some client refactoring

6 files changed, 356 insertions, 291 deletions

diff --git a/SConstruct b/SConstruct
index 9aa8d85d4fd..996814bbf84 100644
--- a/SConstruct
+++ b/SConstruct
@@ -364,7 +364,7 @@ commonFiles += [ "util/background.cpp" , "util/mmap.cpp" , "util/ramstore.cpp",
                  "util/assert_util.cpp" , "util/httpclient.cpp" , "util/md5main.cpp" , "util/base64.cpp", "util/debug_util.cpp",
                  "util/thread_pool.cpp" ]
 commonFiles += Glob( "util/*.c" )
-commonFiles += Split( "client/connpool.cpp client/dbclient.cpp client/model.cpp client/syncclusterconnection.cpp" )
+commonFiles += Split( "client/connpool.cpp client/dbclient.cpp client/dbclientcursor.cpp client/model.cpp client/syncclusterconnection.cpp" )
 commonFiles += [ "scripting/engine.cpp" , "scripting/utils.cpp" ]
 
 #mmap stuff
diff --git a/client/connpool.h b/client/connpool.h
index 70ad46a9651..f39fc8da8ae 100644
--- a/client/connpool.h
+++ b/client/connpool.h
@@ -102,18 +102,20 @@ namespace mongo {
         }
         
         ScopedDbConnection()
-            : _host( "" ) , _conn(0 ){
+            : _host( "" ) , _conn(0) {
         }
 
         /** throws UserException if can't connect */
         ScopedDbConnection(const string& host)
             : _host(host), _conn( pool.get(host) ) {
         }
-
+        
         ScopedDbConnection(const string& host, DBClientBase* conn )
             : _host( host ) , _conn( conn ){
         }
         
+        string getHost() const { return _host; }
+
         /** Force closure of the connection.  You should call this if you leave it in
             a bad state.  Destructor will do this too, but it is verbose.
         */
diff --git a/client/dbclient.cpp b/client/dbclient.cpp
index 310b7a11870..d7ff9cb1d82 100644
--- a/client/dbclient.cpp
+++ b/client/dbclient.cpp
@@ -764,151 +764,6 @@ namespace mongo {
         }
     }
 
-    int DBClientCursor::nextBatchSize(){
-        if ( nToReturn == 0 )
-            return batchSize;
-        if ( batchSize == 0 )
-            return nToReturn;
-        
-        return batchSize < nToReturn ? batchSize : nToReturn;
-    }
-
-    bool DBClientCursor::init() {
-        Message toSend;
-        if ( !cursorId ) {
-            assembleRequest( ns, query, nextBatchSize() , nToSkip, fieldsToReturn, opts, toSend );
-        } else {
-            BufBuilder b;
-            b.append( opts );
-            b.append( ns.c_str() );
-            b.append( nToReturn );
-            b.append( cursorId );
-            toSend.setData( dbGetMore, b.buf(), b.len() );
-        }
-        if ( !connector->call( toSend, *m, false ) )
-            return false;
-        if ( ! m->data )
-            return false;
-        dataReceived();
-        return true;
-    }
-
-    void DBClientCursor::requestMore() {
-        assert( cursorId && pos == nReturned );
-
-        if (haveLimit){
-            nToReturn -= nReturned;
-            assert(nToReturn > 0);
-        }
-        BufBuilder b;
-        b.append(opts);
-        b.append(ns.c_str());
-        b.append(nextBatchSize());
-        b.append(cursorId);
-
-        Message toSend;
-        toSend.setData(dbGetMore, b.buf(), b.len());
-        auto_ptr<Message> response(new Message());
-        connector->call( toSend, *response );
-
-        m = response;
-        dataReceived();
-    }
-
-    void DBClientCursor::dataReceived() {
-        QueryResult *qr = (QueryResult *) m->data;
-        resultFlags = qr->resultFlags();
-        
-        if ( qr->resultFlags() & QueryResult::ResultFlag_CursorNotFound ) {
-            // cursor id no longer valid at the server.
-            assert( qr->cursorId == 0 );
-            cursorId = 0; // 0 indicates no longer valid (dead)
-            if ( ! ( opts & QueryOption_CursorTailable ) )
-                throw UserException( 13127 , "getMore: cursor didn't exist on server, possible restart or timeout?" );
-        }
-        
-        if ( cursorId == 0 || ! ( opts & QueryOption_CursorTailable ) ) {
-            // only set initially: we don't want to kill it on end of data
-            // if it's a tailable cursor
-            cursorId = qr->cursorId;
-        }
-
-        nReturned = qr->nReturned;
-        pos = 0;
-        data = qr->data();
-
-        connector->checkResponse( data, nReturned );
-        /* this assert would fire the way we currently work:
-            assert( nReturned || cursorId == 0 );
-        */
-    }
-
-    /** If true, safe to call next().  Requests more from server if necessary. */
-    bool DBClientCursor::more() {
-        if ( !_putBack.empty() )
-            return true;
-        
-        if (haveLimit && pos >= nToReturn)
-            return false;
-
-        if ( pos < nReturned )
-            return true;
-
-        if ( cursorId == 0 )
-            return false;
-
-        requestMore();
-        return pos < nReturned;
-    }
-
-    BSONObj DBClientCursor::next() {
-        assert( more() );
-        if ( !_putBack.empty() ) {
-            BSONObj ret = _putBack.top();
-            _putBack.pop();
-            return ret;
-        }
-        pos++;
-        BSONObj o(data);
-        data += o.objsize();
-        return o;
-    }
-
-    void DBClientCursor::attach( ScopedDbConnection * conn ){
-        assert( ! _scopedConn );
-        _scopedConn = conn->steal();
-    }
-
-
-
-    DBClientCursor::~DBClientCursor() {
-        DESTRUCTOR_GUARD (
-
-            if ( cursorId && _ownCursor ) {
-                BufBuilder b;
-                b.append( (int)0 ); // reserved
-                b.append( (int)1 ); // number
-                b.append( cursorId );
-
-                Message m;
-                m.setData( dbKillCursors , b.buf() , b.len() );
-                
-                connector->sayPiggyBack( m );
-            }
-
-            if ( _scopedConn ){
-                if ( moreInCurrentBatch() ){
-                    log() << "warning: cursor deleted, but moreInCurrentBatch and scoped conn." << endl;
-                }
-                else {
-                    _scopedConn->done();
-                }
-                delete _scopedConn;
-            }
-
-        );
-    }
-
     /* --- class dbclientpaired --- */
 
     string DBClientPaired::toString() {
diff --git a/client/dbclient.h b/client/dbclient.h
index 4e8e2aa5314..0c69a4f0cec 100644
--- a/client/dbclient.h
+++ b/client/dbclient.h
@@ -84,6 +84,7 @@ namespace mongo {
 
     class BSONObj;
     class ScopedDbConnection;
+    class DBClientCursor;
 
     /** Represents a Mongo query expression.  Typically one uses the QUERY(...) macro to construct a Query object. 
         Examples:
@@ -209,149 +210,6 @@ namespace mongo {
         virtual void checkResponse( const string &data, int nReturned ) {}
     };
 
-	/** Queries return a cursor object */
-    class DBClientCursor : boost::noncopyable {
-    public:
-		/** If true, safe to call next().  Requests more from server if necessary. */
-        bool more();
-
-        /** If true, there is more in our local buffers to be fetched via next(). Returns 
-            false when a getMore request back to server would be required.  You can use this 
-            if you want to exhaust whatever data has been fetched to the client already but 
-            then perhaps stop.
-        */
-        bool moreInCurrentBatch() { return !_putBack.empty() || pos < nReturned; }
-
-        /** next
-		   @return next object in the result cursor.
-           on an error at the remote server, you will get back:
-             { $err: <string> }
-           if you do not want to handle that yourself, call nextSafe().
-        */
-        BSONObj next();
-        
-        /** 
-            restore an object previously returned by next() to the cursor
-         */
-        void putBack( const BSONObj &o ) { _putBack.push( o.getOwned() ); }
-
-		/** throws AssertionException if get back { $err : ... } */
-        BSONObj nextSafe() {
-            BSONObj o = next();
-            BSONElement e = o.firstElement();
-            if( strcmp(e.fieldName(), "$err") == 0 ) { 
-                if( logLevel >= 5 )
-                    log() << "nextSafe() error " << o.toString() << endl;
-                uassert(13106, "nextSafe() returns $err", false);
-            }
-            return o;
-        }
-
-        /**
-           iterate the rest of the cursor and return the number if items
-         */
-        int itcount(){
-            int c = 0;
-            while ( more() ){
-                next();
-                c++;
-            }
-            return c;
-        }
-
-        /** cursor no longer valid -- use with tailable cursors.
-           note you should only rely on this once more() returns false;
-           'dead' may be preset yet some data still queued and locally
-           available from the dbclientcursor.
-        */
-        bool isDead() const {
-            return cursorId == 0;
-        }
-
-        bool tailable() const {
-            return (opts & QueryOption_CursorTailable) != 0;
-        }
-        
-        /** see QueryResult::ResultFlagType (db/dbmessage.h) for flag values 
-            mostly these flags are for internal purposes - 
-            ResultFlag_ErrSet is the possible exception to that
-        */
-        bool hasResultFlag( int flag ){
-            return (resultFlags & flag) != 0;
-        }
-
-        DBClientCursor( DBConnector *_connector, const string &_ns, BSONObj _query, int _nToReturn,
-                        int _nToSkip, const BSONObj *_fieldsToReturn, int queryOptions , int bs ) :
-                connector(_connector),
-                ns(_ns),
-                query(_query),
-                nToReturn(_nToReturn),
-                haveLimit( _nToReturn > 0 && !(queryOptions & QueryOption_CursorTailable)),
-                nToSkip(_nToSkip),
-                fieldsToReturn(_fieldsToReturn),
-                opts(queryOptions),
-                batchSize(bs),
-                m(new Message()),
-                cursorId(),
-                nReturned(),
-                pos(),
-                data(),
-                _ownCursor( true ),
-                _scopedConn(0){
-        }
-        
-        DBClientCursor( DBConnector *_connector, const string &_ns, long long _cursorId, int _nToReturn, int options ) :
-                connector(_connector),
-                ns(_ns),
-                nToReturn( _nToReturn ),
-                haveLimit( _nToReturn > 0 && !(options & QueryOption_CursorTailable)),
-                opts( options ),
-                m(new Message()),
-                cursorId( _cursorId ),
-                nReturned(),
-                pos(),
-                data(),
-                _ownCursor( true ),
-                _scopedConn(0){
-        }            
-
-        virtual ~DBClientCursor();
-
-        long long getCursorId() const { return cursorId; }
-
-        /** by default we "own" the cursor and will send the server a KillCursor
-            message when ~DBClientCursor() is called. This function overrides that.
-        */
-        void decouple() { _ownCursor = false; }
-        
-        void attach( ScopedDbConnection * conn );
-        
-    private:
-        friend class DBClientBase;
-        bool init();        
-        int nextBatchSize();
-        DBConnector *connector;
-        string ns;
-        BSONObj query;
-        int nToReturn;
-        bool haveLimit;
-        int nToSkip;
-        const BSONObj *fieldsToReturn;
-        int opts;
-        int batchSize;
-        auto_ptr<Message> m;
-        stack< BSONObj > _putBack;
-        int resultFlags;
-        long long cursorId;
-        int nReturned;
-        int pos;
-        const char *data;
-        void dataReceived();
-        void requestMore();
-        bool _ownCursor; // see decouple()
-        ScopedDbConnection * _scopedConn;
-    };
-    
     /**
        The interface that any db connection should implement
      */
@@ -967,4 +825,6 @@ namespace mongo {
     
 } // namespace mongo
 
+#include "dbclientcursor.h"
+
 #include "undef_macros.h"
diff --git a/client/dbclientcursor.cpp b/client/dbclientcursor.cpp
new file mode 100644
index 00000000000..a50b1cb14b6
--- /dev/null
+++ b/client/dbclientcursor.cpp
@@ -0,0 +1,174 @@
+// dbclient.cpp - connect to a Mongo database as a database, from C++
+
+/*    Copyright 2009 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#include "pch.h"
+#include "dbclient.h"
+#include "../db/dbmessage.h"
+#include "../db/cmdline.h"
+#include "connpool.h"
+
+namespace mongo {
+
+    void assembleRequest( const string &ns, BSONObj query, int nToReturn, int nToSkip, const BSONObj *fieldsToReturn, int queryOptions, Message &toSend );
+
+    int DBClientCursor::nextBatchSize(){
+        if ( nToReturn == 0 )
+            return batchSize;
+        if ( batchSize == 0 )
+            return nToReturn;
+        
+        return batchSize < nToReturn ? batchSize : nToReturn;
+    }
+
+    bool DBClientCursor::init() {
+        Message toSend;
+        if ( !cursorId ) {
+            assembleRequest( ns, query, nextBatchSize() , nToSkip, fieldsToReturn, opts, toSend );
+        } else {
+            BufBuilder b;
+            b.append( opts );
+            b.append( ns.c_str() );
+            b.append( nToReturn );
+            b.append( cursorId );
+            toSend.setData( dbGetMore, b.buf(), b.len() );
+        }
+        if ( !connector->call( toSend, *m, false ) )
+            return false;
+        if ( ! m->data )
+            return false;
+        dataReceived();
+        return true;
+    }
+
+    void DBClientCursor::requestMore() {
+        assert( cursorId && pos == nReturned );
+
+        if (haveLimit){
+            nToReturn -= nReturned;
+            assert(nToReturn > 0);
+        }
+        BufBuilder b;
+        b.append(opts);
+        b.append(ns.c_str());
+        b.append(nextBatchSize());
+        b.append(cursorId);
+
+        Message toSend;
+        toSend.setData(dbGetMore, b.buf(), b.len());
+        auto_ptr<Message> response(new Message());
+        connector->call( toSend, *response );
+
+        m = response;
+        dataReceived();
+    }
+
+    void DBClientCursor::dataReceived() {
+        QueryResult *qr = (QueryResult *) m->data;
+        resultFlags = qr->resultFlags();
+        
+        if ( qr->resultFlags() & QueryResult::ResultFlag_CursorNotFound ) {
+            // cursor id no longer valid at the server.
+            assert( qr->cursorId == 0 );
+            cursorId = 0; // 0 indicates no longer valid (dead)
+            if ( ! ( opts & QueryOption_CursorTailable ) )
+                throw UserException( 13127 , "getMore: cursor didn't exist on server, possible restart or timeout?" );
+        }
+        
+        if ( cursorId == 0 || ! ( opts & QueryOption_CursorTailable ) ) {
+            // only set initially: we don't want to kill it on end of data
+            // if it's a tailable cursor
+            cursorId = qr->cursorId;
+        }
+
+        nReturned = qr->nReturned;
+        pos = 0;
+        data = qr->data();
+
+        connector->checkResponse( data, nReturned );
+        /* this assert would fire the way we currently work:
+            assert( nReturned || cursorId == 0 );
+        */
+    }
+
+    /** If true, safe to call next().  Requests more from server if necessary. */
+    bool DBClientCursor::more() {
+        if ( !_putBack.empty() )
+            return true;
+        
+        if (haveLimit && pos >= nToReturn)
+            return false;
+
+        if ( pos < nReturned )
+            return true;
+
+        if ( cursorId == 0 )
+            return false;
+
+        requestMore();
+        return pos < nReturned;
+    }
+
+    BSONObj DBClientCursor::next() {
+        assert( more() );
+        if ( !_putBack.empty() ) {
+            BSONObj ret = _putBack.top();
+            _putBack.pop();
+            return ret;
+        }
+        pos++;
+        BSONObj o(data);
+        data += o.objsize();
+        return o;
+    }
+
+    void DBClientCursor::attach( ScopedDbConnection * conn ){
+        assert( ! _scopedConn );
+        _scopedConn = conn->steal();
+    }
+
+
+
+    DBClientCursor::~DBClientCursor() {
+        DESTRUCTOR_GUARD (
+
+            if ( cursorId && _ownCursor ) {
+                BufBuilder b;
+                b.append( (int)0 ); // reserved
+                b.append( (int)1 ); // number
+                b.append( cursorId );
+
+                Message m;
+                m.setData( dbKillCursors , b.buf() , b.len() );
+                
+                connector->sayPiggyBack( m );
+            }
+
+            if ( _scopedConn ){
+                if ( moreInCurrentBatch() ){
+                    log() << "warning: cursor deleted, but moreInCurrentBatch and scoped conn." << endl;
+                }
+                else {
+                    _scopedConn->done();
+                }
+                delete _scopedConn;
+            }
+
+        );
+    }
+
+    
+} // namespace mongo
diff --git a/client/dbclientcursor.h b/client/dbclientcursor.h
new file mode 100644
index 00000000000..8755a11ee0f
--- /dev/null
+++ b/client/dbclientcursor.h
@@ -0,0 +1,174 @@
+// file dbclientcursor.h 
+
+/*    Copyright 2009 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#pragma once
+
+#include "../pch.h"
+#include "../util/message.h"
+#include "../db/jsobj.h"
+#include "../db/json.h"
+#include <stack>
+
+namespace mongo {
+
+	/** Queries return a cursor object */
+    class DBClientCursor : boost::noncopyable {
+    public:
+		/** If true, safe to call next().  Requests more from server if necessary. */
+        bool more();
+
+        /** If true, there is more in our local buffers to be fetched via next(). Returns 
+            false when a getMore request back to server would be required.  You can use this 
+            if you want to exhaust whatever data has been fetched to the client already but 
+            then perhaps stop.
+        */
+        bool moreInCurrentBatch() { return !_putBack.empty() || pos < nReturned; }
+
+        /** next
+		   @return next object in the result cursor.
+           on an error at the remote server, you will get back:
+             { $err: <string> }
+           if you do not want to handle that yourself, call nextSafe().
+        */
+        BSONObj next();
+        
+        /** 
+            restore an object previously returned by next() to the cursor
+         */
+        void putBack( const BSONObj &o ) { _putBack.push( o.getOwned() ); }
+
+		/** throws AssertionException if get back { $err : ... } */
+        BSONObj nextSafe() {
+            BSONObj o = next();
+            BSONElement e = o.firstElement();
+            if( strcmp(e.fieldName(), "$err") == 0 ) { 
+                if( logLevel >= 5 )
+                    log() << "nextSafe() error " << o.toString() << endl;
+                uassert(13106, "nextSafe() returns $err", false);
+            }
+            return o;
+        }
+
+        /**
+           iterate the rest of the cursor and return the number if items
+         */
+        int itcount(){
+            int c = 0;
+            while ( more() ){
+                next();
+                c++;
+            }
+            return c;
+        }
+
+        /** cursor no longer valid -- use with tailable cursors.
+           note you should only rely on this once more() returns false;
+           'dead' may be preset yet some data still queued and locally
+           available from the dbclientcursor.
+        */
+        bool isDead() const {
+            return cursorId == 0;
+        }
+
+        bool tailable() const {
+            return (opts & QueryOption_CursorTailable) != 0;
+        }
+        
+        /** see QueryResult::ResultFlagType (db/dbmessage.h) for flag values 
+            mostly these flags are for internal purposes - 
+            ResultFlag_ErrSet is the possible exception to that
+        */
+        bool hasResultFlag( int flag ){
+            return (resultFlags & flag) != 0;
+        }
+
+        DBClientCursor( DBConnector *_connector, const string &_ns, BSONObj _query, int _nToReturn,
+                        int _nToSkip, const BSONObj *_fieldsToReturn, int queryOptions , int bs ) :
+                connector(_connector),
+                ns(_ns),
+                query(_query),
+                nToReturn(_nToReturn),
+                haveLimit( _nToReturn > 0 && !(queryOptions & QueryOption_CursorTailable)),
+                nToSkip(_nToSkip),
+                fieldsToReturn(_fieldsToReturn),
+                opts(queryOptions),
+                batchSize(bs),
+                m(new Message()),
+                cursorId(),
+                nReturned(),
+                pos(),
+                data(),
+                _ownCursor( true ),
+                _scopedConn(0){
+        }
+        
+        DBClientCursor( DBConnector *_connector, const string &_ns, long long _cursorId, int _nToReturn, int options ) :
+                connector(_connector),
+                ns(_ns),
+                nToReturn( _nToReturn ),
+                haveLimit( _nToReturn > 0 && !(options & QueryOption_CursorTailable)),
+                opts( options ),
+                m(new Message()),
+                cursorId( _cursorId ),
+                nReturned(),
+                pos(),
+                data(),
+                _ownCursor( true ),
+                _scopedConn(0){
+        }            
+
+        virtual ~DBClientCursor();
+
+        long long getCursorId() const { return cursorId; }
+
+        /** by default we "own" the cursor and will send the server a KillCursor
+            message when ~DBClientCursor() is called. This function overrides that.
+        */
+        void decouple() { _ownCursor = false; }
+        
+        void attach( ScopedDbConnection * conn );
+        
+    private:
+        friend class DBClientBase;
+        bool init();        
+        int nextBatchSize();
+        DBConnector *connector;
+        string ns;
+        BSONObj query;
+        int nToReturn;
+        bool haveLimit;
+        int nToSkip;
+        const BSONObj *fieldsToReturn;
+        int opts;
+        int batchSize;
+        auto_ptr<Message> m;
+        stack< BSONObj > _putBack;
+        int resultFlags;
+        long long cursorId;
+        int nReturned;
+        int pos;
+        const char *data;
+        void dataReceived();
+        void requestMore();
+        bool _ownCursor; // see decouple()
+        ScopedDbConnection * _scopedConn;
+    };
+    
+    
+} // namespace mongo
+
+#include "undef_macros.h"