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

webkit/fileapi/path_obfuscator.cc

+// 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.
+
+#include "webkit/fileapi/path_obfuscator.h"
+
+#include <vector>
+#include "base/logging.h"
+
+namespace fileapi {
+
+PathObfuscator::PathObfuscator(const FilePath& root_path) :
+  from_map_valid_(false), to_map_valid_(false), root_path_(root_path) {
+}
+
+FilePath PathObfuscator::ObfuscatedPathFromClearPath(
+    const FilePath& virtual_path) {
+  std::vector<StringType> components;
+  virtual_path.GetComponents(&components);
+
+  FilePath obfuscated_path;
+  std::vector<StringType>::const_iterator iter;
+  for (iter = components.begin(); iter != components.end(); ++iter)
+    obfuscated_path = obfuscated_path.Append(
+        ObfuscatedNameMap::ObfuscatedNameFromClearName(*iter));
+  return obfuscated_path;
+}
+
+PlatformFileError PathObfuscator::ClearPathFromObfuscatedPath(
+    const FilePath& obfuscated_path,
+    FilePath* clear_path) {
+  std::vector<StringType> components;
+  obfuscated_path.GetComponents(&components);
+
+  FilePath dict_path = root_path_;
+  FilePath path;
+  std::vector<StringType>::const_iterator iter;
+  ObfuscatedNameMap map;
+  for (iter = components.begin(); iter != components.end(); ++iter) {
+    StringType clear_name;
+    map.Init(dict_path);
+    PlatformFileError error =
+        map.ClearNameFromObfuscatedName(*iter, &clear_name);
+    if (error != base::PLATFORM_FILE_OK)
+      return error;
+    path = path.Append(clear_name);
+    dict_path.Append(*iter);
+  }
+  *clear_path = path;
+  return base::PLATFORM_FILE_OK;
+}
+
+PlatformFileError PathObfuscator::PrepareAdd(
+    const FilePath& clear_path,
+    const FilePath& obfuscated_path) {
+  CHECK(!from_map_valid_);
+#ifndef NDEBUG
+  FilePath test_path(ObfuscatedPathFromClearPath(clear_path));
+  CHECK(test_path == obfuscated_path);
+#endif
+  FilePath dict_dir = root_path_.Append(obfuscated_path).DirName();
+  from_map_.Init(dict_dir);
+  PlatformFileError error =
+      from_map_.PrepareAdd(clear_path.BaseName().value(),
+          obfuscated_path.BaseName().value());
+  if (error != base::PLATFORM_FILE_OK)
+    return error;
+  from_map_valid_ = true;
+  return base::PLATFORM_FILE_OK;
+}
+
+PlatformFileError PathObfuscator::PrepareDelete(
+    const FilePath& clear_path,
+    const FilePath& obfuscated_path) {
+  CHECK(!from_map_valid_);
+#ifndef NDEBUG
+  FilePath test_path(ObfuscatedPathFromClearPath(clear_path));
+  CHECK(test_path == obfuscated_path);
+#endif
+  FilePath dict_dir = root_path_.Append(obfuscated_path).DirName();
+  from_map_.Init(dict_dir);
+  {
+    PlatformFileError error =
+        from_map_.PrepareDelete(clear_path.BaseName().value(),
+            obfuscated_path.BaseName().value());
+    if (error != base::PLATFORM_FILE_OK)
+      return error;
+  }
+  from_map_valid_ = true;
+  return base::PLATFORM_FILE_OK;
+}
+
+PlatformFileError PathObfuscator::PrepareMove(
+    const FilePath& old_clear_path,
+    const FilePath& old_obfuscated_path,
+    const FilePath& new_clear_path,
+    const FilePath& new_obfuscated_path) {
+  CHECK(!from_map_valid_);
+#ifndef NDEBUG
+  FilePath test_path(ObfuscatedPathFromClearPath(old_clear_path));
+  CHECK(test_path == old_obfuscated_path);
+  test_path = ObfuscatedPathFromClearPath(new_clear_path);
+  CHECK(test_path == new_obfuscated_path);
+#endif
+  FilePath dict_dir = root_path_.Append(old_obfuscated_path).DirName();
+  from_map_.Init(dict_dir);
+  if (old_obfuscated_path.DirName() == new_obfuscated_path.DirName()) {
+    PlatformFileError error =
+        from_map_.PrepareMove(
+            old_clear_path.BaseName().value(),
+            old_obfuscated_path.BaseName().value(),
+            new_clear_path.BaseName().value(),
+            new_obfuscated_path.BaseName().value());
+    if (error != base::PLATFORM_FILE_OK)
+      return error;
+    from_map_valid_ = true;
+  } else {
+    dict_dir = root_path_.Append(new_obfuscated_path).DirName();
+    to_map_.Init(new_obfuscated_path);
+    PlatformFileError error =
+        from_map_.PrepareDelete(old_clear_path.BaseName().value(),
+            old_obfuscated_path.BaseName().value());
+    if (error != base::PLATFORM_FILE_OK)
+      return error;
+    error = to_map_.PrepareAdd(new_clear_path.BaseName().value(),
+        new_obfuscated_path.BaseName().value());
+    if (error != base::PLATFORM_FILE_OK) {
+      from_map_.Rollback();
+      return error;
+    }
+    from_map_valid_ = true;
+    to_map_valid_ = true;
+  }
+  return base::PLATFORM_FILE_OK;
+}
+
+PlatformFileError PathObfuscator::Commit() {
+  CHECK(from_map_valid_);
+  PlatformFileError error = from_map_.Commit();
+  if (error != base::PLATFORM_FILE_OK)
+    return error;
+  if (to_map_valid_)
+    error = to_map_.Commit();
+  from_map_valid_ = false;
+  to_map_valid_ = false;
+  return error;
+}
+
+void PathObfuscator::Rollback() {
+  if (from_map_valid_) {
+    from_map_.Rollback();
+    from_map_valid_ = false;
+  }
+  if (to_map_valid_) {
+    to_map_.Rollback();
+    to_map_valid_ = false;
+  }
+}
+
+}  // namespace fileapi