SERVER-18036 removed NamespaceString construction from DBClientCursor

2 files changed, 93 insertions, 52 deletions

diff --git a/src/mongo/client/dbclientcursor.cpp b/src/mongo/client/dbclientcursor.cpp
index f30cd35b963..058c74ed74e 100644
--- a/src/mongo/client/dbclientcursor.cpp
+++ b/src/mongo/client/dbclientcursor.cpp
@@ -94,10 +94,6 @@ namespace {
 
 }  // namespace
 
-    void DBClientCursor::_finishConsInit() {
-        _originalHost = _client->getServerAddress();
-    }
-
     int DBClientCursor::nextBatchSize() {
 
         if ( nToReturn == 0 )
@@ -112,8 +108,6 @@ namespace {
     void DBClientCursor::_assembleInit( Message& toSend ) {
         // If we haven't gotten a cursorId yet, we need to issue a new query or command.
         if ( !cursorId ) {
-            auto nss = NamespaceString(ns);
-
             // HACK:
             // Unfortunately, this code is used by the shell to run commands,
             // so we need to allow the shell to send invalid options so that we can
@@ -124,9 +118,9 @@ namespace {
             bool hasValidNToReturnForCommand = (nToReturn == 1 || nToReturn == -1);
             bool hasValidFlagsForCommand = !(opts & mongo::QueryOption_Exhaust);
 
-            if (nss.isCommand() && hasValidNToReturnForCommand && hasValidFlagsForCommand) {
+            if (_isCommand && hasValidNToReturnForCommand && hasValidFlagsForCommand) {
                 toSend = *assembleCommandRequest(_client,
-                                                 nss.db(),
+                                                 nsToDatabaseSubstring(ns),
                                                  opts,
                                                  query);
                 return;
@@ -294,9 +288,8 @@ namespace {
     }
 
     void DBClientCursor::dataReceived( bool& retry, string& host ) {
-        NamespaceString nss(ns);
         // If this is a reply to our initial command request.
-        if (nss.isCommand() && cursorId == 0) {
+        if (_isCommand && cursorId == 0) {
             commandDataReceived();
             return;
         }
@@ -459,6 +452,64 @@ namespace {
         _lazyHost = "";
     }
 
+    DBClientCursor::DBClientCursor(DBClientBase* client,
+                                   const std::string& ns,
+                                   const BSONObj& query,
+                                   int nToReturn,
+                                   int nToSkip,
+                                   const BSONObj* fieldsToReturn,
+                                   int queryOptions,
+                                   int batchSize)
+        : DBClientCursor(client,
+                         ns,
+                         query,
+                         0, // cursorId
+                         nToReturn,
+                         nToSkip,
+                         fieldsToReturn,
+                         queryOptions,
+                         batchSize) {}
+
+    DBClientCursor::DBClientCursor(DBClientBase* client,
+                                   const std::string& ns,
+                                   long long cursorId,
+                                   int nToReturn,
+                                   int queryOptions)
+        : DBClientCursor(client,
+                         ns,
+                         BSONObj(), // query
+                         cursorId,
+                         nToReturn,
+                         0, // nToSkip
+                         nullptr, // fieldsToReturn
+                         queryOptions,
+                         0) {} // batchSize
+
+    DBClientCursor::DBClientCursor(DBClientBase* client,
+                                   const std::string& ns,
+                                   const BSONObj& query,
+                                   long long cursorId,
+                                   int nToReturn,
+                                   int nToSkip,
+                                   const BSONObj* fieldsToReturn,
+                                   int queryOptions,
+                                   int batchSize)
+        : _client(client),
+          _originalHost(_client->getServerAddress()),
+          ns(ns),
+          _isCommand(nsIsFull(ns) ? nsToCollectionSubstring(ns) == "$cmd" : false),
+          query(query),
+          nToReturn(nToReturn),
+          haveLimit(nToReturn > 0 && !(queryOptions & QueryOption_CursorTailable)),
+          nToSkip(nToSkip),
+          fieldsToReturn(fieldsToReturn),
+          opts(queryOptions),
+          batchSize(batchSize == 1 ? 2 : batchSize),
+          resultFlags(0),
+          cursorId(cursorId),
+          _ownCursor(true),
+          wasError(false) {}
+
     DBClientCursor::~DBClientCursor() {
         DESTRUCTOR_GUARD (
 
diff --git a/src/mongo/client/dbclientcursor.h b/src/mongo/client/dbclientcursor.h
index 6f125063b60..1e110a4d317 100644
--- a/src/mongo/client/dbclientcursor.h
+++ b/src/mongo/client/dbclientcursor.h
@@ -31,6 +31,7 @@
 
 #include <stack>
 
+#include "mongo/base/disallow_copying.h"
 #include "mongo/client/dbclientinterface.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/db/json.h"
@@ -56,6 +57,7 @@ namespace mongo {
 
     /** Queries return a cursor object */
     class DBClientCursor : public DBClientCursorInterface {
+        MONGO_DISALLOW_COPYING(DBClientCursor);
     public:
         /** If true, safe to call next().  Requests more from server if necessary. */
         bool more();
@@ -135,39 +137,20 @@ namespace mongo {
         /// Change batchSize after construction. Can change after requesting first batch.
         void setBatchSize(int newBatchSize) { batchSize = newBatchSize; }
 
-        DBClientCursor( DBClientBase* client, const std::string &_ns, BSONObj _query, int _nToReturn,
-                        int _nToSkip, const BSONObj *_fieldsToReturn, int queryOptions , int bs ) :
-            _client(client),
-            ns(_ns),
-            query(_query),
-            nToReturn(_nToReturn),
-            haveLimit( _nToReturn > 0 && !(queryOptions & QueryOption_CursorTailable)),
-            nToSkip(_nToSkip),
-            fieldsToReturn(_fieldsToReturn),
-            opts(queryOptions),
-            batchSize(bs==1?2:bs),
-            resultFlags(0),
-            cursorId(),
-            _ownCursor( true ),
-            wasError( false ) {
-            _finishConsInit();
-        }
-
-        DBClientCursor( DBClientBase* client, const std::string &_ns, long long _cursorId, int _nToReturn, int options ) :
-            _client(client),
-            ns(_ns),
-            nToReturn( _nToReturn ),
-            haveLimit( _nToReturn > 0 && !(options & QueryOption_CursorTailable)),
-            nToSkip(0),
-            fieldsToReturn(0),
-            opts( options ),
-            batchSize(0),
-            resultFlags(0),
-            cursorId(_cursorId),
-            _ownCursor(true),
-            wasError(false) {
-            _finishConsInit();
-        }
+        DBClientCursor(DBClientBase* client,
+                       const std::string& ns,
+                       const BSONObj& query,
+                       int nToReturn,
+                       int nToSkip,
+                       const BSONObj* fieldsToReturn,
+                       int queryOptions,
+                       int bs);
+
+        DBClientCursor(DBClientBase* client,
+                       const std::string& ns,
+                       long long cursorId,
+                       int nToReturn,
+                       int options );
 
         virtual ~DBClientCursor();
 
@@ -215,17 +198,29 @@ namespace mongo {
             Batch() : m( new Message() ), nReturned(), pos(), data() { }
         };
 
+        /**
+         * For exhaust. Used in DBClientConnection.
+         */
+        void exhaustReceiveMore();
+
     private:
-        friend class DBClientBase;
-        friend class DBClientConnection;
+        DBClientCursor(DBClientBase* client,
+                       const std::string& ns,
+                       const BSONObj& query,
+                       long long cursorId,
+                       int nToReturn,
+                       int nToSkip,
+                       const BSONObj* fieldsToReturn,
+                       int queryOptions,
+                       int bs);
 
         int nextBatchSize();
-        void _finishConsInit();
 
         Batch batch;
         DBClientBase* _client;
         std::string _originalHost;
-        std::string ns;
+        const std::string ns;
+        const bool _isCommand;
         BSONObj query;
         int nToReturn;
         bool haveLimit;
@@ -252,15 +247,10 @@ namespace mongo {
         void commandDataReceived();
 
         void requestMore();
-        void exhaustReceiveMore(); // for exhaust
 
         // Don't call from a virtual function
         void _assertIfNull() const { uassert(13348, "connection died", this); }
 
-        // non-copyable , non-assignable
-        DBClientCursor( const DBClientCursor& );
-        DBClientCursor& operator=( const DBClientCursor& );
-
         // init pieces
         void _assembleInit( Message& toSend );
     };