libartbase/base/os.h

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ART_LIBARTBASE_BASE_OS_H_
#define ART_LIBARTBASE_BASE_OS_H_

#include <stdint.h>

namespace unix_file {
class FdFile;
}  // namespace unix_file

namespace art {

using File = ::unix_file::FdFile;

// Interface to the underlying OS platform.

class OS {
 public:
  // Open an existing file with read only access.
  static File* OpenFileForReading(const char* name);

  // Open an existing file with read/write access.
  static File* OpenFileReadWrite(const char* name);

  // Create an empty file with read/write access. This is a *new* file, that is, if the file
  // already exists, it is *not* overwritten, but unlinked, and a new inode will be used.
  static File* CreateEmptyFile(const char* name);

  // Create an empty file with write access. This is a *new* file, that is, if the file
  // already exists, it is *not* overwritten, but unlinked, and a new inode will be used.
  static File* CreateEmptyFileWriteOnly(const char* name);

  // Open a file with the specified open(2) flags.
  static File* OpenFileWithFlags(const char* name, int flags, bool auto_flush = true);

  // Check if a file exists.
  static bool FileExists(const char* name, bool check_file_type = true);

  // Check if a directory exists.
  static bool DirectoryExists(const char* name);

  // Get the size of a file (or -1 if it does not exist).
  static int64_t GetFileSizeBytes(const char* name);
};

}  // namespace art

#endif  // ART_LIBARTBASE_BASE_OS_H_