rocksdb/utilities/blob_db/blob_file.cc
Levi Tamasi 1f84611e5d Clean up BlobLogReader and rename it to BlobLogSequentialReader (#7517)
Summary:
The patch does some cleanup in and around the legacy `BlobLogReader` class:
* It renames the class to `BlobLogSequentialReader` to emphasize that it is for
sequentially iterating through blobs in a blob file, as opposed to doing random
point reads using `BlobIndex`es (which is `BlobFileReader`'s jurisdiction).
* It removes some dead code from the old BlobDB implementation that references
`BlobLogReader` (namely the method `BlobFile::OpenRandomAccessReader`).
* It cleans up some `#include`s and forward declarations.
* It fixes some incorrect/outdated comments related to the reader class.
* It adds a few assertions to the `Read` methods of the class.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7517

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D24172611

Pulled By: ltamasi

fbshipit-source-id: 43e2ae1eba5c3dd30c1070cb00f217edc45bd64f
2020-10-07 17:48:16 -07:00

314 lines
9.6 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).
#ifndef ROCKSDB_LITE
#include "utilities/blob_db/blob_file.h"
#include <stdio.h>
#include <cinttypes>
#include <algorithm>
#include <memory>
#include "db/column_family.h"
#include "db/db_impl/db_impl.h"
#include "db/dbformat.h"
#include "env/composite_env_wrapper.h"
#include "file/filename.h"
#include "file/readahead_raf.h"
#include "logging/logging.h"
#include "utilities/blob_db/blob_db_impl.h"
namespace ROCKSDB_NAMESPACE {
namespace blob_db {
BlobFile::BlobFile(const BlobDBImpl* p, const std::string& bdir, uint64_t fn,
Logger* info_log)
: parent_(p), path_to_dir_(bdir), file_number_(fn), info_log_(info_log) {}
BlobFile::BlobFile(const BlobDBImpl* p, const std::string& bdir, uint64_t fn,
Logger* info_log, uint32_t column_family_id,
CompressionType compression, bool has_ttl,
const ExpirationRange& expiration_range)
: parent_(p),
path_to_dir_(bdir),
file_number_(fn),
info_log_(info_log),
column_family_id_(column_family_id),
compression_(compression),
has_ttl_(has_ttl),
expiration_range_(expiration_range),
header_(column_family_id, compression, has_ttl, expiration_range),
header_valid_(true) {}
BlobFile::~BlobFile() {
if (obsolete_) {
std::string pn(PathName());
Status s = Env::Default()->DeleteFile(PathName());
if (!s.ok()) {
// ROCKS_LOG_INFO(db_options_.info_log,
// "File could not be deleted %s", pn.c_str());
}
}
}
uint32_t BlobFile::GetColumnFamilyId() const { return column_family_id_; }
std::string BlobFile::PathName() const {
return BlobFileName(path_to_dir_, file_number_);
}
std::string BlobFile::DumpState() const {
char str[1000];
snprintf(
str, sizeof(str),
"path: %s fn: %" PRIu64 " blob_count: %" PRIu64 " file_size: %" PRIu64
" closed: %d obsolete: %d expiration_range: (%" PRIu64 ", %" PRIu64
"), writer: %d reader: %d",
path_to_dir_.c_str(), file_number_, blob_count_.load(), file_size_.load(),
closed_.load(), obsolete_.load(), expiration_range_.first,
expiration_range_.second, (!!log_writer_), (!!ra_file_reader_));
return str;
}
void BlobFile::MarkObsolete(SequenceNumber sequence) {
assert(Immutable());
obsolete_sequence_ = sequence;
obsolete_.store(true);
}
Status BlobFile::WriteFooterAndCloseLocked(SequenceNumber sequence) {
BlobLogFooter footer;
footer.blob_count = blob_count_;
if (HasTTL()) {
footer.expiration_range = expiration_range_;
}
// this will close the file and reset the Writable File Pointer.
Status s = log_writer_->AppendFooter(footer, /* checksum_method */ nullptr,
/* checksum_value */ nullptr);
if (s.ok()) {
closed_ = true;
immutable_sequence_ = sequence;
file_size_ += BlobLogFooter::kSize;
}
// delete the sequential writer
log_writer_.reset();
return s;
}
Status BlobFile::ReadFooter(BlobLogFooter* bf) {
if (file_size_ < (BlobLogHeader::kSize + BlobLogFooter::kSize)) {
return Status::IOError("File does not have footer", PathName());
}
uint64_t footer_offset = file_size_ - BlobLogFooter::kSize;
// assume that ra_file_reader_ is valid before we enter this
assert(ra_file_reader_);
Slice result;
std::string buf;
AlignedBuf aligned_buf;
Status s;
if (ra_file_reader_->use_direct_io()) {
s = ra_file_reader_->Read(IOOptions(), footer_offset, BlobLogFooter::kSize,
&result, nullptr, &aligned_buf);
} else {
buf.reserve(BlobLogFooter::kSize + 10);
s = ra_file_reader_->Read(IOOptions(), footer_offset, BlobLogFooter::kSize,
&result, &buf[0], nullptr);
}
if (!s.ok()) return s;
if (result.size() != BlobLogFooter::kSize) {
// should not happen
return Status::IOError("EOF reached before footer");
}
s = bf->DecodeFrom(result);
return s;
}
Status BlobFile::SetFromFooterLocked(const BlobLogFooter& footer) {
blob_count_ = footer.blob_count;
expiration_range_ = footer.expiration_range;
closed_ = true;
return Status::OK();
}
Status BlobFile::Fsync() {
Status s;
if (log_writer_.get()) {
s = log_writer_->Sync();
}
return s;
}
void BlobFile::CloseRandomAccessLocked() {
ra_file_reader_.reset();
last_access_ = -1;
}
Status BlobFile::GetReader(Env* env, const EnvOptions& env_options,
std::shared_ptr<RandomAccessFileReader>* reader,
bool* fresh_open) {
assert(reader != nullptr);
assert(fresh_open != nullptr);
*fresh_open = false;
int64_t current_time = 0;
env->GetCurrentTime(&current_time);
last_access_.store(current_time);
Status s;
{
ReadLock lockbfile_r(&mutex_);
if (ra_file_reader_) {
*reader = ra_file_reader_;
return s;
}
}
WriteLock lockbfile_w(&mutex_);
// Double check.
if (ra_file_reader_) {
*reader = ra_file_reader_;
return s;
}
std::unique_ptr<RandomAccessFile> rfile;
s = env->NewRandomAccessFile(PathName(), &rfile, env_options);
if (!s.ok()) {
ROCKS_LOG_ERROR(info_log_,
"Failed to open blob file for random-read: %s status: '%s'"
" exists: '%s'",
PathName().c_str(), s.ToString().c_str(),
env->FileExists(PathName()).ToString().c_str());
return s;
}
ra_file_reader_ = std::make_shared<RandomAccessFileReader>(
NewLegacyRandomAccessFileWrapper(rfile), PathName());
*reader = ra_file_reader_;
*fresh_open = true;
return s;
}
Status BlobFile::ReadMetadata(Env* env, const EnvOptions& env_options) {
assert(Immutable());
// Get file size.
uint64_t file_size = 0;
Status s = env->GetFileSize(PathName(), &file_size);
if (s.ok()) {
file_size_ = file_size;
} else {
ROCKS_LOG_ERROR(info_log_,
"Failed to get size of blob file %" PRIu64
", status: %s",
file_number_, s.ToString().c_str());
return s;
}
if (file_size < BlobLogHeader::kSize) {
ROCKS_LOG_ERROR(info_log_,
"Incomplete blob file blob file %" PRIu64
", size: %" PRIu64,
file_number_, file_size);
return Status::Corruption("Incomplete blob file header.");
}
// Create file reader.
std::unique_ptr<RandomAccessFile> file;
s = env->NewRandomAccessFile(PathName(), &file, env_options);
if (!s.ok()) {
ROCKS_LOG_ERROR(info_log_,
"Failed to open blob file %" PRIu64 ", status: %s",
file_number_, s.ToString().c_str());
return s;
}
std::unique_ptr<RandomAccessFileReader> file_reader(
new RandomAccessFileReader(NewLegacyRandomAccessFileWrapper(file),
PathName()));
// Read file header.
std::string header_buf;
AlignedBuf aligned_buf;
Slice header_slice;
if (file_reader->use_direct_io()) {
s = file_reader->Read(IOOptions(), 0, BlobLogHeader::kSize, &header_slice,
nullptr, &aligned_buf);
} else {
header_buf.reserve(BlobLogHeader::kSize);
s = file_reader->Read(IOOptions(), 0, BlobLogHeader::kSize, &header_slice,
&header_buf[0], nullptr);
}
if (!s.ok()) {
ROCKS_LOG_ERROR(info_log_,
"Failed to read header of blob file %" PRIu64
", status: %s",
file_number_, s.ToString().c_str());
return s;
}
BlobLogHeader header;
s = header.DecodeFrom(header_slice);
if (!s.ok()) {
ROCKS_LOG_ERROR(info_log_,
"Failed to decode header of blob file %" PRIu64
", status: %s",
file_number_, s.ToString().c_str());
return s;
}
column_family_id_ = header.column_family_id;
compression_ = header.compression;
has_ttl_ = header.has_ttl;
if (has_ttl_) {
expiration_range_ = header.expiration_range;
}
header_valid_ = true;
// Read file footer.
if (file_size_ < BlobLogHeader::kSize + BlobLogFooter::kSize) {
// OK not to have footer.
assert(!footer_valid_);
return Status::OK();
}
std::string footer_buf;
Slice footer_slice;
if (file_reader->use_direct_io()) {
s = file_reader->Read(IOOptions(), file_size - BlobLogFooter::kSize,
BlobLogFooter::kSize, &footer_slice, nullptr,
&aligned_buf);
} else {
footer_buf.reserve(BlobLogFooter::kSize);
s = file_reader->Read(IOOptions(), file_size - BlobLogFooter::kSize,
BlobLogFooter::kSize, &footer_slice, &footer_buf[0],
nullptr);
}
if (!s.ok()) {
ROCKS_LOG_ERROR(info_log_,
"Failed to read footer of blob file %" PRIu64
", status: %s",
file_number_, s.ToString().c_str());
return s;
}
BlobLogFooter footer;
s = footer.DecodeFrom(footer_slice);
if (!s.ok()) {
// OK not to have footer.
assert(!footer_valid_);
return Status::OK();
}
blob_count_ = footer.blob_count;
if (has_ttl_) {
assert(header.expiration_range.first <= footer.expiration_range.first);
assert(header.expiration_range.second >= footer.expiration_range.second);
expiration_range_ = footer.expiration_range;
}
footer_valid_ = true;
return Status::OK();
}
} // namespace blob_db
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE