Introduce FileSystemFileUtil and -Proxy to decorate base::file_util in webkit/fileapi.

webkit/fileapi/file_system_file_util.h

+// Copyright (c) 2011 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 WEBKIT_FILEAPI_FILE_SYSTEM_FILE_UTIL_H_
+#define WEBKIT_FILEAPI_FILE_SYSTEM_FILE_UTIL_H_
+
+#include "base/callback.h"
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/file_util_proxy.h"
+#include "base/platform_file.h"
+#include "base/ref_counted.h"
+#include "base/singleton.h"
+#include "base/tracked_objects.h"
+
+namespace base {
+struct PlatformFileInfo;
+class MessageLoopProxy;
+class Time;
+}
+
+namespace fileapi {
+
+using base::PlatformFile;
+using base::PlatformFileError;
+
+class FileSystemOperationContext;
+
+class FileSystemFileUtil {

[kinuko, 2011/03/03 21:29:22]

Can we add some comment to note that the implementation is largely taken from
FileUtilProxy and TODO (you can put my name there too) to clean up FileUtilProxy
or factor out common routines.

[Dai Mikurube (google.com), 2011/03/03 22:19:10]

Done.

+ public:
+  static FileSystemFileUtil* GetInstance();
+
+  // Creates or opens a file with the given flags.  It is invalid to pass NULL
+  // for the 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.
+  virtual PlatformFileError CreateOrOpen(
+      FileSystemOperationContext* context,
+      const FilePath& file_path,
+      int file_flags,
+      PlatformFile* file_handle,
+      bool* created);
+
+  // Close the given file handle.
+  virtual PlatformFileError Close(
+      FileSystemOperationContext* context,
+      PlatformFile);
+
+  // Ensures that the given |file_path| exist.  This creates a empty new file
+  // at |file_path| if the |file_path| does not exist.
+  // If a new file han not existed and is created at the |file_path|,
+  // |created| of the callback argument is set true and |error code|
+  // is set PLATFORM_FILE_OK.
+  // If the file already exists, |created| is set false and |error code|
+  // is set PLATFORM_FILE_OK.
+  // If the file hasn't existed but it couldn't be created for some other
+  // reasons, |created| is set false and |error code| indicates the error.
+  virtual PlatformFileError EnsureFileExists(
+      FileSystemOperationContext* context,
+      const FilePath& file_path, bool* created);
+
+  // Retrieves the information about a file. It is invalid to pass NULL for the
+  // callback.
+  virtual PlatformFileError GetFileInfo(
+      FileSystemOperationContext* context,
+      const FilePath& file_, base::PlatformFileInfo* file_info);
+
+  virtual PlatformFileError ReadDirectory(
+      FileSystemOperationContext* context,
+      const FilePath& file_path,
+      std::vector<base::FileUtilProxy::Entry>* entries);
+
+  // Creates directory at given path. It's an error to create
+  // if |exclusive| is true and dir already exists.
+  virtual PlatformFileError CreateDirectory(
+      FileSystemOperationContext* context,
+      const FilePath& file_path,
+      bool exclusive);
+
+  // Copies a file or a directory from |src_file_path| to |dest_file_path|
+  // Error cases:
+  // If destination file doesn't exist or destination's parent
+  // doesn't exists.
+  // If source dir exists but destination path is an existing file.
+  // If source file exists but destination path is an existing directory.
+  // If source is a parent of destination.
+  // If source doesn't exists.
+  virtual PlatformFileError Copy(
+      FileSystemOperationContext* context,
+      const FilePath& src_file_path,
+      const FilePath& dest_file_path);
+
+  // Moves a file or a directory from src_file_path to dest_file_path.
+  // Error cases are similar to Copy method's error cases.
+  virtual PlatformFileError Move(
+      FileSystemOperationContext* context,
+      const FilePath& src_file_path,
+      const FilePath& dest_file_path);
+
+  // Deletes a file or a directory.
+  // It is an error to delete a non-empty directory with recursive=false.
+  virtual PlatformFileError Delete(
+      FileSystemOperationContext* context,
+      const FilePath& file_path,
+      bool recursive);
+
+  // Touches a file. The callback can be NULL.
+  virtual PlatformFileError Touch(
+      FileSystemOperationContext* context,
+      const FilePath& file_path,
+      const base::Time& last_access_time,
+      const base::Time& last_modified_time);
+
+  // 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.
+  virtual PlatformFileError Truncate(
+      FileSystemOperationContext* context,
+      const FilePath& path,
+      int64 length);
+
+ protected:
+  FileSystemFileUtil() { }
+  friend struct DefaultSingletonTraits<FileSystemFileUtil>;
+  DISALLOW_COPY_AND_ASSIGN(FileSystemFileUtil);
+};
+
+}  // namespace fileapi
+
+#endif  // WEBKIT_FILEAPI_FILE_SYSTEM_FILE_UTIL_H_