// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_FILES_FILE_UTIL_PROXY_H_
#define BASE_FILES_FILE_UTIL_PROXY_H_
#include "base/base_export.h"
#include "base/callback_forward.h"
#include "base/files/file.h"
#include "base/files/file_path.h"
#include "base/memory/ref_counted.h"
#include "base/platform_file.h"
namespace tracked_objects {
class Location;
};
namespace base {
class TaskRunner;
class Time;
// This class provides asynchronous access to common file routines.
class BASE_EXPORT FileUtilProxy {
public:
// This callback is used by methods that report only an error code. It is
// valid to pass a null callback to any function that takes a StatusCallback,
// in which case the operation will complete silently.
typedef Callback<void(File::Error)> StatusCallback;
typedef Callback<void(File::Error,
PassPlatformFile,
bool /* created */)> CreateOrOpenCallback;
typedef Callback<void(File::Error,
PassPlatformFile,
const FilePath&)> CreateTemporaryCallback;
typedef Callback<void(File::Error,
const File::Info&)> GetFileInfoCallback;
typedef Callback<void(File::Error,
const char* /* data */,
int /* bytes read */)> ReadCallback;
typedef Callback<void(File::Error,
int /* bytes written */)> WriteCallback;
typedef Callback<File::Error(PlatformFile*, bool*)> CreateOrOpenTask;
typedef Callback<File::Error(PlatformFile)> CloseTask;
typedef Callback<File::Error(void)> FileTask;
// Creates or opens a file with the given flags. It is invalid to pass a null
// callback. If PLATFORM_FILE_CREATE is set in |file_flags| it always tries to
// create a new file at the given |file_path| and calls back with
// PLATFORM_FILE_ERROR_FILE_EXISTS if the |file_path| already exists.
//
// This returns false if task posting to |task_runner| has failed.
static bool CreateOrOpen(TaskRunner* task_runner,
const FilePath& file_path,
int file_flags,
const CreateOrOpenCallback& callback);
// Creates a temporary file for writing. The path and an open file handle are
// returned. It is invalid to pass a null callback. The additional file flags
// will be added on top of the default file flags which are:
// base::PLATFORM_FILE_CREATE_ALWAYS
// base::PLATFORM_FILE_WRITE
// base::PLATFORM_FILE_TEMPORARY.
// Set |additional_file_flags| to 0 for synchronous writes and set to
// base::PLATFORM_FILE_ASYNC to support asynchronous file operations.
//
// This returns false if task posting to |task_runner| has failed.
static bool CreateTemporary(
TaskRunner* task_runner,
int additional_file_flags,
const CreateTemporaryCallback& callback);
// Close the given file handle.
// This returns false if task posting to |task_runner| has failed.
static bool Close(TaskRunner* task_runner,
PlatformFile,
const StatusCallback& callback);
// Retrieves the information about a file. It is invalid to pass a null
// callback.
// This returns false if task posting to |task_runner| has failed.
static bool GetFileInfo(
TaskRunner* task_runner,
const FilePath& file_path,
const GetFileInfoCallback& callback);
// Does the same as GetFileInfo but takes PlatformFile instead of FilePath.
// This returns false if task posting to |task_runner| has failed.
static bool GetFileInfoFromPlatformFile(
TaskRunner* task_runner,
PlatformFile file,
const GetFileInfoCallback& callback);
// Deletes a file or a directory.
// It is an error to delete a non-empty directory with recursive=false.
// This returns false if task posting to |task_runner| has failed.
static bool DeleteFile(TaskRunner* task_runner,
const FilePath& file_path,
bool recursive,
const StatusCallback& callback);
// Reads from a file. On success, the file pointer is moved to position
// |offset + bytes_to_read| in the file. The callback can be null.
//
// This returns false if |bytes_to_read| is less than zero, or
// if task posting to |task_runner| has failed.
static bool Read(
TaskRunner* task_runner,
PlatformFile file,
int64 offset,
int bytes_to_read,
const ReadCallback& callback);
// Writes to a file. If |offset| is greater than the length of the file,
// |false| is returned. On success, the file pointer is moved to position
// |offset + bytes_to_write| in the file. The callback can be null.
// |bytes_to_write| must be greater than zero.
//
// This returns false if |bytes_to_write| is less than or equal to zero,
// if |buffer| is NULL, or if task posting to |task_runner| has failed.
static bool Write(
TaskRunner* task_runner,
PlatformFile file,
int64 offset,
const char* buffer,
int bytes_to_write,
const WriteCallback& callback);
// Touches a file. The callback can be null.
// This returns false if task posting to |task_runner| has failed.
static bool Touch(
TaskRunner* task_runner,
PlatformFile file,
const Time& last_access_time,
const Time& last_modified_time,
const StatusCallback& callback);
// Touches a file. The callback can be null.
// This returns false if task posting to |task_runner| has failed.
static bool Touch(
TaskRunner* task_runner,
const FilePath& file_path,
const Time& last_access_time,
const Time& last_modified_time,
const StatusCallback& callback);
// Truncates a file to the given length. If |length| is greater than the
// current length of the file, the file will be extended with zeroes.
// The callback can be null.
// This returns false if task posting to |task_runner| has failed.
static bool Truncate(
TaskRunner* task_runner,
PlatformFile file,
int64 length,
const StatusCallback& callback);
// Truncates a file to the given length. If |length| is greater than the
// current length of the file, the file will be extended with zeroes.
// The callback can be null.
// This returns false if task posting to |task_runner| has failed.
static bool Truncate(
TaskRunner* task_runner,
const FilePath& path,
int64 length,
const StatusCallback& callback);
// Flushes a file. The callback can be null.
// This returns false if task posting to |task_runner| has failed.
static bool Flush(
TaskRunner* task_runner,
PlatformFile file,
const StatusCallback& callback);
// Relay helpers.
// They return false if posting a given task to |task_runner| has failed.
static bool RelayCreateOrOpen(
TaskRunner* task_runner,
const CreateOrOpenTask& open_task,
const CloseTask& close_task,
const CreateOrOpenCallback& callback);
static bool RelayClose(
TaskRunner* task_runner,
const CloseTask& close_task,
PlatformFile,
const StatusCallback& callback);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(FileUtilProxy);
};
} // namespace base
#endif // BASE_FILES_FILE_UTIL_PROXY_H_