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

webkit/fileapi/obfuscated_file_util.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.
+
+// Useful functions: FilePath::CompareIgnoreCase, FilePath::value [returns a
+// StringType].
+
+#include "webkit/fileapi/obfuscated_file_util.h"
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "webkit/fileapi/file_system_context.h"
+#include "webkit/fileapi/file_system_operation_context.h"
+#include "webkit/fileapi/file_system_path_manager.h"
+#include "webkit/fileapi/path_obfuscator.h"
+
+namespace fileapi {
+
+ObfuscatedFileUtil* ObfuscatedFileUtil::GetInstance() {
+  return Singleton<ObfuscatedFileUtil>::get();
+}
+
+PlatformFileError ObfuscatedFileUtil::CreateOrOpen(
+    FileSystemOperationContext* context,
+    const FilePath& file_path,
+    int file_flags,
+    PlatformFile* file_handle,
+    bool *created) {
+  FilePath root_path;
+  FilePath virtual_path;
+
+  CHECK(context->file_system_context()->path_manager()->CrackFileSystemPath(
+      file_path, NULL, NULL, &root_path, &virtual_path));
+
+  fileapi::PathObfuscator obfuscator(root_path);
+  FilePath obfuscated_path =
+      obfuscator.ObfuscatedPathFromClearPath(virtual_path);
+  FilePath full_path = root_path.Append(obfuscated_path);
+
+  if (!file_util::DirectoryExists(full_path.DirName())) {
+    // If its parent does not exist, should return NOT_FOUND error.
+    *file_handle = base::kInvalidPlatformFileValue;
+    return base::PLATFORM_FILE_ERROR_NOT_FOUND;
+  }
+  FilePath temp;
+  bool need_commit = false;
+
+  // Check whether we have a dictionary entry for the file first, so that we can
+  // record that we're going to try to create it if we don't.
+  PlatformFileError error =
+      obfuscator.ClearPathFromObfuscatedPath(obfuscated_path, &temp);
+  if (error == base::PLATFORM_FILE_ERROR_NOT_FOUND) {
+    error = obfuscator.PrepareAdd(virtual_path, obfuscated_path);
+    need_commit = true;
+  }
+  if (error != base::PLATFORM_FILE_OK) {
+    *file_handle = base::kInvalidPlatformFileValue;
+    return error;
+  }
+  *file_handle =
+      base::CreatePlatformFile(full_path, file_flags, NULL, &error);
+  const int CREATE_EXCLUSIVE =
+      base::PLATFORM_FILE_CREATE | base::PLATFORM_FILE_EXCLUSIVE_WRITE;
+  if (error == base::PLATFORM_FILE_ERROR_EXISTS && need_commit &&
+      ((file_flags & CREATE_EXCLUSIVE) == CREATE_EXCLUSIVE)) {
+    // The file existed, but wasn't in the dictionary.  The user tried an
+    // exclusive create, and it failed by collision.  We should add the file to
+    // the dictionary [recovering from some corruption], but report the
+    // collision.
+    obfuscator.Commit();
+    *file_handle = base::kInvalidPlatformFileValue;
+    return error;
+  } else if (error != base::PLATFORM_FILE_OK) {
+    if (need_commit)
+      obfuscator.Rollback();
+    *file_handle = base::kInvalidPlatformFileValue;
+    return error;
+  }
+  if (need_commit)
+    obfuscator.Commit();
+  return base::PLATFORM_FILE_OK;
+}
+
+
+PlatformFileError ObfuscatedFileUtil::CreateDirectory(
+    FileSystemOperationContext* context,
+    const FilePath& file_path,
+    bool exclusive) {
+  FilePath root_path;
+  FilePath virtual_path;
+
+  CHECK(context->file_system_context()->path_manager()->CrackFileSystemPath(
+      file_path, NULL, NULL, &root_path, &virtual_path));
+
+  fileapi::PathObfuscator obfuscator(root_path);
+  FilePath obfuscated_path =
+      obfuscator.ObfuscatedPathFromClearPath(virtual_path);
+  FilePath full_path = root_path.Append(obfuscated_path);
+  if (!file_util::PathExists(full_path.DirName())) {
+    return base::PLATFORM_FILE_ERROR_NOT_FOUND;
+  }
+  bool path_exists = file_util::PathExists(full_path);
+  if (exclusive && path_exists) {
+    // TODO(ericu): What if it's not in the dictionary?
+    return base::PLATFORM_FILE_ERROR_EXISTS;
+  }
+  if (path_exists && !file_util::DirectoryExists(full_path)) {
+    return base::PLATFORM_FILE_ERROR_EXISTS;
+  }
+  bool inhibit_commit = false;
+  PlatformFileError error =
+      obfuscator.PrepareAdd(virtual_path, obfuscated_path);
+  if (error != base::PLATFORM_FILE_OK) {
+    if (path_exists && !exclusive &&
+        error == base::PLATFORM_FILE_ERROR_EXISTS) {
+      return base::PLATFORM_FILE_OK;
+    }
+    if (path_exists || error != base::PLATFORM_FILE_ERROR_EXISTS) {
+      return error;
+    }
+    // Else it's in the dictionary, but not on the disk.  We recover from this
+    // corruption by just creating the directory and leaving the dictionary
+    // alone.
+    inhibit_commit = true;
+  }
+
+  // TODO: Replace this call with a call to
+  // QuotaFileUtil::GetInstance()->CreateDirectory().
+  if (!file_util::CreateDirectory(full_path)) {
+    obfuscator.Rollback();
+    return base::PLATFORM_FILE_ERROR_FAILED;
+  }
+  if (!inhibit_commit)
+    obfuscator.Commit();
+  return base::PLATFORM_FILE_OK;
+}
+
+}  // namespace fileapi