Add initial code to do filename munging in the FileSystem....

base/file_util_proxy.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 BASE_FILE_UTIL_PROXY_H_
 #define BASE_FILE_UTIL_PROXY_H_
 
 #include <vector>
 
 #include "base/callback.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
+#include "base/file_util_proxy_base.h"
 #include "base/platform_file.h"
 #include "base/ref_counted.h"
+#include "base/singleton.h"
 #include "base/tracked_objects.h"
 
 namespace base {
 
 class MessageLoopProxy;
 class Time;
 
 // This class provides asynchronous access to common file routines.
-class FileUtilProxy {
+class FileUtilProxy : public FileUtilProxyBase {
  public:
-  // Holds metadata for file or directory entry. Used by ReadDirectoryCallback.
-  struct Entry {
-    FilePath::StringType name;
-    bool is_directory;
-  };
-
-  // This callback is used by methods that report only an error code.  It is
-  // valid to pass NULL as the callback parameter to any function that takes a
-  // StatusCallback, in which case the operation will complete silently.
-  typedef Callback1<PlatformFileError /* error code */>::Type StatusCallback;
-
-  typedef Callback3<PlatformFileError /* error code */,
-                    PassPlatformFile,
-                    bool /* created */>::Type CreateOrOpenCallback;
-  typedef Callback3<PlatformFileError /* error code */,
-                    PassPlatformFile,
-                    FilePath>::Type CreateTemporaryCallback;
-  typedef Callback2<PlatformFileError /* error code */,
-                    bool /* created */>::Type EnsureFileExistsCallback;
-  typedef Callback2<PlatformFileError /* error code */,
-                    const PlatformFileInfo& /* file_info */
-                    >::Type GetFileInfoCallback;
-  typedef Callback2<PlatformFileError /* error code */,
-                    const std::vector<Entry>&>::Type ReadDirectoryCallback;
-  typedef Callback2<PlatformFileError /* error code */,
-                    int /* bytes read/written */>::Type ReadWriteCallback;
+  static FileUtilProxy* GetInstance();  // Always call through this singleton
+  virtual ~FileUtilProxy() {}
 
   // 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.
-  static bool CreateOrOpen(scoped_refptr<MessageLoopProxy> message_loop_proxy,
-                           const FilePath& file_path,
-                           int file_flags,
-                           CreateOrOpenCallback* callback);
+  bool CreateOrOpen(scoped_refptr<MessageLoopProxy> message_loop_proxy,
+                    const FilePath& file_path,
+                    int file_flags,
+                    CreateOrOpenCallback* callback);
 
   // Creates a temporary file for writing.  The path and an open file handle
   // are returned.  It is invalid to pass NULL for the callback.
-  static bool CreateTemporary(
+  bool CreateTemporary(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       CreateTemporaryCallback* callback);
 
   // Close the given file handle.
-  static bool Close(scoped_refptr<MessageLoopProxy> message_loop_proxy,
-                    PlatformFile,
-                    StatusCallback* callback);
+  bool Close(scoped_refptr<MessageLoopProxy> message_loop_proxy,
+             PlatformFile,
+             StatusCallback* callback);
 
-  // Ensures that the given |file_path| exist.  This creates a empty new file
+  // Ensures that the given |file_path| exists.  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.
-  static bool EnsureFileExists(
+  // If the file had not existed and is created at the |file_path|,
+  // |created| of the callback argument is set to true and |error code|
+  // is set to PLATFORM_FILE_OK.
+  // If the file already exists, |created| is set to false and |error code|
+  // is set to PLATFORM_FILE_OK.
+  // If the file hadn't existed but it couldn't be created for any reason,
+  // |created| is set to false and |error code| indicates the error.
+  bool EnsureFileExists(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       const FilePath& file_path,
       EnsureFileExistsCallback* callback);
 
   // Retrieves the information about a file. It is invalid to pass NULL for the
   // callback.
-  static bool GetFileInfo(
+  bool GetFileInfo(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       const FilePath& file_path,
       GetFileInfoCallback* callback);
 
-  static bool GetFileInfoFromPlatformFile(
+  bool GetFileInfoFromPlatformFile(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       PlatformFile file,
       GetFileInfoCallback* callback);
 
-  static bool ReadDirectory(scoped_refptr<MessageLoopProxy> message_loop_proxy,
+  bool ReadDirectory(scoped_refptr<MessageLoopProxy> message_loop_proxy,
                             const FilePath& file_path,
                             ReadDirectoryCallback* callback);
 
   // Creates directory at given path. It's an error to create
   // if |exclusive| is true and dir already exists.
-  static bool CreateDirectory(
+  bool CreateDirectory(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       const FilePath& file_path,
       bool exclusive,
       bool recursive,
       StatusCallback* callback);
 
   // 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.
-  static bool Copy(scoped_refptr<MessageLoopProxy> message_loop_proxy,
+  bool Copy(scoped_refptr<MessageLoopProxy> message_loop_proxy,
                    const FilePath& src_file_path,
                    const FilePath& dest_file_path,
                    StatusCallback* callback);
 
   // Moves a file or a directory from src_file_path to dest_file_path.
   // Error cases are similar to Copy method's error cases.
-  static bool Move(
+  bool Move(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       const FilePath& src_file_path,
       const FilePath& dest_file_path,
       StatusCallback* callback);
 
   // Deletes a file or a directory.
   // It is an error to delete a non-empty directory with recursive=false.
-  static bool Delete(scoped_refptr<MessageLoopProxy> message_loop_proxy,
+  bool Delete(scoped_refptr<MessageLoopProxy> message_loop_proxy,
                      const FilePath& file_path,
                      bool recursive,
                      StatusCallback* callback);
 
   // Deletes a directory and all of its contents.
-  static bool RecursiveDelete(
+  bool RecursiveDelete(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       const FilePath& file_path,
       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.
-  static bool Read(
+  bool Read(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       PlatformFile file,
       int64 offset,
       char* buffer,
       int bytes_to_read,
       ReadWriteCallback* 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.
-  static bool Write(
+  bool Write(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       PlatformFile file,
       int64 offset,
       const char* buffer,
       int bytes_to_write,
       ReadWriteCallback* callback);
 
   // Touches a file. The callback can be NULL.
-  static bool Touch(
+  bool Touch(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       PlatformFile file,
       const Time& last_access_time,
       const Time& last_modified_time,
       StatusCallback* callback);
 
   // Touches a file. The callback can be NULL.
-  static bool Touch(
+  bool Touch(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       const FilePath& file_path,
       const Time& last_access_time,
       const Time& last_modified_time,
       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.
-  static bool Truncate(
+  bool Truncate(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       PlatformFile file,
       int64 length,
       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.
-  static bool Truncate(
+  bool Truncate(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       const FilePath& path,
       int64 length,
       StatusCallback* callback);
 
   // Flushes a file. The callback can be NULL.
-  static bool Flush(
+  bool Flush(
       scoped_refptr<MessageLoopProxy> message_loop_proxy,
       PlatformFile file,
       StatusCallback* callback);
 
+ protected:
+  FileUtilProxy() {}
+
  private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(FileUtilProxy);
+  friend struct DefaultSingletonTraits<FileUtilProxy>;
+  DISALLOW_COPY_AND_ASSIGN(FileUtilProxy);
 };
 
 }  // namespace base
 
 #endif  // BASE_FILE_UTIL_PROXY_H_