SERVER-4844

5 files changed, 45 insertions, 12 deletions

diff --git a/src/mongo/db/pipeline/document_source.h b/src/mongo/db/pipeline/document_source.h
index 0a3614198e7..f3fba64922a 100755
--- a/src/mongo/db/pipeline/document_source.h
+++ b/src/mongo/db/pipeline/document_source.h
@@ -953,8 +953,9 @@ namespace mongo {
         virtual ~DocumentSourceLimit();

         virtual bool eof();

         virtual bool advance();

-        virtual const char *getSourceName() const;

         virtual intrusive_ptr<Document> getCurrent();

+        virtual const char *getSourceName() const;

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

 

         /**

           Create a new limiting DocumentSource.

@@ -1003,8 +1004,9 @@ namespace mongo {
         virtual ~DocumentSourceSkip();

         virtual bool eof();

         virtual bool advance();

-        virtual const char *getSourceName() const;

         virtual intrusive_ptr<Document> getCurrent();

+        virtual const char *getSourceName() const;

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

 

         /**

           Create a new skipping DocumentSource.

diff --git a/src/mongo/db/pipeline/document_source_limit.cpp b/src/mongo/db/pipeline/document_source_limit.cpp
index 74fefbd0424..7b04a6c02ce 100644
--- a/src/mongo/db/pipeline/document_source_limit.cpp
+++ b/src/mongo/db/pipeline/document_source_limit.cpp
@@ -41,6 +41,21 @@ namespace mongo {
         return limitName;
     }
 
+    bool DocumentSourceLimit::coalesce(
+        const intrusive_ptr<DocumentSource> &pNextSource) {
+        DocumentSourceLimit *pLimit =
+            dynamic_cast<DocumentSourceLimit *>(pNextSource.get());
+
+        /* if it's not another $skip, we can't coalesce */
+        if (!pLimit)
+            return false;
+
+        /* we need to limit by the minimum of the two limits */
+        if (pLimit->limit < limit)
+            limit = pLimit->limit;
+        return true;
+    }
+
     bool DocumentSourceLimit::eof() {
         return pSource->eof() || count >= limit;
     }
diff --git a/src/mongo/db/pipeline/document_source_skip.cpp b/src/mongo/db/pipeline/document_source_skip.cpp
index f0b2d3d44d9..605f85e7f92 100644
--- a/src/mongo/db/pipeline/document_source_skip.cpp
+++ b/src/mongo/db/pipeline/document_source_skip.cpp
@@ -42,6 +42,20 @@ namespace mongo {
         return skipName;
     }
 
+    bool DocumentSourceSkip::coalesce(
+        const intrusive_ptr<DocumentSource> &pNextSource) {
+        DocumentSourceSkip *pSkip =
+            dynamic_cast<DocumentSourceSkip *>(pNextSource.get());
+
+        /* if it's not another $skip, we can't coalesce */
+        if (!pSkip)
+            return false;
+
+        /* we need to skip over the sum of the two consecutive $skips */
+        skip += pSkip->skip;
+        return true;
+    }
+
     void DocumentSourceSkip::skipper() {
         if (count == 0) {
             while (!pSource->eof() && count++ < skip) {
diff --git a/src/mongo/db/pipeline/expression_context.cpp b/src/mongo/db/pipeline/expression_context.cpp
index cfde1670bfb..b56b243f25f 100755
--- a/src/mongo/db/pipeline/expression_context.cpp
+++ b/src/mongo/db/pipeline/expression_context.cpp
@@ -16,7 +16,7 @@
 

 #include "pch.h"

 

-#include "db/curop.h"

+#include "db/interrupt_status.h"

 #include "db/pipeline/expression_context.h"

 

 namespace mongo {

@@ -24,10 +24,11 @@ namespace mongo {
     ExpressionContext::~ExpressionContext() {

     }

 

-    inline ExpressionContext::ExpressionContext():

+    inline ExpressionContext::ExpressionContext(InterruptStatus *pS):

         inShard(false),

         inRouter(false),

-        intCheckCounter(1) {

+        intCheckCounter(1),

+        pStatus(pS) {

     }

 

     void ExpressionContext::checkForInterrupt() {

@@ -35,14 +36,12 @@ namespace mongo {
           Only really check periodically; the check gets a mutex, and could

           be expensive, at least in relative terms.

         */

-#ifdef MONGO_LATER_SERVER_4844

         if ((++intCheckCounter % 128) == 0)

-            killCurrentOp.checkForInterrupt();

-#endif /* MONGO_LATER_SERVER_4844 */

+            pStatus->checkForInterrupt();

     }

 

-    ExpressionContext *ExpressionContext::create() {

-        return new ExpressionContext();

+    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 0f4de1461ae..893826af222 100755
--- a/src/mongo/db/pipeline/expression_context.h
+++ b/src/mongo/db/pipeline/expression_context.h
@@ -22,6 +22,8 @@
 

 namespace mongo {

 

+    class InterruptStatus;

+

     class ExpressionContext :

         public IntrusiveCounterUnsigned {

     public:

@@ -40,14 +42,15 @@ namespace mongo {
          */

         void checkForInterrupt();

 

-        static ExpressionContext *create();

+        static ExpressionContext *create(InterruptStatus *pStatus);

 

     private:

-        ExpressionContext();

+        ExpressionContext(InterruptStatus *pStatus);

         

         bool inShard;

         bool inRouter;

         unsigned intCheckCounter; // interrupt check counter

+        InterruptStatus *const pStatus;

     };

 }