rocksdb/file/file_util.h
mrambacher 12f1137355 Add a SystemClock class to capture the time functions of an Env (#7858)
Summary:
Introduces and uses a SystemClock class to RocksDB.  This class contains the time-related functions of an Env and these functions can be redirected from the Env to the SystemClock.

Many of the places that used an Env (Timer, PerfStepTimer, RepeatableThread, RateLimiter, WriteController) for time-related functions have been changed to use SystemClock instead.  There are likely more places that can be changed, but this is a start to show what can/should be done.  Over time it would be nice to migrate most (if not all) of the uses of the time functions from the Env to the SystemClock.

There are several Env classes that implement these functions.  Most of these have not been converted yet to SystemClock implementations; that will come in a subsequent PR.  It would be good to unify many of the Mock Timer implementations, so that they behave similarly and be tested similarly (some override Sleep, some use a MockSleep, etc).

Additionally, this change will allow new methods to be introduced to the SystemClock (like https://github.com/facebook/rocksdb/issues/7101 WaitFor) in a consistent manner across a smaller number of classes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7858

Reviewed By: pdillinger

Differential Revision: D26006406

Pulled By: mrambacher

fbshipit-source-id: ed10a8abbdab7ff2e23d69d85bd25b3e7e899e90
2021-01-25 22:09:11 -08:00

96 lines
3.9 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).
//
#pragma once
#include <string>
#include "file/filename.h"
#include "options/db_options.h"
#include "rocksdb/env.h"
#include "rocksdb/file_system.h"
#include "rocksdb/sst_file_writer.h"
#include "rocksdb/status.h"
#include "rocksdb/system_clock.h"
#include "rocksdb/types.h"
#include "trace_replay/io_tracer.h"
namespace ROCKSDB_NAMESPACE {
// use_fsync maps to options.use_fsync, which determines the way that
// the file is synced after copying.
extern IOStatus CopyFile(FileSystem* fs, const std::string& source,
const std::string& destination, uint64_t size,
bool use_fsync,
const std::shared_ptr<IOTracer>& io_tracer = nullptr);
inline IOStatus CopyFile(const std::shared_ptr<FileSystem>& fs,
const std::string& source,
const std::string& destination, uint64_t size,
bool use_fsync,
const std::shared_ptr<IOTracer>& io_tracer = nullptr) {
return CopyFile(fs.get(), source, destination, size, use_fsync, io_tracer);
}
extern IOStatus CreateFile(FileSystem* fs, const std::string& destination,
const std::string& contents, bool use_fsync);
inline IOStatus CreateFile(const std::shared_ptr<FileSystem>& fs,
const std::string& destination,
const std::string& contents, bool use_fsync) {
return CreateFile(fs.get(), destination, contents, use_fsync);
}
extern Status DeleteDBFile(const ImmutableDBOptions* db_options,
const std::string& fname,
const std::string& path_to_sync, const bool force_bg,
const bool force_fg);
extern bool IsWalDirSameAsDBPath(const ImmutableDBOptions* db_options);
extern IOStatus GenerateOneFileChecksum(
FileSystem* fs, const std::string& file_path,
FileChecksumGenFactory* checksum_factory,
const std::string& requested_checksum_func_name, std::string* file_checksum,
std::string* file_checksum_func_name,
size_t verify_checksums_readahead_size, bool allow_mmap_reads,
std::shared_ptr<IOTracer>& io_tracer, RateLimiter* rate_limiter = nullptr);
inline IOStatus GenerateOneFileChecksum(
const std::shared_ptr<FileSystem>& fs, const std::string& file_path,
FileChecksumGenFactory* checksum_factory,
const std::string& requested_checksum_func_name, std::string* file_checksum,
std::string* file_checksum_func_name,
size_t verify_checksums_readahead_size, bool allow_mmap_reads,
std::shared_ptr<IOTracer>& io_tracer) {
return GenerateOneFileChecksum(
fs.get(), file_path, checksum_factory, requested_checksum_func_name,
file_checksum, file_checksum_func_name, verify_checksums_readahead_size,
allow_mmap_reads, io_tracer);
}
inline IOStatus PrepareIOFromReadOptions(
const ReadOptions& ro, const std::shared_ptr<SystemClock>& clock,
IOOptions& opts) {
if (ro.deadline.count()) {
std::chrono::microseconds now =
std::chrono::microseconds(clock->NowMicros());
// Ensure there is atleast 1us available. We don't want to pass a value of
// 0 as that means no timeout
if (now >= ro.deadline) {
return IOStatus::TimedOut("Deadline exceeded");
}
opts.timeout = ro.deadline - now;
}
if (ro.io_timeout.count() &&
(!opts.timeout.count() || ro.io_timeout < opts.timeout)) {
opts.timeout = ro.io_timeout;
}
return IOStatus::OK();
}
// Test method to delete the input directory and all of its contents.
// This method is destructive and is meant for use only in tests!!!
Status DestroyDir(Env* env, const std::string& dir);
} // namespace ROCKSDB_NAMESPACE