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// Copyright (c) 2013 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 STORAGE_BROWSER_FILEAPI_ASYNC_FILE_UTIL_H_
#define STORAGE_BROWSER_FILEAPI_ASYNC_FILE_UTIL_H_
#include <stdint.h>
#include <memory>
#include <vector>
#include "base/callback_forward.h"
#include "base/files/file.h"
#include "base/files/file_util_proxy.h"
#include "base/macros.h"
#include "storage/browser/fileapi/file_system_operation.h"
#include "storage/browser/storage_browser_export.h"
#include "storage/common/fileapi/directory_entry.h"
namespace base {
class Time;
}
namespace storage {
class ShareableFileReference;
}
namespace storage {
class FileSystemOperationContext;
class FileSystemURL;
// An interface which provides filesystem-specific file operations for
// FileSystemOperationImpl.
//
// Each filesystem which needs to be dispatched from FileSystemOperationImpl
// must implement this interface or a synchronous version of interface:
// FileSystemFileUtil.
//
// As far as an instance of this class is owned by a FileSystemBackend
// (which is owned by FileSystemContext), it's guaranteed that this instance's
// alive while FileSystemOperationContext given to each operation is kept
// alive. (Note that this instance might be freed on different thread
// from the thread it is created.)
//
// It is NOT valid to give null callback to this class, and implementors
// can assume that they don't get any null callbacks.
//
class AsyncFileUtil {
public:
typedef base::Callback<void(base::File::Error result)> StatusCallback;
// |on_close_callback| will be called after the |file| is closed in the
// child process. |on_close_callback|.is_null() can be true, if no operation
// is needed on closing the file.
typedef base::Callback<
void(base::File file,
const base::Closure& on_close_callback)> CreateOrOpenCallback;
typedef base::Callback<
void(base::File::Error result,
bool created)> EnsureFileExistsCallback;
typedef base::Callback<
void(base::File::Error result,
const base::File::Info& file_info)> GetFileInfoCallback;
typedef std::vector<DirectoryEntry> EntryList;
typedef base::Callback<
void(base::File::Error result,
const EntryList& file_list,
bool has_more)> ReadDirectoryCallback;
typedef base::Callback<
void(base::File::Error result,
const base::File::Info& file_info,
const base::FilePath& platform_path,
const scoped_refptr<storage::ShareableFileReference>& file_ref)>
CreateSnapshotFileCallback;
typedef base::Callback<void(int64_t size)> CopyFileProgressCallback;
typedef FileSystemOperation::CopyOrMoveOption CopyOrMoveOption;
typedef FileSystemOperation::GetMetadataField GetMetadataField;
// Creates an AsyncFileUtil instance which performs file operations on
// local native file system. The created instance assumes
// FileSystemURL::path() has the target platform path.
STORAGE_EXPORT static AsyncFileUtil*
CreateForLocalFileSystem();
AsyncFileUtil() {}
virtual ~AsyncFileUtil() {}
// Creates or opens a file with the given flags.
// If File::FLAG_CREATE is set in |file_flags| it always tries to create
// a new file at the given |url| and calls back with
// File::FILE_ERROR_FILE_EXISTS if the |url| already exists.
//
// FileSystemOperationImpl::OpenFile calls this.
// This is used only by Pepper/NaCl File API.
//
virtual void CreateOrOpen(std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
int file_flags,
const CreateOrOpenCallback& callback) = 0;
// Ensures that the given |url| exist. This creates a empty new file
// at |url| if the |url| does not exist.
//
// FileSystemOperationImpl::CreateFile calls this.
//
// This reports following error code via |callback|:
// - File::FILE_OK and created==true if a file has not existed and
// is created at |url|.
// - File::FILE_OK and created==false if the file already exists.
// - Other error code (with created=false) if a file hasn't existed yet
// and there was an error while creating a new file.
//
virtual void EnsureFileExists(
std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
const EnsureFileExistsCallback& callback) = 0;
// Creates directory at given url.
//
// FileSystemOperationImpl::CreateDirectory calls this.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if the |url|'s parent directory
// does not exist and |recursive| is false.
// - File::FILE_ERROR_EXISTS if a directory already exists at |url|
// and |exclusive| is true.
// - File::FILE_ERROR_EXISTS if a file already exists at |url|
// (regardless of |exclusive| value).
// - Other error code if it failed to create a directory.
//
virtual void CreateDirectory(
std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
bool exclusive,
bool recursive,
const StatusCallback& callback) = 0;
// Retrieves the information about a file.
//
// FileSystemOperationImpl::GetMetadata calls this.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if the file doesn't exist.
// - Other error code if there was an error while retrieving the file info.
//
virtual void GetFileInfo(std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
int fields,
const GetFileInfoCallback& callback) = 0;
// Reads contents of a directory at |path|.
//
// FileSystemOperationImpl::ReadDirectory calls this.
//
// Note that the |name| field of each entry in |file_list|
// returned by |callback| should have a base file name
// of the entry relative to the directory, but not an absolute path.
//
// (E.g. if ReadDirectory is called for a directory
// 'path/to/dir' and the directory has entries 'a' and 'b',
// the returned |file_list| should include entries whose names
// are 'a' and 'b', but not '/path/to/dir/a' and '/path/to/dir/b'.)
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if the target directory doesn't exist.
// - File::FILE_ERROR_NOT_A_DIRECTORY if an entry exists at |url| but
// is a file (not a directory).
//
virtual void ReadDirectory(
std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
const ReadDirectoryCallback& callback) = 0;
// Modifies timestamps of a file or directory at |url| with
// |last_access_time| and |last_modified_time|. The function DOES NOT
// create a file unlike 'touch' command on Linux.
//
// FileSystemOperationImpl::TouchFile calls this.
// This is used only by Pepper/NaCl File API.
//
virtual void Touch(std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
const base::Time& last_access_time,
const base::Time& last_modified_time,
const StatusCallback& callback) = 0;
// Truncates a file at |path| to |length|. If |length| is larger than
// the original file size, the file will be extended, and the extended
// part is filled with null bytes.
//
// FileSystemOperationImpl::Truncate calls this.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if the file doesn't exist.
//
virtual void Truncate(std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
int64_t length,
const StatusCallback& callback) = 0;
// Copies a file from |src_url| to |dest_url|.
// This must be called for files that belong to the same filesystem
// (i.e. type() and origin() of the |src_url| and |dest_url| must match).
// |progress_callback| is a callback to report the progress update.
// See file_system_operations.h for details. This should be called on the
// same thread as where the method's called (IO thread). Calling this
// is optional. It is recommended to use this callback for heavier operations
// (such as file network downloading), so that, e.g., clients (UIs) can
// update its state to show progress to users. This may be a null callback.
//
// FileSystemOperationImpl::Copy calls this for same-filesystem copy case.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if |src_url|
// or the parent directory of |dest_url| does not exist.
// - File::FILE_ERROR_NOT_A_FILE if |src_url| exists but is not a file.
// - File::FILE_ERROR_INVALID_OPERATION if |dest_url| exists and
// is not a file.
// - File::FILE_ERROR_FAILED if |dest_url| does not exist and
// its parent path is a file.
//
virtual void CopyFileLocal(
std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& src_url,
const FileSystemURL& dest_url,
CopyOrMoveOption option,
const CopyFileProgressCallback& progress_callback,
const StatusCallback& callback) = 0;
// Moves a local file from |src_url| to |dest_url|.
// This must be called for files that belong to the same filesystem
// (i.e. type() and origin() of the |src_url| and |dest_url| must match).
//
// FileSystemOperationImpl::Move calls this for same-filesystem move case.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if |src_url|
// or the parent directory of |dest_url| does not exist.
// - File::FILE_ERROR_NOT_A_FILE if |src_url| exists but is not a file.
// - File::FILE_ERROR_INVALID_OPERATION if |dest_url| exists and
// is not a file.
// - File::FILE_ERROR_FAILED if |dest_url| does not exist and
// its parent path is a file.
//
virtual void MoveFileLocal(
std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& src_url,
const FileSystemURL& dest_url,
CopyOrMoveOption option,
const StatusCallback& callback) = 0;
// Copies in a single file from a different filesystem.
//
// FileSystemOperationImpl::Copy or Move calls this for cross-filesystem
// cases.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if |src_file_path|
// or the parent directory of |dest_url| does not exist.
// - File::FILE_ERROR_INVALID_OPERATION if |dest_url| exists and
// is not a file.
// - File::FILE_ERROR_FAILED if |dest_url| does not exist and
// its parent path is a file.
//
virtual void CopyInForeignFile(
std::unique_ptr<FileSystemOperationContext> context,
const base::FilePath& src_file_path,
const FileSystemURL& dest_url,
const StatusCallback& callback) = 0;
// Deletes a single file.
//
// FileSystemOperationImpl::RemoveFile calls this.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if |url| does not exist.
// - File::FILE_ERROR_NOT_A_FILE if |url| is not a file.
//
virtual void DeleteFile(std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
const StatusCallback& callback) = 0;
// Removes a single empty directory.
//
// FileSystemOperationImpl::RemoveDirectory calls this.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if |url| does not exist.
// - File::FILE_ERROR_NOT_A_DIRECTORY if |url| is not a directory.
// - File::FILE_ERROR_NOT_EMPTY if |url| is not empty.
//
virtual void DeleteDirectory(
std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
const StatusCallback& callback) = 0;
// Removes a single file or a single directory with its contents
// (i.e. files/subdirectories under the directory).
//
// FileSystemOperationImpl::Remove calls this.
// On some platforms, such as Chrome OS Drive File System, recursive file
// deletion can be implemented more efficiently than calling DeleteFile() and
// DeleteDirectory() for each files/directories.
// This method is optional, so if not supported,
// File::FILE_ERROR_INVALID_OPERATION should be returned via |callback|.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if |url| does not exist.
// - File::FILE_ERROR_INVALID_OPERATION if this operation is not supported.
virtual void DeleteRecursively(
std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
const StatusCallback& callback) = 0;
// Creates a local snapshot file for a given |url| and returns the
// metadata and platform path of the snapshot file via |callback|.
// In regular filesystem cases the implementation may simply return
// the metadata of the file itself (as well as GetMetadata does),
// while in non-regular filesystem case the backend may create a
// temporary snapshot file which holds the file data and return
// the metadata of the temporary file.
//
// In the callback, it returns:
// |file_info| is the metadata of the snapshot file created.
// |platform_path| is the full absolute platform path to the snapshot
// file created. If a file is not backed by a real local file in
// the implementor's FileSystem, the implementor must create a
// local snapshot file and return the path of the created file.
//
// If implementors creates a temporary file for snapshotting and wants
// FileAPI backend to take care of the lifetime of the file (so that
// it won't get deleted while JS layer has any references to the created
// File/Blob object), it should return non-empty |file_ref|.
// Via the |file_ref| implementors can schedule a file deletion
// or arbitrary callbacks when the last reference of File/Blob is dropped.
//
// FileSystemOperationImpl::CreateSnapshotFile calls this.
//
// This reports following error code via |callback|:
// - File::FILE_ERROR_NOT_FOUND if |url| does not exist.
// - File::FILE_ERROR_NOT_A_FILE if |url| exists but is a directory.
//
// The field values of |file_info| are undefined (implementation
// dependent) in error cases, and the caller should always
// check the return code.
virtual void CreateSnapshotFile(
std::unique_ptr<FileSystemOperationContext> context,
const FileSystemURL& url,
const CreateSnapshotFileCallback& callback) = 0;
private:
DISALLOW_COPY_AND_ASSIGN(AsyncFileUtil);
};
} // namespace storage
#endif // STORAGE_BROWSER_FILEAPI_ASYNC_FILE_UTIL_H_