rocksdb/file/file_util.h
mrambacher 3dff28cf9b Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033)
Summary:
For performance purposes, the lower level routines were changed to use a SystemClock* instead of a std::shared_ptr<SystemClock>.  The shared ptr has some performance degradation on certain hardware classes.

For most of the system, there is no risk of the pointer being deleted/invalid because the shared_ptr will be stored elsewhere.  For example, the ImmutableDBOptions stores the Env which has a std::shared_ptr<SystemClock> in it.  The SystemClock* within the ImmutableDBOptions is essentially a "short cut" to gain access to this constant resource.

There were a few classes (PeriodicWorkScheduler?) where the "short cut" property did not hold.  In those cases, the shared pointer was preserved.

Using db_bench readrandom perf_level=3 on my EC2 box, this change performed as well or better than 6.17:

6.17: readrandom   :      28.046 micros/op 854902 ops/sec;   61.3 MB/s (355999 of 355999 found)
6.18: readrandom   :      32.615 micros/op 735306 ops/sec;   52.7 MB/s (290999 of 290999 found)
PR: readrandom   :      27.500 micros/op 871909 ops/sec;   62.5 MB/s (367999 of 367999 found)

(Note that the times for 6.18 are prior to revert of the SystemClock).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8033

Reviewed By: pdillinger

Differential Revision: D27014563

Pulled By: mrambacher

fbshipit-source-id: ad0459eba03182e454391b5926bf5cdd45657b67
2021-03-15 04:34:11 -07:00

95 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,
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