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0376869f05
Summary: As title. This is part of an fb-internal task. First, remove all `using namespace` statements if applicable. Next, utilize multiple build platforms and see if anything is broken. Should anything become broken, fix the compilation errors with as little extra change as possible. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9369 Test Plan: internal build and make check make clean && make static_lib && cd examples && make all Reviewed By: pdillinger Differential Revision: D33517260 Pulled By: riversand963 fbshipit-source-id: 3fc4ce6402a073421dfd9a9b2d1c79441dca7a40
107 lines
3.6 KiB
C++
107 lines
3.6 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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//
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#include "util/compression_context_cache.h"
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#include "util/compression.h"
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#include "util/core_local.h"
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#include <atomic>
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namespace ROCKSDB_NAMESPACE {
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namespace compression_cache {
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void* const SentinelValue = nullptr;
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// Cache ZSTD uncompression contexts for reads
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// if needed we can add ZSTD compression context caching
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// which is currently is not done since BlockBasedTableBuilder
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// simply creates one compression context per new SST file.
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struct ZSTDCachedData {
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// We choose to cache the below structure instead of a ptr
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// because we want to avoid a) native types leak b) make
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// cache use transparent for the user
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ZSTDUncompressCachedData uncomp_cached_data_;
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std::atomic<void*> zstd_uncomp_sentinel_;
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char
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padding[(CACHE_LINE_SIZE -
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(sizeof(ZSTDUncompressCachedData) + sizeof(std::atomic<void*>)) %
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CACHE_LINE_SIZE)]; // unused padding field
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ZSTDCachedData() : zstd_uncomp_sentinel_(&uncomp_cached_data_) {}
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ZSTDCachedData(const ZSTDCachedData&) = delete;
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ZSTDCachedData& operator=(const ZSTDCachedData&) = delete;
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ZSTDUncompressCachedData GetUncompressData(int64_t idx) {
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ZSTDUncompressCachedData result;
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void* expected = &uncomp_cached_data_;
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if (zstd_uncomp_sentinel_.compare_exchange_strong(expected,
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SentinelValue)) {
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uncomp_cached_data_.CreateIfNeeded();
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result.InitFromCache(uncomp_cached_data_, idx);
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} else {
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// Creates one time use data
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result.CreateIfNeeded();
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}
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return result;
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}
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// Return the entry back into circulation
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// This is executed only when we successfully obtained
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// in the first place
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void ReturnUncompressData() {
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if (zstd_uncomp_sentinel_.exchange(&uncomp_cached_data_) != SentinelValue) {
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// Means we are returning while not having it acquired.
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assert(false);
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}
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}
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};
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static_assert(sizeof(ZSTDCachedData) % CACHE_LINE_SIZE == 0,
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"Expected CACHE_LINE_SIZE alignment");
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} // namespace compression_cache
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class CompressionContextCache::Rep {
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public:
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Rep() {}
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ZSTDUncompressCachedData GetZSTDUncompressData() {
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auto p = per_core_uncompr_.AccessElementAndIndex();
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int64_t idx = static_cast<int64_t>(p.second);
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return p.first->GetUncompressData(idx);
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}
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void ReturnZSTDUncompressData(int64_t idx) {
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assert(idx >= 0);
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auto* cn = per_core_uncompr_.AccessAtCore(static_cast<size_t>(idx));
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cn->ReturnUncompressData();
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}
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private:
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CoreLocalArray<compression_cache::ZSTDCachedData> per_core_uncompr_;
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};
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CompressionContextCache::CompressionContextCache() : rep_(new Rep()) {}
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CompressionContextCache* CompressionContextCache::Instance() {
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static CompressionContextCache instance;
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return &instance;
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}
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void CompressionContextCache::InitSingleton() { Instance(); }
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ZSTDUncompressCachedData
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CompressionContextCache::GetCachedZSTDUncompressData() {
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return rep_->GetZSTDUncompressData();
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}
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void CompressionContextCache::ReturnCachedZSTDUncompressData(int64_t idx) {
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rep_->ReturnZSTDUncompressData(idx);
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}
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CompressionContextCache::~CompressionContextCache() { delete rep_; }
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} // namespace ROCKSDB_NAMESPACE
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