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;
+
+// A large part of this implementation is taken from base::FileUtilProxy.
+// TODO(dmikurube, kinuko): Clean up base::FileUtilProxy to factor out common
+// routines. It includes dropping FileAPI-specific routines from FileUtilProxy.
+class FileSystemFileUtil {
+ 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_