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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
commit | e6918187568dbd01842d8d1d2c808ce16a894239 (patch) | |
tree | 64f88b554b444a49f656b6c656111a145cbbaa28 /src/rocksdb/util/compression_context_cache.cc | |
parent | Initial commit. (diff) | |
download | ceph-e6918187568dbd01842d8d1d2c808ce16a894239.tar.xz ceph-e6918187568dbd01842d8d1d2c808ce16a894239.zip |
Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/rocksdb/util/compression_context_cache.cc | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/src/rocksdb/util/compression_context_cache.cc b/src/rocksdb/util/compression_context_cache.cc new file mode 100644 index 000000000..52c3fac72 --- /dev/null +++ b/src/rocksdb/util/compression_context_cache.cc @@ -0,0 +1,106 @@ +// 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. +// + +#include "util/compression_context_cache.h" + +#include <atomic> + +#include "util/compression.h" +#include "util/core_local.h" + +namespace ROCKSDB_NAMESPACE { +namespace compression_cache { + +void* const SentinelValue = nullptr; +// Cache ZSTD uncompression contexts for reads +// if needed we can add ZSTD compression context caching +// which is currently is not done since BlockBasedTableBuilder +// simply creates one compression context per new SST file. +struct ZSTDCachedData { + // We choose to cache the below structure instead of a ptr + // because we want to avoid a) native types leak b) make + // cache use transparent for the user + ZSTDUncompressCachedData uncomp_cached_data_; + std::atomic<void*> zstd_uncomp_sentinel_; + + char + padding[(CACHE_LINE_SIZE - + (sizeof(ZSTDUncompressCachedData) + sizeof(std::atomic<void*>)) % + CACHE_LINE_SIZE)]; // unused padding field + + ZSTDCachedData() : zstd_uncomp_sentinel_(&uncomp_cached_data_) {} + ZSTDCachedData(const ZSTDCachedData&) = delete; + ZSTDCachedData& operator=(const ZSTDCachedData&) = delete; + + ZSTDUncompressCachedData GetUncompressData(int64_t idx) { + ZSTDUncompressCachedData result; + void* expected = &uncomp_cached_data_; + if (zstd_uncomp_sentinel_.compare_exchange_strong(expected, + SentinelValue)) { + uncomp_cached_data_.CreateIfNeeded(); + result.InitFromCache(uncomp_cached_data_, idx); + } else { + // Creates one time use data + result.CreateIfNeeded(); + } + return result; + } + // Return the entry back into circulation + // This is executed only when we successfully obtained + // in the first place + void ReturnUncompressData() { + if (zstd_uncomp_sentinel_.exchange(&uncomp_cached_data_) != SentinelValue) { + // Means we are returning while not having it acquired. + assert(false); + } + } +}; +static_assert(sizeof(ZSTDCachedData) % CACHE_LINE_SIZE == 0, + "Expected CACHE_LINE_SIZE alignment"); +} // namespace compression_cache + +class CompressionContextCache::Rep { + public: + Rep() {} + ZSTDUncompressCachedData GetZSTDUncompressData() { + auto p = per_core_uncompr_.AccessElementAndIndex(); + int64_t idx = static_cast<int64_t>(p.second); + return p.first->GetUncompressData(idx); + } + void ReturnZSTDUncompressData(int64_t idx) { + assert(idx >= 0); + auto* cn = per_core_uncompr_.AccessAtCore(static_cast<size_t>(idx)); + cn->ReturnUncompressData(); + } + + private: + CoreLocalArray<compression_cache::ZSTDCachedData> per_core_uncompr_; +}; + +CompressionContextCache::CompressionContextCache() : rep_(new Rep()) {} + +CompressionContextCache* CompressionContextCache::Instance() { + static CompressionContextCache instance; + return &instance; +} + +void CompressionContextCache::InitSingleton() { Instance(); } + +ZSTDUncompressCachedData +CompressionContextCache::GetCachedZSTDUncompressData() { + return rep_->GetZSTDUncompressData(); +} + +void CompressionContextCache::ReturnCachedZSTDUncompressData(int64_t idx) { + rep_->ReturnZSTDUncompressData(idx); +} + +CompressionContextCache::~CompressionContextCache() { delete rep_; } + +} // namespace ROCKSDB_NAMESPACE |