a bunch of refactoring for mongos linking

1 files changed, 173 insertions, 0 deletions

diff --git a/db/indexkey.h b/db/indexkey.h
new file mode 100644
index 00000000000..3c98a9dd8bc
--- /dev/null
+++ b/db/indexkey.h
@@ -0,0 +1,173 @@
+// index_key.h
+
+/**
+*    Copyright (C) 2008 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 "../stdafx.h"
+#include "diskloc.h"
+#include "jsobj.h"
+#include <map>
+
+namespace mongo {
+
+    class IndexSpec;
+    class IndexType; // TODO: this name sucks
+    class IndexPlugin;
+    class IndexDetails;
+
+    enum IndexSuitability { USELESS = 0 , HELPFUL = 1 , OPTIMAL = 2 };
+
+    /**
+     * this represents an instance of a index plugin
+     * done this way so parsing, etc... can be cached
+     * so if there is a FTS IndexPlugin, for each index using FTS
+     * there will be 1 of these, and it can have things pre-parsed, etc...
+     */
+    class IndexType : boost::noncopyable {
+    public:
+        IndexType( const IndexPlugin * plugin , const IndexSpec * spec );
+        virtual ~IndexType();
+
+        virtual void getKeys( const BSONObj &obj, BSONObjSetDefaultOrder &keys ) const = 0;
+        virtual auto_ptr<Cursor> newCursor( const BSONObj& query , const BSONObj& order , int numWanted ) const = 0;
+        
+        /** optional op : changes query to match what's in the index */
+        virtual BSONObj fixKey( const BSONObj& in ) { return in; }
+
+        /** optional op : compare 2 objects with regards to this index */
+        virtual int compare( const BSONObj& l , const BSONObj& r ) const;        
+
+        /** @return plugin */
+        const IndexPlugin * getPlugin() const { return _plugin; }
+        
+        const BSONObj& keyPattern() const;
+
+        virtual IndexSuitability suitability( const BSONObj& query , const BSONObj& order ) const ;
+
+        virtual bool scanAndOrderRequired( const BSONObj& query , const BSONObj& order ) const ;
+
+    protected:
+        const IndexPlugin * _plugin;
+        const IndexSpec * _spec;
+    };
+    
+    /**
+     * this represents a plugin
+     * a plugin could be something like full text search, sparse index, etc...
+     * 1 of these exists per type of index per server
+     * 1 IndexType is created per index using this plugin
+     */
+    class IndexPlugin : boost::noncopyable {
+    public:
+        IndexPlugin( const string& name );
+        virtual ~IndexPlugin(){}
+        
+        virtual IndexType* generate( const IndexSpec * spec ) const = 0;
+
+        static IndexPlugin* get( const string& name ){
+            if ( ! _plugins )
+                return 0;
+            map<string,IndexPlugin*>::iterator i = _plugins->find( name );
+            if ( i == _plugins->end() )
+                return 0;
+            return i->second;
+        }
+
+        string getName() const { return _name; }
+    private:
+        string _name;
+        static map<string,IndexPlugin*> * _plugins;
+    };
+
+    /* precomputed details about an index, used for inserting keys on updates
+       stored/cached in NamespaceDetailsTransient, or can be used standalone
+       */
+    class IndexSpec {
+    public:
+        BSONObj keyPattern; // e.g., { name : 1 }
+        BSONObj info; // this is the same as IndexDetails::info.obj()
+        
+        IndexSpec()
+            : _details(0) , _finishedInit(false){
+        }
+
+        IndexSpec( const BSONObj& k , const BSONObj& m = BSONObj() )
+            : keyPattern(k) , info(m) , _details(0) , _finishedInit(false){
+            _init();
+        }
+        
+        /**
+           this is a DiscLoc of an IndexDetails info
+           should have a key field 
+         */
+        IndexSpec( const DiskLoc& loc ){
+            reset( loc );
+        }
+        
+        void reset( const DiskLoc& loc );
+        void reset( const IndexDetails * details );
+        
+        void getKeys( const BSONObj &obj, BSONObjSetDefaultOrder &keys ) const;
+
+        BSONElement missingField() const { return _nullElt; }
+        
+        string getTypeName() const {
+            if ( _indexType.get() )
+                return _indexType->getPlugin()->getName();
+            return "";
+        }
+
+        IndexType* getType() const {
+            return _indexType.get();
+        }
+
+        const IndexDetails * getDetails() const {
+            return _details;
+        }
+
+        IndexSuitability suitability( const BSONObj& query , const BSONObj& order ) const ;
+
+    protected:
+
+        IndexSuitability _suitability( const BSONObj& query , const BSONObj& order ) const ;
+
+        void _getKeys( vector<const char*> fieldNames , vector<BSONElement> fixed , const BSONObj &obj, BSONObjSetDefaultOrder &keys ) const;
+        
+        BSONSizeTracker _sizeTracker;
+
+        vector<const char*> _fieldNames;
+        vector<BSONElement> _fixed;
+        BSONObj _nullKey;
+        
+        BSONObj _nullObj;
+        BSONElement _nullElt;
+        
+        shared_ptr<IndexType> _indexType;
+
+        const IndexDetails * _details;
+        
+        void _init();
+
+    public:
+        bool _finishedInit;
+
+        friend class IndexType;
+    };
+
+
+} // namespace mongo