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

webkit/fileapi/obfuscated_name_map.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_OBFUSCATED_NAME_MAP_H_
+#define WEBKIT_FILEAPI_OBFUSCATED_NAME_MAP_H_
+
+#include "base/file_path.h"
+#include "base/hash_tables.h"
+#include "base/platform_file.h"
+
+namespace obfuscated_file_util {
+
+using base::PlatformFile;
+using base::PlatformFileError;
+
+typedef FilePath::StringType StringType;
+
+// This can be reused, but call Init between uses if you want to switch
+// directory.  You must either RollBack or Commit each change individually.  If
+// you get an error, call either Init or RollBack before trying to reuse the
+// object.

[michaeln, 2011/02/11 00:03:34]

class comments about what this class does might be better here, these comments
about Rollback/Commit usage might be better in next to those methods down below?

[ericu, 2011/02/11 01:57:47]

Hmm...I thought it best to put "how to reuse this class" type stuff up here,
since it concerns object lifetime.  I can clean it up a bit and add some stuff
near RollBack and Commit as well, but I don't want to have redundant comments.

+class ObfuscatedNameMap {
+ public:
+  ObfuscatedNameMap();
+  ~ObfuscatedNameMap() {
+    RollBack();
+  }
+
+  void Init(const FilePath& directory);
+
+  PlatformFileError ClearNameFromObfuscatedName(
+      StringType obfuscated_name,
+      StringType* clear_name);
+
+  static StringType ObfuscatedNameFromClearName(StringType clear_name);
+
+  PlatformFileError PrepareAdd(
+      const StringType& clear_name, const StringType& obfuscated_name);
+
+  PlatformFileError PrepareDelete(
+      const StringType& clear_name, const StringType& obfuscated_name);
+
+  PlatformFileError PrepareMove(
+      const StringType& old_clear_name,
+      const StringType& old_obfuscated_name,
+      const StringType& new_clear_name,
+      const StringType& new_obfuscated_name);
+
+  PlatformFileError Commit();
+
+  // Harmless if there no operation in progress.
+  void RollBack();

[michaeln, 2011/02/11 00:03:34]

There's precedence in the project for 'Rollback' w/o the capital B, see
transaction.h for example.

[ericu, 2011/02/11 01:57:47]

OK, will change.

+
+ private:
+  typedef base::hash_map<StringType, StringType> MapType;
+
+  static size_t hash(const FilePath& f);
+  FilePath GetDictionaryLocation();
+  FilePath GetDictionaryNextLocation();
+  PlatformFileError LoadFromFile();
+  void LoadMapFromString(MapType* map, const StringType& serialized);
+  StringType ConvertMapToString(const MapType& map);
+  PlatformFileError InitDictNext();
+  PlatformFileError RecoverIfNeeded();
+  PlatformFileError WriteToNextFile();
+
+  static const StringType DICTIONARY_NAME;
+  static const StringType DICTIONARY_NEXT_NAME;
+  static const StringType SEPARATOR;
+  static const StringType TERMINATOR;
+
+  MapType map_;
+  MapType map_next_;
+  bool map_valid_;
+  bool map_next_valid_;  // == operation in progress
+  FilePath directory_;
+};
+
+}  // namespace obfuscated_file_util
+
+#endif  // WEBKIT_FILEAPI_OBFUSCATED_NAME_MAP_H_