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

webkit/fileapi/path_obfuscator.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_PATH_OBFUSCATOR_H
+#define WEBKIT_FILEAPI_PATH_OBFUSCATOR_H
+
+#include "base/file_path.h"
+#include "base/platform_file.h"
+#include "webkit/fileapi/obfuscated_name_map.h"
+
+using base::PlatformFileError;
+
+namespace fileapi {
+
+// This class is for use on the file thread only.  TODO(ericu): Add CHECKs for
+// this.
+// The lifetime of the PathObfuscator must be limited such that any operation
+// that could move the directory to which it refers happens outside that
+// lifetime--otherwise you might be looking up keys in the wrong dictionary.
+// Also, you shouldn't have more than one of these for the same directory at the
+// same time, or they could get out of sync.
+// You can reuse one of these for multiple operations as long as you manage it
+// carefully: Rollback or Commit between each operation, and don't let it get
+// out of sync.
+class PathObfuscator {
+ public:
+  PathObfuscator(const FilePath& root_path);
+  ~PathObfuscator() {
+    Rollback();
+  }
+
+  // As long as there's no salting on the hash, this can be static.
+  FilePath ObfuscatedPathFromClearPath(const FilePath& virtual_path);
+
+  PlatformFileError ClearPathFromObfuscatedPath(
+      const FilePath& obfuscated_path,
+      FilePath* clear_path);
+
+  PlatformFileError PrepareAdd(
+      const FilePath& clear_path,
+      const FilePath& obfuscated_path);
+
+  PlatformFileError PrepareDelete(
+      const FilePath& clear_path,
+      const FilePath& obfuscated_path);
+
+  PlatformFileError PrepareMove(
+      const FilePath& old_clear_path,
+      const FilePath& old_obfuscated_path,
+      const FilePath& new_clear_path,
+      const FilePath& new_obfuscated_path);
+
+  PlatformFileError Commit();
+
+  // Harmless if there no operation in progress.
+  void Rollback();
+
+ private:
+  ObfuscatedNameMap from_map_;
+  ObfuscatedNameMap to_map_;
+  bool from_map_valid_, to_map_valid_;
+  FilePath root_path_;
+};
+
+}  // namespace fileapi
+
+#endif  // WEBKIT_FILEAPI_PATH_OBFUSCATOR_H