Imported Upstream version 1.3.1

1 files changed, 122 insertions, 0 deletions

diff --git a/db/dbhelpers.h b/db/dbhelpers.h
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+// dbhelpers.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/>.
+*/
+
+/* db helpers are helper functions and classes that let us easily manipulate the local
+   database instance.
+*/
+
+#pragma once
+
+#include "../stdafx.h"
+#include "client.h"
+#include "db.h"
+
+namespace mongo {
+
+    class Cursor;
+    class CoveredIndexMatcher;
+
+    class CursorIterator {
+    public:
+        CursorIterator( auto_ptr<Cursor> c , BSONObj filter = BSONObj() );
+        BSONObj next();
+        bool hasNext();
+
+    private:
+        void _advance();
+
+        auto_ptr<Cursor> _cursor;
+        auto_ptr<CoveredIndexMatcher> _matcher;
+        BSONObj _o;
+    };
+
+    /**
+       all helpers assume locking is handled above them
+     */
+    struct Helpers { 
+
+        /* ensure the specified index exists.
+
+           @param keyPattern key pattern, e.g., { ts : 1 }
+           @param name index name, e.g., "name_1"
+
+           This method can be a little (not much) cpu-slow, so you may wish to use
+             OCCASIONALLY ensureIndex(...);
+
+           Note: use ensureHaveIdIndex() for the _id index: it is faster.
+           Note: does nothing if collection does not yet exist.
+        */
+        static void ensureIndex(const char *ns, BSONObj keyPattern, bool unique, const char *name);
+
+        /* fetch a single object from collection ns that matches query.
+           set your db SavedContext first.
+
+           @param requireIndex if true, complain if no index for the query.  a way to guard against
+           writing a slow query.
+
+           @return true if object found
+        */
+        static bool findOne(const char *ns, BSONObj query, BSONObj& result, bool requireIndex = false);
+        
+
+        /**
+         * @param foundIndex if passed in will be set to 1 if ns and index found
+         * @return true if object found
+         */
+        static bool findById(Client&, const char *ns, BSONObj query, BSONObj& result , 
+                             bool * nsFound = 0 , bool * indexFound = 0 );
+
+        static auto_ptr<CursorIterator> find( const char *ns , BSONObj query = BSONObj() , bool requireIndex = false );
+
+        /* Get/put the first object from a collection.  Generally only useful if the collection
+           only ever has a single object -- which is a "singleton collection".
+
+		   You do not need to set the database before calling.
+		   
+		   Returns: true if object exists.
+        */
+        static bool getSingleton(const char *ns, BSONObj& result);
+        static void putSingleton(const char *ns, BSONObj obj);
+
+
+        /* Remove all objects from a collection.
+        You do not need to set the database before calling.
+        */
+        static void emptyCollection(const char *ns);
+
+    };
+
+    class Database;
+
+    // manage a set using collection backed storage
+    class DbSet {
+    public:
+        DbSet( const string &name = "", const BSONObj &key = BSONObj() ) :
+            name_( name ),
+            key_( key.getOwned() ) {
+        }
+        ~DbSet();
+        void reset( const string &name = "", const BSONObj &key = BSONObj() );
+        bool get( const BSONObj &obj ) const;
+        void set( const BSONObj &obj, bool val );
+    private:
+        string name_;
+        BSONObj key_;
+    };
+    
+} // namespace mongo