rocksdb/env/file_system.cc

111 lines
3.4 KiB
C++

// Copyright (c) 2019-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).
//
#include "env/composite_env_wrapper.h"
#include "rocksdb/file_system.h"
#include "options/db_options.h"
#include "rocksdb/utilities/object_registry.h"
namespace rocksdb {
FileSystem::FileSystem() {}
FileSystem::~FileSystem() {}
Status FileSystem::Load(const std::string& value,
std::shared_ptr<FileSystem>* result) {
Status s;
#ifndef ROCKSDB_LITE
s = ObjectRegistry::NewInstance()->NewSharedObject<FileSystem>(value, result);
#else
(void)result;
s = Status::NotSupported("Cannot load FileSystem in LITE mode: ", value);
#endif
return s;
}
FileOptions FileSystem::OptimizeForLogRead(
const FileOptions& file_options) const {
FileOptions optimized_file_options(file_options);
optimized_file_options.use_direct_reads = false;
return optimized_file_options;
}
FileOptions FileSystem::OptimizeForManifestRead(
const FileOptions& file_options) const {
FileOptions optimized_file_options(file_options);
optimized_file_options.use_direct_reads = false;
return optimized_file_options;
}
FileOptions FileSystem::OptimizeForLogWrite(const FileOptions& file_options,
const DBOptions& db_options) const {
FileOptions optimized_file_options(file_options);
optimized_file_options.bytes_per_sync = db_options.wal_bytes_per_sync;
optimized_file_options.writable_file_max_buffer_size =
db_options.writable_file_max_buffer_size;
return optimized_file_options;
}
FileOptions FileSystem::OptimizeForManifestWrite(
const FileOptions& file_options) const {
return file_options;
}
FileOptions FileSystem::OptimizeForCompactionTableWrite(
const FileOptions& file_options,
const ImmutableDBOptions& db_options) const {
FileOptions optimized_file_options(file_options);
optimized_file_options.use_direct_writes =
db_options.use_direct_io_for_flush_and_compaction;
return optimized_file_options;
}
FileOptions FileSystem::OptimizeForCompactionTableRead(
const FileOptions& file_options,
const ImmutableDBOptions& db_options) const {
FileOptions optimized_file_options(file_options);
optimized_file_options.use_direct_reads = db_options.use_direct_reads;
return optimized_file_options;
}
Status ReadFileToString(FileSystem* fs, const std::string& fname,
std::string* data) {
FileOptions soptions;
data->clear();
std::unique_ptr<FSSequentialFile> file;
Status s = fs->NewSequentialFile(fname, soptions, &file, nullptr);
if (!s.ok()) {
return s;
}
static const int kBufferSize = 8192;
char* space = new char[kBufferSize];
while (true) {
Slice fragment;
s = file->Read(kBufferSize, IOOptions(), &fragment, space,
nullptr);
if (!s.ok()) {
break;
}
data->append(fragment.data(), fragment.size());
if (fragment.empty()) {
break;
}
}
delete[] space;
return s;
}
#ifdef OS_WIN
std::shared_ptr<FileSystem> FileSystem::Default() {
static LegacyFileSystemWrapper default_fs(Env::Default());
static std::shared_ptr<LegacyFileSystemWrapper> default_fs_ptr(
&default_fs, [](LegacyFileSystemWrapper*) {});
return default_fs_ptr;
}
#endif
} // namespace rocksdb