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Diffstat (limited to 'src/rocksdb/table/block_based/partitioned_index_reader.h')
-rw-r--r-- | src/rocksdb/table/block_based/partitioned_index_reader.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/rocksdb/table/block_based/partitioned_index_reader.h b/src/rocksdb/table/block_based/partitioned_index_reader.h new file mode 100644 index 000000000..58a7877ab --- /dev/null +++ b/src/rocksdb/table/block_based/partitioned_index_reader.h @@ -0,0 +1,55 @@ +// 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" +#include "util/hash_containers.h" + +namespace ROCKSDB_NAMESPACE { +// Index that allows binary search lookup in a two-level index structure. +class PartitionIndexReader : public BlockBasedTable::IndexReaderCommon { + public: + // Read the partition index from the file and create an instance for + // `PartitionIndexReader`. + // On success, index_reader will be populated; otherwise it will remain + // unmodified. + static Status Create(const BlockBasedTable* table, const ReadOptions& ro, + FilePrefetchBuffer* prefetch_buffer, bool use_cache, + bool prefetch, bool pin, + BlockCacheLookupContext* lookup_context, + std::unique_ptr<IndexReader>* index_reader); + + // return a two-level iterator: first level is on the partition index + InternalIteratorBase<IndexValue>* NewIterator( + const ReadOptions& read_options, bool /* disable_prefix_seek */, + IndexBlockIter* iter, GetContext* get_context, + BlockCacheLookupContext* lookup_context) override; + + Status CacheDependencies(const ReadOptions& ro, bool pin) override; + size_t ApproximateMemoryUsage() const override { + size_t usage = ApproximateIndexBlockMemoryUsage(); +#ifdef ROCKSDB_MALLOC_USABLE_SIZE + usage += malloc_usable_size(const_cast<PartitionIndexReader*>(this)); +#else + usage += sizeof(*this); +#endif // ROCKSDB_MALLOC_USABLE_SIZE + // TODO(myabandeh): more accurate estimate of partition_map_ mem usage + return usage; + } + + private: + PartitionIndexReader(const BlockBasedTable* t, + CachableEntry<Block>&& index_block) + : IndexReaderCommon(t, std::move(index_block)) {} + + // For partition blocks pinned in cache. This is expected to be "all or + // none" so that !partition_map_.empty() can use an iterator expecting + // all partitions to be saved here. + UnorderedMap<uint64_t, CachableEntry<Block>> partition_map_; +}; +} // namespace ROCKSDB_NAMESPACE |