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Diffstat (limited to 'src/rocksdb/util/compression_context_cache.h')
-rw-r--r-- | src/rocksdb/util/compression_context_cache.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/src/rocksdb/util/compression_context_cache.h b/src/rocksdb/util/compression_context_cache.h new file mode 100644 index 000000000..7b7b2d507 --- /dev/null +++ b/src/rocksdb/util/compression_context_cache.h @@ -0,0 +1,47 @@ +// 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. +// + +// Compression context cache allows to cache compression/uncompression contexts +// This helps with Random Read latencies and reduces CPU utilization +// Caching is implemented using CoreLocal facility. Compression/Uncompression +// instances are cached on a per core basis using CoreLocalArray. A borrowed +// instance is atomically replaced with a sentinel value for the time of being +// used. If it turns out that another thread is already makes use of the +// instance we still create one on the heap which is later is destroyed. + +#pragma once + +#include <stdint.h> + +#include "rocksdb/rocksdb_namespace.h" + +namespace ROCKSDB_NAMESPACE { +class ZSTDUncompressCachedData; + +class CompressionContextCache { + public: + // Singleton + static CompressionContextCache* Instance(); + static void InitSingleton(); + CompressionContextCache(const CompressionContextCache&) = delete; + CompressionContextCache& operator=(const CompressionContextCache&) = delete; + + ZSTDUncompressCachedData GetCachedZSTDUncompressData(); + void ReturnCachedZSTDUncompressData(int64_t idx); + + private: + // Singleton + CompressionContextCache(); + ~CompressionContextCache(); + + class Rep; + Rep* rep_; +}; + +} // namespace ROCKSDB_NAMESPACE |