rocksdb/env/fs_remap.h
mrambacher f72c834eab Make FileSystem a Customizable Class (#8649)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8649

Reviewed By: zhichao-cao

Differential Revision: D32036059

Pulled By: mrambacher

fbshipit-source-id: 4f1e7557ecac52eb849b83ae02b8d7d232112295
2021-11-02 09:07:11 -07:00

140 lines
5.7 KiB
C++

// Copyright (c) Facebook, Inc. and its affiliates. 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).
#pragma once
#ifndef ROCKSDB_LITE
#include <utility>
#include "rocksdb/file_system.h"
namespace ROCKSDB_NAMESPACE {
// An abstract FileSystem wrapper that creates a view of an existing
// FileSystem by remapping names in some way.
//
// This class has not been fully analyzed for providing strong security
// guarantees.
class RemapFileSystem : public FileSystemWrapper {
public:
explicit RemapFileSystem(const std::shared_ptr<FileSystem>& base);
protected:
// Returns status and mapped-to path in the wrapped filesystem.
// If it returns non-OK status, the returned path should not be used.
virtual std::pair<IOStatus, std::string> EncodePath(
const std::string& path) = 0;
// Similar to EncodePath() except used in cases in which it is OK for
// no file or directory on 'path' to already exist, such as if the
// operation would create one. However, the parent of 'path' is expected
// to exist for the operation to succeed.
// Default implementation: call EncodePath
virtual std::pair<IOStatus, std::string> EncodePathWithNewBasename(
const std::string& path);
public:
// Left abstract:
// const char* Name() const override { ... }
static const char* kClassName() { return "RemapFileSystem"; }
bool IsInstanceOf(const std::string& id) const override {
if (id == kClassName()) {
return true;
} else {
return FileSystemWrapper::IsInstanceOf(id);
}
}
Status RegisterDbPaths(const std::vector<std::string>& paths) override;
Status UnregisterDbPaths(const std::vector<std::string>& paths) override;
IOStatus NewSequentialFile(const std::string& fname,
const FileOptions& options,
std::unique_ptr<FSSequentialFile>* result,
IODebugContext* dbg) override;
IOStatus NewRandomAccessFile(const std::string& fname,
const FileOptions& options,
std::unique_ptr<FSRandomAccessFile>* result,
IODebugContext* dbg) override;
IOStatus NewWritableFile(const std::string& fname, const FileOptions& options,
std::unique_ptr<FSWritableFile>* result,
IODebugContext* dbg) override;
IOStatus ReuseWritableFile(const std::string& fname,
const std::string& old_fname,
const FileOptions& options,
std::unique_ptr<FSWritableFile>* result,
IODebugContext* dbg) override;
IOStatus NewRandomRWFile(const std::string& fname, const FileOptions& options,
std::unique_ptr<FSRandomRWFile>* result,
IODebugContext* dbg) override;
IOStatus NewDirectory(const std::string& dir, const IOOptions& options,
std::unique_ptr<FSDirectory>* result,
IODebugContext* dbg) override;
IOStatus FileExists(const std::string& fname, const IOOptions& options,
IODebugContext* dbg) override;
IOStatus GetChildren(const std::string& dir, const IOOptions& options,
std::vector<std::string>* result,
IODebugContext* dbg) override;
IOStatus GetChildrenFileAttributes(const std::string& dir,
const IOOptions& options,
std::vector<FileAttributes>* result,
IODebugContext* dbg) override;
IOStatus DeleteFile(const std::string& fname, const IOOptions& options,
IODebugContext* dbg) override;
IOStatus CreateDir(const std::string& dirname, const IOOptions& options,
IODebugContext* dbg) override;
IOStatus CreateDirIfMissing(const std::string& dirname,
const IOOptions& options,
IODebugContext* dbg) override;
IOStatus DeleteDir(const std::string& dirname, const IOOptions& options,
IODebugContext* dbg) override;
IOStatus GetFileSize(const std::string& fname, const IOOptions& options,
uint64_t* file_size, IODebugContext* dbg) override;
IOStatus GetFileModificationTime(const std::string& fname,
const IOOptions& options,
uint64_t* file_mtime,
IODebugContext* dbg) override;
IOStatus IsDirectory(const std::string& path, const IOOptions& options,
bool* is_dir, IODebugContext* dbg) override;
IOStatus RenameFile(const std::string& src, const std::string& dest,
const IOOptions& options, IODebugContext* dbg) override;
IOStatus LinkFile(const std::string& src, const std::string& dest,
const IOOptions& options, IODebugContext* dbg) override;
IOStatus LockFile(const std::string& fname, const IOOptions& options,
FileLock** lock, IODebugContext* dbg) override;
IOStatus NewLogger(const std::string& fname, const IOOptions& options,
std::shared_ptr<Logger>* result,
IODebugContext* dbg) override;
IOStatus GetAbsolutePath(const std::string& db_path, const IOOptions& options,
std::string* output_path,
IODebugContext* dbg) override;
};
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE