+             */
+            DependencyChecker(
+                const intrusive_ptr<DependencyTracker> &pTracker,
+                const DocumentSourceProject *pThis);
+
+        private:
+            const intrusive_ptr<DependencyTracker> &pTracker;
+            const DocumentSourceProject *pThis;
+        };
+    };
+
+
+    class DocumentSourceSort :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceSort();
+        virtual bool eof();
+        virtual bool advance();
+        virtual const char *getSourceName() const;
+        virtual intrusive_ptr<Document> getCurrent();
+        virtual void manageDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker);
+        /*
+          TODO
+          Adjacent sorts should reduce to the last sort.
+        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);
+        */
+
+        /**
+          Create a new sorting DocumentSource.
+          
+          @param pExpCtx the expression context for the pipeline
+          @returns the DocumentSource
+         */
+        static intrusive_ptr<DocumentSourceSort> create(
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Add sort key field.
+
+          Adds a sort key field to the key being built up.  A concatenated
+          key is built up by calling this repeatedly.
+
+          @param fieldPath the field path to the key component
+          @param ascending if true, use the key for an ascending sort,
+            otherwise, use it for descending
+        */
+        void addKey(const string &fieldPath, bool ascending);
+
+        /**
+          Write out an object whose contents are the sort key.
+
+          @param pBuilder initialized object builder.
+          @param fieldPrefix specify whether or not to include the field prefix
+         */
+        void sortKeyToBson(BSONObjBuilder *pBuilder, bool usePrefix) const;
+
+        /**
+          Create a sorting DocumentSource from BSON.
+
+          This is a convenience method that uses the above, and operates on
+          a BSONElement that has been deteremined to be an Object with an
+          element named $group.
+
+          @param pBsonElement the BSONELement that defines the group
+          @param pExpCtx the expression context for the pipeline
+          @returns the grouping DocumentSource
+         */
+        static intrusive_ptr<DocumentSource> createFromBson(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+
+        static const char sortName[];
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceSort(const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /*
+          Before returning anything, this source must fetch everything from
+          the underlying source and group it.  populate() is used to do that
+          on the first call to any method on this source.  The populated
+          boolean indicates that this has been done.
+         */
+        void populate();
+        bool populated;
+        long long count;
+
+        /* these two parallel each other */
+        typedef vector<intrusive_ptr<ExpressionFieldPath> > SortPaths;
+        SortPaths vSortKey;
+        vector<bool> vAscending;
+
+        /*
+          Compare two documents according to the specified sort key.
+
+          @param rL reference to the left document
+          @param rR reference to the right document
+          @returns a number less than, equal to, or greater than zero,
+            indicating pL < pR, pL == pR, or pL > pR, respectively
+         */
+        int compare(const intrusive_ptr<Document> &pL,
+                    const intrusive_ptr<Document> &pR);
+
+        /*
+          This is a utility class just for the STL sort that is done
+          inside.
+         */
+        class Comparator {
+        public:
+            bool operator()(
+                const intrusive_ptr<Document> &pL,
+                const intrusive_ptr<Document> &pR) {
+                return (pSort->compare(pL, pR) < 0);
+            }
+
+            inline Comparator(DocumentSourceSort *pS):
+                pSort(pS) {
+            }
+
+        private:
+            DocumentSourceSort *pSort;
+        };
+
+        typedef vector<intrusive_ptr<Document> > VectorType;
+        VectorType documents;
+
+        VectorType::iterator docIterator;
+        intrusive_ptr<Document> pCurrent;
+    };
+
+
+    class DocumentSourceLimit :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceLimit();
+        virtual bool eof();
+        virtual bool advance();
+        virtual intrusive_ptr<Document> getCurrent();
+        virtual const char *getSourceName() const;
+        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);
+
+        /**
+          Create a new limiting DocumentSource.
+
+          @param pExpCtx the expression context for the pipeline
+          @returns the DocumentSource
+         */
+        static intrusive_ptr<DocumentSourceLimit> create(
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Create a limiting DocumentSource from BSON.
+
+          This is a convenience method that uses the above, and operates on
+          a BSONElement that has been deteremined to be an Object with an
+          element named $limit.
+
+          @param pBsonElement the BSONELement that defines the limit
+          @param pExpCtx the expression context
+          @returns the grouping DocumentSource
+         */
+        static intrusive_ptr<DocumentSource> createFromBson(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+
+        static const char limitName[];
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceLimit(
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        long long limit;
+        long long count;
+        intrusive_ptr<Document> pCurrent;
+    };
+
+    class DocumentSourceSkip :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceSkip();
+        virtual bool eof();
+        virtual bool advance();
+        virtual intrusive_ptr<Document> getCurrent();
+        virtual const char *getSourceName() const;
+        virtual bool coalesce(const intrusive_ptr<DocumentSource> &pNextSource);
+
+        /**
+          Create a new skipping DocumentSource.
+
+          @param pExpCtx the expression context
+          @returns the DocumentSource
+         */
+        static intrusive_ptr<DocumentSourceSkip> create(
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Create a skipping DocumentSource from BSON.
+
+          This is a convenience method that uses the above, and operates on
+          a BSONElement that has been deteremined to be an Object with an
+          element named $skip.
+
+          @param pBsonElement the BSONELement that defines the skip
+          @param pExpCtx the expression context
+          @returns the grouping DocumentSource
+         */
+        static intrusive_ptr<DocumentSource> createFromBson(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+
+        static const char skipName[];
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceSkip(const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /*
+          Skips initial documents.
+         */
+        void skipper();
+
+        long long skip;
+        long long count;
+        intrusive_ptr<Document> pCurrent;
+    };
+
+
+    class DocumentSourceUnwind :
+        public DocumentSource {
+    public:
+        // virtuals from DocumentSource
+        virtual ~DocumentSourceUnwind();
+        virtual bool eof();
+        virtual bool advance();
+        virtual const char *getSourceName() const;
+        virtual intrusive_ptr<Document> getCurrent();
+        virtual void manageDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker);
+
+        /**
+          Create a new DocumentSource that can implement unwind.
+
+          @param pExpCtx the expression context for the pipeline
+          @returns the projection DocumentSource
+        */
+        static intrusive_ptr<DocumentSourceUnwind> create(
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        /**
+          Specify the field to unwind.  There must be exactly one before
+          the pipeline begins execution.
+
+          @param rFieldPath - path to the field to unwind
+        */
+        void unwindField(const FieldPath &rFieldPath);
+
+        /**
+          Create a new projection DocumentSource from BSON.
+
+          This is a convenience for directly handling BSON, and relies on the
+          above methods.
+
+          @param pBsonElement the BSONElement with an object named $project
+          @param pExpCtx the expression context for the pipeline
+          @returns the created projection
+         */
+        static intrusive_ptr<DocumentSource> createFromBson(
+            BSONElement *pBsonElement,
+            const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        static const char unwindName[];
+
+    protected:
+        // virtuals from DocumentSource
+        virtual void sourceToBson(BSONObjBuilder *pBuilder, bool explain) const;
+
+    private:
+        DocumentSourceUnwind(const intrusive_ptr<ExpressionContext> &pExpCtx);
+
+        // configuration state
+        FieldPath unwindPath;
+
+        vector<int> fieldIndex; /* for the current document, the indices
+                                   leading down to the field being unwound */
+
+        // iteration state
+        intrusive_ptr<Document> pNoUnwindDocument;
+                                              // document to return, pre-unwind
+        intrusive_ptr<const Value> pUnwindArray; // field being unwound
+        intrusive_ptr<ValueIterator> pUnwinder; // iterator used for unwinding
+        intrusive_ptr<const Value> pUnwindValue; // current value
+
+        /*
+          Clear all the state related to unwinding an array.
+         */
+        void resetArray();
+
+        /*
+          Clone the current document being unwound.
+
+          This is a partial deep clone.  Because we're going to replace the
+          value at the end, we have to replace everything along the path
+          leading to that in order to not share that change with any other
+          clones (or the original) that we've made.
+
+          This expects pUnwindValue to have been set by a prior call to
+          advance().  However, pUnwindValue may also be NULL, in which case
+          the field will be removed -- this is the action for an empty
+          array.
+
+          @returns a partial deep clone of pNoUnwindDocument
+         */
+        intrusive_ptr<Document> clonePath() const;
+    };
+
+}
+
+
+/* ======================= INLINED IMPLEMENTATIONS ========================== */
+
+namespace mongo {
+
+    inline void DocumentSource::setPipelineStep(int s) {
+        step = s;
+    }
+
+    inline int DocumentSource::getPipelineStep() const {
+        return step;
+    }
+    
+    inline void DocumentSourceGroup::setIdExpression(
+        const intrusive_ptr<Expression> &pExpression) {
+        pIdExpression = pExpression;
+    }
+
+    inline DocumentSourceProject::DependencyRemover::DependencyRemover(
+        const intrusive_ptr<DependencyTracker> &pT):
+        pTracker(pT) {
+    }
+
+    inline DocumentSourceProject::DependencyChecker::DependencyChecker(
+        const intrusive_ptr<DependencyTracker> &pTrack,
+        const DocumentSourceProject *pT):
+        pTracker(pTrack),
+        pThis(pT) {
+    }
+
+    inline void DocumentSourceUnwind::resetArray() {
+        pNoUnwindDocument.reset();
+        pUnwindArray.reset();
+        pUnwinder.reset();
+        pUnwindValue.reset();
+    }
+
+}
diff --git a/src/mongo/db/pipeline/document_source_bson_array.cpp b/src/mongo/db/pipeline/document_source_bson_array.cpp
index eee951dc1f9..79bce29220a 100755
--- a/src/mongo/db/pipeline/document_source_bson_array.cpp
+++ b/src/mongo/db/pipeline/document_source_bson_array.cpp
@@ -1,93 +1,93 @@
-/**

- * Copyright 2011 (c) 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-

-#include "db/pipeline/document_source.h"

-#include "db/pipeline/document.h"

-

-

-namespace mongo {

-

-    DocumentSourceBsonArray::~DocumentSourceBsonArray() {

-    }

-

-    bool DocumentSourceBsonArray::eof() {

-        return !haveCurrent;

-    }

-

-    bool DocumentSourceBsonArray::advance() {

-        DocumentSource::advance(); // check for interrupts

-

-        if (eof())

-            return false;

-

-        if (!arrayIterator.more()) {

-            haveCurrent = false;

-            return false;

-        }

-

-        currentElement = arrayIterator.next();

-        return true;

-    }

-

-    intrusive_ptr<Document> DocumentSourceBsonArray::getCurrent() {

-        verify(haveCurrent);

-        BSONObj documentObj(currentElement.Obj());

-        intrusive_ptr<Document> pDocument(

-            Document::createFromBsonObj(&documentObj));

-        return pDocument;

-    }

-

-    void DocumentSourceBsonArray::setSource(DocumentSource *pSource) {

-        /* this doesn't take a source */

-        verify(false);

-    }

-

-    DocumentSourceBsonArray::DocumentSourceBsonArray(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSource(pExpCtx),

-        embeddedObject(pBsonElement->embeddedObject()),

-        arrayIterator(embeddedObject),

-        haveCurrent(false) {

-        if (arrayIterator.more()) {

-            currentElement = arrayIterator.next();

-            haveCurrent = true;

-        }

-    }

-

-    intrusive_ptr<DocumentSourceBsonArray> DocumentSourceBsonArray::create(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-

-        verify(pBsonElement->type() == Array);

-        intrusive_ptr<DocumentSourceBsonArray> pSource(

-            new DocumentSourceBsonArray(pBsonElement, pExpCtx));

-

-        return pSource;

-    }

-

-    void DocumentSourceBsonArray::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-

-        if (explain) {

-            BSONObj empty;

-

-            pBuilder->append("bsonArray", empty);

-        }

-    }

-}

+/**
+ * Copyright 2011 (c) 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+
+#include "db/pipeline/document_source.h"
+#include "db/pipeline/document.h"
+
+
+namespace mongo {
+
+    DocumentSourceBsonArray::~DocumentSourceBsonArray() {
+    }
+
+    bool DocumentSourceBsonArray::eof() {
+        return !haveCurrent;
+    }
+
+    bool DocumentSourceBsonArray::advance() {
+        DocumentSource::advance(); // check for interrupts
+
+        if (eof())
+            return false;
+
+        if (!arrayIterator.more()) {
+            haveCurrent = false;
+            return false;
+        }
+
+        currentElement = arrayIterator.next();
+        return true;
+    }
+
+    intrusive_ptr<Document> DocumentSourceBsonArray::getCurrent() {
+        verify(haveCurrent);
+        BSONObj documentObj(currentElement.Obj());
+        intrusive_ptr<Document> pDocument(
+            Document::createFromBsonObj(&documentObj));
+        return pDocument;
+    }
+
+    void DocumentSourceBsonArray::setSource(DocumentSource *pSource) {
+        /* this doesn't take a source */
+        verify(false);
+    }
+
+    DocumentSourceBsonArray::DocumentSourceBsonArray(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSource(pExpCtx),
+        embeddedObject(pBsonElement->embeddedObject()),
+        arrayIterator(embeddedObject),
+        haveCurrent(false) {
+        if (arrayIterator.more()) {
+            currentElement = arrayIterator.next();
+            haveCurrent = true;
+        }
+    }
+
+    intrusive_ptr<DocumentSourceBsonArray> DocumentSourceBsonArray::create(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+
+        verify(pBsonElement->type() == Array);
+        intrusive_ptr<DocumentSourceBsonArray> pSource(
+            new DocumentSourceBsonArray(pBsonElement, pExpCtx));
+
+        return pSource;
+    }
+
+    void DocumentSourceBsonArray::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+
+        if (explain) {
+            BSONObj empty;
+
+            pBuilder->append("bsonArray", empty);
+        }
+    }
+}
diff --git a/src/mongo/db/pipeline/document_source_command_futures.cpp b/src/mongo/db/pipeline/document_source_command_futures.cpp
index 283be179de5..d4b92356108 100755
--- a/src/mongo/db/pipeline/document_source_command_futures.cpp
+++ b/src/mongo/db/pipeline/document_source_command_futures.cpp
@@ -1,137 +1,137 @@
-/**

- * Copyright 2011 (c) 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-

-#include "db/pipeline/document_source.h"

-

-namespace mongo {

-

-    DocumentSourceCommandFutures::~DocumentSourceCommandFutures() {

-    }

-

-    bool DocumentSourceCommandFutures::eof() {

-        /* if we haven't even started yet, do so */

-        if (!pCurrent.get())

-            getNextDocument();

-

-        return (pCurrent.get() == NULL);

-    }

-

-    bool DocumentSourceCommandFutures::advance() {

-        DocumentSource::advance(); // check for interrupts

-

-        if (eof())

-            return false;

-

-        /* advance */

-        getNextDocument();

-

-        return (pCurrent.get() != NULL);

-    }

-

-    intrusive_ptr<Document> DocumentSourceCommandFutures::getCurrent() {

-        verify(!eof());

-        return pCurrent;

-    }

-

-    void DocumentSourceCommandFutures::setSource(DocumentSource *pSource) {

-        /* this doesn't take a source */

-        verify(false);

-    }

-

-    void DocumentSourceCommandFutures::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-        /* this has no BSON equivalent */

-        verify(false);

-    }

-

-    DocumentSourceCommandFutures::DocumentSourceCommandFutures(

-        string &theErrmsg, FuturesList *pList,

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSource(pExpCtx),

-        newSource(false),

-        pBsonSource(),

-        pCurrent(),

-        iterator(pList->begin()),

-        listEnd(pList->end()),

-        errmsg(theErrmsg) {

-    }

-

-    intrusive_ptr<DocumentSourceCommandFutures>

-    DocumentSourceCommandFutures::create(

-        string &errmsg, FuturesList *pList,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        intrusive_ptr<DocumentSourceCommandFutures> pSource(

-            new DocumentSourceCommandFutures(errmsg, pList, pExpCtx));

-        return pSource;

-    }

-

-    void DocumentSourceCommandFutures::getNextDocument() {

-        while(true) {

-            if (!pBsonSource.get()) {

-                /* if there aren't any more futures, we're done */

-                if (iterator == listEnd) {

-                    pCurrent.reset();

-                    return;

-                }

-

-                /* grab the next command result */

-                shared_ptr<Future::CommandResult> pResult(*iterator);

-                ++iterator;

-

-                /* try to wait for it */

-                if (!pResult->join()) {

-                    error() << "sharded pipeline failed on shard: " <<

-                        pResult->getServer() << " error: " <<

-                        pResult->result() << endl;

-                    errmsg += "-- mongod pipeline failed: ";

-                    errmsg += pResult->result().toString();

-

-                    /* move on to the next command future */

-                    continue;

-                }

-

-                /* grab the result array out of the shard server's response */

-                BSONObj shardResult(pResult->result());

-                BSONObjIterator objIterator(shardResult);

-                while(objIterator.more()) {

-                    BSONElement element(objIterator.next());

-                    const char *pFieldName = element.fieldName();

-

-                    /* find the result array and quit this loop */

-                    if (strcmp(pFieldName, "result") == 0) {

-                        pBsonSource = DocumentSourceBsonArray::create(

-                            &element, pExpCtx);

-                        newSource = true;

-                        break;

-                    }

-                }

-            }

-

-            /* if we're done with this shard's results, try the next */

-            if (pBsonSource->eof() ||

-                (!newSource && !pBsonSource->advance())) {

-                pBsonSource.reset();

-                continue;

-            }

-

-            pCurrent = pBsonSource->getCurrent();

-            newSource = false;

-            return;

-        }

-    }

-}

+/**
+ * Copyright 2011 (c) 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+
+#include "db/pipeline/document_source.h"
+
+namespace mongo {
+
+    DocumentSourceCommandFutures::~DocumentSourceCommandFutures() {
+    }
+
+    bool DocumentSourceCommandFutures::eof() {
+        /* if we haven't even started yet, do so */
+        if (!pCurrent.get())
+            getNextDocument();
+
+        return (pCurrent.get() == NULL);
+    }
+
+    bool DocumentSourceCommandFutures::advance() {
+        DocumentSource::advance(); // check for interrupts
+
+        if (eof())
+            return false;
+
+        /* advance */
+        getNextDocument();
+
+        return (pCurrent.get() != NULL);
+    }
+
+    intrusive_ptr<Document> DocumentSourceCommandFutures::getCurrent() {
+        verify(!eof());
+        return pCurrent;
+    }
+
+    void DocumentSourceCommandFutures::setSource(DocumentSource *pSource) {
+        /* this doesn't take a source */
+        verify(false);
+    }
+
+    void DocumentSourceCommandFutures::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+        /* this has no BSON equivalent */
+        verify(false);
+    }
+
+    DocumentSourceCommandFutures::DocumentSourceCommandFutures(
+        string &theErrmsg, FuturesList *pList,
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSource(pExpCtx),
+        newSource(false),
+        pBsonSource(),
+        pCurrent(),
+        iterator(pList->begin()),
+        listEnd(pList->end()),
+        errmsg(theErrmsg) {
+    }
+
+    intrusive_ptr<DocumentSourceCommandFutures>
+    DocumentSourceCommandFutures::create(
+        string &errmsg, FuturesList *pList,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        intrusive_ptr<DocumentSourceCommandFutures> pSource(
+            new DocumentSourceCommandFutures(errmsg, pList, pExpCtx));
+        return pSource;
+    }
+
+    void DocumentSourceCommandFutures::getNextDocument() {
+        while(true) {
+            if (!pBsonSource.get()) {
+                /* if there aren't any more futures, we're done */
+                if (iterator == listEnd) {
+                    pCurrent.reset();
+                    return;
+                }
+
+                /* grab the next command result */
+                shared_ptr<Future::CommandResult> pResult(*iterator);
+                ++iterator;
+
+                /* try to wait for it */
+                if (!pResult->join()) {
+                    error() << "sharded pipeline failed on shard: " <<
+                        pResult->getServer() << " error: " <<
+                        pResult->result() << endl;
+                    errmsg += "-- mongod pipeline failed: ";
+                    errmsg += pResult->result().toString();
+
+                    /* move on to the next command future */
+                    continue;
+                }
+
+                /* grab the result array out of the shard server's response */
+                BSONObj shardResult(pResult->result());
+                BSONObjIterator objIterator(shardResult);
+                while(objIterator.more()) {
+                    BSONElement element(objIterator.next());
+                    const char *pFieldName = element.fieldName();
+
+                    /* find the result array and quit this loop */
+                    if (strcmp(pFieldName, "result") == 0) {
+                        pBsonSource = DocumentSourceBsonArray::create(
+                            &element, pExpCtx);
+                        newSource = true;
+                        break;
+                    }
+                }
+            }
+
+            /* if we're done with this shard's results, try the next */
+            if (pBsonSource->eof() ||
+                (!newSource && !pBsonSource->advance())) {
+                pBsonSource.reset();
+                continue;
+            }
+
+            pCurrent = pBsonSource->getCurrent();
+            newSource = false;
+            return;
+        }
+    }
+}
diff --git a/src/mongo/db/pipeline/document_source_filter.cpp b/src/mongo/db/pipeline/document_source_filter.cpp
index 156772fc335..b9cb0a369d1 100755
--- a/src/mongo/db/pipeline/document_source_filter.cpp
+++ b/src/mongo/db/pipeline/document_source_filter.cpp
@@ -1,105 +1,105 @@
-/**

-*    Copyright (C) 2011 10gen Inc.

-*

-*    This program is free software: you can redistribute it and/or  modify

-*    it under the terms of the GNU Affero General Public License, version 3,

-*    as published by the Free Software Foundation.

-*

-*    This program is distributed in the hope that it will be useful,

-*    but WITHOUT ANY WARRANTY; without even the implied warranty of

-*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

-*    GNU Affero General Public License for more details.

-*

-*    You should have received a copy of the GNU Affero General Public License

-*    along with this program.  If not, see <http://www.gnu.org/licenses/>.

-*/

-

-#include "pch.h"

-

-#include "db/pipeline/document_source.h"

-

-#include "db/jsobj.h"

-#include "db/pipeline/expression.h"

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    const char DocumentSourceFilter::filterName[] = "$filter";

-

-    DocumentSourceFilter::~DocumentSourceFilter() {

-    }

-

-    const char *DocumentSourceFilter::getSourceName() const {

-        return filterName;

-    }

-

-    bool DocumentSourceFilter::coalesce(

-        const intrusive_ptr<DocumentSource> &pNextSource) {

-

-        /* we only know how to coalesce other filters */

-        DocumentSourceFilter *pDocFilter =

-            dynamic_cast<DocumentSourceFilter *>(pNextSource.get());

-        if (!pDocFilter)

-            return false;

-

-        /*

-          Two adjacent filters can be combined by creating a conjunction of

-          their predicates.

-         */

-        intrusive_ptr<ExpressionNary> pAnd(ExpressionAnd::create());

-        pAnd->addOperand(pFilter);

-        pAnd->addOperand(pDocFilter->pFilter);

-        pFilter = pAnd;

-

-        return true;

-    }

-

-    void DocumentSourceFilter::optimize() {

-        pFilter = pFilter->optimize();

-    }

-

-    void DocumentSourceFilter::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-        pFilter->addToBsonObj(pBuilder, filterName, false);

-    }

-

-    bool DocumentSourceFilter::accept(

-        const intrusive_ptr<Document> &pDocument) const {

-        intrusive_ptr<const Value> pValue(pFilter->evaluate(pDocument));

-        return pValue->coerceToBool();

-    }

-

-    intrusive_ptr<DocumentSource> DocumentSourceFilter::createFromBson(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pCtx) {

-        uassert(15946, "a document filter expression must be an object",

-                pBsonElement->type() == Object);

-

-        Expression::ObjectCtx oCtx(0);

-        intrusive_ptr<Expression> pExpression(

-            Expression::parseObject(pBsonElement, &oCtx));

-        intrusive_ptr<DocumentSourceFilter> pFilter(

-            DocumentSourceFilter::create(pExpression, pCtx));

-

-        return pFilter;

-    }

-

-    intrusive_ptr<DocumentSourceFilter> DocumentSourceFilter::create(

-        const intrusive_ptr<Expression> &pFilter,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        intrusive_ptr<DocumentSourceFilter> pSource(

-            new DocumentSourceFilter(pFilter, pExpCtx));

-        return pSource;

-    }

-

-    DocumentSourceFilter::DocumentSourceFilter(

-        const intrusive_ptr<Expression> &pTheFilter,

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSourceFilterBase(pExpCtx),

-        pFilter(pTheFilter) {

-    }

-

-    void DocumentSourceFilter::toMatcherBson(BSONObjBuilder *pBuilder) const {

-        pFilter->toMatcherBson(pBuilder);

-    }

-}

+/**
+*    Copyright (C) 2011 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "pch.h"
+
+#include "db/pipeline/document_source.h"
+
+#include "db/jsobj.h"
+#include "db/pipeline/expression.h"
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    const char DocumentSourceFilter::filterName[] = "$filter";
+
+    DocumentSourceFilter::~DocumentSourceFilter() {
+    }
+
+    const char *DocumentSourceFilter::getSourceName() const {
+        return filterName;
+    }
+
+    bool DocumentSourceFilter::coalesce(
+        const intrusive_ptr<DocumentSource> &pNextSource) {
+
+        /* we only know how to coalesce other filters */
+        DocumentSourceFilter *pDocFilter =
+            dynamic_cast<DocumentSourceFilter *>(pNextSource.get());
+        if (!pDocFilter)
+            return false;
+
+        /*
+          Two adjacent filters can be combined by creating a conjunction of
+          their predicates.
+         */
+        intrusive_ptr<ExpressionNary> pAnd(ExpressionAnd::create());
+        pAnd->addOperand(pFilter);
+        pAnd->addOperand(pDocFilter->pFilter);
+        pFilter = pAnd;
+
+        return true;
+    }
+
+    void DocumentSourceFilter::optimize() {
+        pFilter = pFilter->optimize();
+    }
+
+    void DocumentSourceFilter::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+        pFilter->addToBsonObj(pBuilder, filterName, false);
+    }
+
+    bool DocumentSourceFilter::accept(
+        const intrusive_ptr<Document> &pDocument) const {
+        intrusive_ptr<const Value> pValue(pFilter->evaluate(pDocument));
+        return pValue->coerceToBool();
+    }
+
+    intrusive_ptr<DocumentSource> DocumentSourceFilter::createFromBson(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        uassert(15946, "a document filter expression must be an object",
+                pBsonElement->type() == Object);
+
+        Expression::ObjectCtx oCtx(0);
+        intrusive_ptr<Expression> pExpression(
+            Expression::parseObject(pBsonElement, &oCtx));
+        intrusive_ptr<DocumentSourceFilter> pFilter(
+            DocumentSourceFilter::create(pExpression, pCtx));
+
+        return pFilter;
+    }
+
+    intrusive_ptr<DocumentSourceFilter> DocumentSourceFilter::create(
+        const intrusive_ptr<Expression> &pFilter,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        intrusive_ptr<DocumentSourceFilter> pSource(
+            new DocumentSourceFilter(pFilter, pExpCtx));
+        return pSource;
+    }
+
+    DocumentSourceFilter::DocumentSourceFilter(
+        const intrusive_ptr<Expression> &pTheFilter,
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSourceFilterBase(pExpCtx),
+        pFilter(pTheFilter) {
+    }
+
+    void DocumentSourceFilter::toMatcherBson(BSONObjBuilder *pBuilder) const {
+        pFilter->toMatcherBson(pBuilder);
+    }
+}
diff --git a/src/mongo/db/pipeline/document_source_filter_base.cpp b/src/mongo/db/pipeline/document_source_filter_base.cpp
index c04ff7a9f29..3354b3c6bc2 100755
--- a/src/mongo/db/pipeline/document_source_filter_base.cpp
+++ b/src/mongo/db/pipeline/document_source_filter_base.cpp
@@ -1,89 +1,89 @@
-/**

-*    Copyright (C) 2011 10gen Inc.

-*

-*    This program is free software: you can redistribute it and/or  modify

-*    it under the terms of the GNU Affero General Public License, version 3,

-*    as published by the Free Software Foundation.

-*

-*    This program is distributed in the hope that it will be useful,

-*    but WITHOUT ANY WARRANTY; without even the implied warranty of

-*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

-*    GNU Affero General Public License for more details.

-*

-*    You should have received a copy of the GNU Affero General Public License

-*    along with this program.  If not, see <http://www.gnu.org/licenses/>.

-*/

-

-#include "pch.h"

-

-#include "db/pipeline/document_source.h"

-

-#include "db/jsobj.h"

-#include "db/pipeline/expression.h"

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    DocumentSourceFilterBase::~DocumentSourceFilterBase() {

-    }

-

-    void DocumentSourceFilterBase::findNext() {

-        /* only do this the first time */

-        if (unstarted) {

-            hasNext = !pSource->eof();

-            unstarted = false;

-        }

-

-        while(hasNext) {

-            boost::intrusive_ptr<Document> pDocument(pSource->getCurrent());

-            hasNext = pSource->advance();

-

-            if (accept(pDocument)) {

-                pCurrent = pDocument;

-                return;

-            }

-        }

-

-        pCurrent.reset();

-    }

-

-    bool DocumentSourceFilterBase::eof() {

-        if (unstarted)

-            findNext();

-

-        return (pCurrent.get() == NULL);

-    }

-

-    bool DocumentSourceFilterBase::advance() {

-        DocumentSource::advance(); // check for interrupts

-

-        if (unstarted)

-            findNext();

-

-        /*

-          This looks weird after the above, but is correct.  Note that calling

-          getCurrent() when first starting already yields the first document

-          in the collection.  Calling advance() without using getCurrent()

-          first will skip over the first item.

-         */

-        findNext();

-

-        return (pCurrent.get() != NULL);

-    }

-

-    boost::intrusive_ptr<Document> DocumentSourceFilterBase::getCurrent() {

-        if (unstarted)

-            findNext();

-

-        verify(pCurrent.get() != NULL);

-        return pCurrent;

-    }

-

-    DocumentSourceFilterBase::DocumentSourceFilterBase(

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSource(pExpCtx),

-        unstarted(true),

-        hasNext(false),

-        pCurrent() {

-    }

-}

+/**
+*    Copyright (C) 2011 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "pch.h"
+
+#include "db/pipeline/document_source.h"
+
+#include "db/jsobj.h"
+#include "db/pipeline/expression.h"
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    DocumentSourceFilterBase::~DocumentSourceFilterBase() {
+    }
+
+    void DocumentSourceFilterBase::findNext() {
+        /* only do this the first time */
+        if (unstarted) {
+            hasNext = !pSource->eof();
+            unstarted = false;
+        }
+
+        while(hasNext) {
+            boost::intrusive_ptr<Document> pDocument(pSource->getCurrent());
+            hasNext = pSource->advance();
+
+            if (accept(pDocument)) {
+                pCurrent = pDocument;
+                return;
+            }
+        }
+
+        pCurrent.reset();
+    }
+
+    bool DocumentSourceFilterBase::eof() {
+        if (unstarted)
+            findNext();
+
+        return (pCurrent.get() == NULL);
+    }
+
+    bool DocumentSourceFilterBase::advance() {
+        DocumentSource::advance(); // check for interrupts
+
+        if (unstarted)
+            findNext();
+
+        /*
+          This looks weird after the above, but is correct.  Note that calling
+          getCurrent() when first starting already yields the first document
+          in the collection.  Calling advance() without using getCurrent()
+          first will skip over the first item.
+         */
+        findNext();
+
+        return (pCurrent.get() != NULL);
+    }
+
+    boost::intrusive_ptr<Document> DocumentSourceFilterBase::getCurrent() {
+        if (unstarted)
+            findNext();
+
+        verify(pCurrent.get() != NULL);
+        return pCurrent;
+    }
+
+    DocumentSourceFilterBase::DocumentSourceFilterBase(
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSource(pExpCtx),
+        unstarted(true),
+        hasNext(false),
+        pCurrent() {
+    }
+}
diff --git a/src/mongo/db/pipeline/document_source_group.cpp b/src/mongo/db/pipeline/document_source_group.cpp
index 69f42e20868..f829c3b609b 100755
--- a/src/mongo/db/pipeline/document_source_group.cpp
+++ b/src/mongo/db/pipeline/document_source_group.cpp
@@ -1,398 +1,398 @@
-/**

-*    Copyright (C) 2011 10gen Inc.

-*

-*    This program is free software: you can redistribute it and/or  modify

-*    it under the terms of the GNU Affero General Public License, version 3,

-*    as published by the Free Software Foundation.

-*

-*    This program is distributed in the hope that it will be useful,

-*    but WITHOUT ANY WARRANTY; without even the implied warranty of

-*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

-*    GNU Affero General Public License for more details.

-*

-*    You should have received a copy of the GNU Affero General Public License

-*    along with this program.  If not, see <http://www.gnu.org/licenses/>.

-*/

-

-#include "pch.h"

-

-#include "db/pipeline/document_source.h"

-

-#include "db/jsobj.h"

-#include "db/pipeline/accumulator.h"

-#include "db/pipeline/document.h"

-#include "db/pipeline/expression.h"

-#include "db/pipeline/expression_context.h"

-#include "db/pipeline/value.h"

-

-namespace mongo {

-    const char DocumentSourceGroup::groupName[] = "$group";

-

-    DocumentSourceGroup::~DocumentSourceGroup() {

-    }

-

-    const char *DocumentSourceGroup::getSourceName() const {

-        return groupName;

-    }

-

-    bool DocumentSourceGroup::eof() {

-        if (!populated)

-            populate();

-

-        return (groupsIterator == groups.end());

-    }

-

-    bool DocumentSourceGroup::advance() {

-        DocumentSource::advance(); // check for interrupts

-

-        if (!populated)

-            populate();

-

-        verify(groupsIterator != groups.end());

-

-        ++groupsIterator;

-        if (groupsIterator == groups.end()) {

-            pCurrent.reset();

-            return false;

-        }

-

-        pCurrent = makeDocument(groupsIterator);

-        return true;

-    }

-

-    intrusive_ptr<Document> DocumentSourceGroup::getCurrent() {

-        if (!populated)

-            populate();

-

-        return pCurrent;

-    }

-

-    void DocumentSourceGroup::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-        BSONObjBuilder insides;

-

-        /* add the _id */

-        pIdExpression->addToBsonObj(&insides, Document::idName.c_str(), false);

-

-        /* add the remaining fields */

-        const size_t n = vFieldName.size();

-        for(size_t i = 0; i < n; ++i) {

-            intrusive_ptr<Accumulator> pA((*vpAccumulatorFactory[i])(pExpCtx));

-            pA->addOperand(vpExpression[i]);

-            pA->addToBsonObj(&insides, vFieldName[i], false);

-        }

-

-        pBuilder->append(groupName, insides.done());

-    }

-

-    intrusive_ptr<DocumentSourceGroup> DocumentSourceGroup::create(

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        intrusive_ptr<DocumentSourceGroup> pSource(

-            new DocumentSourceGroup(pExpCtx));

-        return pSource;

-    }

-

-    DocumentSourceGroup::DocumentSourceGroup(

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSource(pExpCtx),

-        populated(false),

-        pIdExpression(),

-        groups(),

-        vFieldName(),

-        vpAccumulatorFactory(),

-        vpExpression() {

-    }

-

-    void DocumentSourceGroup::addAccumulator(

-        string fieldName,

-        intrusive_ptr<Accumulator> (*pAccumulatorFactory)(

-            const intrusive_ptr<ExpressionContext> &),

-        const intrusive_ptr<Expression> &pExpression) {

-        vFieldName.push_back(fieldName);

-        vpAccumulatorFactory.push_back(pAccumulatorFactory);

-        vpExpression.push_back(pExpression);

-    }

-

-

-    struct GroupOpDesc {

-        const char *pName;

-        intrusive_ptr<Accumulator> (*pFactory)(

-            const intrusive_ptr<ExpressionContext> &);

-    };

-

-    static int GroupOpDescCmp(const void *pL, const void *pR) {

-        return strcmp(((const GroupOpDesc *)pL)->pName,

-                      ((const GroupOpDesc *)pR)->pName);

-    }

-

-    /*

-      Keep these sorted alphabetically so we can bsearch() them using

-      GroupOpDescCmp() above.

-    */

-    static const GroupOpDesc GroupOpTable[] = {

-        {"$addToSet", AccumulatorAddToSet::create},

-        {"$avg", AccumulatorAvg::create},

-        {"$first", AccumulatorFirst::create},

-        {"$last", AccumulatorLast::create},

-        {"$max", AccumulatorMinMax::createMax},

-        {"$min", AccumulatorMinMax::createMin},

-        {"$push", AccumulatorPush::create},

-        {"$sum", AccumulatorSum::create},

-    };

-

-    static const size_t NGroupOp = sizeof(GroupOpTable)/sizeof(GroupOpTable[0]);

-

-    intrusive_ptr<DocumentSource> DocumentSourceGroup::createFromBson(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        uassert(15947, "a group's fields must be specified in an object",

-                pBsonElement->type() == Object);

-

-        intrusive_ptr<DocumentSourceGroup> pGroup(

-            DocumentSourceGroup::create(pExpCtx));

-        bool idSet = false;

-

-        BSONObj groupObj(pBsonElement->Obj());

-        BSONObjIterator groupIterator(groupObj);

-        while(groupIterator.more()) {

-            BSONElement groupField(groupIterator.next());

-            const char *pFieldName = groupField.fieldName();

-

-            if (strcmp(pFieldName, Document::idName.c_str()) == 0) {

-                uassert(15948, "a group's _id may only be specified once",

-                        !idSet);

-

-                BSONType groupType = groupField.type();

-

-                if (groupType == Object) {

-                    /*

-                      Use the projection-like set of field paths to create the

-                      group-by key.

-                    */

-                    Expression::ObjectCtx oCtx(

-                        Expression::ObjectCtx::DOCUMENT_OK);

-                    intrusive_ptr<Expression> pId(

-                        Expression::parseObject(&groupField, &oCtx));

-

-                    pGroup->setIdExpression(pId);

-                    idSet = true;

-                }

-                else if (groupType == String) {

-                    string groupString(groupField.String());

-                    const char *pGroupString = groupString.c_str();

-                    if ((groupString.length() == 0) ||

-                        (pGroupString[0] != '$'))

-                        goto StringConstantId;

-

-                    string pathString(

-                        Expression::removeFieldPrefix(groupString));

-                    intrusive_ptr<ExpressionFieldPath> pFieldPath(

-                        ExpressionFieldPath::create(pathString));

-                    pGroup->setIdExpression(pFieldPath);

-                    idSet = true;

-                }

-                else {

-                    /* pick out the constant types that are allowed */

-                    switch(groupType) {

-                    case NumberDouble:

-                    case String:

-                    case Object:

-                    case Array:

-                    case jstOID:

-                    case Bool:

-                    case Date:

-                    case NumberInt:

-                    case Timestamp:

-                    case NumberLong:

-                    case jstNULL:

-                    StringConstantId: // from string case above

-                    {

-                        intrusive_ptr<const Value> pValue(

-                            Value::createFromBsonElement(&groupField));

-                        intrusive_ptr<ExpressionConstant> pConstant(

-                            ExpressionConstant::create(pValue));

-                        pGroup->setIdExpression(pConstant);

-                        idSet = true;

-                        break;

-                    }

-

-                    default:

-                        uassert(15949, str::stream() <<

-                                "a group's _id may not include fields of BSON type " << groupType,

-                                false);

-                    }

-                }

-            }

-            else {

-                /*

-                  Treat as a projection field with the additional ability to

-                  add aggregation operators.

-                */

-                uassert(15950, str::stream() <<

-                        "the group aggregate field name \"" <<

-                        pFieldName << "\" cannot be an operator name",

-                        *pFieldName != '$');

-

-                uassert(15951, str::stream() <<

-                        "the group aggregate field \"" << pFieldName <<

-                        "\" must be defined as an expression inside an object",

-                        groupField.type() == Object);

-

-                BSONObj subField(groupField.Obj());

-                BSONObjIterator subIterator(subField);

-                size_t subCount = 0;

-                for(; subIterator.more(); ++subCount) {

-                    BSONElement subElement(subIterator.next());

-

-                    /* look for the specified operator */

-                    GroupOpDesc key;

-                    key.pName = subElement.fieldName();

-                    const GroupOpDesc *pOp =

-                        (const GroupOpDesc *)bsearch(

-                              &key, GroupOpTable, NGroupOp, sizeof(GroupOpDesc),

-                                      GroupOpDescCmp);

-

-                    uassert(15952, str::stream() <<

-                            "unknown group operator \"" <<

-                            key.pName << "\"",

-                            pOp);

-

-                    intrusive_ptr<Expression> pGroupExpr;

-

-                    BSONType elementType = subElement.type();

-                    if (elementType == Object) {

-                        Expression::ObjectCtx oCtx(

-                            Expression::ObjectCtx::DOCUMENT_OK);

-                        pGroupExpr = Expression::parseObject(

-                            &subElement, &oCtx);

-                    }

-                    else if (elementType == Array) {

-                        uassert(15953, str::stream() <<

-                                "aggregating group operators are unary (" <<

-                                key.pName << ")", false);

-                    }

-                    else { /* assume its an atomic single operand */

-                        pGroupExpr = Expression::parseOperand(&subElement);

-                    }

-

-                    pGroup->addAccumulator(

-                        pFieldName, pOp->pFactory, pGroupExpr);

-                }

-

-                uassert(15954, str::stream() <<

-                        "the computed aggregate \"" <<

-                        pFieldName << "\" must specify exactly one operator",

-                        subCount == 1);

-            }

-        }

-

-        uassert(15955, "a group specification must include an _id", idSet);

-

-        return pGroup;

-    }

-

-    void DocumentSourceGroup::populate() {

-        for(bool hasNext = !pSource->eof(); hasNext;

-                hasNext = pSource->advance()) {

-            intrusive_ptr<Document> pDocument(pSource->getCurrent());

-

-            /* get the _id document */

-            intrusive_ptr<const Value> pId(pIdExpression->evaluate(pDocument));

-

-            /* treat Undefined the same as NULL SERVER-4674 */

-            if (pId->getType() == Undefined)

-                pId = Value::getNull();

-

-            /*

-              Look for the _id value in the map; if it's not there, add a

-              new entry with a blank accumulator.

-            */

-            vector<intrusive_ptr<Accumulator> > *pGroup;

-            GroupsType::iterator it(groups.find(pId));

-            if (it != groups.end()) {

-                /* point at the existing accumulators */

-                pGroup = &it->second;

-            }

-            else {

-                /* insert a new group into the map */

-                groups.insert(it,

-                              pair<intrusive_ptr<const Value>,

-                              vector<intrusive_ptr<Accumulator> > >(

-                                  pId, vector<intrusive_ptr<Accumulator> >()));

-

-                /* find the accumulator vector (the map value) */

-                it = groups.find(pId);

-                pGroup = &it->second;

-

-                /* add the accumulators */

-                const size_t n = vpAccumulatorFactory.size();

-                pGroup->reserve(n);

-                for(size_t i = 0; i < n; ++i) {

-                    intrusive_ptr<Accumulator> pAccumulator(

-                        (*vpAccumulatorFactory[i])(pExpCtx));

-                    pAccumulator->addOperand(vpExpression[i]);

-                    pGroup->push_back(pAccumulator);

-                }

-            }

-

-            /* point at the existing key */

-            // unneeded atm // pId = it.first;

-

-            /* tickle all the accumulators for the group we found */

-            const size_t n = pGroup->size();

-            for(size_t i = 0; i < n; ++i)

-                (*pGroup)[i]->evaluate(pDocument);

-        }

-

-        /* start the group iterator */

-        groupsIterator = groups.begin();

-        if (groupsIterator != groups.end())

-            pCurrent = makeDocument(groupsIterator);

-        populated = true;

-    }

-

-    intrusive_ptr<Document> DocumentSourceGroup::makeDocument(

-        const GroupsType::iterator &rIter) {

-        vector<intrusive_ptr<Accumulator> > *pGroup = &rIter->second;

-        const size_t n = vFieldName.size();

-        intrusive_ptr<Document> pResult(Document::create(1 + n));

-

-        /* add the _id field */

-        pResult->addField(Document::idName, rIter->first);

-

-        /* add the rest of the fields */

-        for(size_t i = 0; i < n; ++i) {

-            intrusive_ptr<const Value> pValue((*pGroup)[i]->getValue());

-            if (pValue->getType() != Undefined)

-                pResult->addField(vFieldName[i], pValue);

-        }

-

-        return pResult;

-    }

-

-    intrusive_ptr<DocumentSource> DocumentSourceGroup::createMerger() {

-        intrusive_ptr<DocumentSourceGroup> pMerger(

-            DocumentSourceGroup::create(pExpCtx));

-

-        /* the merger will use the same grouping key */

-        pMerger->setIdExpression(ExpressionFieldPath::create(

-                                     Document::idName.c_str()));

-

-        const size_t n = vFieldName.size();

-        for(size_t i = 0; i < n; ++i) {

-            /*

-              The merger's output field names will be the same, as will the

-              accumulator factories.  However, for some accumulators, the

-              expression to be accumulated will be different.  The original

-              accumulator may be collecting an expression based on a field

-              expression or constant.  Here, we accumulate the output of the

-              same name from the prior group.

-            */

-            pMerger->addAccumulator(

-                vFieldName[i], vpAccumulatorFactory[i],

-                ExpressionFieldPath::create(vFieldName[i]));

-        }

-

-        return pMerger;

-    }

-}

+/**
+*    Copyright (C) 2011 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "pch.h"
+
+#include "db/pipeline/document_source.h"
+
+#include "db/jsobj.h"
+#include "db/pipeline/accumulator.h"
+#include "db/pipeline/document.h"
+#include "db/pipeline/expression.h"
+#include "db/pipeline/expression_context.h"
+#include "db/pipeline/value.h"
+
+namespace mongo {
+    const char DocumentSourceGroup::groupName[] = "$group";
+
+    DocumentSourceGroup::~DocumentSourceGroup() {
+    }
+
+    const char *DocumentSourceGroup::getSourceName() const {
+        return groupName;
+    }
+
+    bool DocumentSourceGroup::eof() {
+        if (!populated)
+            populate();
+
+        return (groupsIterator == groups.end());
+    }
+
+    bool DocumentSourceGroup::advance() {
+        DocumentSource::advance(); // check for interrupts
+
+        if (!populated)
+            populate();
+
+        verify(groupsIterator != groups.end());
+
+        ++groupsIterator;
+        if (groupsIterator == groups.end()) {
+            pCurrent.reset();
+            return false;
+        }
+
+        pCurrent = makeDocument(groupsIterator);
+        return true;
+    }
+
+    intrusive_ptr<Document> DocumentSourceGroup::getCurrent() {
+        if (!populated)
+            populate();
+
+        return pCurrent;
+    }
+
+    void DocumentSourceGroup::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+        BSONObjBuilder insides;
+
+        /* add the _id */
+        pIdExpression->addToBsonObj(&insides, Document::idName.c_str(), false);
+
+        /* add the remaining fields */
+        const size_t n = vFieldName.size();
+        for(size_t i = 0; i < n; ++i) {
+            intrusive_ptr<Accumulator> pA((*vpAccumulatorFactory[i])(pExpCtx));
+            pA->addOperand(vpExpression[i]);
+            pA->addToBsonObj(&insides, vFieldName[i], false);
+        }
+
+        pBuilder->append(groupName, insides.done());
+    }
+
+    intrusive_ptr<DocumentSourceGroup> DocumentSourceGroup::create(
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        intrusive_ptr<DocumentSourceGroup> pSource(
+            new DocumentSourceGroup(pExpCtx));
+        return pSource;
+    }
+
+    DocumentSourceGroup::DocumentSourceGroup(
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSource(pExpCtx),
+        populated(false),
+        pIdExpression(),
+        groups(),
+        vFieldName(),
+        vpAccumulatorFactory(),
+        vpExpression() {
+    }
+
+    void DocumentSourceGroup::addAccumulator(
+        string fieldName,
+        intrusive_ptr<Accumulator> (*pAccumulatorFactory)(
+            const intrusive_ptr<ExpressionContext> &),
+        const intrusive_ptr<Expression> &pExpression) {
+        vFieldName.push_back(fieldName);
+        vpAccumulatorFactory.push_back(pAccumulatorFactory);
+        vpExpression.push_back(pExpression);
+    }
+
+
+    struct GroupOpDesc {
+        const char *pName;
+        intrusive_ptr<Accumulator> (*pFactory)(
+            const intrusive_ptr<ExpressionContext> &);
+    };
+
+    static int GroupOpDescCmp(const void *pL, const void *pR) {
+        return strcmp(((const GroupOpDesc *)pL)->pName,
+                      ((const GroupOpDesc *)pR)->pName);
+    }
+
+    /*
+      Keep these sorted alphabetically so we can bsearch() them using
+      GroupOpDescCmp() above.
+    */
+    static const GroupOpDesc GroupOpTable[] = {
+        {"$addToSet", AccumulatorAddToSet::create},
+        {"$avg", AccumulatorAvg::create},
+        {"$first", AccumulatorFirst::create},
+        {"$last", AccumulatorLast::create},
+        {"$max", AccumulatorMinMax::createMax},
+        {"$min", AccumulatorMinMax::createMin},
+        {"$push", AccumulatorPush::create},
+        {"$sum", AccumulatorSum::create},
+    };
+
+    static const size_t NGroupOp = sizeof(GroupOpTable)/sizeof(GroupOpTable[0]);
+
+    intrusive_ptr<DocumentSource> DocumentSourceGroup::createFromBson(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        uassert(15947, "a group's fields must be specified in an object",
+                pBsonElement->type() == Object);
+
+        intrusive_ptr<DocumentSourceGroup> pGroup(
+            DocumentSourceGroup::create(pExpCtx));
+        bool idSet = false;
+
+        BSONObj groupObj(pBsonElement->Obj());
+        BSONObjIterator groupIterator(groupObj);
+        while(groupIterator.more()) {
+            BSONElement groupField(groupIterator.next());
+            const char *pFieldName = groupField.fieldName();
+
+            if (strcmp(pFieldName, Document::idName.c_str()) == 0) {
+                uassert(15948, "a group's _id may only be specified once",
+                        !idSet);
+
+                BSONType groupType = groupField.type();
+
+                if (groupType == Object) {
+                    /*
+                      Use the projection-like set of field paths to create the
+                      group-by key.
+                    */
+                    Expression::ObjectCtx oCtx(
+                        Expression::ObjectCtx::DOCUMENT_OK);
+                    intrusive_ptr<Expression> pId(
+                        Expression::parseObject(&groupField, &oCtx));
+
+                    pGroup->setIdExpression(pId);
+                    idSet = true;
+                }
+                else if (groupType == String) {
+                    string groupString(groupField.String());
+                    const char *pGroupString = groupString.c_str();
+                    if ((groupString.length() == 0) ||
+                        (pGroupString[0] != '$'))
+                        goto StringConstantId;
+
+                    string pathString(
+                        Expression::removeFieldPrefix(groupString));
+                    intrusive_ptr<ExpressionFieldPath> pFieldPath(
+                        ExpressionFieldPath::create(pathString));
+                    pGroup->setIdExpression(pFieldPath);
+                    idSet = true;
+                }
+                else {
+                    /* pick out the constant types that are allowed */
+                    switch(groupType) {
+                    case NumberDouble:
+                    case String:
+                    case Object:
+                    case Array:
+                    case jstOID:
+                    case Bool:
+                    case Date:
+                    case NumberInt:
+                    case Timestamp:
+                    case NumberLong:
+                    case jstNULL:
+                    StringConstantId: // from string case above
+                    {
+                        intrusive_ptr<const Value> pValue(
+                            Value::createFromBsonElement(&groupField));
+                        intrusive_ptr<ExpressionConstant> pConstant(
+                            ExpressionConstant::create(pValue));
+                        pGroup->setIdExpression(pConstant);
+                        idSet = true;
+                        break;
+                    }
+
+                    default:
+                        uassert(15949, str::stream() <<
+                                "a group's _id may not include fields of BSON type " << groupType,
+                                false);
+                    }
+                }
+            }
+            else {
+                /*
+                  Treat as a projection field with the additional ability to
+                  add aggregation operators.
+                */
+                uassert(15950, str::stream() <<
+                        "the group aggregate field name \"" <<
+                        pFieldName << "\" cannot be an operator name",
+                        *pFieldName != '$');
+
+                uassert(15951, str::stream() <<
+                        "the group aggregate field \"" << pFieldName <<
+                        "\" must be defined as an expression inside an object",
+                        groupField.type() == Object);
+
+                BSONObj subField(groupField.Obj());
+                BSONObjIterator subIterator(subField);
+                size_t subCount = 0;
+                for(; subIterator.more(); ++subCount) {
+                    BSONElement subElement(subIterator.next());
+
+                    /* look for the specified operator */
+                    GroupOpDesc key;
+                    key.pName = subElement.fieldName();
+                    const GroupOpDesc *pOp =
+                        (const GroupOpDesc *)bsearch(
+                              &key, GroupOpTable, NGroupOp, sizeof(GroupOpDesc),
+                                      GroupOpDescCmp);
+
+                    uassert(15952, str::stream() <<
+                            "unknown group operator \"" <<
+                            key.pName << "\"",
+                            pOp);
+
+                    intrusive_ptr<Expression> pGroupExpr;
+
+                    BSONType elementType = subElement.type();
+                    if (elementType == Object) {
+                        Expression::ObjectCtx oCtx(
+                            Expression::ObjectCtx::DOCUMENT_OK);
+                        pGroupExpr = Expression::parseObject(
+                            &subElement, &oCtx);
+                    }
+                    else if (elementType == Array) {
+                        uassert(15953, str::stream() <<
+                                "aggregating group operators are unary (" <<
+                                key.pName << ")", false);
+                    }
+                    else { /* assume its an atomic single operand */
+                        pGroupExpr = Expression::parseOperand(&subElement);
+                    }
+
+                    pGroup->addAccumulator(
+                        pFieldName, pOp->pFactory, pGroupExpr);
+                }
+
+                uassert(15954, str::stream() <<
+                        "the computed aggregate \"" <<
+                        pFieldName << "\" must specify exactly one operator",
+                        subCount == 1);
+            }
+        }
+
+        uassert(15955, "a group specification must include an _id", idSet);
+
+        return pGroup;
+    }
+
+    void DocumentSourceGroup::populate() {
+        for(bool hasNext = !pSource->eof(); hasNext;
+                hasNext = pSource->advance()) {
+            intrusive_ptr<Document> pDocument(pSource->getCurrent());
+
+            /* get the _id document */
+            intrusive_ptr<const Value> pId(pIdExpression->evaluate(pDocument));
+
+            /* treat Undefined the same as NULL SERVER-4674 */
+            if (pId->getType() == Undefined)
+                pId = Value::getNull();
+
+            /*
+              Look for the _id value in the map; if it's not there, add a
+              new entry with a blank accumulator.
+            */
+            vector<intrusive_ptr<Accumulator> > *pGroup;
+            GroupsType::iterator it(groups.find(pId));
+            if (it != groups.end()) {
+                /* point at the existing accumulators */
+                pGroup = &it->second;
+            }
+            else {
+                /* insert a new group into the map */
+                groups.insert(it,
+                              pair<intrusive_ptr<const Value>,
+                              vector<intrusive_ptr<Accumulator> > >(
+                                  pId, vector<intrusive_ptr<Accumulator> >()));
+
+                /* find the accumulator vector (the map value) */
+                it = groups.find(pId);
+                pGroup = &it->second;
+
+                /* add the accumulators */
+                const size_t n = vpAccumulatorFactory.size();
+                pGroup->reserve(n);
+                for(size_t i = 0; i < n; ++i) {
+                    intrusive_ptr<Accumulator> pAccumulator(
+                        (*vpAccumulatorFactory[i])(pExpCtx));
+                    pAccumulator->addOperand(vpExpression[i]);
+                    pGroup->push_back(pAccumulator);
+                }
+            }
+
+            /* point at the existing key */
+            // unneeded atm // pId = it.first;
+
+            /* tickle all the accumulators for the group we found */
+            const size_t n = pGroup->size();
+            for(size_t i = 0; i < n; ++i)
+                (*pGroup)[i]->evaluate(pDocument);
+        }
+
+        /* start the group iterator */
+        groupsIterator = groups.begin();
+        if (groupsIterator != groups.end())
+            pCurrent = makeDocument(groupsIterator);
+        populated = true;
+    }
+
+    intrusive_ptr<Document> DocumentSourceGroup::makeDocument(
+        const GroupsType::iterator &rIter) {
+        vector<intrusive_ptr<Accumulator> > *pGroup = &rIter->second;
+        const size_t n = vFieldName.size();
+        intrusive_ptr<Document> pResult(Document::create(1 + n));
+
+        /* add the _id field */
+        pResult->addField(Document::idName, rIter->first);
+
+        /* add the rest of the fields */
+        for(size_t i = 0; i < n; ++i) {
+            intrusive_ptr<const Value> pValue((*pGroup)[i]->getValue());
+            if (pValue->getType() != Undefined)
+                pResult->addField(vFieldName[i], pValue);
+        }
+
+        return pResult;
+    }
+
+    intrusive_ptr<DocumentSource> DocumentSourceGroup::createMerger() {
+        intrusive_ptr<DocumentSourceGroup> pMerger(
+            DocumentSourceGroup::create(pExpCtx));
+
+        /* the merger will use the same grouping key */
+        pMerger->setIdExpression(ExpressionFieldPath::create(
+                                     Document::idName.c_str()));
+
+        const size_t n = vFieldName.size();
+        for(size_t i = 0; i < n; ++i) {
+            /*
+              The merger's output field names will be the same, as will the
+              accumulator factories.  However, for some accumulators, the
+              expression to be accumulated will be different.  The original
+              accumulator may be collecting an expression based on a field
+              expression or constant.  Here, we accumulate the output of the
+              same name from the prior group.
+            */
+            pMerger->addAccumulator(
+                vFieldName[i], vpAccumulatorFactory[i],
+                ExpressionFieldPath::create(vFieldName[i]));
+        }
+
+        return pMerger;
+    }
+}
diff --git a/src/mongo/db/pipeline/document_source_match.cpp b/src/mongo/db/pipeline/document_source_match.cpp
index 0141e5fc7b4..3ae327d6102 100755
--- a/src/mongo/db/pipeline/document_source_match.cpp
+++ b/src/mongo/db/pipeline/document_source_match.cpp
@@ -1,94 +1,94 @@
-/**

-*    Copyright (C) 2011 10gen Inc.

-*

-*    This program is free software: you can redistribute it and/or  modify

-*    it under the terms of the GNU Affero General Public License, version 3,

-*    as published by the Free Software Foundation.

-*

-*    This program is distributed in the hope that it will be useful,

-*    but WITHOUT ANY WARRANTY; without even the implied warranty of

-*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

-*    GNU Affero General Public License for more details.

-*

-*    You should have received a copy of the GNU Affero General Public License

-*    along with this program.  If not, see <http://www.gnu.org/licenses/>.

-*/

-

-#include "pch.h"

-

-#include "db/pipeline/document_source.h"

-

-#include "db/jsobj.h"

-#include "db/matcher.h"

-#include "db/pipeline/document.h"

-#include "db/pipeline/expression.h"

-

-namespace mongo {

-

-    const char DocumentSourceMatch::matchName[] = "$match";

-

-    DocumentSourceMatch::~DocumentSourceMatch() {

-    }

-

-    const char *DocumentSourceMatch::getSourceName() const {

-        return matchName;

-    }

-

-    void DocumentSourceMatch::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-        const BSONObj *pQuery = matcher.getQuery();

-        pBuilder->append(matchName, *pQuery);

-    }

-

-    bool DocumentSourceMatch::accept(

-        const intrusive_ptr<Document> &pDocument) const {

-

-        /*

-          The matcher only takes BSON documents, so we have to make one.

-

-          LATER

-          We could optimize this by making a document with only the

-          fields referenced by the Matcher.  We could do this by looking inside

-          the Matcher's BSON before it is created, and recording those.  The

-          easiest implementation might be to hold onto an ExpressionDocument

-          in here, and give that pDocument to create the created subset of

-          fields, and then convert that instead.

-        */

-        BSONObjBuilder objBuilder;

-        pDocument->toBson(&objBuilder);

-        BSONObj obj(objBuilder.done());

-

-        return matcher.matches(obj);

-    }

-

-    intrusive_ptr<DocumentSource> DocumentSourceMatch::createFromBson(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        uassert(15959, "the match filter must be an expression in an object",

-                pBsonElement->type() == Object);

-

-        intrusive_ptr<DocumentSourceMatch> pMatcher(

-            new DocumentSourceMatch(pBsonElement->Obj(), pExpCtx));

-

-        return pMatcher;

-    }

-

-    void DocumentSourceMatch::toMatcherBson(BSONObjBuilder *pBuilder) const {

-        const BSONObj *pQuery = matcher.getQuery();

-        pBuilder->appendElements(*pQuery);

-    }

-

-    DocumentSourceMatch::DocumentSourceMatch(

-        const BSONObj &query,

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSourceFilterBase(pExpCtx),

-        matcher(query) {

-    }

-

-    void DocumentSourceMatch::manageDependencies(

-        const intrusive_ptr<DependencyTracker> &pTracker) {

-#ifdef MONGO_LATER_SERVER_4644

-        verify(false); // $$$ implement dependencies on Matcher

-#endif /* MONGO_LATER_SERVER_4644 */

-    }

-}

+/**
+*    Copyright (C) 2011 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "pch.h"
+
+#include "db/pipeline/document_source.h"
+
+#include "db/jsobj.h"
+#include "db/matcher.h"
+#include "db/pipeline/document.h"
+#include "db/pipeline/expression.h"
+
+namespace mongo {
+
+    const char DocumentSourceMatch::matchName[] = "$match";
+
+    DocumentSourceMatch::~DocumentSourceMatch() {
+    }
+
+    const char *DocumentSourceMatch::getSourceName() const {
+        return matchName;
+    }
+
+    void DocumentSourceMatch::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+        const BSONObj *pQuery = matcher.getQuery();
+        pBuilder->append(matchName, *pQuery);
+    }
+
+    bool DocumentSourceMatch::accept(
+        const intrusive_ptr<Document> &pDocument) const {
+
+        /*
+          The matcher only takes BSON documents, so we have to make one.
+
+          LATER
+          We could optimize this by making a document with only the
+          fields referenced by the Matcher.  We could do this by looking inside
+          the Matcher's BSON before it is created, and recording those.  The
+          easiest implementation might be to hold onto an ExpressionDocument
+          in here, and give that pDocument to create the created subset of
+          fields, and then convert that instead.
+        */
+        BSONObjBuilder objBuilder;
+        pDocument->toBson(&objBuilder);
+        BSONObj obj(objBuilder.done());
+
+        return matcher.matches(obj);
+    }
+
+    intrusive_ptr<DocumentSource> DocumentSourceMatch::createFromBson(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        uassert(15959, "the match filter must be an expression in an object",
+                pBsonElement->type() == Object);
+
+        intrusive_ptr<DocumentSourceMatch> pMatcher(
+            new DocumentSourceMatch(pBsonElement->Obj(), pExpCtx));
+
+        return pMatcher;
+    }
+
+    void DocumentSourceMatch::toMatcherBson(BSONObjBuilder *pBuilder) const {
+        const BSONObj *pQuery = matcher.getQuery();
+        pBuilder->appendElements(*pQuery);
+    }
+
+    DocumentSourceMatch::DocumentSourceMatch(
+        const BSONObj &query,
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSourceFilterBase(pExpCtx),
+        matcher(query) {
+    }
+
+    void DocumentSourceMatch::manageDependencies(
+        const intrusive_ptr<DependencyTracker> &pTracker) {
+#ifdef MONGO_LATER_SERVER_4644
+        verify(false); // $$$ implement dependencies on Matcher
+#endif /* MONGO_LATER_SERVER_4644 */
+    }
+}
diff --git a/src/mongo/db/pipeline/document_source_out.cpp b/src/mongo/db/pipeline/document_source_out.cpp
index d62b830cab0..c19e066efe6 100755
--- a/src/mongo/db/pipeline/document_source_out.cpp
+++ b/src/mongo/db/pipeline/document_source_out.cpp
@@ -1,67 +1,67 @@
-/**

- * Copyright 2011 (c) 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-

-#include "db/pipeline/document_source.h"

-

-

-namespace mongo {

-

-    const char DocumentSourceOut::outName[] = "$out";

-

-    DocumentSourceOut::~DocumentSourceOut() {

-    }

-

-    const char *DocumentSourceOut::getSourceName() const {

-        return outName;

-    }

-

-    bool DocumentSourceOut::eof() {

-        return pSource->eof();

-    }

-

-    bool DocumentSourceOut::advance() {

-        DocumentSource::advance(); // check for interrupts

-

-        return pSource->advance();

-    }

-

-    boost::intrusive_ptr<Document> DocumentSourceOut::getCurrent() {

-        return pSource->getCurrent();

-    }

-

-    DocumentSourceOut::DocumentSourceOut(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSource(pExpCtx) {

-        verify(false && "unimplemented");

-    }

-

-    intrusive_ptr<DocumentSourceOut> DocumentSourceOut::createFromBson(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        intrusive_ptr<DocumentSourceOut> pSource(

-            new DocumentSourceOut(pBsonElement, pExpCtx));

-

-        return pSource;

-    }

-

-    void DocumentSourceOut::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-        verify(false); // CW TODO

-    }

-}

+/**
+ * Copyright 2011 (c) 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+
+#include "db/pipeline/document_source.h"
+
+
+namespace mongo {
+
+    const char DocumentSourceOut::outName[] = "$out";
+
+    DocumentSourceOut::~DocumentSourceOut() {
+    }
+
+    const char *DocumentSourceOut::getSourceName() const {
+        return outName;
+    }
+
+    bool DocumentSourceOut::eof() {
+        return pSource->eof();
+    }
+
+    bool DocumentSourceOut::advance() {
+        DocumentSource::advance(); // check for interrupts
+
+        return pSource->advance();
+    }
+
+    boost::intrusive_ptr<Document> DocumentSourceOut::getCurrent() {
+        return pSource->getCurrent();
+    }
+
+    DocumentSourceOut::DocumentSourceOut(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSource(pExpCtx) {
+        verify(false && "unimplemented");
+    }
+
+    intrusive_ptr<DocumentSourceOut> DocumentSourceOut::createFromBson(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        intrusive_ptr<DocumentSourceOut> pSource(
+            new DocumentSourceOut(pBsonElement, pExpCtx));
+
+        return pSource;
+    }
+
+    void DocumentSourceOut::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+        verify(false); // CW TODO
+    }
+}
diff --git a/src/mongo/db/pipeline/document_source_project.cpp b/src/mongo/db/pipeline/document_source_project.cpp
index dc841931dee..c42c3eec683 100755
--- a/src/mongo/db/pipeline/document_source_project.cpp
+++ b/src/mongo/db/pipeline/document_source_project.cpp
@@ -1,289 +1,289 @@
-/**

- * Copyright 2011 (c) 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "db/pipeline/document_source.h"

-

-#include "db/jsobj.h"

-#include "db/pipeline/document.h"

-#include "db/pipeline/expression.h"

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    const char DocumentSourceProject::projectName[] = "$project";

-

-    DocumentSourceProject::~DocumentSourceProject() {

-    }

-

-    DocumentSourceProject::DocumentSourceProject(

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSource(pExpCtx),

-        excludeId(false),

-        pEO(ExpressionObject::create()) {

-    }

-

-    const char *DocumentSourceProject::getSourceName() const {

-        return projectName;

-    }

-

-    bool DocumentSourceProject::eof() {

-        return pSource->eof();

-    }

-

-    bool DocumentSourceProject::advance() {

-        DocumentSource::advance(); // check for interrupts

-

-        return pSource->advance();

-    }

-

-    intrusive_ptr<Document> DocumentSourceProject::getCurrent() {

-        intrusive_ptr<Document> pInDocument(pSource->getCurrent());

-

-        /* create the result document */

-        const size_t sizeHint =

-            pEO->getSizeHint(pInDocument) + (excludeId ? 0 : 1);

-        intrusive_ptr<Document> pResultDocument(Document::create(sizeHint));

-

-        if (!excludeId) {

-            intrusive_ptr<const Value> pId(

-                pInDocument->getField(Document::idName));

-

-            /*

-              Previous projections could have removed _id, (or declined to

-              generate it) so it might already not exist.  Only attempt to add

-              if we found it.

-            */

-            if (pId.get())

-                pResultDocument->addField(Document::idName, pId);

-        }

-

-        /*

-          Use the ExpressionObject to create the base result.

-

-          If we're excluding fields at the top level, leave out the _id if

-          it is found, because we took care of it above.

-        */

-        pEO->addToDocument(pResultDocument, pInDocument, true);

-

-        return pResultDocument;

-    }

-

-    void DocumentSourceProject::optimize() {

-        intrusive_ptr<Expression> pE(pEO->optimize());

-        pEO = dynamic_pointer_cast<ExpressionObject>(pE);

-    }

-

-    void DocumentSourceProject::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-        BSONObjBuilder insides;

-        if (excludeId)

-            insides.append(Document::idName, false);

-        pEO->documentToBson(&insides, true);

-        pBuilder->append(projectName, insides.done());

-    }

-

-    intrusive_ptr<DocumentSourceProject> DocumentSourceProject::create(

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        intrusive_ptr<DocumentSourceProject> pSource(

-            new DocumentSourceProject(pExpCtx));

-        return pSource;

-    }

-

-    void DocumentSourceProject::addField(

-        const string &fieldName, const intrusive_ptr<Expression> &pExpression) {

-        uassert(15960,

-                "projection fields must be defined by non-empty expressions",

-                pExpression);

-

-        pEO->addField(fieldName, pExpression);

-    }

-

-    void DocumentSourceProject::includePath(const string &fieldPath) {

-        if (Document::idName.compare(fieldPath) == 0) {

-            uassert(15961, str::stream() << projectName <<

-                    ":  _id cannot be included once it has been excluded",

-                    !excludeId);

-

-            return;

-        }

-

-        pEO->includePath(fieldPath);

-    }

-

-    void DocumentSourceProject::excludePath(const string &fieldPath) {

-        if (Document::idName.compare(fieldPath) == 0) {

-            excludeId = true;

-            return;

-        }

-

-        pEO->excludePath(fieldPath);

-    }

-

-    intrusive_ptr<DocumentSource> DocumentSourceProject::createFromBson(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        /* validate */

-        uassert(15969, str::stream() << projectName <<

-                " specification must be an object",

-                pBsonElement->type() == Object);

-

-        /* chain the projection onto the original source */

-        intrusive_ptr<DocumentSourceProject> pProject(

-            DocumentSourceProject::create(pExpCtx));

-

-        /*

-          Pull out the $project object.  This should just be a list of

-          field inclusion or exclusion specifications.  Note you can't do

-          both, except for the case of _id.

-         */

-        BSONObj projectObj(pBsonElement->Obj());

-        BSONObjIterator fieldIterator(projectObj);

-        Expression::ObjectCtx objectCtx(

-            Expression::ObjectCtx::DOCUMENT_OK);

-        while(fieldIterator.more()) {

-            BSONElement outFieldElement(fieldIterator.next());

-            string outFieldPath(outFieldElement.fieldName());

-            string inFieldName(outFieldPath);

-            BSONType specType = outFieldElement.type();

-            int fieldInclusion = -1;

-

-            switch(specType) {

-            case NumberDouble: {

-                double inclusion = outFieldElement.numberDouble();

-                fieldInclusion = static_cast<int>(inclusion);

-                goto IncludeExclude;

-            }

-

-            case NumberLong: {

-                long long inclusion = outFieldElement.numberLong();

-                fieldInclusion = static_cast<int>(inclusion);

-                goto IncludeExclude;

-            }

-

-            case NumberInt:

-                /* just a plain integer include/exclude specification */

-                fieldInclusion = outFieldElement.numberInt();

-

-IncludeExclude:

-                uassert(15970, str::stream() <<

-                        "field inclusion or exclusion specification for \"" <<

-                        outFieldPath <<

-                        "\" must be true, 1, false, or zero",

-                        ((fieldInclusion == 0) || (fieldInclusion == 1)));

-

-                if (fieldInclusion == 0)

-                    pProject->excludePath(outFieldPath);

-                else 

-                    pProject->includePath(outFieldPath);

-                break;

-

-            case Bool:

-                /* just a plain boolean include/exclude specification */

-                fieldInclusion = (outFieldElement.Bool() ? 1 : 0);

-                goto IncludeExclude;

-

-            case String:

-                /* include a field, with rename */

-                fieldInclusion = 1;

-                inFieldName = outFieldElement.String();

-                pProject->addField(

-                    outFieldPath,

-                    ExpressionFieldPath::create(

-                        Expression::removeFieldPrefix(inFieldName)));

-                break;

-

-            case Object: {

-                intrusive_ptr<Expression> pDocument(

-                    Expression::parseObject(&outFieldElement, &objectCtx));

-

-                /* add The document expression to the projection */

-                pProject->addField(outFieldPath, pDocument);

-                break;

-            }

-

-            default:

-                uassert(15971, str::stream() <<

-                        "invalid BSON type (" << specType <<

-                        ") for " << projectName <<

-                        " field " << outFieldPath, false);

-            }

-

-        }

-

-        return pProject;

-    }

-

-    void DocumentSourceProject::DependencyRemover::path(

-        const string &path, bool include) {

-        if (include)

-            pTracker->removeDependency(path);

-    }

-

-    void DocumentSourceProject::DependencyChecker::path(

-        const string &path, bool include) {

-        /* if the specified path is included, there's nothing to check */

-        if (include)

-            return;

-

-        /* if the specified path is excluded, see if it is required */

-        intrusive_ptr<const DocumentSource> pSource;

-        if (pTracker->getDependency(&pSource, path)) {

-            uassert(15984, str::stream() <<

-                    "unable to satisfy dependency on " <<

-                    FieldPath::getPrefix() <<

-                    path << " in pipeline step " <<

-                    pSource->getPipelineStep() <<

-                    " (" << pSource->getSourceName() << "), because step " <<

-                    pThis->getPipelineStep() << " ("

-                    << pThis->getSourceName() << ") excludes it",

-                    false); // printf() is way easier to read than this crap

-        }

-    }

-

-    void DocumentSourceProject::manageDependencies(

-        const intrusive_ptr<DependencyTracker> &pTracker) {

-        /*

-          Look at all the products (inclusions and computed fields) of this

-          projection.  For each one that is a dependency, remove it from the

-          list of dependencies, because this product will satisfy that

-          dependency.

-         */

-        DependencyRemover dependencyRemover(pTracker);

-        pEO->emitPaths(&dependencyRemover);

-

-        /*

-          Look at the exclusions of this projection.  If any of them are

-          dependencies, inform the user (error/usassert) that the dependency

-          can't be satisfied.

-

-          Note we need to do this after the product examination above because

-          it is possible for there to be an exclusion field name that matches

-          a new computed product field name.  The latter would satisfy the

-          dependency.

-         */

-        DependencyChecker dependencyChecker(pTracker, this);

-        pEO->emitPaths(&dependencyChecker);

-

-        /*

-          Look at the products of this projection.  For inclusions, add the

-          field names to the list of dependencies.  For computed expressions,

-          add their dependencies to the list of dependencies.

-         */

-        pEO->addDependencies(pTracker, this);

-    }

-

-}

+/**
+ * Copyright 2011 (c) 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "db/pipeline/document_source.h"
+
+#include "db/jsobj.h"
+#include "db/pipeline/document.h"
+#include "db/pipeline/expression.h"
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    const char DocumentSourceProject::projectName[] = "$project";
+
+    DocumentSourceProject::~DocumentSourceProject() {
+    }
+
+    DocumentSourceProject::DocumentSourceProject(
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSource(pExpCtx),
+        excludeId(false),
+        pEO(ExpressionObject::create()) {
+    }
+
+    const char *DocumentSourceProject::getSourceName() const {
+        return projectName;
+    }
+
+    bool DocumentSourceProject::eof() {
+        return pSource->eof();
+    }
+
+    bool DocumentSourceProject::advance() {
+        DocumentSource::advance(); // check for interrupts
+
+        return pSource->advance();
+    }
+
+    intrusive_ptr<Document> DocumentSourceProject::getCurrent() {
+        intrusive_ptr<Document> pInDocument(pSource->getCurrent());
+
+        /* create the result document */
+        const size_t sizeHint =
+            pEO->getSizeHint(pInDocument) + (excludeId ? 0 : 1);
+        intrusive_ptr<Document> pResultDocument(Document::create(sizeHint));
+
+        if (!excludeId) {
+            intrusive_ptr<const Value> pId(
+                pInDocument->getField(Document::idName));
+
+            /*
+              Previous projections could have removed _id, (or declined to
+              generate it) so it might already not exist.  Only attempt to add
+              if we found it.
+            */
+            if (pId.get())
+                pResultDocument->addField(Document::idName, pId);
+        }
+
+        /*
+          Use the ExpressionObject to create the base result.
+
+          If we're excluding fields at the top level, leave out the _id if
+          it is found, because we took care of it above.
+        */
+        pEO->addToDocument(pResultDocument, pInDocument, true);
+
+        return pResultDocument;
+    }
+
+    void DocumentSourceProject::optimize() {
+        intrusive_ptr<Expression> pE(pEO->optimize());
+        pEO = dynamic_pointer_cast<ExpressionObject>(pE);
+    }
+
+    void DocumentSourceProject::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+        BSONObjBuilder insides;
+        if (excludeId)
+            insides.append(Document::idName, false);
+        pEO->documentToBson(&insides, true);
+        pBuilder->append(projectName, insides.done());
+    }
+
+    intrusive_ptr<DocumentSourceProject> DocumentSourceProject::create(
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        intrusive_ptr<DocumentSourceProject> pSource(
+            new DocumentSourceProject(pExpCtx));
+        return pSource;
+    }
+
+    void DocumentSourceProject::addField(
+        const string &fieldName, const intrusive_ptr<Expression> &pExpression) {
+        uassert(15960,
+                "projection fields must be defined by non-empty expressions",
+                pExpression);
+
+        pEO->addField(fieldName, pExpression);
+    }
+
+    void DocumentSourceProject::includePath(const string &fieldPath) {
+        if (Document::idName.compare(fieldPath) == 0) {
+            uassert(15961, str::stream() << projectName <<
+                    ":  _id cannot be included once it has been excluded",
+                    !excludeId);
+
+            return;
+        }
+
+        pEO->includePath(fieldPath);
+    }
+
+    void DocumentSourceProject::excludePath(const string &fieldPath) {
+        if (Document::idName.compare(fieldPath) == 0) {
+            excludeId = true;
+            return;
+        }
+
+        pEO->excludePath(fieldPath);
+    }
+
+    intrusive_ptr<DocumentSource> DocumentSourceProject::createFromBson(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        /* validate */
+        uassert(15969, str::stream() << projectName <<
+                " specification must be an object",
+                pBsonElement->type() == Object);
+
+        /* chain the projection onto the original source */
+        intrusive_ptr<DocumentSourceProject> pProject(
+            DocumentSourceProject::create(pExpCtx));
+
+        /*
+          Pull out the $project object.  This should just be a list of
+          field inclusion or exclusion specifications.  Note you can't do
+          both, except for the case of _id.
+         */
+        BSONObj projectObj(pBsonElement->Obj());
+        BSONObjIterator fieldIterator(projectObj);
+        Expression::ObjectCtx objectCtx(
+            Expression::ObjectCtx::DOCUMENT_OK);
+        while(fieldIterator.more()) {
+            BSONElement outFieldElement(fieldIterator.next());
+            string outFieldPath(outFieldElement.fieldName());
+            string inFieldName(outFieldPath);
+            BSONType specType = outFieldElement.type();
+            int fieldInclusion = -1;
+
+            switch(specType) {
+            case NumberDouble: {
+                double inclusion = outFieldElement.numberDouble();
+                fieldInclusion = static_cast<int>(inclusion);
+                goto IncludeExclude;
+            }
+
+            case NumberLong: {
+                long long inclusion = outFieldElement.numberLong();
+                fieldInclusion = static_cast<int>(inclusion);
+                goto IncludeExclude;
+            }
+
+            case NumberInt:
+                /* just a plain integer include/exclude specification */
+                fieldInclusion = outFieldElement.numberInt();
+
+IncludeExclude:
+                uassert(15970, str::stream() <<
+                        "field inclusion or exclusion specification for \"" <<
+                        outFieldPath <<
+                        "\" must be true, 1, false, or zero",
+                        ((fieldInclusion == 0) || (fieldInclusion == 1)));
+
+                if (fieldInclusion == 0)
+                    pProject->excludePath(outFieldPath);
+                else 
+                    pProject->includePath(outFieldPath);
+                break;
+
+            case Bool:
+                /* just a plain boolean include/exclude specification */
+                fieldInclusion = (outFieldElement.Bool() ? 1 : 0);
+                goto IncludeExclude;
+
+            case String:
+                /* include a field, with rename */
+                fieldInclusion = 1;
+                inFieldName = outFieldElement.String();
+                pProject->addField(
+                    outFieldPath,
+                    ExpressionFieldPath::create(
+                        Expression::removeFieldPrefix(inFieldName)));
+                break;
+
+            case Object: {
+                intrusive_ptr<Expression> pDocument(
+                    Expression::parseObject(&outFieldElement, &objectCtx));
+
+                /* add The document expression to the projection */
+                pProject->addField(outFieldPath, pDocument);
+                break;
+            }
+
+            default:
+                uassert(15971, str::stream() <<
+                        "invalid BSON type (" << specType <<
+                        ") for " << projectName <<
+                        " field " << outFieldPath, false);
+            }
+
+        }
+
+        return pProject;
+    }
+
+    void DocumentSourceProject::DependencyRemover::path(
+        const string &path, bool include) {
+        if (include)
+            pTracker->removeDependency(path);
+    }
+
+    void DocumentSourceProject::DependencyChecker::path(
+        const string &path, bool include) {
+        /* if the specified path is included, there's nothing to check */
+        if (include)
+            return;
+
+        /* if the specified path is excluded, see if it is required */
+        intrusive_ptr<const DocumentSource> pSource;
+        if (pTracker->getDependency(&pSource, path)) {
+            uassert(15984, str::stream() <<
+                    "unable to satisfy dependency on " <<
+                    FieldPath::getPrefix() <<
+                    path << " in pipeline step " <<
+                    pSource->getPipelineStep() <<
+                    " (" << pSource->getSourceName() << "), because step " <<
+                    pThis->getPipelineStep() << " ("
+                    << pThis->getSourceName() << ") excludes it",
+                    false); // printf() is way easier to read than this crap
+        }
+    }
+
+    void DocumentSourceProject::manageDependencies(
+        const intrusive_ptr<DependencyTracker> &pTracker) {
+        /*
+          Look at all the products (inclusions and computed fields) of this
+          projection.  For each one that is a dependency, remove it from the
+          list of dependencies, because this product will satisfy that
+          dependency.
+         */
+        DependencyRemover dependencyRemover(pTracker);
+        pEO->emitPaths(&dependencyRemover);
+
+        /*
+          Look at the exclusions of this projection.  If any of them are
+          dependencies, inform the user (error/usassert) that the dependency
+          can't be satisfied.
+
+          Note we need to do this after the product examination above because
+          it is possible for there to be an exclusion field name that matches
+          a new computed product field name.  The latter would satisfy the
+          dependency.
+         */
+        DependencyChecker dependencyChecker(pTracker, this);
+        pEO->emitPaths(&dependencyChecker);
+
+        /*
+          Look at the products of this projection.  For inclusions, add the
+          field names to the list of dependencies.  For computed expressions,
+          add their dependencies to the list of dependencies.
+         */
+        pEO->addDependencies(pTracker, this);
+    }
+
+}
diff --git a/src/mongo/db/pipeline/document_source_sort.cpp b/src/mongo/db/pipeline/document_source_sort.cpp
index ebb39dbc1a2..77b9a15c181 100755
--- a/src/mongo/db/pipeline/document_source_sort.cpp
+++ b/src/mongo/db/pipeline/document_source_sort.cpp
@@ -1,226 +1,226 @@
-/**

-*    Copyright (C) 2011 10gen Inc.

-*

-*    This program is free software: you can redistribute it and/or  modify

-*    it under the terms of the GNU Affero General Public License, version 3,

-*    as published by the Free Software Foundation.

-*

-*    This program is distributed in the hope that it will be useful,

-*    but WITHOUT ANY WARRANTY; without even the implied warranty of

-*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

-*    GNU Affero General Public License for more details.

-*

-*    You should have received a copy of the GNU Affero General Public License

-*    along with this program.  If not, see <http://www.gnu.org/licenses/>.

-*/

-

-#include "pch.h"

-

-#include "db/pipeline/document_source.h"

-

-#include "db/jsobj.h"

-#include "db/pipeline/dependency_tracker.h"

-#include "db/pipeline/doc_mem_monitor.h"

-#include "db/pipeline/document.h"

-#include "db/pipeline/expression.h"

-#include "db/pipeline/expression_context.h"

-#include "db/pipeline/value.h"

-

-

-namespace mongo {

-    const char DocumentSourceSort::sortName[] = "$sort";

-

-    DocumentSourceSort::~DocumentSourceSort() {

-    }

-

-    const char *DocumentSourceSort::getSourceName() const {

-        return sortName;

-    }

-

-    bool DocumentSourceSort::eof() {

-        if (!populated)

-            populate();

-

-        return (docIterator == documents.end());

-    }

-

-    bool DocumentSourceSort::advance() {

-        DocumentSource::advance(); // check for interrupts

-

-        if (!populated)

-            populate();

-

-        verify(docIterator != documents.end());

-

-        ++docIterator;

-        if (docIterator == documents.end()) {

-            pCurrent.reset();

-            count = 0;

-            return false;

-        }

-        pCurrent = *docIterator;

-

-        return true;

-    }

-

-    intrusive_ptr<Document> DocumentSourceSort::getCurrent() {

-        if (!populated)

-            populate();

-

-        return pCurrent;

-    }

-

-    void DocumentSourceSort::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-        BSONObjBuilder insides;

-        sortKeyToBson(&insides, false);

-        pBuilder->append(sortName, insides.done());

-    }

-

-    intrusive_ptr<DocumentSourceSort> DocumentSourceSort::create(

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        intrusive_ptr<DocumentSourceSort> pSource(

-            new DocumentSourceSort(pExpCtx));

-        return pSource;

-    }

-

-    DocumentSourceSort::DocumentSourceSort(

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSource(pExpCtx),

-        populated(false) {

-    }

-

-    void DocumentSourceSort::addKey(const string &fieldPath, bool ascending) {

-        intrusive_ptr<ExpressionFieldPath> pE(

-            ExpressionFieldPath::create(fieldPath));

-        vSortKey.push_back(pE);

-        vAscending.push_back(ascending);

-    }

-

-    void DocumentSourceSort::sortKeyToBson(

-        BSONObjBuilder *pBuilder, bool usePrefix) const {

-        /* add the key fields */

-        const size_t n = vSortKey.size();

-        for(size_t i = 0; i < n; ++i) {

-            /* create the "field name" */

-            stringstream ss;

-            vSortKey[i]->writeFieldPath(ss, usePrefix);

-

-            /* append a named integer based on the sort order */

-            pBuilder->append(ss.str(), (vAscending[i] ? 1 : -1));

-        }

-    }

-

-    intrusive_ptr<DocumentSource> DocumentSourceSort::createFromBson(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        uassert(15973, str::stream() << " the " <<

-                sortName << " key specification must be an object",

-                pBsonElement->type() == Object);

-

-        intrusive_ptr<DocumentSourceSort> pSort(

-            DocumentSourceSort::create(pExpCtx));

-

-        /* check for then iterate over the sort object */

-        size_t sortKeys = 0;

-        for(BSONObjIterator keyIterator(pBsonElement->Obj().begin());

-            keyIterator.more();) {

-            BSONElement keyField(keyIterator.next());

-            const char *pKeyFieldName = keyField.fieldName();

-            int sortOrder = 0;

-                

-            uassert(15974, str::stream() << sortName <<

-                    " key ordering must be specified using a number",

-                    keyField.isNumber());

-            sortOrder = (int)keyField.numberInt();

-

-            uassert(15975,  str::stream() << sortName <<

-                    " key ordering must be 1 (for ascending) or -1 (for descending",

-                    ((sortOrder == 1) || (sortOrder == -1)));

-

-            pSort->addKey(pKeyFieldName, (sortOrder > 0));

-            ++sortKeys;

-        }

-

-        uassert(15976, str::stream() << sortName <<

-                " must have at least one sort key", (sortKeys > 0));

-

-        return pSort;

-    }

-

-    void DocumentSourceSort::populate() {

-        /* make sure we've got a sort key */

-        verify(vSortKey.size());

-

-        /* track and warn about how much physical memory has been used */

-        DocMemMonitor dmm(this);

-

-        /* pull everything from the underlying source */

-        for(bool hasNext = !pSource->eof(); hasNext;

-            hasNext = pSource->advance()) {

-            intrusive_ptr<Document> pDocument(pSource->getCurrent());

-            documents.push_back(pDocument);

-

-            dmm.addToTotal(pDocument->getApproximateSize());

-        }

-

-        /* sort the list */

-        Comparator comparator(this);

-        sort(documents.begin(), documents.end(), comparator);

-

-        /* start the sort iterator */

-        docIterator = documents.begin();

-

-        if (docIterator != documents.end())

-            pCurrent = *docIterator;

-        populated = true;

-    }

-

-    int DocumentSourceSort::compare(

-        const intrusive_ptr<Document> &pL, const intrusive_ptr<Document> &pR) {

-

-        /*

-          populate() already checked that there is a non-empty sort key,

-          so we shouldn't have to worry about that here.

-

-          However, the tricky part is what to do is none of the sort keys are

-          present.  In this case, consider the document less.

-        */

-        const size_t n = vSortKey.size();

-        for(size_t i = 0; i < n; ++i) {

-            /* evaluate the sort keys */

-            ExpressionFieldPath *pE = vSortKey[i].get();

-            intrusive_ptr<const Value> pLeft(pE->evaluate(pL));

-            intrusive_ptr<const Value> pRight(pE->evaluate(pR));

-

-            /*

-              Compare the two values; if they differ, return.  If they are

-              the same, move on to the next key.

-            */

-            int cmp = Value::compare(pLeft, pRight);

-            if (cmp) {

-                /* if necessary, adjust the return value by the key ordering */

-                if (!vAscending[i])

-                    cmp = -cmp;

-

-                return cmp;

-            }

-        }

-

-        /*

-          If we got here, everything matched (or didn't exist), so we'll

-          consider the documents equal for purposes of this sort.

-        */

-        return 0;

-    }

-

-    void DocumentSourceSort::manageDependencies(

-        const intrusive_ptr<DependencyTracker> &pTracker) {

-        /* get the dependencies out of the matcher */

-        for(SortPaths::iterator i(vSortKey.begin()); i != vSortKey.end(); ++i) {

-            string fieldPath((*i)->getFieldPath(false));

-            pTracker->addDependency(fieldPath, this);

-        }

-    }

-

-}

+/**
+*    Copyright (C) 2011 10gen Inc.
+*
+*    This program is free software: you can redistribute it and/or  modify
+*    it under the terms of the GNU Affero General Public License, version 3,
+*    as published by the Free Software Foundation.
+*
+*    This program is distributed in the hope that it will be useful,
+*    but WITHOUT ANY WARRANTY; without even the implied warranty of
+*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*    GNU Affero General Public License for more details.
+*
+*    You should have received a copy of the GNU Affero General Public License
+*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "pch.h"
+
+#include "db/pipeline/document_source.h"
+
+#include "db/jsobj.h"
+#include "db/pipeline/dependency_tracker.h"
+#include "db/pipeline/doc_mem_monitor.h"
+#include "db/pipeline/document.h"
+#include "db/pipeline/expression.h"
+#include "db/pipeline/expression_context.h"
+#include "db/pipeline/value.h"
+
+
+namespace mongo {
+    const char DocumentSourceSort::sortName[] = "$sort";
+
+    DocumentSourceSort::~DocumentSourceSort() {
+    }
+
+    const char *DocumentSourceSort::getSourceName() const {
+        return sortName;
+    }
+
+    bool DocumentSourceSort::eof() {
+        if (!populated)
+            populate();
+
+        return (docIterator == documents.end());
+    }
+
+    bool DocumentSourceSort::advance() {
+        DocumentSource::advance(); // check for interrupts
+
+        if (!populated)
+            populate();
+
+        verify(docIterator != documents.end());
+
+        ++docIterator;
+        if (docIterator == documents.end()) {
+            pCurrent.reset();
+            count = 0;
+            return false;
+        }
+        pCurrent = *docIterator;
+
+        return true;
+    }
+
+    intrusive_ptr<Document> DocumentSourceSort::getCurrent() {
+        if (!populated)
+            populate();
+
+        return pCurrent;
+    }
+
+    void DocumentSourceSort::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+        BSONObjBuilder insides;
+        sortKeyToBson(&insides, false);
+        pBuilder->append(sortName, insides.done());
+    }
+
+    intrusive_ptr<DocumentSourceSort> DocumentSourceSort::create(
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        intrusive_ptr<DocumentSourceSort> pSource(
+            new DocumentSourceSort(pExpCtx));
+        return pSource;
+    }
+
+    DocumentSourceSort::DocumentSourceSort(
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSource(pExpCtx),
+        populated(false) {
+    }
+
+    void DocumentSourceSort::addKey(const string &fieldPath, bool ascending) {
+        intrusive_ptr<ExpressionFieldPath> pE(
+            ExpressionFieldPath::create(fieldPath));
+        vSortKey.push_back(pE);
+        vAscending.push_back(ascending);
+    }
+
+    void DocumentSourceSort::sortKeyToBson(
+        BSONObjBuilder *pBuilder, bool usePrefix) const {
+        /* add the key fields */
+        const size_t n = vSortKey.size();
+        for(size_t i = 0; i < n; ++i) {
+            /* create the "field name" */
+            stringstream ss;
+            vSortKey[i]->writeFieldPath(ss, usePrefix);
+
+            /* append a named integer based on the sort order */
+            pBuilder->append(ss.str(), (vAscending[i] ? 1 : -1));
+        }
+    }
+
+    intrusive_ptr<DocumentSource> DocumentSourceSort::createFromBson(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        uassert(15973, str::stream() << " the " <<
+                sortName << " key specification must be an object",
+                pBsonElement->type() == Object);
+
+        intrusive_ptr<DocumentSourceSort> pSort(
+            DocumentSourceSort::create(pExpCtx));
+
+        /* check for then iterate over the sort object */
+        size_t sortKeys = 0;
+        for(BSONObjIterator keyIterator(pBsonElement->Obj().begin());
+            keyIterator.more();) {
+            BSONElement keyField(keyIterator.next());
+            const char *pKeyFieldName = keyField.fieldName();
+            int sortOrder = 0;
+                
+            uassert(15974, str::stream() << sortName <<
+                    " key ordering must be specified using a number",
+                    keyField.isNumber());
+            sortOrder = (int)keyField.numberInt();
+
+            uassert(15975,  str::stream() << sortName <<
+                    " key ordering must be 1 (for ascending) or -1 (for descending",
+                    ((sortOrder == 1) || (sortOrder == -1)));
+
+            pSort->addKey(pKeyFieldName, (sortOrder > 0));
+            ++sortKeys;
+        }
+
+        uassert(15976, str::stream() << sortName <<
+                " must have at least one sort key", (sortKeys > 0));
+
+        return pSort;
+    }
+
+    void DocumentSourceSort::populate() {
+        /* make sure we've got a sort key */
+        verify(vSortKey.size());
+
+        /* track and warn about how much physical memory has been used */
+        DocMemMonitor dmm(this);
+
+        /* pull everything from the underlying source */
+        for(bool hasNext = !pSource->eof(); hasNext;
+            hasNext = pSource->advance()) {
+            intrusive_ptr<Document> pDocument(pSource->getCurrent());
+            documents.push_back(pDocument);
+
+            dmm.addToTotal(pDocument->getApproximateSize());
+        }
+
+        /* sort the list */
+        Comparator comparator(this);
+        sort(documents.begin(), documents.end(), comparator);
+
+        /* start the sort iterator */
+        docIterator = documents.begin();
+
+        if (docIterator != documents.end())
+            pCurrent = *docIterator;
+        populated = true;
+    }
+
+    int DocumentSourceSort::compare(
+        const intrusive_ptr<Document> &pL, const intrusive_ptr<Document> &pR) {
+
+        /*
+          populate() already checked that there is a non-empty sort key,
+          so we shouldn't have to worry about that here.
+
+          However, the tricky part is what to do is none of the sort keys are
+          present.  In this case, consider the document less.
+        */
+        const size_t n = vSortKey.size();
+        for(size_t i = 0; i < n; ++i) {
+            /* evaluate the sort keys */
+            ExpressionFieldPath *pE = vSortKey[i].get();
+            intrusive_ptr<const Value> pLeft(pE->evaluate(pL));
+            intrusive_ptr<const Value> pRight(pE->evaluate(pR));
+
+            /*
+              Compare the two values; if they differ, return.  If they are
+              the same, move on to the next key.
+            */
+            int cmp = Value::compare(pLeft, pRight);
+            if (cmp) {
+                /* if necessary, adjust the return value by the key ordering */
+                if (!vAscending[i])
+                    cmp = -cmp;
+
+                return cmp;
+            }
+        }
+
+        /*
+          If we got here, everything matched (or didn't exist), so we'll
+          consider the documents equal for purposes of this sort.
+        */
+        return 0;
+    }
+
+    void DocumentSourceSort::manageDependencies(
+        const intrusive_ptr<DependencyTracker> &pTracker) {
+        /* get the dependencies out of the matcher */
+        for(SortPaths::iterator i(vSortKey.begin()); i != vSortKey.end(); ++i) {
+            string fieldPath((*i)->getFieldPath(false));
+            pTracker->addDependency(fieldPath, this);
+        }
+    }
+
+}
diff --git a/src/mongo/db/pipeline/document_source_unwind.cpp b/src/mongo/db/pipeline/document_source_unwind.cpp
index 58999bb6942..ec5d2236800 100755
--- a/src/mongo/db/pipeline/document_source_unwind.cpp
+++ b/src/mongo/db/pipeline/document_source_unwind.cpp
@@ -1,249 +1,249 @@
-/**

- * Copyright 2011 (c) 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "db/pipeline/document_source.h"

-

-#include "db/jsobj.h"

-#include "db/pipeline/document.h"

-#include "db/pipeline/expression.h"

-#include "db/pipeline/value.h"

-

-namespace mongo {

-

-    const char DocumentSourceUnwind::unwindName[] = "$unwind";

-

-    DocumentSourceUnwind::~DocumentSourceUnwind() {

-    }

-

-    DocumentSourceUnwind::DocumentSourceUnwind(

-        const intrusive_ptr<ExpressionContext> &pExpCtx):

-        DocumentSource(pExpCtx),

-        unwindPath(),

-        pNoUnwindDocument(),

-        pUnwindArray(),

-        pUnwinder(),

-        pUnwindValue() {

-    }

-

-    const char *DocumentSourceUnwind::getSourceName() const {

-        return unwindName;

-    }

-

-    bool DocumentSourceUnwind::eof() {

-        /*

-          If we're unwinding an array, and there are more elements, then we

-          can return more documents.

-        */

-        if (pUnwinder.get() && pUnwinder->more())

-            return false;

-

-        return pSource->eof();

-    }

-

-    bool DocumentSourceUnwind::advance() {

-        DocumentSource::advance(); // check for interrupts

-

-        if (pUnwinder.get() && pUnwinder->more()) {

-            pUnwindValue = pUnwinder->next();

-            return true;

-        }

-

-        /* release the last document and advance */

-        resetArray();

-        return pSource->advance();

-    }

-

-    intrusive_ptr<Document> DocumentSourceUnwind::getCurrent() {

-        if (!pNoUnwindDocument.get()) {

-            intrusive_ptr<Document> pInDocument(pSource->getCurrent());

-

-            /* create the result document */

-            pNoUnwindDocument = pInDocument;

-            fieldIndex.clear();

-

-            /*

-              First we'll look to see if the path is there.  If it isn't,

-              we'll pass this document through.  If it is, we record the

-              indexes of the fields down the field path so that we can

-              quickly replace them as we clone the documents along the

-              field path.

-

-              We have to clone all the documents along the field path so

-              that we don't share the end value across documents that have

-              come out of this pipeline operator.

-             */

-            intrusive_ptr<Document> pCurrent(pInDocument);

-            const size_t pathLength = unwindPath.getPathLength();

-            for(size_t i = 0; i < pathLength; ++i) {

-                size_t idx = pCurrent->getFieldIndex(

-                    unwindPath.getFieldName(i));

-                if (idx == pCurrent->getFieldCount() ) {

-                    /* this document doesn't contain the target field */

-                    resetArray();

-                    return pInDocument;

-                    break;

-                }

-

-                fieldIndex.push_back(idx);

-                Document::FieldPair fp(pCurrent->getField(idx));

-                intrusive_ptr<const Value> pPathValue(fp.second);

-                if (i < pathLength - 1) {

-                    if (pPathValue->getType() != Object) {

-                        /* can't walk down the field path */

-                        resetArray();

-                        uassert(15977, str::stream() << unwindName <<

-                                ":  cannot traverse field path past scalar value for \"" <<

-                                fp.first << "\"", false);

-                        break;

-                    }

-

-                    /* move down the object tree */

-                    pCurrent = pPathValue->getDocument();

-                }

-                else /* (i == pathLength - 1) */ {

-                    if (pPathValue->getType() != Array) {

-                        /* last item on path must be an array to unwind */

-                        resetArray();

-                        uassert(15978, str::stream() << unwindName <<

-                                ":  value at end of field path must be an array",

-                                false);

-                        break;

-                    }

-

-                    /* keep track of the array we're unwinding */

-                    pUnwindArray = pPathValue;

-                    if (pUnwindArray->getArrayLength() == 0) {

-                        /*

-                          The $unwind of an empty array is a NULL value.  If we

-                          encounter this, use the non-unwind path, but replace

-                          pOutField with a null.

-

-                          Make sure unwind value is clear so the array is

-                          removed.

-                        */

-                        pUnwindValue.reset();

-                        intrusive_ptr<Document> pClone(clonePath());

-                        resetArray();

-                        return pClone;

-                    }

-

-                    /* get the iterator we'll use to unwind the array */

-                    pUnwinder = pUnwindArray->getArray();

-                    verify(pUnwinder->more()); // we just checked above...

-                    pUnwindValue = pUnwinder->next();

-                }

-            }

-        }

-

-        /*

-          If we're unwinding a field, create an alternate document.  In the

-          alternate (clone), replace the unwound array field with the element

-          at the appropriate index.

-         */

-        if (pUnwindArray.get()) {

-            /* clone the document with an array we're unwinding */

-            intrusive_ptr<Document> pUnwindDocument(clonePath());

-

-            return pUnwindDocument;

-        }

-

-        return pNoUnwindDocument;

-    }

-

-    intrusive_ptr<Document> DocumentSourceUnwind::clonePath() const {

-        /*

-          For this to be valid, we must already have pNoUnwindDocument set,

-          and have set up the vector of indices for that document in fieldIndex.

-         */

-        verify(pNoUnwindDocument.get());

-

-        intrusive_ptr<Document> pClone(pNoUnwindDocument->clone());

-        intrusive_ptr<Document> pCurrent(pClone);

-        const size_t n = fieldIndex.size();

-        verify(n);

-        for(size_t i = 0; i < n; ++i) {

-            const size_t fi = fieldIndex[i];

-            Document::FieldPair fp(pCurrent->getField(fi));

-            if (i + 1 < n) {

-                /*

-                  For every object in the path but the last, clone it and

-                  continue on down.

-                */

-                intrusive_ptr<Document> pNext(

-                    fp.second->getDocument()->clone());

-                pCurrent->setField(fi, fp.first, Value::createDocument(pNext));

-                pCurrent = pNext;

-            }

-            else {

-                /* for the last, subsitute the next unwound value */

-                pCurrent->setField(fi, fp.first, pUnwindValue);

-            }

-        }

-

-        return pClone;

-    }

-

-    void DocumentSourceUnwind::sourceToBson(

-        BSONObjBuilder *pBuilder, bool explain) const {

-        pBuilder->append(unwindName, unwindPath.getPath(true));

-    }

-

-    intrusive_ptr<DocumentSourceUnwind> DocumentSourceUnwind::create(

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        intrusive_ptr<DocumentSourceUnwind> pSource(

-            new DocumentSourceUnwind(pExpCtx));

-        return pSource;

-    }

-

-    void DocumentSourceUnwind::unwindField(const FieldPath &rFieldPath) {

-        /* can't set more than one unwind field */

-        uassert(15979, str::stream() << unwindName <<

-                "can't unwind more than one path at once",

-                !unwindPath.getPathLength());

-

-        uassert(15980, "the path of the field to unwind cannot be empty",

-                false);

-

-        /* record the field path */

-        unwindPath = rFieldPath;

-    }

-

-    intrusive_ptr<DocumentSource> DocumentSourceUnwind::createFromBson(

-        BSONElement *pBsonElement,

-        const intrusive_ptr<ExpressionContext> &pExpCtx) {

-        /*

-          The value of $unwind should just be a field path.

-         */

-        uassert(15981, str::stream() << "the " << unwindName <<

-                " field path must be specified as a string",

-                pBsonElement->type() == String);

-

-        string prefixedPathString(pBsonElement->String());

-        string pathString(Expression::removeFieldPrefix(prefixedPathString));

-        intrusive_ptr<DocumentSourceUnwind> pUnwind(

-            DocumentSourceUnwind::create(pExpCtx));

-        pUnwind->unwindPath = FieldPath(pathString);

-

-        return pUnwind;

-    }

-

-    void DocumentSourceUnwind::manageDependencies(

-        const intrusive_ptr<DependencyTracker> &pTracker) {

-        pTracker->addDependency(unwindPath.getPath(false), this);

-    }

-    

-}

+/**
+ * Copyright 2011 (c) 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "db/pipeline/document_source.h"
+
+#include "db/jsobj.h"
+#include "db/pipeline/document.h"
+#include "db/pipeline/expression.h"
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    const char DocumentSourceUnwind::unwindName[] = "$unwind";
+
+    DocumentSourceUnwind::~DocumentSourceUnwind() {
+    }
+
+    DocumentSourceUnwind::DocumentSourceUnwind(
+        const intrusive_ptr<ExpressionContext> &pExpCtx):
+        DocumentSource(pExpCtx),
+        unwindPath(),
+        pNoUnwindDocument(),
+        pUnwindArray(),
+        pUnwinder(),
+        pUnwindValue() {
+    }
+
+    const char *DocumentSourceUnwind::getSourceName() const {
+        return unwindName;
+    }
+
+    bool DocumentSourceUnwind::eof() {
+        /*
+          If we're unwinding an array, and there are more elements, then we
+          can return more documents.
+        */
+        if (pUnwinder.get() && pUnwinder->more())
+            return false;
+
+        return pSource->eof();
+    }
+
+    bool DocumentSourceUnwind::advance() {
+        DocumentSource::advance(); // check for interrupts
+
+        if (pUnwinder.get() && pUnwinder->more()) {
+            pUnwindValue = pUnwinder->next();
+            return true;
+        }
+
+        /* release the last document and advance */
+        resetArray();
+        return pSource->advance();
+    }
+
+    intrusive_ptr<Document> DocumentSourceUnwind::getCurrent() {
+        if (!pNoUnwindDocument.get()) {
+            intrusive_ptr<Document> pInDocument(pSource->getCurrent());
+
+            /* create the result document */
+            pNoUnwindDocument = pInDocument;
+            fieldIndex.clear();
+
+            /*
+              First we'll look to see if the path is there.  If it isn't,
+              we'll pass this document through.  If it is, we record the
+              indexes of the fields down the field path so that we can
+              quickly replace them as we clone the documents along the
+              field path.
+
+              We have to clone all the documents along the field path so
+              that we don't share the end value across documents that have
+              come out of this pipeline operator.
+             */
+            intrusive_ptr<Document> pCurrent(pInDocument);
+            const size_t pathLength = unwindPath.getPathLength();
+            for(size_t i = 0; i < pathLength; ++i) {
+                size_t idx = pCurrent->getFieldIndex(
+                    unwindPath.getFieldName(i));
+                if (idx == pCurrent->getFieldCount() ) {
+                    /* this document doesn't contain the target field */
+                    resetArray();
+                    return pInDocument;
+                    break;
+                }
+
+                fieldIndex.push_back(idx);
+                Document::FieldPair fp(pCurrent->getField(idx));
+                intrusive_ptr<const Value> pPathValue(fp.second);
+                if (i < pathLength - 1) {
+                    if (pPathValue->getType() != Object) {
+                        /* can't walk down the field path */
+                        resetArray();
+                        uassert(15977, str::stream() << unwindName <<
+                                ":  cannot traverse field path past scalar value for \"" <<
+                                fp.first << "\"", false);
+                        break;
+                    }
+
+                    /* move down the object tree */
+                    pCurrent = pPathValue->getDocument();
+                }
+                else /* (i == pathLength - 1) */ {
+                    if (pPathValue->getType() != Array) {
+                        /* last item on path must be an array to unwind */
+                        resetArray();
+                        uassert(15978, str::stream() << unwindName <<
+                                ":  value at end of field path must be an array",
+                                false);
+                        break;
+                    }
+
+                    /* keep track of the array we're unwinding */
+                    pUnwindArray = pPathValue;
+                    if (pUnwindArray->getArrayLength() == 0) {
+                        /*
+                          The $unwind of an empty array is a NULL value.  If we
+                          encounter this, use the non-unwind path, but replace
+                          pOutField with a null.
+
+                          Make sure unwind value is clear so the array is
+                          removed.
+                        */
+                        pUnwindValue.reset();
+                        intrusive_ptr<Document> pClone(clonePath());
+                        resetArray();
+                        return pClone;
+                    }
+
+                    /* get the iterator we'll use to unwind the array */
+                    pUnwinder = pUnwindArray->getArray();
+                    verify(pUnwinder->more()); // we just checked above...
+                    pUnwindValue = pUnwinder->next();
+                }
+            }
+        }
+
+        /*
+          If we're unwinding a field, create an alternate document.  In the
+          alternate (clone), replace the unwound array field with the element
+          at the appropriate index.
+         */
+        if (pUnwindArray.get()) {
+            /* clone the document with an array we're unwinding */
+            intrusive_ptr<Document> pUnwindDocument(clonePath());
+
+            return pUnwindDocument;
+        }
+
+        return pNoUnwindDocument;
+    }
+
+    intrusive_ptr<Document> DocumentSourceUnwind::clonePath() const {
+        /*
+          For this to be valid, we must already have pNoUnwindDocument set,
+          and have set up the vector of indices for that document in fieldIndex.
+         */
+        verify(pNoUnwindDocument.get());
+
+        intrusive_ptr<Document> pClone(pNoUnwindDocument->clone());
+        intrusive_ptr<Document> pCurrent(pClone);
+        const size_t n = fieldIndex.size();
+        verify(n);
+        for(size_t i = 0; i < n; ++i) {
+            const size_t fi = fieldIndex[i];
+            Document::FieldPair fp(pCurrent->getField(fi));
+            if (i + 1 < n) {
+                /*
+                  For every object in the path but the last, clone it and
+                  continue on down.
+                */
+                intrusive_ptr<Document> pNext(
+                    fp.second->getDocument()->clone());
+                pCurrent->setField(fi, fp.first, Value::createDocument(pNext));
+                pCurrent = pNext;
+            }
+            else {
+                /* for the last, subsitute the next unwound value */
+                pCurrent->setField(fi, fp.first, pUnwindValue);
+            }
+        }
+
+        return pClone;
+    }
+
+    void DocumentSourceUnwind::sourceToBson(
+        BSONObjBuilder *pBuilder, bool explain) const {
+        pBuilder->append(unwindName, unwindPath.getPath(true));
+    }
+
+    intrusive_ptr<DocumentSourceUnwind> DocumentSourceUnwind::create(
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        intrusive_ptr<DocumentSourceUnwind> pSource(
+            new DocumentSourceUnwind(pExpCtx));
+        return pSource;
+    }
+
+    void DocumentSourceUnwind::unwindField(const FieldPath &rFieldPath) {
+        /* can't set more than one unwind field */
+        uassert(15979, str::stream() << unwindName <<
+                "can't unwind more than one path at once",
+                !unwindPath.getPathLength());
+
+        uassert(15980, "the path of the field to unwind cannot be empty",
+                false);
+
+        /* record the field path */
+        unwindPath = rFieldPath;
+    }
+
+    intrusive_ptr<DocumentSource> DocumentSourceUnwind::createFromBson(
+        BSONElement *pBsonElement,
+        const intrusive_ptr<ExpressionContext> &pExpCtx) {
+        /*
+          The value of $unwind should just be a field path.
+         */
+        uassert(15981, str::stream() << "the " << unwindName <<
+                " field path must be specified as a string",
+                pBsonElement->type() == String);
+
+        string prefixedPathString(pBsonElement->String());
+        string pathString(Expression::removeFieldPrefix(prefixedPathString));
+        intrusive_ptr<DocumentSourceUnwind> pUnwind(
+            DocumentSourceUnwind::create(pExpCtx));
+        pUnwind->unwindPath = FieldPath(pathString);
+
+        return pUnwind;
+    }
+
+    void DocumentSourceUnwind::manageDependencies(
+        const intrusive_ptr<DependencyTracker> &pTracker) {
+        pTracker->addDependency(unwindPath.getPath(false), this);
+    }
+    
+}
diff --git a/src/mongo/db/pipeline/expression.h b/src/mongo/db/pipeline/expression.h
index e2d2abbd672..eda7cdb7805 100755
--- a/src/mongo/db/pipeline/expression.h
+++ b/src/mongo/db/pipeline/expression.h
@@ -1,830 +1,830 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#pragma once

-

-#include "pch.h"

-

-#include "db/pipeline/field_path.h"

-#include "util/intrusive_counter.h"

-#include "util/iterator.h"

-

-

-namespace mongo {

-

-    class BSONArrayBuilder;

-    class BSONElement;

-    class BSONObjBuilder;

-    class Builder;

-    class DependencyTracker;

-    class Document;

-    class DocumentSource;

-    class ExpressionContext;

-    class Value;

-

-

-    class Expression :

-        public IntrusiveCounterUnsigned {

-    public:

-        virtual ~Expression() {};

-

-        /*

-          Optimize the Expression.

-

-          This provides an opportunity to do constant folding, or to

-          collapse nested operators that have the same precedence, such as

-          $add, $and, or $or.

-

-          The Expression should be replaced with the return value, which may

-          or may not be the same object.  In the case of constant folding,

-          a computed expression may be replaced by a constant.

-

-          @returns the optimized Expression

-         */

-        virtual intrusive_ptr<Expression> optimize() = 0;

-

-        /**

-           Add this expression's field dependencies to the dependency tracker.

-

-           Expressions are trees, so this is often recursive.

-

-           @params pTracker the tracker to add the dependencies to

-         */

-        virtual void addDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker,

-            const DocumentSource *pSource) const = 0;

-

-        /*

-          Evaluate the Expression using the given document as input.

-

-          @returns the computed value

-        */

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const = 0;

-

-        /*

-          Add the Expression (and any descendant Expressions) into a BSON

-          object that is under construction.

-

-          Unevaluated Expressions always materialize as objects.  Evaluation

-          may produce a scalar or another object, either of which will be

-          substituted inline.

-

-          @param pBuilder the builder to add the expression to

-          @param fieldName the name the object should be given

-          @param requireExpression specify true if the value must appear

-            as an expression; this is used by DocumentSources like

-            $project which distinguish between field inclusion and virtual

-            field specification;  See ExpressionConstant.

-         */

-        virtual void addToBsonObj(

-            BSONObjBuilder *pBuilder, string fieldName,

-            bool requireExpression) const = 0;

-

-        /*

-          Add the Expression (and any descendant Expressions) into a BSON

-          array that is under construction.

-

-          Unevaluated Expressions always materialize as objects.  Evaluation

-          may produce a scalar or another object, either of which will be

-          substituted inline.

-

-          @param pBuilder the builder to add the expression to

-         */

-        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const = 0;

-

-        /*

-          Convert the expression into a BSONObj that corresponds to the

-          db.collection.find() predicate language.  This is intended for

-          use by DocumentSourceFilter.

-

-          This is more limited than the full expression language supported

-          by all available expressions in a DocumentSource processing

-          pipeline, and will fail with an assertion if an attempt is made

-          to go outside the bounds of the recognized patterns, which don't

-          include full computed expressions.  There are other methods available

-          on DocumentSourceFilter which can be used to analyze a filter

-          predicate and break it up into appropriate expressions which can

-          be translated within these constraints.  As a result, the default

-          implementation is to fail with an assertion; only a subset of

-          operators will be able to fulfill this request.

-

-          @param pBuilder the builder to add the expression to.

-         */

-        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const;

-

-        /*

-          Utility class for parseObject() below.

-

-          Only one array can be unwound in a processing pipeline.  If the

-          UNWIND_OK option is used, unwindOk() will return true, and a field

-          can be declared as unwound using unwind(), after which unwindUsed()

-          will return true.  Only specify UNWIND_OK if it is OK to unwind an

-          array in the current context.

-

-          DOCUMENT_OK indicates that it is OK to use a Document in the current

-          context.

-         */

-        class ObjectCtx {

-        public:

-            ObjectCtx(int options);

-            static const int UNWIND_OK = 0x0001;

-            static const int DOCUMENT_OK = 0x0002;

-

-            bool unwindOk() const;

-            bool unwindUsed() const;

-            void unwind(string fieldName);

-

-            bool documentOk() const;

-

-        private:

-            int options;

-            string unwindField;

-        };

-

-        /*

-          Parse a BSONElement Object.  The object could represent a functional

-          expression or a Document expression.

-

-          @param pBsonElement the element representing the object

-          @param pCtx a MiniCtx representing the options above

-          @returns the parsed Expression

-         */

-        static intrusive_ptr<Expression> parseObject(

-            BSONElement *pBsonElement, ObjectCtx *pCtx);

-

-        static const char unwindName[];

-

-        /*

-          Parse a BSONElement Object which has already been determined to be

-          functional expression.

-

-          @param pOpName the name of the (prefix) operator

-          @param pBsonElement the BSONElement to parse

-          @returns the parsed Expression

-        */

-        static intrusive_ptr<Expression> parseExpression(

-            const char *pOpName, BSONElement *pBsonElement);

-

-

-        /*

-          Parse a BSONElement which is an operand in an Expression.

-

-          @param pBsonElement the expected operand's BSONElement

-          @returns the parsed operand, as an Expression

-         */

-        static intrusive_ptr<Expression> parseOperand(

-            BSONElement *pBsonElement);

-

-        /*

-          Produce a field path string with the field prefix removed.

-

-          Throws an error if the field prefix is not present.

-

-          @param prefixedField the prefixed field

-          @returns the field path with the prefix removed

-         */

-        static string removeFieldPrefix(const string &prefixedField);

-

-        /*

-          Enumeration of comparison operators.  These are shared between a

-          few expression implementations, so they are factored out here.

-

-          Any changes to these values require adjustment of the lookup

-          table in the implementation.

-        */

-        enum CmpOp {

-            EQ = 0, // return true for a == b, false otherwise

-            NE = 1, // return true for a != b, false otherwise

-            GT = 2, // return true for a > b, false otherwise

-            GTE = 3, // return true for a >= b, false otherwise

-            LT = 4, // return true for a < b, false otherwise

-            LTE = 5, // return true for a <= b, false otherwise

-            CMP = 6, // return -1, 0, 1 for a < b, a == b, a > b

-        };

-

-        static int signum(int i);

-

-    protected:

-        typedef vector<intrusive_ptr<Expression> > ExpressionVector;

-

-    };

-

-

-    class ExpressionNary :

-        public Expression {

-    public:

-        // virtuals from Expression

-        virtual intrusive_ptr<Expression> optimize();

-        virtual void addToBsonObj(

-            BSONObjBuilder *pBuilder, string fieldName,

-            bool requireExpression) const;

-        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;

-        virtual void addDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker,

-            const DocumentSource *pSource) const;

-

-        /*

-          Add an operand to the n-ary expression.

-

-          @param pExpression the expression to add

-        */

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        /*

-          Return a factory function that will make Expression nodes of

-          the same type as this.  This will be used to create constant

-          expressions for constant folding for optimize().  Only return

-          a factory function if this operator is both associative and

-          commutative.  The default implementation returns NULL; optimize()

-          will recognize that and stop.

-

-          Note that ExpressionNary::optimize() promises that if it uses this

-          to fold constants, then if optimize() returns an ExpressionNary,

-          any remaining constant will be the last one in vpOperand.  Derived

-          classes may take advantage of this to do further optimizations in

-          their optimize().

-

-          @returns pointer to a factory function or NULL

-         */

-        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();

-

-        /*

-          Get the name of the operator.

-

-          @returns the name of the operator; this string belongs to the class

-            implementation, and should not be deleted

-            and should not

-        */

-        virtual const char *getOpName() const = 0;

-

-    protected:

-        ExpressionNary();

-

-        ExpressionVector vpOperand;

-

-        /*

-          Add the expression to the builder.

-

-          If there is only one operand (a unary operator), then the operand

-          is added directly, without an array.  For more than one operand,

-          a named array is created.  In both cases, the result is an object.

-

-          @param pBuilder the (blank) builder to add the expression to

-          @param pOpName the name of the operator

-         */

-        virtual void toBson(BSONObjBuilder *pBuilder,

-                            const char *pOpName) const;

-

-        /*

-          Checks the current size of vpOperand; if the size equal to or

-          greater than maxArgs, fires a user assertion indicating that this

-          operator cannot have this many arguments.

-

-          The equal is there because this is intended to be used in

-          addOperand() to check for the limit *before* adding the requested

-          argument.

-

-          @param maxArgs the maximum number of arguments the operator accepts

-        */

-        void checkArgLimit(unsigned maxArgs) const;

-

-        /*

-          Checks the current size of vpOperand; if the size is not equal to

-          reqArgs, fires a user assertion indicating that this must have

-          exactly reqArgs arguments.

-

-          This is meant to be used in evaluate(), *before* the evaluation

-          takes place.

-

-          @param reqArgs the number of arguments this operator requires

-        */

-        void checkArgCount(unsigned reqArgs) const;

-    };

-

-

-    class ExpressionAdd :

-        public ExpressionNary {

-    public:

-        // virtuals from Expression

-        virtual ~ExpressionAdd();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-

-        // virtuals from ExpressionNary

-        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();

-

-        /*

-          Create an expression that finds the sum of n operands.

-

-          @returns addition expression

-         */

-        static intrusive_ptr<ExpressionNary> create();

-

-    protected:

-        // virtuals from ExpressionNary

-        virtual void toBson(BSONObjBuilder *pBuilder,

-                            const char *pOpName) const;

-

-    private:

-        ExpressionAdd();

-

-        /*

-          If the operator can be optimized, we save the original here.

-

-          This is necessary because addition must follow its original operand

-          ordering strictly if a string is detected, otherwise string

-          concatenation may appear to have re-ordered the operands.

-         */

-        intrusive_ptr<ExpressionAdd> pAdd;

-        mutable bool useOriginal;

-    };

-

-

-    class ExpressionAnd :

-        public ExpressionNary {

-    public:

-        // virtuals from Expression

-        virtual ~ExpressionAnd();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const;

-

-        // virtuals from ExpressionNary

-        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();

-

-        /*

-          Create an expression that finds the conjunction of n operands.

-          The conjunction uses short-circuit logic; the expressions are

-          evaluated in the order they were added to the conjunction, and

-          the evaluation stops and returns false on the first operand that

-          evaluates to false.

-

-          @returns conjunction expression

-         */

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionAnd();

-    };

-

-

-    class ExpressionCoerceToBool :

-        public Expression {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionCoerceToBool();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual void addDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker,

-            const DocumentSource *pSource) const;

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual void addToBsonObj(

-            BSONObjBuilder *pBuilder, string fieldName,

-            bool requireExpression) const;

-        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;

-

-        static intrusive_ptr<ExpressionCoerceToBool> create(

-            const intrusive_ptr<Expression> &pExpression);

-

-    private:

-        ExpressionCoerceToBool(const intrusive_ptr<Expression> &pExpression);

-

-        intrusive_ptr<Expression> pExpression;

-    };

-

-

-    class ExpressionCompare :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionCompare();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        /*

-          Shorthands for creating various comparisons expressions.

-          Provide for conformance with the uniform function pointer signature

-          required for parsing.

-

-          These create a particular comparision operand, without any

-          operands.  Those must be added via ExpressionNary::addOperand().

-        */

-        static intrusive_ptr<ExpressionNary> createCmp();

-        static intrusive_ptr<ExpressionNary> createEq();

-        static intrusive_ptr<ExpressionNary> createNe();

-        static intrusive_ptr<ExpressionNary> createGt();

-        static intrusive_ptr<ExpressionNary> createGte();

-        static intrusive_ptr<ExpressionNary> createLt();

-        static intrusive_ptr<ExpressionNary> createLte();

-

-    private:

-        friend class ExpressionFieldRange;

-        ExpressionCompare(CmpOp cmpOp);

-

-        CmpOp cmpOp;

-    };

-

-

-    class ExpressionCond :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionCond();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionCond();

-    };

-

-

-    class ExpressionConstant :

-        public Expression {

-    public:

-        // virtuals from Expression

-        virtual ~ExpressionConstant();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual void addDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker,

-            const DocumentSource *pSource) const;

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addToBsonObj(

-            BSONObjBuilder *pBuilder, string fieldName,

-            bool requireExpression) const;

-        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;

-

-        static intrusive_ptr<ExpressionConstant> createFromBsonElement(

-            BSONElement *pBsonElement);

-        static intrusive_ptr<ExpressionConstant> create(

-            const intrusive_ptr<const Value> &pValue);

-

-        /*

-          Get the constant value represented by this Expression.

-

-          @returns the value

-         */

-        intrusive_ptr<const Value> getValue() const;

-

-    private:

-        ExpressionConstant(BSONElement *pBsonElement);

-        ExpressionConstant(const intrusive_ptr<const Value> &pValue);

-

-        intrusive_ptr<const Value> pValue;

-    };

-

-

-    class ExpressionDayOfMonth :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionDayOfMonth();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionDayOfMonth();

-    };

-

-

-    class ExpressionDayOfWeek :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionDayOfWeek();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionDayOfWeek();

-    };

-

-

-    class ExpressionDayOfYear :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionDayOfYear();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionDayOfYear();

-    };

-

-

-    class ExpressionDivide :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionDivide();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionDivide();

-    };

-

-

-    class ExpressionFieldPath :

-        public Expression {

-    public:

-        // virtuals from Expression

-        virtual ~ExpressionFieldPath();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual void addDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker,

-            const DocumentSource *pSource) const;

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual void addToBsonObj(

-            BSONObjBuilder *pBuilder, string fieldName,

-            bool requireExpression) const;

-        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;

-

-        /*

-          Create a field path expression.

-

-          Evaluation will extract the value associated with the given field

-          path from the source document.

-

-          @param fieldPath the field path string, without any leading document

-            indicator

-          @returns the newly created field path expression

-         */

-        static intrusive_ptr<ExpressionFieldPath> create(

-            const string &fieldPath);

-

-        /*

-          Return a string representation of the field path.

-

-          @param fieldPrefix whether or not to include the document field

-            indicator prefix

-          @returns the dot-delimited field path

-         */

-        string getFieldPath(bool fieldPrefix) const;

-

-        /*

-          Write a string representation of the field path to a stream.

-

-          @param the stream to write to

-          @param fieldPrefix whether or not to include the document field

-            indicator prefix

-         */

-        void writeFieldPath(ostream &outStream, bool fieldPrefix) const;

-

-    private:

-        ExpressionFieldPath(const string &fieldPath);

-

-        /*

-          Internal implementation of evaluate(), used recursively.

-

-          The internal implementation doesn't just use a loop because of

-          the possibility that we need to skip over an array.  If the path

-          is "a.b.c", and a is an array, then we fan out from there, and

-          traverse "b.c" for each element of a:[...].  This requires that

-          a be an array of objects in order to navigate more deeply.

-

-          @param index current path field index to extract

-          @param pathLength maximum number of fields on field path

-          @param pDocument current document traversed to (not the top-level one)

-          @returns the field found; could be an array

-         */

-        intrusive_ptr<const Value> evaluatePath(

-            size_t index, const size_t pathLength, 

-            intrusive_ptr<Document> pDocument) const;

-

-        FieldPath fieldPath;

-    };

-

-

-    class ExpressionFieldRange :

-        public Expression {

-    public:

-        // virtuals from expression

-        virtual ~ExpressionFieldRange();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual void addDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker,

-            const DocumentSource *pSource) const;

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual void addToBsonObj(

-            BSONObjBuilder *pBuilder, string fieldName,

-            bool requireExpression) const;

-        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;

-        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const;

-

-        /*

-          Create a field range expression.

-

-          Field ranges are meant to match up with classic Matcher semantics,

-          and therefore are conjunctions.  For example, these appear in

-          mongo shell predicates in one of these forms:

-          { a : C } -> (a == C) // degenerate "point" range

-          { a : { $lt : C } } -> (a < C) // open range

-          { a : { $gt : C1, $lte : C2 } } -> ((a > C1) && (a <= C2)) // closed

-

-          When initially created, a field range only includes one end of

-          the range.  Additional points may be added via intersect().

-

-          Note that NE and CMP are not supported.

-

-          @param pFieldPath the field path for extracting the field value

-          @param cmpOp the comparison operator

-          @param pValue the value to compare against

-          @returns the newly created field range expression

-         */

-        static intrusive_ptr<ExpressionFieldRange> create(

-            const intrusive_ptr<ExpressionFieldPath> &pFieldPath,

-            CmpOp cmpOp, const intrusive_ptr<const Value> &pValue);

-

-        /*

-          Add an intersecting range.

-

-          This can be done any number of times after creation.  The

-          range is internally optimized for each new addition.  If the new

-          intersection extends or reduces the values within the range, the

-          internal representation is adjusted to reflect that.

-

-          Note that NE and CMP are not supported.

-

-          @param cmpOp the comparison operator

-          @param pValue the value to compare against

-         */

-        void intersect(CmpOp cmpOp, const intrusive_ptr<const Value> &pValue);

-

-    private:

-        ExpressionFieldRange(const intrusive_ptr<ExpressionFieldPath> &pFieldPath,

-                             CmpOp cmpOp,

-                             const intrusive_ptr<const Value> &pValue);

-

-        intrusive_ptr<ExpressionFieldPath> pFieldPath;

-

-        class Range {

-        public:

-            Range(CmpOp cmpOp, const intrusive_ptr<const Value> &pValue);

-            Range(const Range &rRange);

-

-            Range *intersect(const Range *pRange) const;

-            bool contains(const intrusive_ptr<const Value> &pValue) const;

-

-            Range(const intrusive_ptr<const Value> &pBottom, bool bottomOpen,

-                  const intrusive_ptr<const Value> &pTop, bool topOpen);

-

-            bool bottomOpen;

-            bool topOpen;

-            intrusive_ptr<const Value> pBottom;

-            intrusive_ptr<const Value> pTop;

-        };

-

-        scoped_ptr<Range> pRange;

-

-        /*

-          Add to a generic Builder.

-

-          The methods to append items to an object and an array differ by

-          their inclusion of a field name.  For more complicated objects,

-          it makes sense to abstract that out and use a generic builder that

-          always looks the same, and then implement addToBsonObj() and

-          addToBsonArray() by using the common method.

-         */

-        void addToBson(Builder *pBuilder) const;

-    };

-

-

-    class ExpressionHour :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionHour();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionHour();

-    };

-

-

-    class ExpressionIfNull :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionIfNull();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionIfNull();

-    };

-

-

-    class ExpressionIsoDate :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionIsoDate();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionIsoDate();

-

-        static const char argYear[];

-        static const char argMonth[];

-        static const char argDayOfMonth[];

-        static const char argHour[];

-        static const char argMinute[];

-        static const char argSecond[];

-

-        static const unsigned flagYear;

-        static const unsigned flagMonth;

-        static const unsigned flagDayOfMonth;

-        static const unsigned flagHour;

-        static const unsigned flagMinute;

-        static const unsigned flagSecond;

-        unsigned flag;

-

-        /**

-           Get a named long argument out of the given document.

-

-           @param pArgs the evaluated document with the named arguments in it

-           @param pName the name of the argument

-           @param defaultValue the value to return if the argument isn't found

-           @returns the value if found, otherwise zero

-           @throws uassert for non-whole numbers or non-numbers

-         */

-        int getIntArg(

-            const intrusive_ptr<Document> &pArgs,

-            const char *pName, int defaultValue) const;

-

-        /**

-           Check that the named argument fits in an integer.

-

-           @params pName the name of the argument

-           @params value the long value of the argument

-           @returns the integer value

-           @throws uassert if the value is out of range

-         */

-        int checkIntRange(const char *pName, long long value) const;

-    };

-

-

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "pch.h"
+
+#include "db/pipeline/field_path.h"
+#include "util/intrusive_counter.h"
+#include "util/iterator.h"
+
+
+namespace mongo {
+
+    class BSONArrayBuilder;
+    class BSONElement;
+    class BSONObjBuilder;
+    class Builder;
+    class DependencyTracker;
+    class Document;
+    class DocumentSource;
+    class ExpressionContext;
+    class Value;
+
+
+    class Expression :
+        public IntrusiveCounterUnsigned {
+    public:
+        virtual ~Expression() {};
+
+        /*
+          Optimize the Expression.
+
+          This provides an opportunity to do constant folding, or to
+          collapse nested operators that have the same precedence, such as
+          $add, $and, or $or.
+
+          The Expression should be replaced with the return value, which may
+          or may not be the same object.  In the case of constant folding,
+          a computed expression may be replaced by a constant.
+
+          @returns the optimized Expression
+         */
+        virtual intrusive_ptr<Expression> optimize() = 0;
+
+        /**
+           Add this expression's field dependencies to the dependency tracker.
+
+           Expressions are trees, so this is often recursive.
+
+           @params pTracker the tracker to add the dependencies to
+         */
+        virtual void addDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker,
+            const DocumentSource *pSource) const = 0;
+
+        /*
+          Evaluate the Expression using the given document as input.
+
+          @returns the computed value
+        */
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const = 0;
+
+        /*
+          Add the Expression (and any descendant Expressions) into a BSON
+          object that is under construction.
+
+          Unevaluated Expressions always materialize as objects.  Evaluation
+          may produce a scalar or another object, either of which will be
+          substituted inline.
+
+          @param pBuilder the builder to add the expression to
+          @param fieldName the name the object should be given
+          @param requireExpression specify true if the value must appear
+            as an expression; this is used by DocumentSources like
+            $project which distinguish between field inclusion and virtual
+            field specification;  See ExpressionConstant.
+         */
+        virtual void addToBsonObj(
+            BSONObjBuilder *pBuilder, string fieldName,
+            bool requireExpression) const = 0;
+
+        /*
+          Add the Expression (and any descendant Expressions) into a BSON
+          array that is under construction.
+
+          Unevaluated Expressions always materialize as objects.  Evaluation
+          may produce a scalar or another object, either of which will be
+          substituted inline.
+
+          @param pBuilder the builder to add the expression to
+         */
+        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const = 0;
+
+        /*
+          Convert the expression into a BSONObj that corresponds to the
+          db.collection.find() predicate language.  This is intended for
+          use by DocumentSourceFilter.
+
+          This is more limited than the full expression language supported
+          by all available expressions in a DocumentSource processing
+          pipeline, and will fail with an assertion if an attempt is made
+          to go outside the bounds of the recognized patterns, which don't
+          include full computed expressions.  There are other methods available
+          on DocumentSourceFilter which can be used to analyze a filter
+          predicate and break it up into appropriate expressions which can
+          be translated within these constraints.  As a result, the default
+          implementation is to fail with an assertion; only a subset of
+          operators will be able to fulfill this request.
+
+          @param pBuilder the builder to add the expression to.
+         */
+        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const;
+
+        /*
+          Utility class for parseObject() below.
+
+          Only one array can be unwound in a processing pipeline.  If the
+          UNWIND_OK option is used, unwindOk() will return true, and a field
+          can be declared as unwound using unwind(), after which unwindUsed()
+          will return true.  Only specify UNWIND_OK if it is OK to unwind an
+          array in the current context.
+
+          DOCUMENT_OK indicates that it is OK to use a Document in the current
+          context.
+         */
+        class ObjectCtx {
+        public:
+            ObjectCtx(int options);
+            static const int UNWIND_OK = 0x0001;
+            static const int DOCUMENT_OK = 0x0002;
+
+            bool unwindOk() const;
+            bool unwindUsed() const;
+            void unwind(string fieldName);
+
+            bool documentOk() const;
+
+        private:
+            int options;
+            string unwindField;
+        };
+
+        /*
+          Parse a BSONElement Object.  The object could represent a functional
+          expression or a Document expression.
+
+          @param pBsonElement the element representing the object
+          @param pCtx a MiniCtx representing the options above
+          @returns the parsed Expression
+         */
+        static intrusive_ptr<Expression> parseObject(
+            BSONElement *pBsonElement, ObjectCtx *pCtx);
+
+        static const char unwindName[];
+
+        /*
+          Parse a BSONElement Object which has already been determined to be
+          functional expression.
+
+          @param pOpName the name of the (prefix) operator
+          @param pBsonElement the BSONElement to parse
+          @returns the parsed Expression
+        */
+        static intrusive_ptr<Expression> parseExpression(
+            const char *pOpName, BSONElement *pBsonElement);
+
+
+        /*
+          Parse a BSONElement which is an operand in an Expression.
+
+          @param pBsonElement the expected operand's BSONElement
+          @returns the parsed operand, as an Expression
+         */
+        static intrusive_ptr<Expression> parseOperand(
+            BSONElement *pBsonElement);
+
+        /*
+          Produce a field path string with the field prefix removed.
+
+          Throws an error if the field prefix is not present.
+
+          @param prefixedField the prefixed field
+          @returns the field path with the prefix removed
+         */
+        static string removeFieldPrefix(const string &prefixedField);
+
+        /*
+          Enumeration of comparison operators.  These are shared between a
+          few expression implementations, so they are factored out here.
+
+          Any changes to these values require adjustment of the lookup
+          table in the implementation.
+        */
+        enum CmpOp {
+            EQ = 0, // return true for a == b, false otherwise
+            NE = 1, // return true for a != b, false otherwise
+            GT = 2, // return true for a > b, false otherwise
+            GTE = 3, // return true for a >= b, false otherwise
+            LT = 4, // return true for a < b, false otherwise
+            LTE = 5, // return true for a <= b, false otherwise
+            CMP = 6, // return -1, 0, 1 for a < b, a == b, a > b
+        };
+
+        static int signum(int i);
+
+    protected:
+        typedef vector<intrusive_ptr<Expression> > ExpressionVector;
+
+    };
+
+
+    class ExpressionNary :
+        public Expression {
+    public:
+        // virtuals from Expression
+        virtual intrusive_ptr<Expression> optimize();
+        virtual void addToBsonObj(
+            BSONObjBuilder *pBuilder, string fieldName,
+            bool requireExpression) const;
+        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;
+        virtual void addDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker,
+            const DocumentSource *pSource) const;
+
+        /*
+          Add an operand to the n-ary expression.
+
+          @param pExpression the expression to add
+        */
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        /*
+          Return a factory function that will make Expression nodes of
+          the same type as this.  This will be used to create constant
+          expressions for constant folding for optimize().  Only return
+          a factory function if this operator is both associative and
+          commutative.  The default implementation returns NULL; optimize()
+          will recognize that and stop.
+
+          Note that ExpressionNary::optimize() promises that if it uses this
+          to fold constants, then if optimize() returns an ExpressionNary,
+          any remaining constant will be the last one in vpOperand.  Derived
+          classes may take advantage of this to do further optimizations in
+          their optimize().
+
+          @returns pointer to a factory function or NULL
+         */
+        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();
+
+        /*
+          Get the name of the operator.
+
+          @returns the name of the operator; this string belongs to the class
+            implementation, and should not be deleted
+            and should not
+        */
+        virtual const char *getOpName() const = 0;
+
+    protected:
+        ExpressionNary();
+
+        ExpressionVector vpOperand;
+
+        /*
+          Add the expression to the builder.
+
+          If there is only one operand (a unary operator), then the operand
+          is added directly, without an array.  For more than one operand,
+          a named array is created.  In both cases, the result is an object.
+
+          @param pBuilder the (blank) builder to add the expression to
+          @param pOpName the name of the operator
+         */
+        virtual void toBson(BSONObjBuilder *pBuilder,
+                            const char *pOpName) const;
+
+        /*
+          Checks the current size of vpOperand; if the size equal to or
+          greater than maxArgs, fires a user assertion indicating that this
+          operator cannot have this many arguments.
+
+          The equal is there because this is intended to be used in
+          addOperand() to check for the limit *before* adding the requested
+          argument.
+
+          @param maxArgs the maximum number of arguments the operator accepts
+        */
+        void checkArgLimit(unsigned maxArgs) const;
+
+        /*
+          Checks the current size of vpOperand; if the size is not equal to
+          reqArgs, fires a user assertion indicating that this must have
+          exactly reqArgs arguments.
+
+          This is meant to be used in evaluate(), *before* the evaluation
+          takes place.
+
+          @param reqArgs the number of arguments this operator requires
+        */
+        void checkArgCount(unsigned reqArgs) const;
+    };
+
+
+    class ExpressionAdd :
+        public ExpressionNary {
+    public:
+        // virtuals from Expression
+        virtual ~ExpressionAdd();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+
+        // virtuals from ExpressionNary
+        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();
+
+        /*
+          Create an expression that finds the sum of n operands.
+
+          @returns addition expression
+         */
+        static intrusive_ptr<ExpressionNary> create();
+
+    protected:
+        // virtuals from ExpressionNary
+        virtual void toBson(BSONObjBuilder *pBuilder,
+                            const char *pOpName) const;
+
+    private:
+        ExpressionAdd();
+
+        /*
+          If the operator can be optimized, we save the original here.
+
+          This is necessary because addition must follow its original operand
+          ordering strictly if a string is detected, otherwise string
+          concatenation may appear to have re-ordered the operands.
+         */
+        intrusive_ptr<ExpressionAdd> pAdd;
+        mutable bool useOriginal;
+    };
+
+
+    class ExpressionAnd :
+        public ExpressionNary {
+    public:
+        // virtuals from Expression
+        virtual ~ExpressionAnd();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const;
+
+        // virtuals from ExpressionNary
+        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();
+
+        /*
+          Create an expression that finds the conjunction of n operands.
+          The conjunction uses short-circuit logic; the expressions are
+          evaluated in the order they were added to the conjunction, and
+          the evaluation stops and returns false on the first operand that
+          evaluates to false.
+
+          @returns conjunction expression
+         */
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionAnd();
+    };
+
+
+    class ExpressionCoerceToBool :
+        public Expression {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionCoerceToBool();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual void addDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker,
+            const DocumentSource *pSource) const;
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual void addToBsonObj(
+            BSONObjBuilder *pBuilder, string fieldName,
+            bool requireExpression) const;
+        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;
+
+        static intrusive_ptr<ExpressionCoerceToBool> create(
+            const intrusive_ptr<Expression> &pExpression);
+
+    private:
+        ExpressionCoerceToBool(const intrusive_ptr<Expression> &pExpression);
+
+        intrusive_ptr<Expression> pExpression;
+    };
+
+
+    class ExpressionCompare :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionCompare();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        /*
+          Shorthands for creating various comparisons expressions.
+          Provide for conformance with the uniform function pointer signature
+          required for parsing.
+
+          These create a particular comparision operand, without any
+          operands.  Those must be added via ExpressionNary::addOperand().
+        */
+        static intrusive_ptr<ExpressionNary> createCmp();
+        static intrusive_ptr<ExpressionNary> createEq();
+        static intrusive_ptr<ExpressionNary> createNe();
+        static intrusive_ptr<ExpressionNary> createGt();
+        static intrusive_ptr<ExpressionNary> createGte();
+        static intrusive_ptr<ExpressionNary> createLt();
+        static intrusive_ptr<ExpressionNary> createLte();
+
+    private:
+        friend class ExpressionFieldRange;
+        ExpressionCompare(CmpOp cmpOp);
+
+        CmpOp cmpOp;
+    };
+
+
+    class ExpressionCond :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionCond();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionCond();
+    };
+
+
+    class ExpressionConstant :
+        public Expression {
+    public:
+        // virtuals from Expression
+        virtual ~ExpressionConstant();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual void addDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker,
+            const DocumentSource *pSource) const;
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addToBsonObj(
+            BSONObjBuilder *pBuilder, string fieldName,
+            bool requireExpression) const;
+        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;
+
+        static intrusive_ptr<ExpressionConstant> createFromBsonElement(
+            BSONElement *pBsonElement);
+        static intrusive_ptr<ExpressionConstant> create(
+            const intrusive_ptr<const Value> &pValue);
+
+        /*
+          Get the constant value represented by this Expression.
+
+          @returns the value
+         */
+        intrusive_ptr<const Value> getValue() const;
+
+    private:
+        ExpressionConstant(BSONElement *pBsonElement);
+        ExpressionConstant(const intrusive_ptr<const Value> &pValue);
+
+        intrusive_ptr<const Value> pValue;
+    };
+
+
+    class ExpressionDayOfMonth :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionDayOfMonth();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionDayOfMonth();
+    };
+
+
+    class ExpressionDayOfWeek :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionDayOfWeek();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionDayOfWeek();
+    };
+
+
+    class ExpressionDayOfYear :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionDayOfYear();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionDayOfYear();
+    };
+
+
+    class ExpressionDivide :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionDivide();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionDivide();
+    };
+
+
+    class ExpressionFieldPath :
+        public Expression {
+    public:
+        // virtuals from Expression
+        virtual ~ExpressionFieldPath();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual void addDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker,
+            const DocumentSource *pSource) const;
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual void addToBsonObj(
+            BSONObjBuilder *pBuilder, string fieldName,
+            bool requireExpression) const;
+        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;
+
+        /*
+          Create a field path expression.
+
+          Evaluation will extract the value associated with the given field
+          path from the source document.
+
+          @param fieldPath the field path string, without any leading document
+            indicator
+          @returns the newly created field path expression
+         */
+        static intrusive_ptr<ExpressionFieldPath> create(
+            const string &fieldPath);
+
+        /*
+          Return a string representation of the field path.
+
+          @param fieldPrefix whether or not to include the document field
+            indicator prefix
+          @returns the dot-delimited field path
+         */
+        string getFieldPath(bool fieldPrefix) const;
+
+        /*
+          Write a string representation of the field path to a stream.
+
+          @param the stream to write to
+          @param fieldPrefix whether or not to include the document field
+            indicator prefix
+         */
+        void writeFieldPath(ostream &outStream, bool fieldPrefix) const;
+
+    private:
+        ExpressionFieldPath(const string &fieldPath);
+
+        /*
+          Internal implementation of evaluate(), used recursively.
+
+          The internal implementation doesn't just use a loop because of
+          the possibility that we need to skip over an array.  If the path
+          is "a.b.c", and a is an array, then we fan out from there, and
+          traverse "b.c" for each element of a:[...].  This requires that
+          a be an array of objects in order to navigate more deeply.
+
+          @param index current path field index to extract
+          @param pathLength maximum number of fields on field path
+          @param pDocument current document traversed to (not the top-level one)
+          @returns the field found; could be an array
+         */
+        intrusive_ptr<const Value> evaluatePath(
+            size_t index, const size_t pathLength, 
+            intrusive_ptr<Document> pDocument) const;
+
+        FieldPath fieldPath;
+    };
+
+
+    class ExpressionFieldRange :
+        public Expression {
+    public:
+        // virtuals from expression
+        virtual ~ExpressionFieldRange();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual void addDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker,
+            const DocumentSource *pSource) const;
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual void addToBsonObj(
+            BSONObjBuilder *pBuilder, string fieldName,
+            bool requireExpression) const;
+        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;
+        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const;
+
+        /*
+          Create a field range expression.
+
+          Field ranges are meant to match up with classic Matcher semantics,
+          and therefore are conjunctions.  For example, these appear in
+          mongo shell predicates in one of these forms:
+          { a : C } -> (a == C) // degenerate "point" range
+          { a : { $lt : C } } -> (a < C) // open range
+          { a : { $gt : C1, $lte : C2 } } -> ((a > C1) && (a <= C2)) // closed
+
+          When initially created, a field range only includes one end of
+          the range.  Additional points may be added via intersect().
+
+          Note that NE and CMP are not supported.
+
+          @param pFieldPath the field path for extracting the field value
+          @param cmpOp the comparison operator
+          @param pValue the value to compare against
+          @returns the newly created field range expression
+         */
+        static intrusive_ptr<ExpressionFieldRange> create(
+            const intrusive_ptr<ExpressionFieldPath> &pFieldPath,
+            CmpOp cmpOp, const intrusive_ptr<const Value> &pValue);
+
+        /*
+          Add an intersecting range.
+
+          This can be done any number of times after creation.  The
+          range is internally optimized for each new addition.  If the new
+          intersection extends or reduces the values within the range, the
+          internal representation is adjusted to reflect that.
+
+          Note that NE and CMP are not supported.
+
+          @param cmpOp the comparison operator
+          @param pValue the value to compare against
+         */
+        void intersect(CmpOp cmpOp, const intrusive_ptr<const Value> &pValue);
+
+    private:
+        ExpressionFieldRange(const intrusive_ptr<ExpressionFieldPath> &pFieldPath,
+                             CmpOp cmpOp,
+                             const intrusive_ptr<const Value> &pValue);
+
+        intrusive_ptr<ExpressionFieldPath> pFieldPath;
+
+        class Range {
+        public:
+            Range(CmpOp cmpOp, const intrusive_ptr<const Value> &pValue);
+            Range(const Range &rRange);
+
+            Range *intersect(const Range *pRange) const;
+            bool contains(const intrusive_ptr<const Value> &pValue) const;
+
+            Range(const intrusive_ptr<const Value> &pBottom, bool bottomOpen,
+                  const intrusive_ptr<const Value> &pTop, bool topOpen);
+
+            bool bottomOpen;
+            bool topOpen;
+            intrusive_ptr<const Value> pBottom;
+            intrusive_ptr<const Value> pTop;
+        };
+
+        scoped_ptr<Range> pRange;
+
+        /*
+          Add to a generic Builder.
+
+          The methods to append items to an object and an array differ by
+          their inclusion of a field name.  For more complicated objects,
+          it makes sense to abstract that out and use a generic builder that
+          always looks the same, and then implement addToBsonObj() and
+          addToBsonArray() by using the common method.
+         */
+        void addToBson(Builder *pBuilder) const;
+    };
+
+
+    class ExpressionHour :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionHour();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionHour();
+    };
+
+
+    class ExpressionIfNull :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionIfNull();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionIfNull();
+    };
+
+
+    class ExpressionIsoDate :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionIsoDate();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionIsoDate();
+
+        static const char argYear[];
+        static const char argMonth[];
+        static const char argDayOfMonth[];
+        static const char argHour[];
+        static const char argMinute[];
+        static const char argSecond[];
+
+        static const unsigned flagYear;
+        static const unsigned flagMonth;
+        static const unsigned flagDayOfMonth;
+        static const unsigned flagHour;
+        static const unsigned flagMinute;
+        static const unsigned flagSecond;
+        unsigned flag;
+
+        /**
+           Get a named long argument out of the given document.
+
+           @param pArgs the evaluated document with the named arguments in it
+           @param pName the name of the argument
+           @param defaultValue the value to return if the argument isn't found
+           @returns the value if found, otherwise zero
+           @throws uassert for non-whole numbers or non-numbers
+         */
+        int getIntArg(
+            const intrusive_ptr<Document> &pArgs,
+            const char *pName, int defaultValue) const;
+
+        /**
+           Check that the named argument fits in an integer.
+
+           @params pName the name of the argument
+           @params value the long value of the argument
+           @returns the integer value
+           @throws uassert if the value is out of range
+         */
+        int checkIntRange(const char *pName, long long value) const;
+    };
+
+
     class ExpressionLiteral :
         public ExpressionNary {
     public:
@@ -842,558 +842,558 @@ namespace mongo {
     };
 
 
-    class ExpressionMinute :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionMinute();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionMinute();

-    };

-

-

-    class ExpressionMod :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionMod();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionMod();

-    };

-    

-

-    class ExpressionMultiply :

-        public ExpressionNary {

-    public:

-        // virtuals from Expression

-        virtual ~ExpressionMultiply();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-

-        // virtuals from ExpressionNary

-        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();

-

-        /*

-          Create an expression that finds the product of n operands.

-

-          @returns multiplication expression

-         */

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionMultiply();

-    };

-

-

-    class ExpressionMonth :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionMonth();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionMonth();

-    };

-

-

-    class ExpressionNoOp :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionNoOp();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionNoOp();

-    };

-

-

-    class ExpressionNot :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionNot();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionNot();

-    };

-

-

-    class ExpressionObject :

-        public Expression {

-    public:

-        // virtuals from Expression

-        virtual ~ExpressionObject();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual void addDependencies(

-            const intrusive_ptr<DependencyTracker> &pTracker,

-            const DocumentSource *pSource) const;

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual void addToBsonObj(

-            BSONObjBuilder *pBuilder, string fieldName,

-            bool requireExpression) const;

-        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;

-

-        /*

-          evaluate(), but return a Document instead of a Value-wrapped

-          Document.

-

-          @param pDocument the input Document

-          @returns the result document

-         */

-        intrusive_ptr<Document> evaluateDocument(

-            const intrusive_ptr<Document> &pDocument) const;

-

-        /*

-          evaluate(), but add the evaluated fields to a given document

-          instead of creating a new one.

-

-          @param pResult the Document to add the evaluated expressions to

-          @param pDocument the input Document

-          @param excludeId for exclusions, exclude the _id, if present

-         */

-        void addToDocument(const intrusive_ptr<Document> &pResult,

-                           const intrusive_ptr<Document> &pDocument,

-            bool excludeId = false) const;

-

-        /*

-          Estimate the number of fields that will result from evaluating

-          this over pDocument.  Does not include _id.  This is an estimate

-          (really an upper bound) because we can't account for undefined

-          fields without actually doing the evaluation.  But this is still

-          useful as an argument to Document::create(), if you plan to use

-          addToDocument().

-

-          @param pDocument the input document

-          @returns estimated number of fields that will result

-         */

-        size_t getSizeHint(const intrusive_ptr<Document> &pDocument) const;

-

-        /*

-          Create an empty expression.  Until fields are added, this

-          will evaluate to an empty document (object).

-         */

-        static intrusive_ptr<ExpressionObject> create();

-

-        /*

-          Add a field to the document expression.

-

-          @param fieldPath the path the evaluated expression will have in the

-                 result Document

-          @param pExpression the expression to evaluate obtain this field's

-                 Value in the result Document

-        */

-        void addField(const string &fieldPath,

-                      const intrusive_ptr<Expression> &pExpression);

-

-        /*

-          Add a field path to the set of those to be included.

-

-          Note that including a nested field implies including everything on

-          the path leading down to it.

-

-          @param fieldPath the name of the field to be included

-        */

-        void includePath(const string &fieldPath);

-

-        /*

-          Add a field path to the set of those to be excluded.

-

-          Note that excluding a nested field implies including everything on

-          the path leading down to it (because you're stating you want to see

-          all the other fields that aren't being excluded).

-

-          @param fieldName the name of the field to be excluded

-         */

-        void excludePath(const string &fieldPath);

-

-        /**

-           Get an iterator that can be used to iterate over all the result

-           field names in this ExpressionObject.

-

-           @returns the (intrusive_ptr'ed) iterator

-         */

-        Iterator<string> *getFieldIterator() const;

-

-        /*

-          Return the expression for a field.

-

-          @param fieldName the field name for the expression to return

-          @returns the expression used to compute the field, if it is present,

-            otherwise NULL.

-        */

-        intrusive_ptr<Expression> getField(const string &fieldName) const;

-

-        /*

-          Get a count of the added fields.

-

-          @returns how many fields have been added

-         */

-        size_t getFieldCount() const;

-

-        /*

-          Get a count of the exclusions.

-

-          @returns how many fields have been excluded.

-        */

-        size_t getExclusionCount() const;

-

-        /*

-          Specialized BSON conversion that allows for writing out a

-          $project specification.  This creates a standalone object, which must

-          be added to a containing object with a name

-

-          @param pBuilder where to write the object to

-          @param requireExpression see Expression::addToBsonObj

-         */

-        void documentToBson(BSONObjBuilder *pBuilder,

-                            bool requireExpression) const;

-

-        /*

-          Visitor abstraction used by emitPaths().  Each path is recorded by

-          calling path().

-         */

-        class PathSink {

-        public:

-            virtual ~PathSink() {};

-

-            /**

-               Record a path.

-

-               @param path the dotted path string

-               @param include if true, the path is included; if false, the path

-                 is excluded

-             */

-            virtual void path(const string &path, bool include) = 0;

-        };

-

-        /**

-          Emit the field paths that have been included or excluded.  "Included"

-          includes paths that are referenced in expressions for computed

-          fields.

-

-          @param pSink where to write the paths to

-          @param pvPath pointer to a vector of strings describing the path on

-            descent; the top-level call should pass an empty vector

-         */

-        void emitPaths(PathSink *pPathSink) const;

-

-    private:

-        ExpressionObject();

-

-        void includePath(

-            const FieldPath *pPath, size_t pathi, size_t pathn,

-            bool excludeLast);

-

-        bool excludePaths;

-        set<string> path;

-

-        /* these two vectors are maintained in parallel */

-        vector<string> vFieldName;

-        vector<intrusive_ptr<Expression> > vpExpression;

-

-

-        /*

-          Utility function used by documentToBson().  Emits inclusion

-          and exclusion paths by recursively walking down the nested

-          ExpressionObject trees these have created.

-

-          @param pSink where to write the paths to

-          @param pvPath pointer to a vector of strings describing the path on

-            descent; the top-level call should pass an empty vector

-         */

-        void emitPaths(PathSink *pPathSink, vector<string> *pvPath) const;

-

-        /*

-          Utility object for collecting emitPaths() results in a BSON

-          object.

-         */

-        class BuilderPathSink :

-            public PathSink {

-        public:

-            // virtuals from PathSink

-            virtual void path(const string &path, bool include);

-

-            /*

-              Create a PathSink that writes paths to a BSONObjBuilder,

-              to create an object in the form of { path:is_included,...}

-

-              This object uses a builder pointer that won't guarantee the

-              lifetime of the builder, so make sure it outlasts the use of

-              this for an emitPaths() call.

-

-              @param pBuilder to the builder to write paths to

-             */

-            BuilderPathSink(BSONObjBuilder *pBuilder);

-

-        private:

-            BSONObjBuilder *pBuilder;

-        };

-

-        /* utility class used by emitPaths() */

-        class PathPusher :

-            boost::noncopyable {

-        public:

-            PathPusher(vector<string> *pvPath, const string &s);

-            ~PathPusher();

-

-        private:

-            vector<string> *pvPath;

-        };

-    };

-

-

-    class ExpressionOr :

-        public ExpressionNary {

-    public:

-        // virtuals from Expression

-        virtual ~ExpressionOr();

-        virtual intrusive_ptr<Expression> optimize();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const;

-

-        // virtuals from ExpressionNary

-        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();

-

-        /*

-          Create an expression that finds the conjunction of n operands.

-          The conjunction uses short-circuit logic; the expressions are

-          evaluated in the order they were added to the conjunction, and

-          the evaluation stops and returns false on the first operand that

-          evaluates to false.

-

-          @returns conjunction expression

-         */

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionOr();

-    };

-

-

-    class ExpressionSecond :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionSecond();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionSecond();

-    };

-

-

-    class ExpressionStrcasecmp :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionStrcasecmp();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionStrcasecmp();

-    };

-

-

-    class ExpressionSubstr :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionSubstr();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionSubstr();

-    };

-

-

-    class ExpressionSubtract :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionSubtract();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionSubtract();

-    };

-

-

-    class ExpressionToLower :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionToLower();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionToLower();

-    };

-

-

-    class ExpressionToUpper :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionToUpper();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionToUpper();

-    };

-

-

-    class ExpressionWeek :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionWeek();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionWeek();

-    };

-

-

-    class ExpressionYear :

-        public ExpressionNary {

-    public:

-        // virtuals from ExpressionNary

-        virtual ~ExpressionYear();

-        virtual intrusive_ptr<const Value> evaluate(

-            const intrusive_ptr<Document> &pDocument) const;

-        virtual const char *getOpName() const;

-        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);

-

-        static intrusive_ptr<ExpressionNary> create();

-

-    private:

-        ExpressionYear();

-    };

-}

-

-

-/* ======================= INLINED IMPLEMENTATIONS ========================== */

-

-namespace mongo {

-

-    inline bool Expression::ObjectCtx::unwindOk() const {

-        return ((options & UNWIND_OK) != 0);

-    }

-

-    inline bool Expression::ObjectCtx::unwindUsed() const {

-        return (unwindField.size() != 0);

-    }

-

-    inline int Expression::signum(int i) {

-        if (i < 0)

-            return -1;

-        if (i > 0)

-            return 1;

-        return 0;

-    }

-

-    inline intrusive_ptr<const Value> ExpressionConstant::getValue() const {

-        return pValue;

-    }

-

-    inline string ExpressionFieldPath::getFieldPath(bool fieldPrefix) const {

-        return fieldPath.getPath(fieldPrefix);

-    }

-

-    inline void ExpressionFieldPath::writeFieldPath(

-        ostream &outStream, bool fieldPrefix) const {

-        return fieldPath.writePath(outStream, fieldPrefix);

-    }

-

-    inline size_t ExpressionObject::getFieldCount() const {

-        return vFieldName.size();

-    }

-

-    inline ExpressionObject::BuilderPathSink::BuilderPathSink(

-        BSONObjBuilder *pB):

-        pBuilder(pB) {

-    }

-

-    inline ExpressionObject::PathPusher::PathPusher(

-        vector<string> *pTheVPath, const string &s):

-        pvPath(pTheVPath) {

-        pvPath->push_back(s);

-    }

-

-    inline ExpressionObject::PathPusher::~PathPusher() {

-        pvPath->pop_back();

-    }

-

-}

+    class ExpressionMinute :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionMinute();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionMinute();
+    };
+
+
+    class ExpressionMod :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionMod();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionMod();
+    };
+    
+
+    class ExpressionMultiply :
+        public ExpressionNary {
+    public:
+        // virtuals from Expression
+        virtual ~ExpressionMultiply();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+
+        // virtuals from ExpressionNary
+        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();
+
+        /*
+          Create an expression that finds the product of n operands.
+
+          @returns multiplication expression
+         */
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionMultiply();
+    };
+
+
+    class ExpressionMonth :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionMonth();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionMonth();
+    };
+
+
+    class ExpressionNoOp :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionNoOp();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionNoOp();
+    };
+
+
+    class ExpressionNot :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionNot();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionNot();
+    };
+
+
+    class ExpressionObject :
+        public Expression {
+    public:
+        // virtuals from Expression
+        virtual ~ExpressionObject();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual void addDependencies(
+            const intrusive_ptr<DependencyTracker> &pTracker,
+            const DocumentSource *pSource) const;
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual void addToBsonObj(
+            BSONObjBuilder *pBuilder, string fieldName,
+            bool requireExpression) const;
+        virtual void addToBsonArray(BSONArrayBuilder *pBuilder) const;
+
+        /*
+          evaluate(), but return a Document instead of a Value-wrapped
+          Document.
+
+          @param pDocument the input Document
+          @returns the result document
+         */
+        intrusive_ptr<Document> evaluateDocument(
+            const intrusive_ptr<Document> &pDocument) const;
+
+        /*
+          evaluate(), but add the evaluated fields to a given document
+          instead of creating a new one.
+
+          @param pResult the Document to add the evaluated expressions to
+          @param pDocument the input Document
+          @param excludeId for exclusions, exclude the _id, if present
+         */
+        void addToDocument(const intrusive_ptr<Document> &pResult,
+                           const intrusive_ptr<Document> &pDocument,
+            bool excludeId = false) const;
+
+        /*
+          Estimate the number of fields that will result from evaluating
+          this over pDocument.  Does not include _id.  This is an estimate
+          (really an upper bound) because we can't account for undefined
+          fields without actually doing the evaluation.  But this is still
+          useful as an argument to Document::create(), if you plan to use
+          addToDocument().
+
+          @param pDocument the input document
+          @returns estimated number of fields that will result
+         */
+        size_t getSizeHint(const intrusive_ptr<Document> &pDocument) const;
+
+        /*
+          Create an empty expression.  Until fields are added, this
+          will evaluate to an empty document (object).
+         */
+        static intrusive_ptr<ExpressionObject> create();
+
+        /*
+          Add a field to the document expression.
+
+          @param fieldPath the path the evaluated expression will have in the
+                 result Document
+          @param pExpression the expression to evaluate obtain this field's
+                 Value in the result Document
+        */
+        void addField(const string &fieldPath,
+                      const intrusive_ptr<Expression> &pExpression);
+
+        /*
+          Add a field path to the set of those to be included.
+
+          Note that including a nested field implies including everything on
+          the path leading down to it.
+
+          @param fieldPath the name of the field to be included
+        */
+        void includePath(const string &fieldPath);
+
+        /*
+          Add a field path to the set of those to be excluded.
+
+          Note that excluding a nested field implies including everything on
+          the path leading down to it (because you're stating you want to see
+          all the other fields that aren't being excluded).
+
+          @param fieldName the name of the field to be excluded
+         */
+        void excludePath(const string &fieldPath);
+
+        /**
+           Get an iterator that can be used to iterate over all the result
+           field names in this ExpressionObject.
+
+           @returns the (intrusive_ptr'ed) iterator
+         */
+        Iterator<string> *getFieldIterator() const;
+
+        /*
+          Return the expression for a field.
+
+          @param fieldName the field name for the expression to return
+          @returns the expression used to compute the field, if it is present,
+            otherwise NULL.
+        */
+        intrusive_ptr<Expression> getField(const string &fieldName) const;
+
+        /*
+          Get a count of the added fields.
+
+          @returns how many fields have been added
+         */
+        size_t getFieldCount() const;
+
+        /*
+          Get a count of the exclusions.
+
+          @returns how many fields have been excluded.
+        */
+        size_t getExclusionCount() const;
+
+        /*
+          Specialized BSON conversion that allows for writing out a
+          $project specification.  This creates a standalone object, which must
+          be added to a containing object with a name
+
+          @param pBuilder where to write the object to
+          @param requireExpression see Expression::addToBsonObj
+         */
+        void documentToBson(BSONObjBuilder *pBuilder,
+                            bool requireExpression) const;
+
+        /*
+          Visitor abstraction used by emitPaths().  Each path is recorded by
+          calling path().
+         */
+        class PathSink {
+        public:
+            virtual ~PathSink() {};
+
+            /**
+               Record a path.
+
+               @param path the dotted path string
+               @param include if true, the path is included; if false, the path
+                 is excluded
+             */
+            virtual void path(const string &path, bool include) = 0;
+        };
+
+        /**
+          Emit the field paths that have been included or excluded.  "Included"
+          includes paths that are referenced in expressions for computed
+          fields.
+
+          @param pSink where to write the paths to
+          @param pvPath pointer to a vector of strings describing the path on
+            descent; the top-level call should pass an empty vector
+         */
+        void emitPaths(PathSink *pPathSink) const;
+
+    private:
+        ExpressionObject();
+
+        void includePath(
+            const FieldPath *pPath, size_t pathi, size_t pathn,
+            bool excludeLast);
+
+        bool excludePaths;
+        set<string> path;
+
+        /* these two vectors are maintained in parallel */
+        vector<string> vFieldName;
+        vector<intrusive_ptr<Expression> > vpExpression;
+
+
+        /*
+          Utility function used by documentToBson().  Emits inclusion
+          and exclusion paths by recursively walking down the nested
+          ExpressionObject trees these have created.
+
+          @param pSink where to write the paths to
+          @param pvPath pointer to a vector of strings describing the path on
+            descent; the top-level call should pass an empty vector
+         */
+        void emitPaths(PathSink *pPathSink, vector<string> *pvPath) const;
+
+        /*
+          Utility object for collecting emitPaths() results in a BSON
+          object.
+         */
+        class BuilderPathSink :
+            public PathSink {
+        public:
+            // virtuals from PathSink
+            virtual void path(const string &path, bool include);
+
+            /*
+              Create a PathSink that writes paths to a BSONObjBuilder,
+              to create an object in the form of { path:is_included,...}
+
+              This object uses a builder pointer that won't guarantee the
+              lifetime of the builder, so make sure it outlasts the use of
+              this for an emitPaths() call.
+
+              @param pBuilder to the builder to write paths to
+             */
+            BuilderPathSink(BSONObjBuilder *pBuilder);
+
+        private:
+            BSONObjBuilder *pBuilder;
+        };
+
+        /* utility class used by emitPaths() */
+        class PathPusher :
+            boost::noncopyable {
+        public:
+            PathPusher(vector<string> *pvPath, const string &s);
+            ~PathPusher();
+
+        private:
+            vector<string> *pvPath;
+        };
+    };
+
+
+    class ExpressionOr :
+        public ExpressionNary {
+    public:
+        // virtuals from Expression
+        virtual ~ExpressionOr();
+        virtual intrusive_ptr<Expression> optimize();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void toMatcherBson(BSONObjBuilder *pBuilder) const;
+
+        // virtuals from ExpressionNary
+        virtual intrusive_ptr<ExpressionNary> (*getFactory() const)();
+
+        /*
+          Create an expression that finds the conjunction of n operands.
+          The conjunction uses short-circuit logic; the expressions are
+          evaluated in the order they were added to the conjunction, and
+          the evaluation stops and returns false on the first operand that
+          evaluates to false.
+
+          @returns conjunction expression
+         */
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionOr();
+    };
+
+
+    class ExpressionSecond :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionSecond();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionSecond();
+    };
+
+
+    class ExpressionStrcasecmp :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionStrcasecmp();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionStrcasecmp();
+    };
+
+
+    class ExpressionSubstr :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionSubstr();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionSubstr();
+    };
+
+
+    class ExpressionSubtract :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionSubtract();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionSubtract();
+    };
+
+
+    class ExpressionToLower :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionToLower();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionToLower();
+    };
+
+
+    class ExpressionToUpper :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionToUpper();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionToUpper();
+    };
+
+
+    class ExpressionWeek :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionWeek();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionWeek();
+    };
+
+
+    class ExpressionYear :
+        public ExpressionNary {
+    public:
+        // virtuals from ExpressionNary
+        virtual ~ExpressionYear();
+        virtual intrusive_ptr<const Value> evaluate(
+            const intrusive_ptr<Document> &pDocument) const;
+        virtual const char *getOpName() const;
+        virtual void addOperand(const intrusive_ptr<Expression> &pExpression);
+
+        static intrusive_ptr<ExpressionNary> create();
+
+    private:
+        ExpressionYear();
+    };
+}
+
+
+/* ======================= INLINED IMPLEMENTATIONS ========================== */
+
+namespace mongo {
+
+    inline bool Expression::ObjectCtx::unwindOk() const {
+        return ((options & UNWIND_OK) != 0);
+    }
+
+    inline bool Expression::ObjectCtx::unwindUsed() const {
+        return (unwindField.size() != 0);
+    }
+
+    inline int Expression::signum(int i) {
+        if (i < 0)
+            return -1;
+        if (i > 0)
+            return 1;
+        return 0;
+    }
+
+    inline intrusive_ptr<const Value> ExpressionConstant::getValue() const {
+        return pValue;
+    }
+
+    inline string ExpressionFieldPath::getFieldPath(bool fieldPrefix) const {
+        return fieldPath.getPath(fieldPrefix);
+    }
+
+    inline void ExpressionFieldPath::writeFieldPath(
+        ostream &outStream, bool fieldPrefix) const {
+        return fieldPath.writePath(outStream, fieldPrefix);
+    }
+
+    inline size_t ExpressionObject::getFieldCount() const {
+        return vFieldName.size();
+    }
+
+    inline ExpressionObject::BuilderPathSink::BuilderPathSink(
+        BSONObjBuilder *pB):
+        pBuilder(pB) {
+    }
+
+    inline ExpressionObject::PathPusher::PathPusher(
+        vector<string> *pTheVPath, const string &s):
+        pvPath(pTheVPath) {
+        pvPath->push_back(s);
+    }
+
+    inline ExpressionObject::PathPusher::~PathPusher() {
+        pvPath->pop_back();
+    }
+
+}
diff --git a/src/mongo/db/pipeline/expression_context.cpp b/src/mongo/db/pipeline/expression_context.cpp
index dcc8680d9ce..c2229486b15 100755
--- a/src/mongo/db/pipeline/expression_context.cpp
+++ b/src/mongo/db/pipeline/expression_context.cpp
@@ -1,48 +1,48 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-

-#include "db/interrupt_status.h"

-#include "db/pipeline/expression_context.h"

-

-namespace mongo {

-

-    ExpressionContext::~ExpressionContext() {

-    }

-

-    inline ExpressionContext::ExpressionContext(InterruptStatus *pS):

-        inShard(false),

-        inRouter(false),

-        intCheckCounter(1),

-        pStatus(pS) {

-    }

-

-    void ExpressionContext::checkForInterrupt() {

-        /*

-          Only really check periodically; the check gets a mutex, and could

-          be expensive, at least in relative terms.

-        */

-        if ((++intCheckCounter % 128) == 0) {

-            pStatus->checkForInterrupt();

-        }

-    }

-

-    ExpressionContext *ExpressionContext::create(InterruptStatus *pStatus) {

-        return new ExpressionContext(pStatus);

-    }

-

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+
+#include "db/interrupt_status.h"
+#include "db/pipeline/expression_context.h"
+
+namespace mongo {
+
+    ExpressionContext::~ExpressionContext() {
+    }
+
+    inline ExpressionContext::ExpressionContext(InterruptStatus *pS):
+        inShard(false),
+        inRouter(false),
+        intCheckCounter(1),
+        pStatus(pS) {
+    }
+
+    void ExpressionContext::checkForInterrupt() {
+        /*
+          Only really check periodically; the check gets a mutex, and could
+          be expensive, at least in relative terms.
+        */
+        if ((++intCheckCounter % 128) == 0) {
+            pStatus->checkForInterrupt();
+        }
+    }
+
+    ExpressionContext *ExpressionContext::create(InterruptStatus *pStatus) {
+        return new ExpressionContext(pStatus);
+    }
+
+}
diff --git a/src/mongo/db/pipeline/expression_context.h b/src/mongo/db/pipeline/expression_context.h
index 893826af222..054d2038cc0 100755
--- a/src/mongo/db/pipeline/expression_context.h
+++ b/src/mongo/db/pipeline/expression_context.h
@@ -1,78 +1,78 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#pragma once

-

-#include "pch.h"

-

-#include "util/intrusive_counter.h"

-

-namespace mongo {

-

-    class InterruptStatus;

-

-    class ExpressionContext :

-        public IntrusiveCounterUnsigned {

-    public:

-        virtual ~ExpressionContext();

-

-        void setInShard(bool b);

-        void setInRouter(bool b);

-

-        bool getInShard() const;

-        bool getInRouter() const;

-

-        /**

-           Used by a pipeline to check for interrupts so that killOp() works.

-

-           @throws if the operation has been interrupted

-         */

-        void checkForInterrupt();

-

-        static ExpressionContext *create(InterruptStatus *pStatus);

-

-    private:

-        ExpressionContext(InterruptStatus *pStatus);

-        

-        bool inShard;

-        bool inRouter;

-        unsigned intCheckCounter; // interrupt check counter

-        InterruptStatus *const pStatus;

-    };

-}

-

-

-/* ======================= INLINED IMPLEMENTATIONS ========================== */

-

-namespace mongo {

-

-    inline void ExpressionContext::setInShard(bool b) {

-        inShard = b;

-    }

-    

-    inline void ExpressionContext::setInRouter(bool b) {

-        inRouter = b;

-    }

-

-    inline bool ExpressionContext::getInShard() const {

-        return inShard;

-    }

-

-    inline bool ExpressionContext::getInRouter() const {

-        return inRouter;

-    }

-

-};

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "pch.h"
+
+#include "util/intrusive_counter.h"
+
+namespace mongo {
+
+    class InterruptStatus;
+
+    class ExpressionContext :
+        public IntrusiveCounterUnsigned {
+    public:
+        virtual ~ExpressionContext();
+
+        void setInShard(bool b);
+        void setInRouter(bool b);
+
+        bool getInShard() const;
+        bool getInRouter() const;
+
+        /**
+           Used by a pipeline to check for interrupts so that killOp() works.
+
+           @throws if the operation has been interrupted
+         */
+        void checkForInterrupt();
+
+        static ExpressionContext *create(InterruptStatus *pStatus);
+
+    private:
+        ExpressionContext(InterruptStatus *pStatus);
+        
+        bool inShard;
+        bool inRouter;
+        unsigned intCheckCounter; // interrupt check counter
+        InterruptStatus *const pStatus;
+    };
+}
+
+
+/* ======================= INLINED IMPLEMENTATIONS ========================== */
+
+namespace mongo {
+
+    inline void ExpressionContext::setInShard(bool b) {
+        inShard = b;
+    }
+    
+    inline void ExpressionContext::setInRouter(bool b) {
+        inRouter = b;
+    }
+
+    inline bool ExpressionContext::getInShard() const {
+        return inShard;
+    }
+
+    inline bool ExpressionContext::getInRouter() const {
+        return inRouter;
+    }
+
+};
diff --git a/src/mongo/db/pipeline/field_path.cpp b/src/mongo/db/pipeline/field_path.cpp
index e79d2b1e940..459c4b69e68 100755
--- a/src/mongo/db/pipeline/field_path.cpp
+++ b/src/mongo/db/pipeline/field_path.cpp
@@ -1,90 +1,90 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#include "pch.h"

-#include "db/pipeline/field_path.h"

-#include "util/mongoutils/str.h"

-

-namespace mongo {

-

-    using namespace mongoutils;

-

-    const char FieldPath::prefix[] = "$";

-

-    FieldPath::~FieldPath() {

-    }

-

-    FieldPath::FieldPath():

-        vFieldName() {

-    }

-

-    FieldPath::FieldPath(const string &fieldPath):

-        vFieldName() {

-        /*

-          The field path could be using dot notation.

-          Break the field path up by peeling off successive pieces.

-        */

-        size_t startpos = 0;

-        while(true) {

-            /* find the next dot */

-            const size_t dotpos = fieldPath.find('.', startpos);

-

-            /* if there are no more dots, use the remainder of the string */

-            if (dotpos == fieldPath.npos) {

-                vFieldName.push_back(fieldPath.substr(startpos, dotpos));

-                break;

-            }

-

-            /* use the string up to the dot */

-            const size_t length = dotpos - startpos;

-            uassert(15998, str::stream() <<

-                    "field names cannot be zero length (in path \"" <<

-                    fieldPath << "\")",

-                    length > 0);

-

-            vFieldName.push_back(fieldPath.substr(startpos, length));

-

-            /* next time, search starting one spot after that */

-            startpos = dotpos + 1;

-        }

-    }

-

-    string FieldPath::getPath(bool fieldPrefix) const {

-        stringstream ss;

-        writePath(ss, fieldPrefix);

-        return ss.str();

-    }

-

-    void FieldPath::writePath(ostream &outStream, bool fieldPrefix) const {

-        if (fieldPrefix)

-            outStream << prefix;

-

-        outStream << vFieldName[0];

-

-        const size_t n = vFieldName.size();

-        for(size_t i = 1; i < n; ++i)

-            outStream << "." << vFieldName[i];

-    }

-

-    FieldPath &FieldPath::operator=(const FieldPath &rRHS) {

-        if (this != &rRHS) {

-            vFieldName = rRHS.vFieldName;

-        }

-

-        return *this;

-    }

-

-}

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "db/pipeline/field_path.h"
+#include "util/mongoutils/str.h"
+
+namespace mongo {
+
+    using namespace mongoutils;
+
+    const char FieldPath::prefix[] = "$";
+
+    FieldPath::~FieldPath() {
+    }
+
+    FieldPath::FieldPath():
+        vFieldName() {
+    }
+
+    FieldPath::FieldPath(const string &fieldPath):
+        vFieldName() {
+        /*
+          The field path could be using dot notation.
+          Break the field path up by peeling off successive pieces.
+        */
+        size_t startpos = 0;
+        while(true) {
+            /* find the next dot */
+            const size_t dotpos = fieldPath.find('.', startpos);
+
+            /* if there are no more dots, use the remainder of the string */
+            if (dotpos == fieldPath.npos) {
+                vFieldName.push_back(fieldPath.substr(startpos, dotpos));
+                break;
+            }
+
+            /* use the string up to the dot */
+            const size_t length = dotpos - startpos;
+            uassert(15998, str::stream() <<
+                    "field names cannot be zero length (in path \"" <<
+                    fieldPath << "\")",
+                    length > 0);
+
+            vFieldName.push_back(fieldPath.substr(startpos, length));
+
+            /* next time, search starting one spot after that */
+            startpos = dotpos + 1;
+        }
+    }
+
+    string FieldPath::getPath(bool fieldPrefix) const {
+        stringstream ss;
+        writePath(ss, fieldPrefix);
+        return ss.str();
+    }
+
+    void FieldPath::writePath(ostream &outStream, bool fieldPrefix) const {
+        if (fieldPrefix)
+            outStream << prefix;
+
+        outStream << vFieldName[0];
+
+        const size_t n = vFieldName.size();
+        for(size_t i = 1; i < n; ++i)
+            outStream << "." << vFieldName[i];
+    }
+
+    FieldPath &FieldPath::operator=(const FieldPath &rRHS) {
+        if (this != &rRHS) {
+            vFieldName = rRHS.vFieldName;
+        }
+
+        return *this;
+    }
+
+}
diff --git a/src/mongo/db/pipeline/field_path.h b/src/mongo/db/pipeline/field_path.h
index 618eb283e3e..f6f59ad3295 100755
--- a/src/mongo/db/pipeline/field_path.h
+++ b/src/mongo/db/pipeline/field_path.h
@@ -1,109 +1,109 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#pragma once

-

-#include "pch.h"

-

-namespace mongo {

-

-    class FieldPath {

-    public:

-        virtual ~FieldPath();

-

-        /**

-           Constructor.

-

-           @param fieldPath the dotted field path string

-         */

-        FieldPath(const string &fieldPath);

-

-        /**

-           Constructor.

-        */

-        FieldPath();

-

-        /**

-          Get the number of path elements in the field path.

-

-          @returns the number of path elements

-         */

-        size_t getPathLength() const;

-

-        /**

-          Get a particular path element from the path.

-

-          @param i the index of the path element

-          @returns the path element

-         */

-        string getFieldName(size_t i) const;

-

-        /**

-          Get the full path.

-

-          @param fieldPrefix whether or not to include the field prefix

-          @returns the complete field path

-         */

-        string getPath(bool fieldPrefix) const;

-

-        /**

-          Write the full path.

-

-          @param outStream where to write the path to

-          @param fieldPrefix whether or not to include the field prefix

-        */

-        void writePath(ostream &outStream, bool fieldPrefix) const;

-

-        /**

-           Assignment operator.

-

-           @param rRHS right hand side of the assignment

-        */

-        FieldPath &operator=(const FieldPath &rRHS);

-

-        /**

-           Get the prefix string.

-

-           @returns the prefix string

-         */

-        static const char *getPrefix();

-

-        static const char prefix[];

-

-    private:

-        vector<string> vFieldName;

-    };

-}

-

-

-/* ======================= INLINED IMPLEMENTATIONS ========================== */

-

-namespace mongo {

-

-    inline size_t FieldPath::getPathLength() const {

-        return vFieldName.size();

-    }

-

-    inline string FieldPath::getFieldName(size_t i) const {

-        return vFieldName[i];

-    }

-

-    inline const char *FieldPath::getPrefix() {

-        return prefix;

-    }

-

-}

-

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "pch.h"
+
+namespace mongo {
+
+    class FieldPath {
+    public:
+        virtual ~FieldPath();
+
+        /**
+           Constructor.
+
+           @param fieldPath the dotted field path string
+         */
+        FieldPath(const string &fieldPath);
+
+        /**
+           Constructor.
+        */
+        FieldPath();
+
+        /**
+          Get the number of path elements in the field path.
+
+          @returns the number of path elements
+         */
+        size_t getPathLength() const;
+
+        /**
+          Get a particular path element from the path.
+
+          @param i the index of the path element
+          @returns the path element
+         */
+        string getFieldName(size_t i) const;
+
+        /**
+          Get the full path.
+
+          @param fieldPrefix whether or not to include the field prefix
+          @returns the complete field path
+         */
+        string getPath(bool fieldPrefix) const;
+
+        /**
+          Write the full path.
+
+          @param outStream where to write the path to
+          @param fieldPrefix whether or not to include the field prefix
+        */
+        void writePath(ostream &outStream, bool fieldPrefix) const;
+
+        /**
+           Assignment operator.
+
+           @param rRHS right hand side of the assignment
+        */
+        FieldPath &operator=(const FieldPath &rRHS);
+
+        /**
+           Get the prefix string.
+
+           @returns the prefix string
+         */
+        static const char *getPrefix();
+
+        static const char prefix[];
+
+    private:
+        vector<string> vFieldName;
+    };
+}
+
+
+/* ======================= INLINED IMPLEMENTATIONS ========================== */
+
+namespace mongo {
+
+    inline size_t FieldPath::getPathLength() const {
+        return vFieldName.size();
+    }
+
+    inline string FieldPath::getFieldName(size_t i) const {
+        return vFieldName[i];
+    }
+
+    inline const char *FieldPath::getPrefix() {
+        return prefix;
+    }
+
+}
+
diff --git a/src/mongo/db/pipeline/value.h b/src/mongo/db/pipeline/value.h
index ddfcade02d4..f3eada1cbce 100755
--- a/src/mongo/db/pipeline/value.h
+++ b/src/mongo/db/pipeline/value.h
@@ -1,469 +1,469 @@
-/**

- * Copyright (c) 2011 10gen Inc.

- *

- * This program is free software: you can redistribute it and/or  modify

- * it under the terms of the GNU Affero General Public License, version 3,

- * as published by the Free Software Foundation.

- *

- * This program is distributed in the hope that it will be useful,

- * but WITHOUT ANY WARRANTY; without even the implied warranty of

- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

- * GNU Affero General Public License for more details.

- *

- * You should have received a copy of the GNU Affero General Public License

- * along with this program.  If not, see <http://www.gnu.org/licenses/>.

- */

-

-#pragma once

-

-#include "pch.h"

-#include "bson/bsontypes.h"

-#include "bson/oid.h"

-#include "util/intrusive_counter.h"

-

-namespace mongo {

-    class BSONElement;

-    class Builder;

-    class Document;

-    class Value;

-

-    class ValueIterator :

-        public IntrusiveCounterUnsigned {

-    public:

-        virtual ~ValueIterator();

-

-        /*

-          Ask if there are more fields to return.

-

-          @returns true if there are more fields, false otherwise

-        */

-        virtual bool more() const = 0;

-

-        /*

-          Move the iterator to point to the next field and return it.

-

-          @returns the next field's <name, Value>

-        */

-        virtual intrusive_ptr<const Value> next() = 0;

-    };

-

-

-    /*

-      Values are immutable, so these are passed around as

-      intrusive_ptr<const Value>.

-     */

-    class Value :

-        public IntrusiveCounterUnsigned {

-    public:

-        ~Value();

-

-        /*

-          Construct a Value from a BSONElement.

-

-          This ignores the name of the element, and only uses the value,

-          whatever type it is.

-

-          @returns a new Value initialized from the bsonElement

-        */

-        static intrusive_ptr<const Value> createFromBsonElement(

-            BSONElement *pBsonElement);

-

-        /*

-          Construct an integer-valued Value.

-

-          For commonly used values, consider using one of the singleton

-          instances defined below.

-

-          @param value the value

-          @returns a Value with the given value

-        */

-        static intrusive_ptr<const Value> createInt(int value);

-

-        /*

-          Construct an long(long)-valued Value.

-

-          For commonly used values, consider using one of the singleton

-          instances defined below.

-

-          @param value the value

-          @returns a Value with the given value

-        */

-        static intrusive_ptr<const Value> createLong(long long value);

-

-        /*

-          Construct a double-valued Value.

-

-          @param value the value

-          @returns a Value with the given value

-        */

-        static intrusive_ptr<const Value> createDouble(double value);

-

-        /*

-          Construct a string-valued Value.

-

-          @param value the value

-          @returns a Value with the given value

-        */

-        static intrusive_ptr<const Value> createString(const string &value);

-

-        /*

-          Construct a date-valued Value.

-

-          @param value the value

-          @returns a Value with the given value

-        */

-        static intrusive_ptr<const Value> createDate(const Date_t &value);

-

-        /*

-          Construct a document-valued Value.

-

-          @param value the value

-          @returns a Value with the given value

-        */

-        static intrusive_ptr<const Value> createDocument(

-            const intrusive_ptr<Document> &pDocument);

-

-        /*

-          Construct an array-valued Value.

-

-          @param value the value

-          @returns a Value with the given value

-        */

-        static intrusive_ptr<const Value> createArray(

-            const vector<intrusive_ptr<const Value> > &vpValue);

-

-        /*

-          Get the BSON type of the field.

-

-          If the type is jstNULL, no value getter will work.

-

-          @return the BSON type of the field.

-        */

-        BSONType getType() const;

-

-        /*

-          Getters.

-

-          @returns the Value's value; asserts if the requested value type is

-          incorrect.

-        */

-        double getDouble() const;

-        string getString() const;

-        intrusive_ptr<Document> getDocument() const;

-        intrusive_ptr<ValueIterator> getArray() const;

-        OID getOid() const;

-        bool getBool() const;

-        Date_t getDate() const;

-        string getRegex() const;

-        string getSymbol() const;

-        int getInt() const;

-        unsigned long long getTimestamp() const;

-        long long getLong() const;

-

-        /*

-          Get the length of an array value.

-

-          @returns the length of the array, if this is array-valued; otherwise

-             throws an error

-        */

-        size_t getArrayLength() const;

-

-        /*

-          Add this value to the BSON object under construction.

-        */

-        void addToBsonObj(BSONObjBuilder *pBuilder, string fieldName) const;

-

-        /*

-          Add this field to the BSON array under construction.

-

-          As part of an array, the Value's name will be ignored.

-        */

-        void addToBsonArray(BSONArrayBuilder *pBuilder) const;

-

-        /*

-          Get references to singleton instances of commonly used field values.

-         */

-        static intrusive_ptr<const Value> getUndefined();

-        static intrusive_ptr<const Value> getNull();

-        static intrusive_ptr<const Value> getTrue();

-        static intrusive_ptr<const Value> getFalse();

-        static intrusive_ptr<const Value> getMinusOne();

-        static intrusive_ptr<const Value> getZero();

-        static intrusive_ptr<const Value> getOne();

-

-        /*

-          Coerce (cast) a value to a native bool, using JSON rules.

-

-          @returns the bool value

-        */

-        bool coerceToBool() const;

-

-        /*

-          Coerce (cast) a value to a Boolean Value, using JSON rules.

-

-          @returns the Boolean Value value

-        */

-        intrusive_ptr<const Value> coerceToBoolean() const;

-

-        /*

-          Coerce (cast) a value to an int, using JSON rules.

-

-          @returns the int value

-        */

-        int coerceToInt() const;

-

-        /*

-          Coerce (cast) a value to a long long, using JSON rules.

-

-          @returns the long value

-        */

-        long long coerceToLong() const;

-

-        /*

-          Coerce (cast) a value to a double, using JSON rules.

-

-          @returns the double value

-        */

-        double coerceToDouble() const;

-

-        /*

-          Coerce (cast) a value to a date, using JSON rules.

-

-          @returns the date value

-        */

-        Date_t coerceToDate() const;

-

-        /*

-          Coerce (cast) a value to a string, using JSON rules.

-

-          @returns the date value

-        */

-        string coerceToString() const;

-

-        /*

-          Compare two Values.

-

-          @param rL left value

-          @param rR right value

-          @returns an integer less than zero, zero, or an integer greater than

-            zero, depending on whether rL < rR, rL == rR, or rL > rR

-         */

-        static int compare(const intrusive_ptr<const Value> &rL,

-                           const intrusive_ptr<const Value> &rR);

-

-

-        /*

-          Figure out what the widest of two numeric types is.

-

-          Widest can be thought of as "most capable," or "able to hold the

-          largest or most precise value."  The progression is Int, Long, Double.

-

-          @param rL left value

-          @param rR right value

-          @returns a BSONType of NumberInt, NumberLong, or NumberDouble

-        */

-        static BSONType getWidestNumeric(BSONType lType, BSONType rType);

-

-        /*

-          Get the approximate storage size of the value, in bytes.

-

-          @returns approximate storage size of the value.

-         */

-        size_t getApproximateSize() const;

-

-        /*

-          Calculate a hash value.

-

-          Meant to be used to create composite hashes suitable for

-          boost classes such as unordered_map<>.

-

-          @param seed value to augment with this' hash

-        */

-        void hash_combine(size_t &seed) const;

-

-        /*

-          struct Hash is defined to enable the use of Values as

-          keys in boost::unordered_map<>.

-

-          Values are always referenced as immutables in the form

-          intrusive_ptr<const Value>, so these operate on that construction.

-        */

-        struct Hash :

-            unary_function<intrusive_ptr<const Value>, size_t> {

-            size_t operator()(const intrusive_ptr<const Value> &rV) const;

-        };

-

-    protected:

-        Value(); // creates null value

-        Value(BSONType type); // creates an empty (unitialized value) of type

-                                                // mostly useful for Undefined

-        Value(bool boolValue);

-        Value(int intValue);

-

-    private:

-        Value(BSONElement *pBsonElement);

-

-        Value(long long longValue);

-        Value(double doubleValue);

-        Value(const Date_t &dateValue);

-        Value(const string &stringValue);

-        Value(const intrusive_ptr<Document> &pDocument);

-        Value(const vector<intrusive_ptr<const Value> > &vpValue);

-

-        void addToBson(Builder *pBuilder) const;

-

-        BSONType type;

-

-        /* store value in one of these */

-        union {

-            double doubleValue;

-            bool boolValue;

-            int intValue;

-            unsigned long long timestampValue;

-            long long longValue;

-

-        } simple; // values that don't need a ctor/dtor

-        OID oidValue;

-        Date_t dateValue;

-        string stringValue; // String, Regex, Symbol

-        intrusive_ptr<Document> pDocumentValue;

-        vector<intrusive_ptr<const Value> > vpValue; // for arrays

-

-

-        /*

-        These are often used as the result of boolean or comparison

-        expressions.

-

-        These are obtained via public static getters defined above.

-        */

-        static const intrusive_ptr<const Value> pFieldUndefined;

-        static const intrusive_ptr<const Value> pFieldNull;

-        static const intrusive_ptr<const Value> pFieldTrue;

-        static const intrusive_ptr<const Value> pFieldFalse;

-        static const intrusive_ptr<const Value> pFieldMinusOne;

-        static const intrusive_ptr<const Value> pFieldZero;

-        static const intrusive_ptr<const Value> pFieldOne;

-

-        /* this implementation is used for getArray() */

-        class vi :

-            public ValueIterator {

-        public:

-            // virtuals from ValueIterator

-            virtual ~vi();

-            virtual bool more() const;

-            virtual intrusive_ptr<const Value> next();

-

-        private:

-            friend class Value;

-            vi(const intrusive_ptr<const Value> &pSource,

-               const vector<intrusive_ptr<const Value> > *pvpValue);

-

-            size_t size;

-            size_t nextIndex;

-            const vector<intrusive_ptr<const Value> > *pvpValue;

-        }; /* class vi */

-

-    };

-

-    /*

-      Equality operator for values.

-

-      Useful for unordered_map<>, etc.

-     */

-    inline bool operator==(const intrusive_ptr<const Value> &v1,

-                    const intrusive_ptr<const Value> &v2) {

-        return (Value::compare(v1, v2) == 0);

-    }

-

-    /*

-      For performance reasons, there are various sharable static values

-      defined in class Value, obtainable by methods such as getUndefined(),

-      getTrue(), getOne(), etc.  We don't want these to go away as they are

-      used by a multitude of threads evaluating pipelines.  In order to avoid

-      having to use atomic integers in the intrusive reference counter, this

-      class overrides the reference counting methods to do nothing, making it

-      safe to use for static Values.

-

-      At this point, only the constructors necessary for the static Values in

-      common use have been defined.  The remainder can be defined if necessary.

-     */

-    class ValueStatic :

-        public Value {

-    public:

-        // virtuals from IntrusiveCounterUnsigned

-        virtual void addRef() const;

-        virtual void release() const;

-

-        // constructors

-        ValueStatic();

-        ValueStatic(BSONType type);

-        ValueStatic(bool boolValue);

-        ValueStatic(int intValue);

-    };

-}

-

-/* ======================= INLINED IMPLEMENTATIONS ========================== */

-

-namespace mongo {

-

-    inline BSONType Value::getType() const {

-        return type;

-    }

-

-    inline size_t Value::getArrayLength() const {

-        verify(getType() == Array);

-        return vpValue.size();

-    }

-

-    inline intrusive_ptr<const Value> Value::getUndefined() {

-        return pFieldUndefined;

-    }

-

-    inline intrusive_ptr<const Value> Value::getNull() {

-        return pFieldNull;

-    }

-

-    inline intrusive_ptr<const Value> Value::getTrue() {

-        return pFieldTrue;

-    }

-

-    inline intrusive_ptr<const Value> Value::getFalse() {

-        return pFieldFalse;

-    }

-

-    inline intrusive_ptr<const Value> Value::getMinusOne() {

-        return pFieldMinusOne;

-    }

-

-    inline intrusive_ptr<const Value> Value::getZero() {

-        return pFieldZero;

-    }

-

-    inline intrusive_ptr<const Value> Value::getOne() {

-        return pFieldOne;

-    }

-

-    inline size_t Value::Hash::operator()(

-        const intrusive_ptr<const Value> &rV) const {

-        size_t seed = 0xf0afbeef;

-        rV->hash_combine(seed);

-        return seed;

-    }

-

-    inline ValueStatic::ValueStatic():

-        Value() {

-    }

-

-    inline ValueStatic::ValueStatic(BSONType type):

-        Value(type) {

-    }

-

-    inline ValueStatic::ValueStatic(bool boolValue):

-        Value(boolValue) {

-    }

-

-    inline ValueStatic::ValueStatic(int intValue):

-        Value(intValue) {

-    }

-

-};

+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "pch.h"
+#include "bson/bsontypes.h"
+#include "bson/oid.h"
+#include "util/intrusive_counter.h"
+
+namespace mongo {
+    class BSONElement;
+    class Builder;
+    class Document;
+    class Value;
+
+    class ValueIterator :
+        public IntrusiveCounterUnsigned {
+    public:
+        virtual ~ValueIterator();
+
+        /*
+          Ask if there are more fields to return.
+
+          @returns true if there are more fields, false otherwise
+        */
+        virtual bool more() const = 0;
+
+        /*
+          Move the iterator to point to the next field and return it.
+
+          @returns the next field's <name, Value>
+        */
+        virtual intrusive_ptr<const Value> next() = 0;
+    };
+
+
+    /*
+      Values are immutable, so these are passed around as
+      intrusive_ptr<const Value>.
+     */
+    class Value :
+        public IntrusiveCounterUnsigned {
+    public:
+        ~Value();
+
+        /*
+          Construct a Value from a BSONElement.
+
+          This ignores the name of the element, and only uses the value,
+          whatever type it is.
+
+          @returns a new Value initialized from the bsonElement
+        */
+        static intrusive_ptr<const Value> createFromBsonElement(
+            BSONElement *pBsonElement);
+
+        /*
+          Construct an integer-valued Value.
+
+          For commonly used values, consider using one of the singleton
+          instances defined below.
+
+          @param value the value
+          @returns a Value with the given value
+        */
+        static intrusive_ptr<const Value> createInt(int value);
+
+        /*
+          Construct an long(long)-valued Value.
+
+          For commonly used values, consider using one of the singleton
+          instances defined below.
+
+          @param value the value
+          @returns a Value with the given value
+        */
+        static intrusive_ptr<const Value> createLong(long long value);
+
+        /*
+          Construct a double-valued Value.
+
+          @param value the value
+          @returns a Value with the given value
+        */
+        static intrusive_ptr<const Value> createDouble(double value);
+
+        /*
+          Construct a string-valued Value.
+
+          @param value the value
+          @returns a Value with the given value
+        */
+        static intrusive_ptr<const Value> createString(const string &value);
+
+        /*
+          Construct a date-valued Value.
+
+          @param value the value
+          @returns a Value with the given value
+        */
+        static intrusive_ptr<const Value> createDate(const Date_t &value);
+
+        /*
+          Construct a document-valued Value.
+
+          @param value the value
+          @returns a Value with the given value
+        */
+        static intrusive_ptr<const Value> createDocument(
+            const intrusive_ptr<Document> &pDocument);
+
+        /*
+          Construct an array-valued Value.
+
+          @param value the value
+          @returns a Value with the given value
+        */
+        static intrusive_ptr<const Value> createArray(
+            const vector<intrusive_ptr<const Value> > &vpValue);
+
+        /*
+          Get the BSON type of the field.
+
+          If the type is jstNULL, no value getter will work.
+
+          @return the BSON type of the field.
+        */
+        BSONType getType() const;
+
+        /*
+          Getters.
+
+          @returns the Value's value; asserts if the requested value type is
+          incorrect.
+        */
+        double getDouble() const;
+        string getString() const;
+        intrusive_ptr<Document> getDocument() const;
+        intrusive_ptr<ValueIterator> getArray() const;
+        OID getOid() const;
+        bool getBool() const;
+        Date_t getDate() const;
+        string getRegex() const;
+        string getSymbol() const;
+        int getInt() const;
+        unsigned long long getTimestamp() const;
+        long long getLong() const;
+
+        /*
+          Get the length of an array value.
+
+          @returns the length of the array, if this is array-valued; otherwise
+             throws an error
+        */
+        size_t getArrayLength() const;
+
+        /*
+          Add this value to the BSON object under construction.
+        */
+        void addToBsonObj(BSONObjBuilder *pBuilder, string fieldName) const;
+
+        /*
+          Add this field to the BSON array under construction.
+
+          As part of an array, the Value's name will be ignored.
+        */
+        void addToBsonArray(BSONArrayBuilder *pBuilder) const;
+
+        /*
+          Get references to singleton instances of commonly used field values.
+         */
+        static intrusive_ptr<const Value> getUndefined();
+        static intrusive_ptr<const Value> getNull();
+        static intrusive_ptr<const Value> getTrue();
+        static intrusive_ptr<const Value> getFalse();
+        static intrusive_ptr<const Value> getMinusOne();
+        static intrusive_ptr<const Value> getZero();
+        static intrusive_ptr<const Value> getOne();
+
+        /*
+          Coerce (cast) a value to a native bool, using JSON rules.
+
+          @returns the bool value
+        */
+        bool coerceToBool() const;
+
+        /*
+          Coerce (cast) a value to a Boolean Value, using JSON rules.
+
+          @returns the Boolean Value value
+        */
+        intrusive_ptr<const Value> coerceToBoolean() const;
+
+        /*
+          Coerce (cast) a value to an int, using JSON rules.
+
+          @returns the int value
+        */
+        int coerceToInt() const;
+
+        /*
+          Coerce (cast) a value to a long long, using JSON rules.
+
+          @returns the long value
+        */
+        long long coerceToLong() const;
+
+        /*
+          Coerce (cast) a value to a double, using JSON rules.
+
+          @returns the double value
+        */
+        double coerceToDouble() const;
+
+        /*
+          Coerce (cast) a value to a date, using JSON rules.
+
+          @returns the date value
+        */
+        Date_t coerceToDate() const;
+
+        /*
+          Coerce (cast) a value to a string, using JSON rules.
+
+          @returns the date value
+        */
+        string coerceToString() const;
+
+        /*
+          Compare two Values.
+
+          @param rL left value
+          @param rR right value
+          @returns an integer less than zero, zero, or an integer greater than
+            zero, depending on whether rL < rR, rL == rR, or rL > rR
+         */
+        static int compare(const intrusive_ptr<const Value> &rL,
+                           const intrusive_ptr<const Value> &rR);
+
+
+        /*
+          Figure out what the widest of two numeric types is.
+
+          Widest can be thought of as "most capable," or "able to hold the
+          largest or most precise value."  The progression is Int, Long, Double.
+
+          @param rL left value
+          @param rR right value
+          @returns a BSONType of NumberInt, NumberLong, or NumberDouble
+        */
+        static BSONType getWidestNumeric(BSONType lType, BSONType rType);
+
+        /*
+          Get the approximate storage size of the value, in bytes.
+
+          @returns approximate storage size of the value.
+         */
+        size_t getApproximateSize() const;
+
+        /*
+          Calculate a hash value.
+
+          Meant to be used to create composite hashes suitable for
+          boost classes such as unordered_map<>.
+
+          @param seed value to augment with this' hash
+        */
+        void hash_combine(size_t &seed) const;
+
+        /*
+          struct Hash is defined to enable the use of Values as
+          keys in boost::unordered_map<>.
+
+          Values are always referenced as immutables in the form
+          intrusive_ptr<const Value>, so these operate on that construction.
+        */
+        struct Hash :
+            unary_function<intrusive_ptr<const Value>, size_t> {
+            size_t operator()(const intrusive_ptr<const Value> &rV) const;
+        };
+
+    protected:
+        Value(); // creates null value
+        Value(BSONType type); // creates an empty (unitialized value) of type
+                                                // mostly useful for Undefined
+        Value(bool boolValue);
+        Value(int intValue);
+
+    private:
+        Value(BSONElement *pBsonElement);
+
+        Value(long long longValue);
+        Value(double doubleValue);
+        Value(const Date_t &dateValue);
+        Value(const string &stringValue);
+        Value(const intrusive_ptr<Document> &pDocument);
+        Value(const vector<intrusive_ptr<const Value> > &vpValue);
+
+        void addToBson(Builder *pBuilder) const;
+
+        BSONType type;
+
+        /* store value in one of these */
+        union {
+            double doubleValue;
+            bool boolValue;
+            int intValue;
+            unsigned long long timestampValue;
+            long long longValue;
+
+        } simple; // values that don't need a ctor/dtor
+        OID oidValue;
+        Date_t dateValue;
+        string stringValue; // String, Regex, Symbol
+        intrusive_ptr<Document> pDocumentValue;
+        vector<intrusive_ptr<const Value> > vpValue; // for arrays
+
+
+        /*
+        These are often used as the result of boolean or comparison
+        expressions.
+
+        These are obtained via public static getters defined above.
+        */
+        static const intrusive_ptr<const Value> pFieldUndefined;
+        static const intrusive_ptr<const Value> pFieldNull;
+        static const intrusive_ptr<const Value> pFieldTrue;
+        static const intrusive_ptr<const Value> pFieldFalse;
+        static const intrusive_ptr<const Value> pFieldMinusOne;
+        static const intrusive_ptr<const Value> pFieldZero;
+        static const intrusive_ptr<const Value> pFieldOne;
+
+        /* this implementation is used for getArray() */
+        class vi :
+            public ValueIterator {
+        public:
+            // virtuals from ValueIterator
+            virtual ~vi();
+            virtual bool more() const;
+            virtual intrusive_ptr<const Value> next();
+
+        private:
+            friend class Value;
+            vi(const intrusive_ptr<const Value> &pSource,
+               const vector<intrusive_ptr<const Value> > *pvpValue);
+
+            size_t size;
+            size_t nextIndex;
+            const vector<intrusive_ptr<const Value> > *pvpValue;
+        }; /* class vi */
+
+    };
+
+    /*
+      Equality operator for values.
+
+      Useful for unordered_map<>, etc.
+     */
+    inline bool operator==(const intrusive_ptr<const Value> &v1,
+                    const intrusive_ptr<const Value> &v2) {
+        return (Value::compare(v1, v2) == 0);
+    }
+
+    /*
+      For performance reasons, there are various sharable static values
+      defined in class Value, obtainable by methods such as getUndefined(),
+      getTrue(), getOne(), etc.  We don't want these to go away as they are
+      used by a multitude of threads evaluating pipelines.  In order to avoid
+      having to use atomic integers in the intrusive reference counter, this
+      class overrides the reference counting methods to do nothing, making it
+      safe to use for static Values.
+
+      At this point, only the constructors necessary for the static Values in
+      common use have been defined.  The remainder can be defined if necessary.
+     */
+    class ValueStatic :
+        public Value {
+    public:
+        // virtuals from IntrusiveCounterUnsigned
+        virtual void addRef() const;
+        virtual void release() const;
+
+        // constructors
+        ValueStatic();
+        ValueStatic(BSONType type);
+        ValueStatic(bool boolValue);
+        ValueStatic(int intValue);
+    };
+}
+
+/* ======================= INLINED IMPLEMENTATIONS ========================== */
+
+namespace mongo {
+
+    inline BSONType Value::getType() const {
+        return type;
+    }
+
+    inline size_t Value::getArrayLength() const {
+        verify(getType() == Array);
+        return vpValue.size();
+    }
+
+    inline intrusive_ptr<const Value> Value::getUndefined() {
+        return pFieldUndefined;
+    }
+
+    inline intrusive_ptr<const Value> Value::getNull() {
+        return pFieldNull;
+    }
+
+    inline intrusive_ptr<const Value> Value::getTrue() {
+        return pFieldTrue;
+    }
+
+    inline intrusive_ptr<const Value> Value::getFalse() {
+        return pFieldFalse;
+    }
+
+    inline intrusive_ptr<const Value> Value::getMinusOne() {
+        return pFieldMinusOne;
+    }
+
+    inline intrusive_ptr<const Value> Value::getZero() {
+        return pFieldZero;
+    }
+
+    inline intrusive_ptr<const Value> Value::getOne() {
+        return pFieldOne;
+    }
+
+    inline size_t Value::Hash::operator()(
+        const intrusive_ptr<const Value> &rV) const {
+        size_t seed = 0xf0afbeef;
+        rV->hash_combine(seed);
+        return seed;
+    }
+
+    inline ValueStatic::ValueStatic():
+        Value() {
+    }
+
+    inline ValueStatic::ValueStatic(BSONType type):
+        Value(type) {
+    }
+
+    inline ValueStatic::ValueStatic(bool boolValue):
+        Value(boolValue) {
+    }
+
+    inline ValueStatic::ValueStatic(int intValue):
+        Value(intValue) {
+    }
+
+};