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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/file/sequence_file_reader.h | |
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/file/sequence_file_reader.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/rocksdb/file/sequence_file_reader.h b/src/rocksdb/file/sequence_file_reader.h new file mode 100644 index 000000000..baea10eb7 --- /dev/null +++ b/src/rocksdb/file/sequence_file_reader.h @@ -0,0 +1,129 @@ +// 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 <atomic> +#include <string> + +#include "env/file_system_tracer.h" +#include "port/port.h" +#include "rocksdb/env.h" +#include "rocksdb/file_system.h" + +namespace ROCKSDB_NAMESPACE { + +// SequentialFileReader is a wrapper on top of Env::SequentialFile. It handles +// Buffered (i.e when page cache is enabled) and Direct (with O_DIRECT / page +// cache disabled) reads appropriately, and also updates the IO stats. +class SequentialFileReader { + private: +#ifndef ROCKSDB_LITE + void NotifyOnFileReadFinish( + uint64_t offset, size_t length, + const FileOperationInfo::StartTimePoint& start_ts, + const FileOperationInfo::FinishTimePoint& finish_ts, + const Status& status) const { + FileOperationInfo info(FileOperationType::kRead, file_name_, start_ts, + finish_ts, status); + info.offset = offset; + info.length = length; + + for (auto& listener : listeners_) { + listener->OnFileReadFinish(info); + } + info.status.PermitUncheckedError(); + } + + void AddFileIOListeners( + const std::vector<std::shared_ptr<EventListener>>& listeners) { + std::for_each(listeners.begin(), listeners.end(), + [this](const std::shared_ptr<EventListener>& e) { + if (e->ShouldBeNotifiedOnFileIO()) { + listeners_.emplace_back(e); + } + }); + } +#endif // ROCKSDB_LITE + + bool ShouldNotifyListeners() const { return !listeners_.empty(); } + + std::string file_name_; + FSSequentialFilePtr file_; + std::atomic<size_t> offset_{0}; // read offset + std::vector<std::shared_ptr<EventListener>> listeners_{}; + RateLimiter* rate_limiter_; + + public: + explicit SequentialFileReader( + std::unique_ptr<FSSequentialFile>&& _file, const std::string& _file_name, + const std::shared_ptr<IOTracer>& io_tracer = nullptr, + const std::vector<std::shared_ptr<EventListener>>& listeners = {}, + RateLimiter* rate_limiter = + nullptr) // TODO: migrate call sites to provide rate limiter + : file_name_(_file_name), + file_(std::move(_file), io_tracer, _file_name), + listeners_(), + rate_limiter_(rate_limiter) { +#ifndef ROCKSDB_LITE + AddFileIOListeners(listeners); +#else + (void)listeners; +#endif + } + + explicit SequentialFileReader( + std::unique_ptr<FSSequentialFile>&& _file, const std::string& _file_name, + size_t _readahead_size, + const std::shared_ptr<IOTracer>& io_tracer = nullptr, + const std::vector<std::shared_ptr<EventListener>>& listeners = {}, + RateLimiter* rate_limiter = + nullptr) // TODO: migrate call sites to provide rate limiter + : file_name_(_file_name), + file_(NewReadaheadSequentialFile(std::move(_file), _readahead_size), + io_tracer, _file_name), + listeners_(), + rate_limiter_(rate_limiter) { +#ifndef ROCKSDB_LITE + AddFileIOListeners(listeners); +#else + (void)listeners; +#endif + } + static IOStatus Create(const std::shared_ptr<FileSystem>& fs, + const std::string& fname, const FileOptions& file_opts, + std::unique_ptr<SequentialFileReader>* reader, + IODebugContext* dbg, RateLimiter* rate_limiter); + + SequentialFileReader(const SequentialFileReader&) = delete; + SequentialFileReader& operator=(const SequentialFileReader&) = delete; + + // `rate_limiter_priority` is used to charge the internal rate limiter when + // enabled. The special value `Env::IO_TOTAL` makes this operation bypass the + // rate limiter. The amount charged to the internal rate limiter is n, even + // when less than n bytes are actually read (e.g. at end of file). To avoid + // overcharging the rate limiter, the caller can use file size to cap n to + // read until end of file. + IOStatus Read(size_t n, Slice* result, char* scratch, + Env::IOPriority rate_limiter_priority); + + IOStatus Skip(uint64_t n); + + FSSequentialFile* file() { return file_.get(); } + + std::string file_name() { return file_name_; } + + bool use_direct_io() const { return file_->use_direct_io(); } + + private: + // NewReadaheadSequentialFile provides a wrapper over SequentialFile to + // always prefetch additional data with every read. + static std::unique_ptr<FSSequentialFile> NewReadaheadSequentialFile( + std::unique_ptr<FSSequentialFile>&& file, size_t readahead_size); +}; +} // namespace ROCKSDB_NAMESPACE |