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Diffstat (limited to 'src/mongo/s/shard_resolver.h')
-rw-r--r-- | src/mongo/s/shard_resolver.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/src/mongo/s/shard_resolver.h b/src/mongo/s/shard_resolver.h new file mode 100644 index 00000000000..4a0fa53f48c --- /dev/null +++ b/src/mongo/s/shard_resolver.h @@ -0,0 +1,61 @@ +/** + * 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 <string> + +#include "mongo/base/status.h" +#include "mongo/client/dbclientinterface.h" +#include "mongo/s/shard_resolver.h" + +namespace mongo { + +class OperationContext; + +/** + * Given a shard name, the ShardResolver resolves a particular host on that shard to contact. + * + * TODO: Internally, this is backed by a cache - do we need explicit refresh mechanisms built + * into this interface? + */ +class ShardResolver { +public: + virtual ~ShardResolver() {} + + /** + * Returns a host we can use for write ops to this shard. + * + * Returns !OK with message if the shard host could not be found for other reasons. + */ + virtual Status chooseWriteHost(OperationContext* txn, + const std::string& shardName, + ConnectionString* shardHost) const = 0; +}; + +} // namespace mongo |