some cleaning/optmizing of Database* storage, also just a little encaspulation

6 files changed, 128 insertions, 56 deletions

diff --git a/db/db.h b/db/db.h
index 4369a3dca30..87e157ab1ed 100644
--- a/db/db.h
+++ b/db/db.h
@@ -40,24 +40,80 @@ namespace mongo {
        could be slightly larger.
     */
     const int MaxBSONObjectSize = 4 * 1024 * 1024;
+    
+    /**
+     * class to hold path + dbname -> Database
+     * might be able to optimizer further
+     */
+    class DatabaseHolder {
+    public:
+        DatabaseHolder() : _size(0){
+        }
 
-    // tempish...move to TLS or pass all the way down as a parm
-    extern map<string,Database*> databases;
-    extern bool master;
+        Database * get( const string& ns , const string& path ){
+            dbMutex.assertAtLeastReadLocked();
+            map<string,Database*>& m = _paths[path];
+            
+            string db = _todb( ns );
 
-    /* sometimes we deal with databases with the same name in different directories - thus this */
-    inline string makeDbKeyStr( const char *ns, const string& path ) {
-        char cl[256];
-        nsToDatabase(ns, cl);
-        return string( cl ) + ":" + path;
-    }
+            map<string,Database*>::iterator it = m.find(db);
+            if ( it != m.end() ) 
+                return it->second;
+            return 0;
+        }
+        
+        void put( const string& ns , const string& path , Database * db ){
+            dbMutex.assertWriteLocked();
+            map<string,Database*>& m = _paths[path];
+            Database*& d = m[_todb(ns)];
+            if ( ! d )
+                _size++;
+            d = db;
+        }
+        
+        void erase( const string& ns , const string& path ){
+            dbMutex.assertWriteLocked();
+            map<string,Database*>& m = _paths[path];
+            _size -= m.erase( _todb( ns ) );
+        }
+
+        bool closeAll( const string& path , BSONObjBuilder& result );
+
+        int size(){
+            return _size;
+        }
+        
+        void getAllShortNames( set<string>& all ) const{
+            dbMutex.assertAtLeastReadLocked();
+            for ( map<string, map<string,Database*> >::const_iterator i=_paths.begin(); i!=_paths.end(); i++ ){
+                map<string,Database*> m = i->second;
+                for( map<string,Database*>::const_iterator j=m.begin(); j!=m.end(); j++ ){
+                    all.insert( j->first );
+                }
+            }
+        }
+        
+    private:
+        
+        string _todb( const string& ns ){
+            size_t i = ns.find( '.' );
+            if ( i == string::npos )
+                return ns;
+            return ns.substr( 0 , i );
+        }
+        
+        map<string, map<string,Database*> > _paths;
+        int _size;
+        
+    };
+
+    extern DatabaseHolder dbHolder;
 
     inline void resetClient(const char *ns, const string& path=dbpath) {
         dbMutex.assertAtLeastReadLocked();
-        string key = makeDbKeyStr( ns, path );
-        map<string,Database*>::iterator it = databases.find(key);
-        if ( it != databases.end() ) {
-            cc().setns(ns, it->second);
+        Database * d = dbHolder.get( ns , path );
+        if ( d ){
+            cc().setns(ns, d);
             return;
         }
         assert(false);
@@ -76,32 +132,22 @@ namespace mongo {
         Client& c = cc();
         c.top.clientStart( ns );
 
-        string key = makeDbKeyStr( ns, path );
-        map<string,Database*>::iterator it = databases.find(key);
-        if ( it != databases.end() ) {
-            c.setns(ns, it->second);
+        Database * db = dbHolder.get( ns , path );
+        if ( db ){
+            c.setns(ns, db );
             return false;
         }
 
         if( lock )
             lock->releaseAndWriteLock();
 
-        // when master for replication, we advertise all the db's, and that
-        // looks like a 'first operation'. so that breaks this log message's
-        // meaningfulness.  instead of fixing (which would be better), we just
-        // stop showing for now.
-        // 2008-12-22 We now open every database on startup, so this log is
-        // no longer helpful.  Commenting.
-        //    if( !master )
-        //        log() << "first operation for database " << key << endl;
-
         assertInWriteLock();
-
+        
         char cl[256];
         nsToDatabase(ns, cl);
         bool justCreated;
         Database *newdb = new Database(cl, justCreated, path);
-        databases[key] = newdb;
+        dbHolder.put(ns,path,newdb);
         c.setns(ns, newdb);
 
         newdb->finishInit();
@@ -109,16 +155,10 @@ namespace mongo {
         return justCreated;
     }
 
-// shared functionality for removing references to a database from this program instance
-// does not delete the files on disk
+    // shared functionality for removing references to a database from this program instance
+    // does not delete the files on disk
     void closeDatabase( const char *cl, const string& path = dbpath );
 
-    /* remove database from the databases map */
-    inline void eraseDatabase( const char *ns, const string& path=dbpath ) {
-        string key = makeDbKeyStr( ns, path );
-        databases.erase( key );
-    }
-
     inline bool clientIsEmpty() {
         return !cc().database()->namespaceIndex.allocated();
     }
@@ -183,6 +223,7 @@ namespace mongo {
 
     extern TicketHolder connTicketHolder;
 
+
 } // namespace mongo
 
 //#include "dbinfo.h"
diff --git a/db/dbcommands.cpp b/db/dbcommands.cpp
index 278565ea151..3464ac7b010 100644
--- a/db/dbcommands.cpp
+++ b/db/dbcommands.cpp
@@ -720,10 +720,11 @@ namespace mongo {
 
                 seen.insert( i->c_str() );
             }
-
-            for ( map<string,Database*>::iterator i = databases.begin(); i != databases.end(); i++ ){
-                string name = i->first;
-                name = name.substr( 0 , name.find( ":" ) );
+            
+            set<string> allShortNames;
+            dbHolder.getAllShortNames( allShortNames );
+            for ( set<string>::iterator i = allShortNames.begin(); i != allShortNames.end(); i++ ){
+                string name = *i;
 
                 if ( seen.count( name ) )
                     continue;
@@ -748,18 +749,7 @@ namespace mongo {
         virtual bool slaveOk() { return false; }
         CmdCloseAllDatabases() : Command( "closeAllDatabases" ) {}
         bool run(const char *ns, BSONObj& jsobj, string& errmsg, BSONObjBuilder& result, bool /*fromRepl*/) {
-            set< string > dbs;
-            for ( map<string,Database*>::iterator i = databases.begin(); i != databases.end(); i++ ) {
-                string name = i->first;
-                name = name.substr( 0 , name.find( ":" ) );
-                dbs.insert( name );
-            }
-            for( set< string >::iterator i = dbs.begin(); i != dbs.end(); ++i ) {
-                setClient( i->c_str() );
-                closeDatabase( i->c_str() );
-            }
-
-            return true;
+            return dbHolder.closeAll( dbpath , result );
         }
     } cmdCloseAllDatabases;
 
diff --git a/db/dbwebserver.cpp b/db/dbwebserver.cpp
index 837cb7caf89..1ba0a6c36e8 100644
--- a/db/dbwebserver.cpp
+++ b/db/dbwebserver.cpp
@@ -117,9 +117,9 @@ namespace mongo {
     public:
         // caller locks
         void doLockedStuff(stringstream& ss) {
-            ss << "# databases: " << databases.size() << '\n';
+            ss << "# databases: " << dbHolder.size() << '\n';
             if ( cc().database() ) {
-                ss << "curclient: " << cc().database()->name;
+                ss << "curclient: " << cc().database()->name; // TODO: isn't this useless?
                 ss << '\n';
             }
             ss << bold(ClientCursor::byLocSize()>10000) << "Cursors byLoc.size(): " << ClientCursor::byLocSize() << bold() << '\n';
diff --git a/db/instance.cpp b/db/instance.cpp
index f9b8619dba1..ec3191e24fa 100644
--- a/db/instance.cpp
+++ b/db/instance.cpp
@@ -444,7 +444,7 @@ namespace mongo {
 
         NamespaceDetailsTransient::clearForPrefix( prefix.c_str() );
 
-        eraseDatabase( cl, path );
+        dbHolder.erase( cl, path );
         delete database; // closes files
         cc().clearns();
     }
diff --git a/db/pdfile.cpp b/db/pdfile.cpp
index 45e3b274571..0d6b000a204 100644
--- a/db/pdfile.cpp
+++ b/db/pdfile.cpp
@@ -46,7 +46,7 @@ namespace mongo {
     string dbpath = "/data/db/";
 
     DataFileMgr theDataFileMgr;
-    map<string,Database*> databases;
+    DatabaseHolder dbHolder;
     int MAGIC = 0x1000;
 //    int curOp = -2;
 
@@ -1812,4 +1812,31 @@ namespace mongo {
 
     NamespaceDetails* nsdetails_notinline(const char *ns) { return nsdetails(ns); }
     
+    bool DatabaseHolder::closeAll( const string& path , BSONObjBuilder& result ){
+        log(2) << "DatabaseHolder::closeAll path:" << path << endl;
+        dbMutex.assertWriteLocked();
+        
+        map<string,Database*>& m = _paths[path];
+        _size -= m.size();
+        
+        set< string > dbs;
+        for ( map<string,Database*>::iterator i = m.begin(); i != m.end(); i++ ) {
+            dbs.insert( i->first );
+        }
+        
+        BSONObjBuilder bb( result.subarrayStart( "dbs" ) );
+        int n = 0;
+        for( set< string >::iterator i = dbs.begin(); i != dbs.end(); ++i ) {
+            string name = *i;
+            log(2) << "DatabaseHolder::closeAll path:" << path << " name:" << name << endl;
+            setClient( name.c_str() , path );
+            closeDatabase( name.c_str() , path );
+            bb.append( bb.numStr( n++ ).c_str() , name );
+        }
+        bb.done();
+        
+        return true;
+    }
+    
+
 } // namespace mongo
diff --git a/jstests/dbadmin.js b/jstests/dbadmin.js
new file mode 100644
index 00000000000..4bf0caed4f6
--- /dev/null
+++ b/jstests/dbadmin.js
@@ -0,0 +1,14 @@
+
+t = db.dbadmin;
+t.save( { x : 1 } );
+
+before = db._adminCommand( "serverStatus" );
+db._adminCommand( "closeAllDatabases" );
+after = db._adminCommand( "serverStatus" );
+assert( before.mem.mapped > after.mem.mapped , "closeAllDatabases does something" );
+
+t.save( { x : 1 } );
+
+res = db._adminCommand( "listDatabases" );
+assert( res.databases.length > 0 , "listDatabases 1" );
+printjson( res );