net/base/platform_mime_util_win.cc

   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
  12 namespace net {
  13
  14 bool 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
  28 bool 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
  43 void 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