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/**
* Copyright (C) 2015 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 <http://www.gnu.org/licenses/>.
*
* 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.
*/
#include "mongo/db/jsobj.h"
namespace mongo {
class BSONObj;
class BSONObjBuilder;
class Status;
template <typename T> class StatusWith;
namespace rpc {
/**
* This class compromises the reply metadata fields that concern sharding. MongoD attaches
* this information to a command reply, which MongoS uses to process getLastError.
*/
class ShardingMetadata {
public:
/**
* Reads ShardingMetadata from a metadata object.
*/
static StatusWith<ShardingMetadata> readFromMetadata(const BSONObj& metadataObj);
/**
* Writes ShardingMetadata to a metadata builder.
*/
Status writeToMetadata(BSONObjBuilder* metadataBob) const;
/**
* Rewrites the ShardingMetadata from the legacy OP_QUERY format to the metadata object
* format.
*/
static Status downconvert(const BSONObj& commandReply,
const BSONObj& replyMetadata,
BSONObjBuilder* legacyCommandReply);
/**
* Rewrites the ShardingMetadata from the legacy OP_QUERY format to the metadata object
* format.
*/
static Status upconvert(const BSONObj& legacyCommandReply,
BSONObjBuilder* commandReplyBob,
BSONObjBuilder* metadataBob);
/**
* Gets the OpTime of the oplog entry of the last succssful write operation executed by the
* server that produced the metadata.
*/
const Timestamp& getLastOpTime() const;
/**
* Gets the most recent election id observed by the server that produced the metadata.
*/
const OID& getLastElectionId() const;
ShardingMetadata(Timestamp lastOpTime, OID lastElectionId);
private:
Timestamp _lastOpTime;
OID _lastElectionId;
};
} // namespace rpc
} // namespace mongo
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