rocksdb/utilities/blob_db/blob_file.cc

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// 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"
Introduce a new storage specific Env API (#5761) Summary: The current Env API encompasses both storage/file operations, as well as OS related operations. Most of the APIs return a Status, which does not have enough metadata about an error, such as whether its retry-able or not, scope (i.e fault domain) of the error etc., that may be required in order to properly handle a storage error. The file APIs also do not provide enough control over the IO SLA, such as timeout, prioritization, hinting about placement and redundancy etc. This PR separates out the file/storage APIs from Env into a new FileSystem class. The APIs are updated to return an IOStatus with metadata about the error, as well as to take an IOOptions structure as input in order to allow more control over the IO. The user can set both ```options.env``` and ```options.file_system``` to specify that RocksDB should use the former for OS related operations and the latter for storage operations. Internally, a ```CompositeEnvWrapper``` has been introduced that inherits from ```Env``` and redirects individual methods to either an ```Env``` implementation or the ```FileSystem``` as appropriate. When options are sanitized during ```DB::Open```, ```options.env``` is replaced with a newly allocated ```CompositeEnvWrapper``` instance if both env and file_system have been specified. This way, the rest of the RocksDB code can continue to function as before. This PR also ports PosixEnv to the new API by splitting it into two - PosixEnv and PosixFileSystem. PosixEnv is defined as a sub-class of CompositeEnvWrapper, and threading/time functions are overridden with Posix specific implementations in order to avoid an extra level of indirection. The ```CompositeEnvWrapper``` translates ```IOStatus``` return code to ```Status```, and sets the severity to ```kSoftError``` if the io_status is retryable. The error handling code in RocksDB can then recover the DB automatically. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5761 Differential Revision: D18868376 Pulled By: anand1976 fbshipit-source-id: 39efe18a162ea746fabac6360ff529baba48486f
2019-12-13 23:47:08 +01:00
#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::shared_ptr<Reader> BlobFile::OpenRandomAccessReader(
Env* env, const DBOptions& db_options,
const EnvOptions& env_options) const {
constexpr size_t kReadaheadSize = 2 * 1024 * 1024;
std::unique_ptr<RandomAccessFile> sfile;
std::string path_name(PathName());
Status s = env->NewRandomAccessFile(path_name, &sfile, env_options);
if (!s.ok()) {
// report something here.
return nullptr;
}
sfile = NewReadaheadRandomAccessFile(std::move(sfile), kReadaheadSize);
std::unique_ptr<RandomAccessFileReader> sfile_reader;
Introduce a new storage specific Env API (#5761) Summary: The current Env API encompasses both storage/file operations, as well as OS related operations. Most of the APIs return a Status, which does not have enough metadata about an error, such as whether its retry-able or not, scope (i.e fault domain) of the error etc., that may be required in order to properly handle a storage error. The file APIs also do not provide enough control over the IO SLA, such as timeout, prioritization, hinting about placement and redundancy etc. This PR separates out the file/storage APIs from Env into a new FileSystem class. The APIs are updated to return an IOStatus with metadata about the error, as well as to take an IOOptions structure as input in order to allow more control over the IO. The user can set both ```options.env``` and ```options.file_system``` to specify that RocksDB should use the former for OS related operations and the latter for storage operations. Internally, a ```CompositeEnvWrapper``` has been introduced that inherits from ```Env``` and redirects individual methods to either an ```Env``` implementation or the ```FileSystem``` as appropriate. When options are sanitized during ```DB::Open```, ```options.env``` is replaced with a newly allocated ```CompositeEnvWrapper``` instance if both env and file_system have been specified. This way, the rest of the RocksDB code can continue to function as before. This PR also ports PosixEnv to the new API by splitting it into two - PosixEnv and PosixFileSystem. PosixEnv is defined as a sub-class of CompositeEnvWrapper, and threading/time functions are overridden with Posix specific implementations in order to avoid an extra level of indirection. The ```CompositeEnvWrapper``` translates ```IOStatus``` return code to ```Status```, and sets the severity to ```kSoftError``` if the io_status is retryable. The error handling code in RocksDB can then recover the DB automatically. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5761 Differential Revision: D18868376 Pulled By: anand1976 fbshipit-source-id: 39efe18a162ea746fabac6360ff529baba48486f
2019-12-13 23:47:08 +01:00
sfile_reader.reset(new RandomAccessFileReader(
NewLegacyRandomAccessFileWrapper(sfile), path_name));
std::shared_ptr<Reader> log_reader = std::make_shared<Reader>(
std::move(sfile_reader), db_options.env, db_options.statistics.get());
return log_reader;
}
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);
}
bool BlobFile::NeedsFsync(bool hard, uint64_t bytes_per_sync) const {
assert(last_fsync_ <= file_size_);
return (hard) ? file_size_ > last_fsync_
: (file_size_ - last_fsync_) >= bytes_per_sync;
}
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);
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;
std::unique_ptr<const char[]> internal_buf;
Status s;
if (ra_file_reader_->use_direct_io()) {
s = ra_file_reader_->Read(footer_offset, BlobLogFooter::kSize, &result,
nullptr, &internal_buf);
} else {
buf.reserve(BlobLogFooter::kSize + 10);
s = ra_file_reader_->Read(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) {
// assume that file has been fully fsync'd
last_fsync_.store(file_size_);
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();
last_fsync_.store(file_size_.load());
}
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;
}
Introduce a new storage specific Env API (#5761) Summary: The current Env API encompasses both storage/file operations, as well as OS related operations. Most of the APIs return a Status, which does not have enough metadata about an error, such as whether its retry-able or not, scope (i.e fault domain) of the error etc., that may be required in order to properly handle a storage error. The file APIs also do not provide enough control over the IO SLA, such as timeout, prioritization, hinting about placement and redundancy etc. This PR separates out the file/storage APIs from Env into a new FileSystem class. The APIs are updated to return an IOStatus with metadata about the error, as well as to take an IOOptions structure as input in order to allow more control over the IO. The user can set both ```options.env``` and ```options.file_system``` to specify that RocksDB should use the former for OS related operations and the latter for storage operations. Internally, a ```CompositeEnvWrapper``` has been introduced that inherits from ```Env``` and redirects individual methods to either an ```Env``` implementation or the ```FileSystem``` as appropriate. When options are sanitized during ```DB::Open```, ```options.env``` is replaced with a newly allocated ```CompositeEnvWrapper``` instance if both env and file_system have been specified. This way, the rest of the RocksDB code can continue to function as before. This PR also ports PosixEnv to the new API by splitting it into two - PosixEnv and PosixFileSystem. PosixEnv is defined as a sub-class of CompositeEnvWrapper, and threading/time functions are overridden with Posix specific implementations in order to avoid an extra level of indirection. The ```CompositeEnvWrapper``` translates ```IOStatus``` return code to ```Status```, and sets the severity to ```kSoftError``` if the io_status is retryable. The error handling code in RocksDB can then recover the DB automatically. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5761 Differential Revision: D18868376 Pulled By: anand1976 fbshipit-source-id: 39efe18a162ea746fabac6360ff529baba48486f
2019-12-13 23:47:08 +01:00
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(
Introduce a new storage specific Env API (#5761) Summary: The current Env API encompasses both storage/file operations, as well as OS related operations. Most of the APIs return a Status, which does not have enough metadata about an error, such as whether its retry-able or not, scope (i.e fault domain) of the error etc., that may be required in order to properly handle a storage error. The file APIs also do not provide enough control over the IO SLA, such as timeout, prioritization, hinting about placement and redundancy etc. This PR separates out the file/storage APIs from Env into a new FileSystem class. The APIs are updated to return an IOStatus with metadata about the error, as well as to take an IOOptions structure as input in order to allow more control over the IO. The user can set both ```options.env``` and ```options.file_system``` to specify that RocksDB should use the former for OS related operations and the latter for storage operations. Internally, a ```CompositeEnvWrapper``` has been introduced that inherits from ```Env``` and redirects individual methods to either an ```Env``` implementation or the ```FileSystem``` as appropriate. When options are sanitized during ```DB::Open```, ```options.env``` is replaced with a newly allocated ```CompositeEnvWrapper``` instance if both env and file_system have been specified. This way, the rest of the RocksDB code can continue to function as before. This PR also ports PosixEnv to the new API by splitting it into two - PosixEnv and PosixFileSystem. PosixEnv is defined as a sub-class of CompositeEnvWrapper, and threading/time functions are overridden with Posix specific implementations in order to avoid an extra level of indirection. The ```CompositeEnvWrapper``` translates ```IOStatus``` return code to ```Status```, and sets the severity to ```kSoftError``` if the io_status is retryable. The error handling code in RocksDB can then recover the DB automatically. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5761 Differential Revision: D18868376 Pulled By: anand1976 fbshipit-source-id: 39efe18a162ea746fabac6360ff529baba48486f
2019-12-13 23:47:08 +01:00
new RandomAccessFileReader(NewLegacyRandomAccessFileWrapper(file),
PathName()));
// Read file header.
std::string header_buf;
std::unique_ptr<const char[]> internal_buf;
Slice header_slice;
if (file_reader->use_direct_io()) {
s = file_reader->Read(0, BlobLogHeader::kSize, &header_slice, nullptr,
&internal_buf);
} else {
header_buf.reserve(BlobLogHeader::kSize);
s = file_reader->Read(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(file_size - BlobLogFooter::kSize, BlobLogFooter::kSize,
&footer_slice, nullptr, &internal_buf);
} else {
footer_buf.reserve(BlobLogFooter::kSize);
s = file_reader->Read(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