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/**
* 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 <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.
*/
#pragma once
#include "mongo/s/shard_resolver.h"
namespace mongo {
/**
* ShardResolver based on the Shard and ReplicaSetMonitor caches.
*
* TODO: Currently it's possible for the shard resolver to be stale after we target and remove
* a shard. We need to figure out how to refresh.
*/
class DBClientShardResolver : public ShardResolver {
public:
DBClientShardResolver() {}
virtual ~DBClientShardResolver() {}
/**
* Returns the current host ConnectionString for a write to a shard.
*
* Note: Does *not* trigger a refresh of either the shard or replica set monitor caches,
* though refreshes may happen unexpectedly between calls.
*
* Returns ShardNotFound if the shard name is unknown
* Returns ReplicaSetNotFound if the replica set is not being tracked
* Returns !OK with message if the shard host could not be found for other reasons.
*/
Status chooseWriteHost(OperationContext* txn,
const std::string& shardName,
ConnectionString* shardHost) const override;
/**
* Resolves a replica set connection string to a master or returns an error.
*
* Returns HostNotFound if the master is not reachable
* Returns ReplicaSetNotFound if the replica set is not being tracked
*/
static Status findMaster(const ConnectionString& connString, ConnectionString* resolvedHost);
};
} // namespace mongo
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