a776406de3
Summary: This change adds File IO Notifications to the SequentialFileReader The SequentialFileReader is extended with a listener parameter. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8982 Test Plan: A new test EventListenerTest::OnWALOperationTest has been added. The test verifies that during restore the sequential file reader is called and the notifications are fired. Reviewed By: riversand963 Differential Revision: D31320844 Pulled By: shrfb fbshipit-source-id: 040b24da7c010d7c14ebb5c6460fae9a19b8c168
115 lines
4.0 KiB
C++
115 lines
4.0 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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//
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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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#pragma once
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#include <atomic>
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#include <string>
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#include "env/file_system_tracer.h"
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#include "port/port.h"
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#include "rocksdb/env.h"
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#include "rocksdb/file_system.h"
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namespace ROCKSDB_NAMESPACE {
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// SequentialFileReader is a wrapper on top of Env::SequentialFile. It handles
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// Buffered (i.e when page cache is enabled) and Direct (with O_DIRECT / page
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// cache disabled) reads appropriately, and also updates the IO stats.
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class SequentialFileReader {
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private:
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#ifndef ROCKSDB_LITE
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void NotifyOnFileReadFinish(
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uint64_t offset, size_t length,
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const FileOperationInfo::StartTimePoint& start_ts,
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const FileOperationInfo::FinishTimePoint& finish_ts,
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const Status& status) const {
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FileOperationInfo info(FileOperationType::kRead, file_name_, start_ts,
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finish_ts, status);
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info.offset = offset;
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info.length = length;
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for (auto& listener : listeners_) {
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listener->OnFileReadFinish(info);
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}
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}
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void AddFileIOListeners(
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const std::vector<std::shared_ptr<EventListener>>& listeners) {
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std::for_each(listeners.begin(), listeners.end(),
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[this](const std::shared_ptr<EventListener>& e) {
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if (e->ShouldBeNotifiedOnFileIO()) {
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listeners_.emplace_back(e);
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}
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});
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}
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#endif // ROCKSDB_LITE
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bool ShouldNotifyListeners() const { return !listeners_.empty(); }
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std::string file_name_;
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FSSequentialFilePtr file_;
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std::atomic<size_t> offset_{0}; // read offset
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std::vector<std::shared_ptr<EventListener>> listeners_{};
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public:
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explicit SequentialFileReader(
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std::unique_ptr<FSSequentialFile>&& _file, const std::string& _file_name,
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const std::shared_ptr<IOTracer>& io_tracer = nullptr,
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const std::vector<std::shared_ptr<EventListener>>& listeners = {})
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: file_name_(_file_name),
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file_(std::move(_file), io_tracer, _file_name),
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listeners_() {
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#ifndef ROCKSDB_LITE
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AddFileIOListeners(listeners);
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#else
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(void)listeners;
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#endif
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}
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explicit SequentialFileReader(
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std::unique_ptr<FSSequentialFile>&& _file, const std::string& _file_name,
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size_t _readahead_size,
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const std::shared_ptr<IOTracer>& io_tracer = nullptr,
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const std::vector<std::shared_ptr<EventListener>>& listeners = {})
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: file_name_(_file_name),
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file_(NewReadaheadSequentialFile(std::move(_file), _readahead_size),
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io_tracer, _file_name),
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listeners_() {
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#ifndef ROCKSDB_LITE
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AddFileIOListeners(listeners);
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#else
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(void)listeners;
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#endif
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}
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static IOStatus Create(const std::shared_ptr<FileSystem>& fs,
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const std::string& fname, const FileOptions& file_opts,
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std::unique_ptr<SequentialFileReader>* reader,
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IODebugContext* dbg);
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SequentialFileReader(const SequentialFileReader&) = delete;
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SequentialFileReader& operator=(const SequentialFileReader&) = delete;
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IOStatus Read(size_t n, Slice* result, char* scratch);
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IOStatus Skip(uint64_t n);
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FSSequentialFile* file() { return file_.get(); }
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std::string file_name() { return file_name_; }
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bool use_direct_io() const { return file_->use_direct_io(); }
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private:
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// NewReadaheadSequentialFile provides a wrapper over SequentialFile to
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// always prefetch additional data with every read.
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static std::unique_ptr<FSSequentialFile> NewReadaheadSequentialFile(
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std::unique_ptr<FSSequentialFile>&& file, size_t readahead_size);
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};
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} // namespace ROCKSDB_NAMESPACE
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