rocksdb/env/fs_readonly.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

108 lines
4 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 "rocksdb/file_system.h"
namespace ROCKSDB_NAMESPACE {
// A FileSystem wrapper that only allows read-only operation.
//
// This class has not been fully analyzed for providing strong security
// guarantees.
class ReadOnlyFileSystem : public FileSystemWrapper {
static inline IOStatus FailReadOnly() {
IOStatus s = IOStatus::IOError("Attempted write to ReadOnlyFileSystem");
assert(s.GetRetryable() == false);
return s;
}
public:
explicit ReadOnlyFileSystem(const std::shared_ptr<FileSystem>& base)
: FileSystemWrapper(base) {}
static const char* kClassName() { return "ReadOnlyFileSystem"; }
const char* Name() const override { return kClassName(); }
IOStatus NewWritableFile(const std::string& /*fname*/,
const FileOptions& /*options*/,
std::unique_ptr<FSWritableFile>* /*result*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus ReuseWritableFile(const std::string& /*fname*/,
const std::string& /*old_fname*/,
const FileOptions& /*options*/,
std::unique_ptr<FSWritableFile>* /*result*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus NewRandomRWFile(const std::string& /*fname*/,
const FileOptions& /*options*/,
std::unique_ptr<FSRandomRWFile>* /*result*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus NewDirectory(const std::string& /*dir*/,
const IOOptions& /*options*/,
std::unique_ptr<FSDirectory>* /*result*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus DeleteFile(const std::string& /*fname*/,
const IOOptions& /*options*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus CreateDir(const std::string& /*dirname*/,
const IOOptions& /*options*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus CreateDirIfMissing(const std::string& dirname,
const IOOptions& options,
IODebugContext* dbg) override {
// Allow if dir already exists
bool is_dir = false;
IOStatus s = IsDirectory(dirname, options, &is_dir, dbg);
if (s.ok() && is_dir) {
return s;
} else {
return FailReadOnly();
}
}
IOStatus DeleteDir(const std::string& /*dirname*/,
const IOOptions& /*options*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus RenameFile(const std::string& /*src*/, const std::string& /*dest*/,
const IOOptions& /*options*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus LinkFile(const std::string& /*src*/, const std::string& /*dest*/,
const IOOptions& /*options*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus LockFile(const std::string& /*fname*/, const IOOptions& /*options*/,
FileLock** /*lock*/, IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
IOStatus NewLogger(const std::string& /*fname*/, const IOOptions& /*options*/,
std::shared_ptr<Logger>* /*result*/,
IODebugContext* /*dbg*/) override {
return FailReadOnly();
}
};
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE