// @file strategy.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 "../client/connpool.h"
#include "../db/commands.h"

#include "grid.h"
#include "request.h"
#include "server.h"
#include "writeback_listener.h"

#include "strategy.h"

namespace mongo {

    // ----- Strategy ------

    void Strategy::doWrite( int op , Request& r , const Shard& shard , bool checkVersion ){
        ShardConnection conn( shard , r.getns() );
        if ( ! checkVersion )
            conn.donotCheckVersion();
        else if ( conn.setVersion() ){
            conn.done();
            throw StaleConfigException( r.getns() , "doWRite" , true );
        }
        conn->say( r.m() );
        conn.done();
    }
    
    void Strategy::doQuery( Request& r , const Shard& shard ){
        try{
            ShardConnection dbcon( shard , r.getns() );
            DBClientBase &c = dbcon.conn();
            
            Message response;
            bool ok = c.call( r.m(), response);

            {
                QueryResult *qr = (QueryResult *) response.singleData();
                if ( qr->resultFlags() & ResultFlag_ShardConfigStale ){
                    dbcon.done();
                    throw StaleConfigException( r.getns() , "Strategy::doQuery" );
                }
            }

            uassert( 10200 , "mongos: error calling db", ok);
            r.reply( response , c.getServerAddress() );
            dbcon.done();
        }
        catch ( AssertionException& e ) {
            BSONObjBuilder err;
            e.getInfo().append( err );
            BSONObj errObj = err.done();
            replyToQuery(ResultFlag_ErrSet, r.p() , r.m() , errObj);
        }
    }
    
    void Strategy::insert( const Shard& shard , const char * ns , const BSONObj& obj ){
        ShardConnection dbcon( shard , ns );
        if ( dbcon.setVersion() ){
            dbcon.done();
            throw StaleConfigException( ns , "for insert" );
        }
        dbcon->insert( ns , obj );
        dbcon.done();
    }
}