/**
* Copyright (C) 2013 MongoDB 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 .
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include
#include
#include "mongo/base/string_data.h"
#include "mongo/bson/bsonobj.h"
#include "mongo/bson/optime.h"
#include "mongo/client/dbclientinterface.h"
#include "mongo/s/multi_command_dispatch.h"
#include "mongo/s/write_ops/batch_write_exec.h"
#include "mongo/s/write_ops/batch_write_op.h"
#include "mongo/s/write_ops/batched_command_request.h"
#include "mongo/s/write_ops/batched_command_response.h"
#include "mongo/s/write_ops/write_error_detail.h"
// TODO: Remove post-2.6
namespace mongo {
/**
* Interface to execute a single safe write and enforce write concern on a connection.
*/
class SafeWriter {
public:
virtual ~SafeWriter() {
}
/**
* Sends a write to a remote host and returns a GLE response.
*/
virtual Status safeWrite( DBClientBase* conn,
const BatchItemRef& batchItem,
const BSONObj& writeConcern,
BSONObj* gleResponse ) = 0;
/**
* Purely enforces a write concern on a remote host by clearing the previous error.
* This is more expensive than a normal safe write, but is sometimes needed to support
* write command emulation.
*/
virtual Status enforceWriteConcern( DBClientBase* conn,
const StringData& dbName,
const BSONObj& writeConcern,
BSONObj* gleResponse ) = 0;
/**
* Clears the error information on this connection.
*/
virtual Status clearErrors( DBClientBase* conn,
const StringData& dbName ) = 0;
};
/**
* Executes a batch write using safe writes.
*
* The actual safe write operation is done via an interface to allow testing the rest of the
* aggregation functionality.
*/
class BatchSafeWriter {
public:
BatchSafeWriter( SafeWriter* safeWriter ) :
_safeWriter( safeWriter ) {
}
// Testable static dispatching method, defers to SafeWriter for actual writes over the
// connection.
void safeWriteBatch( DBClientBase* conn,
const BatchedCommandRequest& request,
BatchedCommandResponse* response );
// Helper that acts as an auto-ptr for write and wc errors
struct GLEErrors {
auto_ptr writeError;
auto_ptr wcError;
};
/**
* Given a GLE response, extracts a write error and a write concern error for the previous
* operation.
*
* Returns !OK if the GLE itself failed in an unknown way.
*/
static Status extractGLEErrors( const BSONObj& gleResponse, GLEErrors* errors );
struct GLEStats {
GLEStats() :
n( 0 ) {
}
int n;
BSONObj upsertedId;
OpTime lastOp;
};
/**
* Given a GLE response, pulls out stats for the previous write operation.
*/
static void extractGLEStats( const BSONObj& gleResponse, GLEStats* stats );
/**
* Given a GLE response, strips out all non-write-concern related information
*/
static BSONObj stripNonWCInfo( const BSONObj& gleResponse );
private:
SafeWriter* _safeWriter;
};
// Used for reporting legacy write concern responses
struct LegacyWCResponse {
string shardHost;
BSONObj gleResponse;
string errToReport;
};
/**
* Uses GLE and the shard hosts and opTimes last written by write commands to enforce a
* write concern across the previously used shards.
*
* Returns OK with the LegacyWCResponses containing only write concern error information
* Returns !OK if there was an error getting a GLE response
*/
Status enforceLegacyWriteConcern( MultiCommandDispatch* dispatcher,
const StringData& dbName,
const BSONObj& options,
const HostOpTimeMap& hostOpTimes,
vector* wcResponses );
}