1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "net/base/platform_mime_util.h"
6
7#include <string>
8
9#include "base/strings/utf_string_conversions.h"
10#include "base/win/registry.h"
11
12namespace net {
13
14bool PlatformMimeUtil::GetPlatformMimeTypeFromExtension(
15    const base::FilePath::StringType& ext, std::string* result) const {
16  // check windows registry for file extension's mime type (registry key
17  // names are not case-sensitive).
18  std::wstring value, key = L"." + ext;
19  base::win::RegKey(HKEY_CLASSES_ROOT, key.c_str(), KEY_READ).ReadValue(
20      L"Content Type", &value);
21  if (!value.empty()) {
22    *result = WideToUTF8(value);
23    return true;
24  }
25  return false;
26}
27
28bool PlatformMimeUtil::GetPreferredExtensionForMimeType(
29    const std::string& mime_type, base::FilePath::StringType* ext) const {
30  std::wstring key(L"MIME\\Database\\Content Type\\" + UTF8ToWide(mime_type));
31  if (base::win::RegKey(HKEY_CLASSES_ROOT, key.c_str(), KEY_READ).ReadValue(
32          L"Extension", ext) != ERROR_SUCCESS) {
33    return false;
34  }
35  // Strip off the leading dot, this should always be the case.
36  if (!ext->empty() && ext->at(0) == L'.')
37    ext->erase(ext->begin());
38
39  return true;
40}
41
42void PlatformMimeUtil::GetPlatformExtensionsForMimeType(
43    const std::string& mime_type,
44    base::hash_set<base::FilePath::StringType>* extensions) const {
45  // Multiple extensions could have the given mime type specified as their types
46  // in their 'HKCR\.<extension>\Content Type' keys. Iterating all the HKCR
47  // entries, though, is wildly impractical. Cheat by returning just the
48  // preferred extension.
49  base::FilePath::StringType ext;
50  if (GetPreferredExtensionForMimeType(mime_type, &ext))
51    extensions->insert(ext);
52}
53
54}  // namespace net
55