Pepper: Create FileRef utility routines.

The host and plugin implementations will need to share some common code for
creating display names from internal and external paths and for validating
internal paths.

BUG=225441

Review URL: https://chromiumcodereview.appspot.com/16830008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@206438 0039d316-1c4b-4281-b951-d872f2087c98

ppapi/ppapi_shared.gypi

@@ -23,6 +23,8 @@
           'shared_impl/file_io_state_manager.h',
           'shared_impl/file_path.cc',
           'shared_impl/file_path.h',
+          'shared_impl/file_ref_util.cc',
+          'shared_impl/file_ref_util.h',
           'shared_impl/file_type_conversion.cc',
           'shared_impl/file_type_conversion.h',
           'shared_impl/flash_clipboard_format_registry.cc',

ppapi/shared_impl/file_ref_util.cc

@@ -0,0 +1,58 @@
+// Copyright 2013 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 "ppapi/shared_impl/file_ref_util.h"
+
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+
+namespace ppapi {
+
+std::string GetNameForInternalFilePath(const std::string& path) {
+  if (path == "/")
+    return path;
+  size_t pos = path.rfind('/');
+  CHECK(pos != std::string::npos);
+  return path.substr(pos + 1);
+}
+
+std::string GetNameForExternalFilePath(const base::FilePath& path) {
+  const base::FilePath::StringType& file_path = path.value();
+  size_t pos = file_path.rfind(base::FilePath::kSeparators[0]);
+  CHECK(pos != base::FilePath::StringType::npos);
+#if defined(OS_WIN)
+  return WideToUTF8(file_path.substr(pos + 1));
+#elif defined(OS_POSIX)
+  return file_path.substr(pos + 1);
+#else
+#error "Unsupported platform."
+#endif
+}
+
+bool IsValidInternalPath(const std::string& path) {
+  // We check that:
+  //   The path starts with '/'
+  //   The path must contain valid UTF-8 characters.
+  //   It must not FilePath::ReferencesParent().
+  if (path.empty() || path[0] != '/')
+    return false;
+  if (!IsStringUTF8(path))
+    return false;
+#if defined(OS_WIN)
+  base::FilePath::StringType path_win(path.begin(), path.end());
+  base::FilePath file_path(path_win);
+#else
+  base::FilePath file_path(path);
+#endif
+  if (file_path.ReferencesParent())
+    return false;
+  return true;
+}
+
+void NormalizeInternalPath(std::string* path) {
+  if (path->size() > 1 && path->at(path->size() - 1) == '/')
+    path->erase(path->size() - 1, 1);
+}
+
+}  // namespace ppapi

ppapi/shared_impl/file_ref_util.h

@@ -0,0 +1,26 @@
+// Copyright 2013 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 PPAPI_SHARED_IMPL_FILE_REF_UTIL_H_
+#define PPAPI_SHARED_IMPL_FILE_REF_UTIL_H_
+
+#include <string>
+
+#include "base/files/file_path.h"
+
+namespace ppapi {
+
+// Routines to generate display names for internal and external file paths.
+std::string GetNameForInternalFilePath(const std::string& path);
+std::string GetNameForExternalFilePath(const base::FilePath& path);
+
+// Determines whether an internal file path is valid.
+bool IsValidInternalPath(const std::string& path);
+
+// If path ends with a slash, normalize it away unless it's the root path.
+void NormalizeInternalPath(std::string* path);
+
+}  // namespace ppapi
+
+#endif  // PPAPI_SHARED_IMPL_FILE_REF_UTIL_H_