diff options
Diffstat (limited to 'src/mongo/db/s/shard_key_index_util.h')
-rw-r--r-- | src/mongo/db/s/shard_key_index_util.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/src/mongo/db/s/shard_key_index_util.h b/src/mongo/db/s/shard_key_index_util.h new file mode 100644 index 00000000000..db59c57ceca --- /dev/null +++ b/src/mongo/db/s/shard_key_index_util.h @@ -0,0 +1,104 @@ +/** + * Copyright (C) 2022-present MongoDB, Inc. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the Server Side Public License, version 1, + * as published by MongoDB, Inc. + * + * 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 + * Server Side Public License for more details. + * + * You should have received a copy of the Server Side Public License + * along with this program. If not, see + * <http://www.mongodb.com/licensing/server-side-public-license>. + * + * 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 Server Side 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/bson/bsonobj.h" +#include "mongo/db/catalog/clustered_collection_options_gen.h" +#include "mongo/db/catalog/index_catalog.h" + +namespace mongo { + +class Collection; +class CollectionPtr; + +class IndexDescriptor; + +class ShardKeyIndex { +public: + /** + * Wraps information pertaining to the 'index' used as the shard key. + * + * A clustered index is not tied to an IndexDescriptor whereas all other types of indexes + * are. Either the 'index' is a clustered index and '_clusteredIndexKeyPattern' is + * non-empty, or '_indexDescriptor' is non-null and a standard index exists. + */ + ShardKeyIndex(const IndexDescriptor* indexDescriptor); + ShardKeyIndex(const ClusteredIndexSpec& clusteredIndexSpec); + + const BSONObj& keyPattern() const; + const IndexDescriptor* descriptor() const { + return _indexDescriptor; + } + +private: + const IndexDescriptor* _indexDescriptor; + + // Stores the keyPattern when the index is a clustered index and there is no + // IndexDescriptor. Empty otherwise. + BSONObj _clusteredIndexKeyPattern; +}; + +/** + * Returns true if the given index is compatible with the shard key pattern. + */ +bool isCompatibleWithShardKey(OperationContext* opCtx, + const CollectionPtr& collection, + const IndexCatalogEntry* indexEntry, + const BSONObj& shardKey, + bool requireSingleKey); + +/** + * Returns an index suitable for shard key range scans if it exists. + * + * This index: + * - must be prefixed by 'shardKey', and + * - must not be a partial index. + * - must have the simple collation. + * + * If the parameter 'requireSingleKey' is true, then this index additionally must not be + * multi-key. + */ +const boost::optional<ShardKeyIndex> findShardKeyPrefixedIndex(OperationContext* opCtx, + const CollectionPtr& collection, + const IndexCatalog* indexCatalog, + const BSONObj& shardKey, + bool requireSingleKey); + +/** + * Returns true if the given index name is the last remaining index that is compatible with the + * shard key index. + */ +bool isLastShardKeyIndex(OperationContext* opCtx, + const CollectionPtr& collection, + const IndexCatalog* indexCatalog, + const std::string& indexName, + const BSONObj& shardKey); + +} // namespace mongo |