mirror of
https://github.com/facebook/rocksdb.git
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0a0151fb99
Summary: In direct IO mode, RandomAccessFileReader::Read allocates an internal aligned buffer, and then copies the result into the scratch buffer. If the result is only temporarily used inside a function, there is no need to do the memcpy and just let the result Slice refer to the internally allocated buffer. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6455 Test Plan: make check Differential Revision: D20106753 Pulled By: cheng-chang fbshipit-source-id: 44f505843837bba47a56e3fa2c4dd3bd76486b58
107 lines
3 KiB
C++
107 lines
3 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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#ifndef ROCKSDB_LITE
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#include "utilities/blob_db/blob_log_reader.h"
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#include <algorithm>
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#include "file/random_access_file_reader.h"
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#include "monitoring/statistics.h"
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#include "util/stop_watch.h"
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namespace ROCKSDB_NAMESPACE {
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namespace blob_db {
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Reader::Reader(std::unique_ptr<RandomAccessFileReader>&& file_reader, Env* env,
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Statistics* statistics)
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: file_(std::move(file_reader)),
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env_(env),
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statistics_(statistics),
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buffer_(),
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next_byte_(0) {}
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Status Reader::ReadSlice(uint64_t size, Slice* slice, char* buf) {
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StopWatch read_sw(env_, statistics_, BLOB_DB_BLOB_FILE_READ_MICROS);
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Status s =
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file_->Read(next_byte_, static_cast<size_t>(size), slice, buf, nullptr);
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next_byte_ += size;
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if (!s.ok()) {
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return s;
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}
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RecordTick(statistics_, BLOB_DB_BLOB_FILE_BYTES_READ, slice->size());
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if (slice->size() != size) {
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return Status::Corruption("EOF reached while reading record");
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}
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return s;
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}
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Status Reader::ReadHeader(BlobLogHeader* header) {
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assert(file_.get() != nullptr);
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assert(next_byte_ == 0);
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Status s = ReadSlice(BlobLogHeader::kSize, &buffer_, header_buf_);
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if (!s.ok()) {
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return s;
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}
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if (buffer_.size() != BlobLogHeader::kSize) {
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return Status::Corruption("EOF reached before file header");
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}
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return header->DecodeFrom(buffer_);
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}
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Status Reader::ReadRecord(BlobLogRecord* record, ReadLevel level,
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uint64_t* blob_offset) {
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Status s = ReadSlice(BlobLogRecord::kHeaderSize, &buffer_, header_buf_);
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if (!s.ok()) {
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return s;
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}
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if (buffer_.size() != BlobLogRecord::kHeaderSize) {
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return Status::Corruption("EOF reached before record header");
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}
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s = record->DecodeHeaderFrom(buffer_);
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if (!s.ok()) {
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return s;
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}
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uint64_t kb_size = record->key_size + record->value_size;
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if (blob_offset != nullptr) {
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*blob_offset = next_byte_ + record->key_size;
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}
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switch (level) {
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case kReadHeader:
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next_byte_ += kb_size;
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break;
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case kReadHeaderKey:
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record->key_buf.reset(new char[record->key_size]);
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s = ReadSlice(record->key_size, &record->key, record->key_buf.get());
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next_byte_ += record->value_size;
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break;
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case kReadHeaderKeyBlob:
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record->key_buf.reset(new char[record->key_size]);
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s = ReadSlice(record->key_size, &record->key, record->key_buf.get());
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if (s.ok()) {
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record->value_buf.reset(new char[record->value_size]);
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s = ReadSlice(record->value_size, &record->value,
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record->value_buf.get());
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}
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if (s.ok()) {
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s = record->CheckBlobCRC();
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}
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break;
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}
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return s;
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}
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} // namespace blob_db
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} // namespace ROCKSDB_NAMESPACE
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#endif // ROCKSDB_LITE
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