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      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 "chrome/common/favicon/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 {
    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     if (HasSubstringAt(path, parsed_index, kOriginParameter)) {
    104       parsed_index += strlen(kOriginParameter);
    105       std::string possibly_invalid_url = path.substr(parsed_index);
    106 
    107       // If the URL does not specify a scheme (e.g., example.com instead of
    108       // http://example.com), add "http://" as a default.
    109       if (!GURL(possibly_invalid_url).has_scheme())
    110         possibly_invalid_url = "http://" + possibly_invalid_url;
    111 
    112       // Strip the path beyond the top-level domain.
    113       parsed->url = GURL(possibly_invalid_url).GetOrigin().spec();
    114     } else {
    115       parsed->url = path.substr(parsed_index);
    116     }
    117   }
    118 
    119   // The parsed index needs to be returned in order to allow Instant Extended
    120   // to translate favicon URLs using advanced parameters.
    121   // Example:
    122   //   "chrome-search://favicon/size/16@2x/<renderer-id>/<most-visited-id>"
    123   // would be translated to:
    124   //   "chrome-search://favicon/size/16@2x/<most-visited-item-with-given-id>".
    125   parsed->path_index = parsed_index;
    126   return true;
    127 }
    128 
    129 }  // namespace chrome
    130