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rocksdb/util/file_reader_writer.cc

466 lines
14 KiB

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same 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.
#include "util/file_reader_writer.h"
#include <algorithm>
#include <mutex>
#include "port/port.h"
#include "util/histogram.h"
#include "util/iostats_context_imp.h"
#include "util/random.h"
#include "util/rate_limiter.h"
#include "util/sync_point.h"
namespace rocksdb {
Status SequentialFileReader::Read(size_t n, Slice* result, char* scratch) {
Status s = file_->Read(n, result, scratch);
IOSTATS_ADD(bytes_read, result->size());
return s;
}
Status SequentialFileReader::Skip(uint64_t n) { return file_->Skip(n); }
Status RandomAccessFileReader::Read(uint64_t offset, size_t n, Slice* result,
char* scratch) const {
Status s;
uint64_t elapsed = 0;
{
StopWatch sw(env_, stats_, hist_type_,
(stats_ != nullptr) ? &elapsed : nullptr);
IOSTATS_TIMER_GUARD(read_nanos);
s = file_->Read(offset, n, result, scratch);
IOSTATS_ADD_IF_POSITIVE(bytes_read, result->size());
}
if (stats_ != nullptr && file_read_hist_ != nullptr) {
file_read_hist_->Add(elapsed);
}
return s;
}
Status WritableFileWriter::Append(const Slice& data) {
const char* src = data.data();
size_t left = data.size();
Status s;
pending_sync_ = true;
pending_fsync_ = true;
TEST_KILL_RANDOM(rocksdb_kill_odds * REDUCE_ODDS2);
{
IOSTATS_TIMER_GUARD(prepare_write_nanos);
TEST_SYNC_POINT("WritableFileWriter::Append:BeforePrepareWrite");
writable_file_->PrepareWrite(static_cast<size_t>(GetFileSize()), left);
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
// Flush only when I/O is buffered
if (use_os_buffer_ &&
(buf_.GetCapacity() - buf_.GetCurrentSize()) < left) {
if (buf_.GetCurrentSize() > 0) {
s = Flush();
if (!s.ok()) {
return s;
}
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
if (buf_.GetCapacity() < (1 << 20)) {
size_t desiredCapacity = buf_.GetCapacity() * 2;
desiredCapacity = std::min(desiredCapacity, size_t(1 << 20));
buf_.AllocateNewBuffer(desiredCapacity);
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
assert(buf_.GetCurrentSize() == 0);
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
// We never write directly to disk with unbuffered I/O on.
// or we simply use it for its original purpose to accumulate many small
// chunks
if (!use_os_buffer_ || (buf_.GetCapacity() >= left)) {
while (left > 0) {
size_t appended = buf_.Append(src, left);
left -= appended;
src += appended;
if (left > 0) {
s = Flush();
if (!s.ok()) {
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
break;
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
// We double the buffer here because
// Flush calls do not keep up with the incoming bytes
// This is the only place when buffer is changed with unbuffered I/O
if (buf_.GetCapacity() < (1 << 20)) {
size_t desiredCapacity = buf_.GetCapacity() * 2;
desiredCapacity = std::min(desiredCapacity, size_t(1 << 20));
buf_.AllocateNewBuffer(desiredCapacity);
}
}
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
} else {
// Writing directly to file bypassing the buffer
assert(buf_.GetCurrentSize() == 0);
s = WriteBuffered(src, left);
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
TEST_KILL_RANDOM(rocksdb_kill_odds);
filesize_ += data.size();
return Status::OK();
}
Status WritableFileWriter::Close() {
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
// Do not quit immediately on failure the file MUST be closed
Status s;
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
// Possible to close it twice now as we MUST close
// in __dtor, simply flushing is not enough
// Windows when pre-allocating does not fill with zeros
// also with unbuffered access we also set the end of data.
if (!writable_file_) {
return s;
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
s = Flush(); // flush cache to OS
// In unbuffered mode we write whole pages so
// we need to let the file know where data ends.
Status interim = writable_file_->Truncate(filesize_);
if (!interim.ok() && s.ok()) {
s = interim;
}
TEST_KILL_RANDOM(rocksdb_kill_odds);
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
interim = writable_file_->Close();
if (!interim.ok() && s.ok()) {
s = interim;
}
writable_file_.reset();
return s;
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
// write out the cached data to the OS cache
Status WritableFileWriter::Flush() {
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
Status s;
TEST_KILL_RANDOM(rocksdb_kill_odds * REDUCE_ODDS2);
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
if (buf_.GetCurrentSize() > 0) {
if (use_os_buffer_) {
s = WriteBuffered(buf_.GetBufferStart(), buf_.GetCurrentSize());
} else {
s = WriteUnbuffered();
}
if (!s.ok()) {
return s;
}
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
s = writable_file_->Flush();
if (!s.ok()) {
return s;
}
// sync OS cache to disk for every bytes_per_sync_
// TODO: give log file and sst file different options (log
// files could be potentially cached in OS for their whole
// life time, thus we might not want to flush at all).
// We try to avoid sync to the last 1MB of data. For two reasons:
// (1) avoid rewrite the same page that is modified later.
// (2) for older version of OS, write can block while writing out
// the page.
// Xfs does neighbor page flushing outside of the specified ranges. We
// need to make sure sync range is far from the write offset.
if (!direct_io_ && bytes_per_sync_) {
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
const uint64_t kBytesNotSyncRange = 1024 * 1024; // recent 1MB is not synced.
const uint64_t kBytesAlignWhenSync = 4 * 1024; // Align 4KB.
if (filesize_ > kBytesNotSyncRange) {
uint64_t offset_sync_to = filesize_ - kBytesNotSyncRange;
offset_sync_to -= offset_sync_to % kBytesAlignWhenSync;
assert(offset_sync_to >= last_sync_size_);
if (offset_sync_to > 0 &&
offset_sync_to - last_sync_size_ >= bytes_per_sync_) {
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
s = RangeSync(last_sync_size_, offset_sync_to - last_sync_size_);
last_sync_size_ = offset_sync_to;
}
}
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
return s;
}
Status WritableFileWriter::Sync(bool use_fsync) {
Status s = Flush();
if (!s.ok()) {
return s;
}
TEST_KILL_RANDOM(rocksdb_kill_odds);
if (!direct_io_ && pending_sync_) {
s = SyncInternal(use_fsync);
if (!s.ok()) {
return s;
}
}
TEST_KILL_RANDOM(rocksdb_kill_odds);
pending_sync_ = false;
if (use_fsync) {
pending_fsync_ = false;
}
return Status::OK();
}
Status WritableFileWriter::SyncWithoutFlush(bool use_fsync) {
if (!writable_file_->IsSyncThreadSafe()) {
return Status::NotSupported(
"Can't WritableFileWriter::SyncWithoutFlush() because "
"WritableFile::IsSyncThreadSafe() is false");
}
TEST_SYNC_POINT("WritableFileWriter::SyncWithoutFlush:1");
Status s = SyncInternal(use_fsync);
TEST_SYNC_POINT("WritableFileWriter::SyncWithoutFlush:2");
return s;
}
Status WritableFileWriter::SyncInternal(bool use_fsync) {
Status s;
IOSTATS_TIMER_GUARD(fsync_nanos);
TEST_SYNC_POINT("WritableFileWriter::SyncInternal:0");
if (use_fsync) {
s = writable_file_->Fsync();
} else {
s = writable_file_->Sync();
}
return s;
}
Status WritableFileWriter::RangeSync(off_t offset, off_t nbytes) {
IOSTATS_TIMER_GUARD(range_sync_nanos);
TEST_SYNC_POINT("WritableFileWriter::RangeSync:0");
return writable_file_->RangeSync(offset, nbytes);
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
size_t WritableFileWriter::RequestToken(size_t bytes, bool align) {
Env::IOPriority io_priority;
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
if (rate_limiter_ && (io_priority = writable_file_->GetIOPriority()) <
Env::IO_TOTAL) {
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
bytes = std::min(
bytes, static_cast<size_t>(rate_limiter_->GetSingleBurstBytes()));
if (align) {
// Here we may actually require more than burst and block
// but we can not write less than one page at a time on unbuffered
// thus we may want not to use ratelimiter s
size_t alignment = buf_.GetAlignment();
bytes = std::max(alignment, TruncateToPageBoundary(alignment, bytes));
}
rate_limiter_->Request(bytes, io_priority);
}
return bytes;
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
// This method writes to disk the specified data and makes use of the rate
// limiter if available
Status WritableFileWriter::WriteBuffered(const char* data, size_t size) {
Status s;
assert(use_os_buffer_);
const char* src = data;
size_t left = size;
while (left > 0) {
size_t allowed = RequestToken(left, false);
{
IOSTATS_TIMER_GUARD(write_nanos);
TEST_SYNC_POINT("WritableFileWriter::Flush:BeforeAppend");
s = writable_file_->Append(Slice(src, allowed));
if (!s.ok()) {
return s;
}
}
IOSTATS_ADD(bytes_written, allowed);
TEST_KILL_RANDOM(rocksdb_kill_odds);
left -= allowed;
src += allowed;
}
buf_.SetSize(0);
return s;
}
// This flushes the accumulated data in the buffer. We pad data with zeros if
// necessary to the whole page.
// However, during automatic flushes padding would not be necessary.
// We always use RateLimiter if available. We move (Refit) any buffer bytes
// that are left over the
// whole number of pages to be written again on the next flush because we can
// only write on aligned
// offsets.
Status WritableFileWriter::WriteUnbuffered() {
Status s;
assert(!use_os_buffer_);
const size_t alignment = buf_.GetAlignment();
assert((next_write_offset_ % alignment) == 0);
// Calculate whole page final file advance if all writes succeed
size_t file_advance =
TruncateToPageBoundary(alignment, buf_.GetCurrentSize());
// Calculate the leftover tail, we write it here padded with zeros BUT we
// will write
// it again in the future either on Close() OR when the current whole page
// fills out
size_t leftover_tail = buf_.GetCurrentSize() - file_advance;
// Round up and pad
buf_.PadToAlignmentWith(0);
const char* src = buf_.GetBufferStart();
uint64_t write_offset = next_write_offset_;
size_t left = buf_.GetCurrentSize();
while (left > 0) {
// Check how much is allowed
size_t size = RequestToken(left, true);
{
IOSTATS_TIMER_GUARD(write_nanos);
TEST_SYNC_POINT("WritableFileWriter::Flush:BeforeAppend");
// Unbuffered writes must be positional
s = writable_file_->Append(Slice(src, size), write_offset);
if (!s.ok()) {
buf_.SetSize(file_advance + leftover_tail);
return s;
}
}
IOSTATS_ADD(bytes_written, size);
left -= size;
src += size;
write_offset += size;
assert((next_write_offset_ % alignment) == 0);
}
if (s.ok()) {
// Move the tail to the beginning of the buffer
// This never happens during normal Append but rather during
// explicit call to Flush()/Sync() or Close()
buf_.RefitTail(file_advance, leftover_tail);
// This is where we start writing next time which may or not be
// the actual file size on disk. They match if the buffer size
// is a multiple of whole pages otherwise filesize_ is leftover_tail
// behind
next_write_offset_ += file_advance;
}
return s;
}
namespace {
class ReadaheadRandomAccessFile : public RandomAccessFile {
public:
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
ReadaheadRandomAccessFile(std::unique_ptr<RandomAccessFile>&& file,
size_t readahead_size)
: file_(std::move(file)),
readahead_size_(readahead_size),
forward_calls_(file_->ReaderWriterForward()),
buffer_(new char[readahead_size_]),
buffer_offset_(0),
buffer_len_(0) {}
ReadaheadRandomAccessFile(const ReadaheadRandomAccessFile&) = delete;
ReadaheadRandomAccessFile& operator=(const ReadaheadRandomAccessFile&) = delete;
virtual Status Read(uint64_t offset, size_t n, Slice* result,
char* scratch) const override {
if (n >= readahead_size_) {
return file_->Read(offset, n, result, scratch);
}
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
// On Windows in unbuffered mode this will lead to double buffering
// and double locking so we avoid that.
// In normal mode Windows caches so much data from disk that we do
// not need readahead.
if (forward_calls_) {
return file_->Read(offset, n, result, scratch);
}
std::unique_lock<std::mutex> lk(lock_);
size_t copied = 0;
// if offset between [buffer_offset_, buffer_offset_ + buffer_len>
if (offset >= buffer_offset_ && offset < buffer_len_ + buffer_offset_) {
uint64_t offset_in_buffer = offset - buffer_offset_;
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
copied = std::min(static_cast<uint64_t>(buffer_len_)-offset_in_buffer,
static_cast<uint64_t>(n));
memcpy(scratch, buffer_.get() + offset_in_buffer, copied);
if (copied == n) {
// fully cached
*result = Slice(scratch, n);
return Status::OK();
}
}
Slice readahead_result;
Status s = file_->Read(offset + copied, readahead_size_, &readahead_result,
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
buffer_.get());
if (!s.ok()) {
return s;
}
auto left_to_copy = std::min(readahead_result.size(), n - copied);
memcpy(scratch + copied, readahead_result.data(), left_to_copy);
*result = Slice(scratch, copied + left_to_copy);
if (readahead_result.data() == buffer_.get()) {
buffer_offset_ = offset + copied;
buffer_len_ = readahead_result.size();
} else {
buffer_len_ = 0;
}
return Status::OK();
}
virtual size_t GetUniqueId(char* id, size_t max_size) const override {
return file_->GetUniqueId(id, max_size);
}
virtual void Hint(AccessPattern pattern) override { file_->Hint(pattern); }
virtual Status InvalidateCache(size_t offset, size_t length) override {
return file_->InvalidateCache(offset, length);
}
private:
std::unique_ptr<RandomAccessFile> file_;
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
size_t readahead_size_;
const bool forward_calls_;
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
mutable std::mutex lock_;
mutable std::unique_ptr<char[]> buffer_;
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
mutable uint64_t buffer_offset_;
mutable size_t buffer_len_;
};
} // namespace
std::unique_ptr<RandomAccessFile> NewReadaheadRandomAccessFile(
Refactor to support file_reader_writer on Windows. Summary. A change https://reviews.facebook.net/differential/diff/224721/ Has attempted to move common functionality out of platform dependent code to a new facility called file_reader_writer. This includes: - perf counters - Buffering - RateLimiting However, the change did not attempt to refactor Windows code. To mitigate, we introduce new quering interfaces such as UseOSBuffer(), GetRequiredBufferAlignment() and ReaderWriterForward() for pure forwarding where required. Introduce WritableFile got a new method Truncate(). This is to communicate to the file as to how much data it has on close. - When space is pre-allocated on Linux it is filled with zeros implicitly, no such thing exist on Windows so we must truncate file on close. - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate. Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has no idea about the file true size. This means that Close() on the wrapper level must always include Truncate() as well as wrapper __dtor should call Close() and against double Close(). Move buffered/unbuffered write logic to the wrapper. Utilize Aligned buffer class. Adjust tests and implement Truncate() where necessary. Come up with reasonable defaults for new virtual interfaces. Forward calls for RandomAccessReadAhead class to avoid double buffering and locking (double locking in unbuffered mode on WIndows).
9 years ago
std::unique_ptr<RandomAccessFile>&& file, size_t readahead_size) {
return std::make_unique<ReadaheadRandomAccessFile> (
std::move(file), readahead_size);
}
} // namespace rocksdb