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 = base::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(
31      L"MIME\\Database\\Content Type\\" + base::UTF8ToWide(mime_type));
32  if (base::win::RegKey(HKEY_CLASSES_ROOT, key.c_str(), KEY_READ).ReadValue(
33          L"Extension", ext) != ERROR_SUCCESS) {
34    return false;
35  }
36  // Strip off the leading dot, this should always be the case.
37  if (!ext->empty() && ext->at(0) == L'.')
38    ext->erase(ext->begin());
39
40  return true;
41}
42
43void PlatformMimeUtil::GetPlatformExtensionsForMimeType(
44    const std::string& mime_type,
45    base::hash_set<base::FilePath::StringType>* extensions) const {
46  // Multiple extensions could have the given mime type specified as their types
47  // in their 'HKCR\.<extension>\Content Type' keys. Iterating all the HKCR
48  // entries, though, is wildly impractical. Cheat by returning just the
49  // preferred extension.
50  base::FilePath::StringType ext;
51  if (GetPreferredExtensionForMimeType(mime_type, &ext))
52    extensions->insert(ext);
53}
54
55}  // namespace net
56