components/favicon_base/favicon_url_parser.cc

   1 // Copyright 2013 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 "components/favicon_base/favicon_url_parser.h"
   6
   7 #include "base/strings/string_number_conversions.h"
   8 #include "components/favicon_base/favicon_types.h"
   9 #include "net/url_request/url_request.h"
  10 #include "ui/base/webui/web_ui_util.h"
  11 #include "ui/gfx/favicon_size.h"
  12
  13 namespace {
  14
  15 // Parameters which can be used in chrome://favicon path. See file
  16 // "chrome/browser/ui/webui/favicon_source.h" for a description of
  17 // what each does.
  18 const char kIconURLParameter[] = "iconurl/";
  19 const char kLargestParameter[] = "largest/";
  20 const char kOriginParameter[] = "origin/";
  21 const char kSizeParameter[] = "size/";
  22
  23 // Returns true if |search| is a substring of |path| which starts at
  24 // |start_index|.
  25 bool HasSubstringAt(const std::string& path,
  26                     size_t start_index,
  27                     const std::string& search) {
  28   return path.compare(start_index, search.length(), search) == 0;
  29 }
  30
  31 }  // namespace
  32
  33 namespace chrome {
  34
  35 bool ParseFaviconPath(const std::string& path,
  36                       int icon_types,
  37                       ParsedFaviconPath* parsed) {
  38   parsed->is_icon_url = false;
  39   parsed->url = "";
  40   parsed->size_in_dip = gfx::kFaviconSize;
  41   parsed->device_scale_factor = 1.0f;
  42   parsed->path_index = std::string::npos;
  43
  44   if (path.empty())
  45     return false;
  46
  47   size_t parsed_index = 0;
  48   if (HasSubstringAt(path, parsed_index, kLargestParameter)) {
  49     parsed_index += strlen(kLargestParameter);
  50     parsed->size_in_dip = 0;
  51   } else if (HasSubstringAt(path, parsed_index, kSizeParameter)) {
  52     parsed_index += strlen(kSizeParameter);
  53
  54     size_t slash = path.find("/", parsed_index);
  55     if (slash == std::string::npos)
  56       return false;
  57
  58     size_t scale_delimiter = path.find("@", parsed_index);
  59     std::string size_str;
  60     std::string scale_str;
  61     if (scale_delimiter == std::string::npos) {
  62       // Support the legacy size format of 'size/aa/' where 'aa' is the desired
  63       // size in DIP for the sake of not regressing the extensions which use it.
  64       size_str = path.substr(parsed_index, slash - parsed_index);
  65     } else {
  66       size_str = path.substr(parsed_index, scale_delimiter - parsed_index);
  67       scale_str = path.substr(scale_delimiter + 1,
  68                               slash - scale_delimiter - 1);
  69     }
  70
  71     if (!base::StringToInt(size_str, &parsed->size_in_dip))
  72       return false;
  73
  74     if (parsed->size_in_dip != (gfx::kFaviconSize * 4) &&
  75         parsed->size_in_dip != (gfx::kFaviconSize * 2)) {
  76       // Only 64x64, 32x32 and 16x16 icons are supported.
  77       parsed->size_in_dip = gfx::kFaviconSize;
  78     }
  79     if (!scale_str.empty())
  80       webui::ParseScaleFactor(scale_str, &parsed->device_scale_factor);
  81
  82     // Return the default favicon (as opposed to a resized favicon) for
  83     // favicon sizes which are not cached by the favicon service.
  84     // Currently the favicon service caches:
  85     // - favicons of sizes "gfx::kFaviconSize * scale factor" px of type FAVICON
  86     //   where scale factor is one of FaviconUtil::GetFaviconScales().
  87     // - the largest TOUCH_ICON / TOUCH_PRECOMPOSED_ICON
  88     if (parsed->size_in_dip != gfx::kFaviconSize &&
  89         icon_types == favicon_base::FAVICON)
  90       return false;
  91
  92     parsed_index = slash + 1;
  93   }
  94
  95   if (HasSubstringAt(path, parsed_index, kIconURLParameter)) {
  96     parsed_index += strlen(kIconURLParameter);
  97     parsed->is_icon_url = true;
  98     parsed->url = path.substr(parsed_index);
  99   } else if (HasSubstringAt(path, parsed_index, kOriginParameter)) {
 100     // URL requests prefixed with "origin/" are converted to a form with an
 101     // empty path and a valid scheme. (e.g., example.com -->
 102     // http://example.com/ or http://example.com/a --> http://example.com/)
 103     parsed_index += strlen(kOriginParameter);
 104     std::string possibly_invalid_url = path.substr(parsed_index);
 105
 106     // If the URL does not specify a scheme (e.g., example.com instead of
 107     // http://example.com), add "http://" as a default.
 108     if (!GURL(possibly_invalid_url).has_scheme())
 109       possibly_invalid_url = "http://" + possibly_invalid_url;
 110
 111     // Strip the path beyond the top-level domain.
 112     parsed->url = GURL(possibly_invalid_url).GetOrigin().spec();
 113   } else {
 114     parsed->url = path.substr(parsed_index);
 115   }
 116
 117   // The parsed index needs to be returned in order to allow Instant Extended
 118   // to translate favicon URLs using advanced parameters.
 119   // Example:
 120   //   "chrome-search://favicon/size/16@2x/<renderer-id>/<most-visited-id>"
 121   // would be translated to:
 122   //   "chrome-search://favicon/size/16@2x/<most-visited-item-with-given-id>".
 123   parsed->path_index = parsed_index;
 124   return true;
 125 }
 126
 127 }  // namespace chrome