file_util.cc
// 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).
//
#include "file/file_util.h"
#include <string>
#include <algorithm>
#include "file/sst_file_manager_impl.h"
#include "rocksdb/env.h"
#include "util/file_reader_writer.h"
namespace rocksdb {
// Utility function to copy a file up to a specified length
Status CopyFile(Env* env, const std::string& source,
const std::string& destination, uint64_t size, bool use_fsync) {
const EnvOptions soptions;
Status s;
std::unique_ptr<SequentialFileReader> src_reader;
std::unique_ptr<WritableFileWriter> dest_writer;
{
std::unique_ptr<SequentialFile> srcfile;
s = env->NewSequentialFile(source, &srcfile, soptions);
if (!s.ok()) {
return s;
}
std::unique_ptr<WritableFile> destfile;
s = env->NewWritableFile(destination, &destfile, soptions);
if (!s.ok()) {
return s;
}
if (size == 0) {
// default argument means copy everything
s = env->GetFileSize(source, &size);
if (!s.ok()) {
return s;
}
}
src_reader.reset(new SequentialFileReader(std::move(srcfile), source));
dest_writer.reset(
new WritableFileWriter(std::move(destfile), destination, soptions));
}
char buffer[4096];
Slice slice;
while (size > 0) {
size_t bytes_to_read = std::min(sizeof(buffer), static_cast<size_t>(size));
s = src_reader->Read(bytes_to_read, &slice, buffer);
if (!s.ok()) {
return s;
}
if (slice.size() == 0) {
return Status::Corruption("file too small");
}
s = dest_writer->Append(slice);
if (!s.ok()) {
return s;
}
size -= slice.size();
}
return dest_writer->Sync(use_fsync);
}
// Utility function to create a file with the provided contents
Status CreateFile(Env* env, const std::string& destination,
const std::string& contents, bool use_fsync) {
const EnvOptions soptions;
Status s;
std::unique_ptr<WritableFileWriter> dest_writer;
std::unique_ptr<WritableFile> destfile;
s = env->NewWritableFile(destination, &destfile, soptions);
if (!s.ok()) {
return s;
}
dest_writer.reset(
new WritableFileWriter(std::move(destfile), destination, soptions));
s = dest_writer->Append(Slice(contents));
if (!s.ok()) {
return s;
}
return dest_writer->Sync(use_fsync);
}
Status DeleteDBFile(const ImmutableDBOptions* db_options,
const std::string& fname, const std::string& dir_to_sync,
const bool force_bg, const bool force_fg) {
#ifndef ROCKSDB_LITE
SstFileManagerImpl* sfm =
static_cast<SstFileManagerImpl*>(db_options->sst_file_manager.get());
if (sfm && !force_fg) {
return sfm->ScheduleFileDeletion(fname, dir_to_sync, force_bg);
} else {
return db_options->env->DeleteFile(fname);
}
#else
(void)dir_to_sync;
(void)force_bg;
(void)force_fg;
// SstFileManager is not supported in ROCKSDB_LITE
// Delete file immediately
return db_options->env->DeleteFile(fname);
#endif
}
bool IsWalDirSameAsDBPath(const ImmutableDBOptions* db_options) {
bool same = false;
assert(!db_options->db_paths.empty());
Status s = db_options->env->AreFilesSame(db_options->wal_dir,
db_options->db_paths[0].path, &same);
if (s.IsNotSupported()) {
same = db_options->wal_dir == db_options->db_paths[0].path;
}
return same;
}
} // namespace rocksdb