rocksdb/db/wal_manager.h
Akanksha Mahajan 1f9f630b27 Store FileSystemPtr object that contains FileSystem ptr (#7180)
Summary:
As part of the IOTracing project, this PR
    1. Caches "FileSystemPtr" object(wrapper class that returns file system pointer based on tracing enabled) instead of "FileSystem" pointer.
    2. FileSystemPtr object is created using FileSystem pointer and IOTracer
    pointer.
    3. IOTracer shared_ptr is created in DBImpl and it is passed to different classes through constructor.
    4. When tracing is enabled through DB::StartIOTrace, FileSystemPtr
    returns FileSystemTracingWrapper pointer for tracing purpose and when
    it is disabled underlying FileSystem pointer is returned.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7180

Test Plan:
make check -j64
                COMPILE_WITH_TSAN=1 make check -j64

Reviewed By: anand1976

Differential Revision: D22987117

Pulled By: akankshamahajan15

fbshipit-source-id: 6073617e4c2d5bc363914f3a1f55ae3b0a58fbf1
2020-08-12 17:31:23 -07:00

120 lines
4 KiB
C++

// 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 <deque>
#include <limits>
#include <set>
#include <utility>
#include <vector>
#include <string>
#include <memory>
#include "db/version_set.h"
#include "file/file_util.h"
#include "options/db_options.h"
#include "port/port.h"
#include "rocksdb/env.h"
#include "rocksdb/status.h"
#include "rocksdb/transaction_log.h"
#include "rocksdb/types.h"
namespace ROCKSDB_NAMESPACE {
#ifndef ROCKSDB_LITE
// WAL manager provides the abstraction for reading the WAL files as a single
// unit. Internally, it opens and reads the files using Reader or Writer
// abstraction.
class WalManager {
public:
WalManager(const ImmutableDBOptions& db_options,
const FileOptions& file_options,
const std::shared_ptr<IOTracer>& io_tracer,
const bool seq_per_batch = false)
: db_options_(db_options),
file_options_(file_options),
env_(db_options.env),
fs_(db_options.fs, io_tracer),
purge_wal_files_last_run_(0),
seq_per_batch_(seq_per_batch),
wal_in_db_path_(IsWalDirSameAsDBPath(&db_options)),
io_tracer_(io_tracer) {}
Status GetSortedWalFiles(VectorLogPtr& files);
// Allow user to tail transaction log to find all recent changes to the
// database that are newer than `seq_number`.
Status GetUpdatesSince(
SequenceNumber seq_number, std::unique_ptr<TransactionLogIterator>* iter,
const TransactionLogIterator::ReadOptions& read_options,
VersionSet* version_set);
void PurgeObsoleteWALFiles();
void ArchiveWALFile(const std::string& fname, uint64_t number);
Status DeleteFile(const std::string& fname, uint64_t number);
Status GetLiveWalFile(uint64_t number, std::unique_ptr<LogFile>* log_file);
Status TEST_ReadFirstRecord(const WalFileType type, const uint64_t number,
SequenceNumber* sequence) {
return ReadFirstRecord(type, number, sequence);
}
Status TEST_ReadFirstLine(const std::string& fname, const uint64_t number,
SequenceNumber* sequence) {
return ReadFirstLine(fname, number, sequence);
}
private:
Status GetSortedWalsOfType(const std::string& path, VectorLogPtr& log_files,
WalFileType type);
// Requires: all_logs should be sorted with earliest log file first
// Retains all log files in all_logs which contain updates with seq no.
// Greater Than or Equal to the requested SequenceNumber.
Status RetainProbableWalFiles(VectorLogPtr& all_logs,
const SequenceNumber target);
Status ReadFirstRecord(const WalFileType type, const uint64_t number,
SequenceNumber* sequence);
Status ReadFirstLine(const std::string& fname, const uint64_t number,
SequenceNumber* sequence);
// ------- state from DBImpl ------
const ImmutableDBOptions& db_options_;
const FileOptions file_options_;
Env* env_;
const FileSystemPtr fs_;
// ------- WalManager state -------
// cache for ReadFirstRecord() calls
std::unordered_map<uint64_t, SequenceNumber> read_first_record_cache_;
port::Mutex read_first_record_cache_mutex_;
// last time when PurgeObsoleteWALFiles ran.
uint64_t purge_wal_files_last_run_;
bool seq_per_batch_;
bool wal_in_db_path_;
// obsolete files will be deleted every this seconds if ttl deletion is
// enabled and archive size_limit is disabled.
static const uint64_t kDefaultIntervalToDeleteObsoleteWAL = 600;
std::shared_ptr<IOTracer> io_tracer_;
};
#endif // ROCKSDB_LITE
} // namespace ROCKSDB_NAMESPACE