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Diffstat (limited to '')
-rw-r--r-- | src/rocksdb/table/block_based/hash_index_reader.h | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/src/rocksdb/table/block_based/hash_index_reader.h b/src/rocksdb/table/block_based/hash_index_reader.h new file mode 100644 index 000000000..9037efc87 --- /dev/null +++ b/src/rocksdb/table/block_based/hash_index_reader.h @@ -0,0 +1,49 @@ +// Copyright (c) 2011-present, Facebook, Inc. All rights reserved. +// This source code is licensed under both the GPLv2 (found in the +// COPYING file in the root directory) and Apache 2.0 License +// (found in the LICENSE.Apache file in the root directory). +// +// Copyright (c) 2011 The LevelDB Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. See the AUTHORS file for names of contributors. +#pragma once + +#include "table/block_based/index_reader_common.h" + +namespace ROCKSDB_NAMESPACE { +// Index that leverages an internal hash table to quicken the lookup for a given +// key. +class HashIndexReader : public BlockBasedTable::IndexReaderCommon { + public: + static Status Create(const BlockBasedTable* table, const ReadOptions& ro, + FilePrefetchBuffer* prefetch_buffer, + InternalIterator* meta_index_iter, bool use_cache, + bool prefetch, bool pin, + BlockCacheLookupContext* lookup_context, + std::unique_ptr<IndexReader>* index_reader); + + InternalIteratorBase<IndexValue>* NewIterator( + const ReadOptions& read_options, bool disable_prefix_seek, + IndexBlockIter* iter, GetContext* get_context, + BlockCacheLookupContext* lookup_context) override; + + size_t ApproximateMemoryUsage() const override { + size_t usage = ApproximateIndexBlockMemoryUsage(); +#ifdef ROCKSDB_MALLOC_USABLE_SIZE + usage += malloc_usable_size(const_cast<HashIndexReader*>(this)); +#else + if (prefix_index_) { + usage += prefix_index_->ApproximateMemoryUsage(); + } + usage += sizeof(*this); +#endif // ROCKSDB_MALLOC_USABLE_SIZE + return usage; + } + + private: + HashIndexReader(const BlockBasedTable* t, CachableEntry<Block>&& index_block) + : IndexReaderCommon(t, std::move(index_block)) {} + + std::unique_ptr<BlockPrefixIndex> prefix_index_; +}; +} // namespace ROCKSDB_NAMESPACE |