SERVER-1292 A bit more prep, separate grid.{h,cpp} from config

11 files changed, 339 insertions, 273 deletions

diff --git a/SConstruct b/SConstruct
index 7e96a50cdb9..04fd6bd742c 100644
--- a/SConstruct
+++ b/SConstruct
@@ -456,7 +456,7 @@ else:
 
 coreServerFiles += scriptingFiles
 
-coreShardFiles = [ "s/config.cpp" , "s/chunk.cpp" , "s/shard.cpp" , "s/shardkey.cpp" ]
+coreShardFiles = [ "s/config.cpp" , "s/grid.cpp" , "s/chunk.cpp" , "s/shard.cpp" , "s/shardkey.cpp" ]
 shardServerFiles = coreShardFiles + Glob( "s/strategy*.cpp" ) + [ "s/commands_admin.cpp" , "s/commands_public.cpp" , "s/request.cpp" ,  "s/cursors.cpp" ,  "s/server.cpp" , "s/config_migrate.cpp" , "s/s_only.cpp" , "s/stats.cpp" , "s/balance.cpp" , "s/balancer_policy.cpp" , "db/cmdline.cpp" ]
 serverOnlyFiles += coreShardFiles + [ "s/d_logic.cpp" , "s/d_writeback.cpp" , "s/d_migrate.cpp" , "s/d_state.cpp" , "s/d_split.cpp" , "client/distlock_test.cpp" ]
 
diff --git a/s/balance.cpp b/s/balance.cpp
index 2da5689db58..f79e1d8e060 100644
--- a/s/balance.cpp
+++ b/s/balance.cpp
@@ -28,6 +28,7 @@
 #include "shard.h"
 #include "config.h"
 #include "chunk.h"
+#include "grid.h"
 
 namespace mongo {
     
diff --git a/s/commands_admin.cpp b/s/commands_admin.cpp
index 5585db8ea99..af50422cba4 100644
--- a/s/commands_admin.cpp
+++ b/s/commands_admin.cpp
@@ -38,6 +38,7 @@
 
 #include "config.h"
 #include "chunk.h"
+#include "grid.h"
 #include "strategy.h"
 #include "stats.h"
 
diff --git a/s/commands_public.cpp b/s/commands_public.cpp
index 0197c38a7bc..3dbc8ad5112 100644
--- a/s/commands_public.cpp
+++ b/s/commands_public.cpp
@@ -28,6 +28,7 @@
 #include "config.h"
 #include "chunk.h"
 #include "strategy.h"
+#include "grid.h"
 
 namespace mongo {
 
diff --git a/s/config.cpp b/s/config.cpp
index 24ef4087dce..e6bb48870c4 100644
--- a/s/config.cpp
+++ b/s/config.cpp
@@ -28,6 +28,7 @@
 #include "server.h"
 #include "config.h"
 #include "chunk.h"
+#include "grid.h"
 
 namespace mongo {
 
@@ -236,7 +237,7 @@ namespace mongo {
 
         return true;
     }
-    
+
     void DBConfig::_save(){
         ScopedDbConnection conn( configServer.modelServer() );
         
@@ -384,201 +385,6 @@ namespace mongo {
         }
     }
 
-    /* --- Grid --- */
-    
-    DBConfigPtr Grid::getDBConfig( string database , bool create ){
-        {
-            string::size_type i = database.find( "." );
-            if ( i != string::npos )
-                database = database.substr( 0 , i );
-        }
-        
-        if ( database == "config" )
-            return configServerPtr;
-
-        scoped_lock l( _lock );
-
-        DBConfigPtr& cc = _databases[database];
-        if ( !cc ){
-            cc.reset(new DBConfig( database ));
-            if ( ! cc->load() ){
-                if ( create ){
-                    // note here that cc->primary == 0.
-                    log() << "couldn't find database [" << database << "] in config db" << endl;
-                    
-                    { // lets check case
-                        ScopedDbConnection conn( configServer.modelServer() );
-                        BSONObjBuilder b;
-                        b.appendRegex( "_id" , (string)"^" + database + "$" , "i" );
-                        BSONObj d = conn->findOne( ShardNS::database , b.obj() );
-                        conn.done();
-
-                        if ( ! d.isEmpty() ){
-                            cc.reset();
-                            stringstream ss;
-                            ss <<  "can't have 2 databases that just differ on case " 
-                               << " have: " << d["_id"].String()
-                               << " want to add: " << database;
-
-                            uasserted( DatabaseDifferCaseCode ,ss.str() );
-                        }
-                    }
-
-                    if ( database == "admin" )
-                        cc->_primary = configServer.getPrimary();
-                    else
-                        cc->_primary = Shard::pick();
-                    
-                    if ( cc->_primary.ok() ){
-                        cc->_save();
-                        log() << "\t put [" << database << "] on: " << cc->_primary.toString() << endl;
-                    }
-                    else {
-                        cc.reset();
-                        log() << "\t can't find a shard to put new db on" << endl;
-                        uasserted( 10185 ,  "can't find a shard to put new db on" );
-                    }
-                }
-                else {
-                    cc.reset();
-                }
-            }
-            
-        }
-        
-        return cc;
-    }
-
-    void Grid::removeDB( string database ){
-        uassert( 10186 ,  "removeDB expects db name" , database.find( '.' ) == string::npos );
-        scoped_lock l( _lock );
-        _databases.erase( database );
-        
-    }
-
-    bool Grid::allowLocalHost() const {
-        return _allowLocalShard;
-    }
-
-    void Grid::setAllowLocalHost( bool allow ){
-        _allowLocalShard = allow;
-    }
-
-    bool Grid::addShard( string* name , const string& host , long long maxSize , string* errMsg ){
-        // errMsg is required but name is optional
-        DEV assert( errMsg );
-        string nameInternal;
-        if ( ! name ) {
-            name = &nameInternal;
-        }
-
-        // check whether host exists and is operative
-        try {
-            ScopedDbConnection newShardConn( host );
-            newShardConn->getLastError();
-            newShardConn.done();
-        }
-        catch ( DBException& e ){
-            ostringstream ss;
-            ss << "couldn't connect to new shard ";
-            ss << e.what();
-            *errMsg = ss.str();
-            return false;
-        }
-                
-        // if a name for a shard wasn't provided, pick one.
-        if ( name->empty() && ! _getNewShardName( name ) ){
-            *errMsg = "error generating new shard name";
-            return false;
-        }
-            
-        // build the ConfigDB shard document.
-        BSONObjBuilder b;
-        b.append( "_id" , *name );
-        b.append( "host" , host );
-        if ( maxSize > 0 ){
-            b.append( ShardFields::maxSize.name() , maxSize );
-        }
-        BSONObj shardDoc = b.obj();
-
-        {
-            ScopedDbConnection conn( configServer.getPrimary() );
-                
-            // check whether this host:port is already a known shard
-            BSONObj old = conn->findOne( ShardNS::shard , BSON( "host" << host ) );
-            if ( ! old.isEmpty() ){
-                *errMsg = "host already used";
-                conn.done();
-                return false;
-            }
-
-            log() << "going to add shard: " << shardDoc << endl;
-
-            conn->insert( ShardNS::shard , shardDoc );
-            *errMsg = conn->getLastError();
-            if ( ! errMsg->empty() ){
-                log() << "error adding shard: " << shardDoc << " err: " << *errMsg << endl;
-                return false;
-            }
-
-            conn.done();
-        }
-
-        Shard::reloadShardInfo();
-        return true;
-    }
-        
-    bool Grid::knowAboutShard( const string& name ) const{
-        ShardConnection conn( configServer.getPrimary() , "" );
-        BSONObj shard = conn->findOne( ShardNS::shard , BSON( "host" << name ) );
-        conn.done();
-        return ! shard.isEmpty();
-    }
-
-    bool Grid::_getNewShardName( string* name ) const{
-        DEV assert( name );
-
-        bool ok = false;
-        int count = 0; 
-
-        ShardConnection conn( configServer.getPrimary() , "" );
-        BSONObj o = conn->findOne( ShardNS::shard , Query( fromjson ( "{_id: /^shard/}" ) ).sort(  BSON( "_id" << -1 ) ) ); 
-        if ( ! o.isEmpty() ) {
-            string last = o["_id"].String();
-            istringstream is( last.substr( 5 ) );
-            is >> count;
-            count++;
-        }                                                                                                               
-        if (count < 9999) {
-            stringstream ss;
-            ss << "shard" << setfill('0') << setw(4) << count;
-            *name = ss.str();
-            ok = true;
-        }
-        conn.done();
-
-        return ok;
-    }
-
-    bool Grid::shouldBalance() const {
-        ShardConnection conn( configServer.getPrimary() , "" );
-
-        // look for the stop balancer marker
-        BSONObj stopMarker = conn->findOne( ShardNS::settings, BSON( "_id" << "balancer" << "stopped" << true ) );
-        conn.done();
-        return stopMarker.isEmpty();
-    }
-
-    unsigned long long Grid::getNextOpTime() const {
-        ScopedDbConnection conn( configServer.getPrimary() );
-        
-        BSONObj result;
-        massert( 10421 ,  "getoptime failed" , conn->simpleCommand( "admin" , &result , "getoptime" ) );
-        conn.done();
-
-        return result["optime"]._numberLong();
-    }
-
     /* --- ConfigServer ---- */
 
     ConfigServer::ConfigServer() : DBConfig( "config" ){
@@ -761,6 +567,5 @@ namespace mongo {
 
     DBConfigPtr configServerPtr (new ConfigServer());    
     ConfigServer& configServer = dynamic_cast<ConfigServer&>(*configServerPtr);    
-    Grid grid;
 
 } 
diff --git a/s/config.h b/s/config.h
index cbefe7283ea..c1767743acd 100644
--- a/s/config.h
+++ b/s/config.h
@@ -51,7 +51,6 @@ namespace mongo {
         static BSONField<long long> currSize;
     };
         
-    class Grid;
     class ConfigServer;
 
     class DBConfig;
@@ -59,7 +58,6 @@ namespace mongo {
 
     extern DBConfigPtr configServerPtr;
     extern ConfigServer& configServer;
-    extern Grid grid;
 
     class ChunkManager;
     typedef shared_ptr<ChunkManager> ChunkManagerPtr;
@@ -192,82 +190,9 @@ namespace mongo {
 
         mongo::mutex _lock; // TODO: change to r/w lock ??
 
-        friend class Grid;
         friend class ChunkManager;
     };
 
-    /**
-     * stores meta-information about the grid
-     * TODO: used shard_ptr for DBConfig pointers
-     */
-    class Grid {
-    public:
-        Grid() : _lock( "Grid" ) , _allowLocalShard( true ) { }
-
-        /**
-         * gets the config the db.
-         * will return an empty DBConfig if not in db already
-         */
-        DBConfigPtr getDBConfig( string ns , bool create=true );
-        
-        /**
-         * removes db entry.
-         * on next getDBConfig call will fetch from db
-         */
-        void removeDB( string db );
-
-        /**
-         * @return true if shards and config servers are allowed to use 'localhost' in address
-         */
-        bool allowLocalHost() const;
-
-        /**
-         * @param whether to allow shards and config servers to use 'localhost' in address
-         */
-        void setAllowLocalHost( bool allow );
-
-        /**
-         *
-         * addShard will create a new shard in the grid. It expects a mongod process to be runing
-         * on the provided address.
-         * TODO - add the mongod's databases to the grid
-         *
-         * @param name is an optional string with the name of the shard. if ommited, grid will
-         * generate one and update the parameter.
-         * @param host is the complete address of the machine where the shard will be
-         * @param maxSize is the optional space quota in bytes. Zeros means there's no limitation to
-         * space usage
-         * @param errMsg is the error description in case the operation failed. 
-         * @return true if shard was successfully added.
-         */
-        bool addShard( string* name , const string& host , long long maxSize , string* errMsg );
-
-        /**
-         * @return true if the config database knows about a host 'name'
-         */
-        bool knowAboutShard( const string& name ) const;
-        
-        /**
-         * @return true if the chunk balancing functionality is enabled
-         */
-        bool shouldBalance() const;
-
-        unsigned long long getNextOpTime() const;
-
-    private:
-        mongo::mutex              _lock;            // protects _databases; TODO: change to r/w lock ??
-        map<string, DBConfigPtr > _databases;       // maps ns to DBConfig's
-        bool                      _allowLocalShard; // can 'localhost' be used in shard addresses?
-
-        /**
-         * @param name is the chose name for the shard. Parameter is mandatory.
-         * @return true if it managed to generate a shard name. May return false if (currently)
-         * 10000 shard 
-         */
-        bool _getNewShardName( string* name ) const;
-
-    };
-
     class ConfigServer : public DBConfig {
     public:
 
diff --git a/s/grid.cpp b/s/grid.cpp
new file mode 100644
index 00000000000..e1e6c4b40a5
--- /dev/null
+++ b/s/grid.cpp
@@ -0,0 +1,226 @@
+// grid.cpp
+
+/**
+*    Copyright (C) 2010 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 <iomanip>
+
+#include "../client/connpool.h"
+
+#include "grid.h"
+#include "shard.h"
+
+namespace mongo {
+    
+    DBConfigPtr Grid::getDBConfig( string database , bool create ){
+        {
+            string::size_type i = database.find( "." );
+            if ( i != string::npos )
+                database = database.substr( 0 , i );
+        }
+        
+        if ( database == "config" )
+            return configServerPtr;
+
+        scoped_lock l( _lock );
+
+        DBConfigPtr& cc = _databases[database];
+        if ( !cc ){
+            cc.reset(new DBConfig( database ));
+            if ( ! cc->load() ){
+                if ( create ){
+                    // note here that cc->primary == 0.
+                    log() << "couldn't find database [" << database << "] in config db" << endl;
+                    
+                    { // lets check case
+                        ScopedDbConnection conn( configServer.modelServer() );
+                        BSONObjBuilder b;
+                        b.appendRegex( "_id" , (string)"^" + database + "$" , "i" );
+                        BSONObj d = conn->findOne( ShardNS::database , b.obj() );
+                        conn.done();
+
+                        if ( ! d.isEmpty() ){
+                            cc.reset();
+                            stringstream ss;
+                            ss <<  "can't have 2 databases that just differ on case " 
+                               << " have: " << d["_id"].String()
+                               << " want to add: " << database;
+
+                            uasserted( DatabaseDifferCaseCode ,ss.str() );
+                        }
+                    }
+
+                    Shard primary;
+                    if ( database == "admin" )
+                        primary = configServer.getPrimary();
+                    else
+                        primary = Shard::pick();
+
+                    if ( primary.ok() ){
+                        cc->setPrimary( primary.getName() ); // saves 'cc' to configDB
+                        log() << "\t put [" << database << "] on: " << primary << endl;
+                    }
+                    else {
+                        cc.reset();
+                        log() << "\t can't find a shard to put new db on" << endl;
+                        uasserted( 10185 ,  "can't find a shard to put new db on" );
+                    }
+                }
+                else {
+                    cc.reset();
+                }
+            }
+            
+        }
+        
+        return cc;
+    }
+
+    void Grid::removeDB( string database ){
+        uassert( 10186 ,  "removeDB expects db name" , database.find( '.' ) == string::npos );
+        scoped_lock l( _lock );
+        _databases.erase( database );
+        
+    }
+
+    bool Grid::allowLocalHost() const {
+        return _allowLocalShard;
+    }
+
+    void Grid::setAllowLocalHost( bool allow ){
+        _allowLocalShard = allow;
+    }
+
+    bool Grid::addShard( string* name , const string& host , long long maxSize , string* errMsg ){
+        // errMsg is required but name is optional
+        DEV assert( errMsg );
+        string nameInternal;
+        if ( ! name ) {
+            name = &nameInternal;
+        }
+
+        // check whether host exists and is operative
+        try {
+            ScopedDbConnection newShardConn( host );
+            newShardConn->getLastError();
+            newShardConn.done();
+        }
+        catch ( DBException& e ){
+            ostringstream ss;
+            ss << "couldn't connect to new shard ";
+            ss << e.what();
+            *errMsg = ss.str();
+            return false;
+        }
+                
+        // if a name for a shard wasn't provided, pick one.
+        if ( name->empty() && ! _getNewShardName( name ) ){
+            *errMsg = "error generating new shard name";
+            return false;
+        }
+            
+        // build the ConfigDB shard document.
+        BSONObjBuilder b;
+        b.append( "_id" , *name );
+        b.append( "host" , host );
+        if ( maxSize > 0 ){
+            b.append( ShardFields::maxSize.name() , maxSize );
+        }
+        BSONObj shardDoc = b.obj();
+
+        {
+            ScopedDbConnection conn( configServer.getPrimary() );
+                
+            // check whether this host:port is already a known shard
+            BSONObj old = conn->findOne( ShardNS::shard , BSON( "host" << host ) );
+            if ( ! old.isEmpty() ){
+                *errMsg = "host already used";
+                conn.done();
+                return false;
+            }
+
+            log() << "going to add shard: " << shardDoc << endl;
+
+            conn->insert( ShardNS::shard , shardDoc );
+            *errMsg = conn->getLastError();
+            if ( ! errMsg->empty() ){
+                log() << "error adding shard: " << shardDoc << " err: " << *errMsg << endl;
+                return false;
+            }
+
+            conn.done();
+        }
+
+        Shard::reloadShardInfo();
+        return true;
+    }
+        
+    bool Grid::knowAboutShard( const string& name ) const{
+        ShardConnection conn( configServer.getPrimary() , "" );
+        BSONObj shard = conn->findOne( ShardNS::shard , BSON( "host" << name ) );
+        conn.done();
+        return ! shard.isEmpty();
+    }
+
+    bool Grid::_getNewShardName( string* name ) const{
+        DEV assert( name );
+
+        bool ok = false;
+        int count = 0; 
+
+        ShardConnection conn( configServer.getPrimary() , "" );
+        BSONObj o = conn->findOne( ShardNS::shard , Query( fromjson ( "{_id: /^shard/}" ) ).sort(  BSON( "_id" << -1 ) ) ); 
+        if ( ! o.isEmpty() ) {
+            string last = o["_id"].String();
+            istringstream is( last.substr( 5 ) );
+            is >> count;
+            count++;
+        }                                                                                                               
+        if (count < 9999) {
+            stringstream ss;
+            ss << "shard" << setfill('0') << setw(4) << count;
+            *name = ss.str();
+            ok = true;
+        }
+        conn.done();
+
+        return ok;
+    }
+
+    bool Grid::shouldBalance() const {
+        ShardConnection conn( configServer.getPrimary() , "" );
+
+        // look for the stop balancer marker
+        BSONObj stopMarker = conn->findOne( ShardNS::settings, BSON( "_id" << "balancer" << "stopped" << true ) );
+        conn.done();
+        return stopMarker.isEmpty();
+    }
+
+    unsigned long long Grid::getNextOpTime() const {
+        ScopedDbConnection conn( configServer.getPrimary() );
+        
+        BSONObj result;
+        massert( 10421 ,  "getoptime failed" , conn->simpleCommand( "admin" , &result , "getoptime" ) );
+        conn.done();
+
+        return result["optime"]._numberLong();
+    }
+
+    Grid grid;
+
+} 
diff --git a/s/grid.h b/s/grid.h
new file mode 100644
index 00000000000..2ebe60e3761
--- /dev/null
+++ b/s/grid.h
@@ -0,0 +1,103 @@
+// grid.h
+
+/**
+*    Copyright (C) 2010 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/concurrency/mutex.h"
+
+#include "config.h"  // DBConfigPtr
+
+namespace mongo {
+
+    /**
+     * stores meta-information about the grid
+     * TODO: used shard_ptr for DBConfig pointers
+     */
+    class Grid {
+    public:
+        Grid() : _lock( "Grid" ) , _allowLocalShard( true ) { }
+
+        /**
+         * gets the config the db.
+         * will return an empty DBConfig if not in db already
+         */
+        DBConfigPtr getDBConfig( string ns , bool create=true );
+        
+        /**
+         * removes db entry.
+         * on next getDBConfig call will fetch from db
+         */
+        void removeDB( string db );
+
+        /**
+         * @return true if shards and config servers are allowed to use 'localhost' in address
+         */
+        bool allowLocalHost() const;
+
+        /**
+         * @param whether to allow shards and config servers to use 'localhost' in address
+         */
+        void setAllowLocalHost( bool allow );
+
+        /**
+         *
+         * addShard will create a new shard in the grid. It expects a mongod process to be runing
+         * on the provided address.
+         * TODO - add the mongod's databases to the grid
+         *
+         * @param name is an optional string with the name of the shard. if ommited, grid will
+         * generate one and update the parameter.
+         * @param host is the complete address of the machine where the shard will be
+         * @param maxSize is the optional space quota in bytes. Zeros means there's no limitation to
+         * space usage
+         * @param errMsg is the error description in case the operation failed. 
+         * @return true if shard was successfully added.
+         */
+        bool addShard( string* name , const string& host , long long maxSize , string* errMsg );
+
+        /**
+         * @return true if the config database knows about a host 'name'
+         */
+        bool knowAboutShard( const string& name ) const;
+        
+        /**
+         * @return true if the chunk balancing functionality is enabled
+         */
+        bool shouldBalance() const;
+
+        unsigned long long getNextOpTime() const;
+
+    private:
+        mongo::mutex              _lock;            // protects _databases; TODO: change to r/w lock ??
+        map<string, DBConfigPtr > _databases;       // maps ns to DBConfig's
+        bool                      _allowLocalShard; // can 'localhost' be used in shard addresses?
+
+        /**
+         * @param name is the chose name for the shard. Parameter is mandatory.
+         * @return true if it managed to generate a shard name. May return false if (currently)
+         * 10000 shard 
+         */
+        bool _getNewShardName( string* name ) const;
+
+    };
+
+    extern Grid grid;
+
+} // namespace mongo
diff --git a/s/request.cpp b/s/request.cpp
index f8877573854..e65aa1532f0 100644
--- a/s/request.cpp
+++ b/s/request.cpp
@@ -33,6 +33,7 @@
 #include "chunk.h"
 #include "stats.h"
 #include "cursors.h"
+#include "grid.h"
 
 namespace mongo {
 
diff --git a/s/server.cpp b/s/server.cpp
index 0c78618aaea..df6b082d335 100644
--- a/s/server.cpp
+++ b/s/server.cpp
@@ -30,6 +30,7 @@
 #include "config.h"
 #include "chunk.h"
 #include "balance.h"
+#include "grid.h"
 
 namespace mongo {
     
diff --git a/s/strategy.cpp b/s/strategy.cpp
index b32ecb5c242..b3c8f5b3b5c 100644
--- a/s/strategy.cpp
+++ b/s/strategy.cpp
@@ -21,7 +21,9 @@
 #include "../util/background.h"
 #include "../client/connpool.h"
 #include "../db/commands.h"
+
 #include "server.h"
+#include "grid.h"
 
 namespace mongo {