src/components/search_provider_logos/google_logo_api.cc

   1 // Copyright 2014 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/search_provider_logos/google_logo_api.h"
   6
   7 #include "base/base64.h"
   8 #include "base/json/json_reader.h"
   9 #include "base/memory/ref_counted_memory.h"
  10 #include "base/strings/string_util.h"
  11 #include "base/values.h"
  12
  13 namespace search_provider_logos {
  14
  15 namespace {
  16 const char kResponsePreamble[] = ")]}'";
  17 }
  18
  19 GURL GoogleAppendFingerprintToLogoURL(const GURL& logo_url,
  20                                       const std::string& fingerprint) {
  21   // Note: we can't just use net::AppendQueryParameter() because it escapes
  22   // ":" to "%3A", but the server requires the colon not to be escaped.
  23   // See: http://crbug.com/413845
  24
  25   // TODO(newt): Switch to using net::AppendQueryParameter once it no longer
  26   // escapes ":"
  27
  28   std::string query(logo_url.query());
  29   if (!query.empty())
  30     query += "&";
  31
  32   query += "async=es_dfp:";
  33   query += fingerprint;
  34   GURL::Replacements replacements;
  35   replacements.SetQueryStr(query);
  36   return logo_url.ReplaceComponents(replacements);
  37 }
  38
  39 scoped_ptr<EncodedLogo> GoogleParseLogoResponse(
  40     const scoped_ptr<std::string>& response,
  41     base::Time response_time) {
  42   // Google doodles are sent as JSON with a prefix. Example:
  43   //   )]}' {"update":{"logo":{
  44   //     "data": "/9j/4QAYRXhpZgAASUkqAAgAAAAAAAAAAAAAAP/...",
  45   //     "mime_type": "image/png",
  46   //     "fingerprint": "db063e32",
  47   //     "target": "http://www.google.com.au/search?q=Wilbur+Christiansen",
  48   //     "alt": "Wilbur Christiansen's Birthday"
  49   //     "time_to_live": 1389304799
  50   //   }}}
  51
  52   // The response may start with )]}'. Ignore this.
  53   base::StringPiece response_sp(*response);
  54   if (response_sp.starts_with(kResponsePreamble))
  55     response_sp.remove_prefix(strlen(kResponsePreamble));
  56
  57   scoped_ptr<base::Value> value(base::JSONReader::Read(response_sp));
  58   if (!value.get())
  59     return scoped_ptr<EncodedLogo>();
  60
  61   // The important data lives inside several nested dictionaries:
  62   // {"update": {"logo": { "mime_type": ..., etc } } }
  63   const base::DictionaryValue* outer_dict;
  64   if (!value->GetAsDictionary(&outer_dict))
  65     return scoped_ptr<EncodedLogo>();
  66   const base::DictionaryValue* update_dict;
  67   if (!outer_dict->GetDictionary("update", &update_dict))
  68     return scoped_ptr<EncodedLogo>();
  69   const base::DictionaryValue* logo_dict;
  70   if (!update_dict->GetDictionary("logo", &logo_dict))
  71     return scoped_ptr<EncodedLogo>();
  72
  73   scoped_ptr<EncodedLogo> logo(new EncodedLogo());
  74
  75   std::string encoded_image_base64;
  76   if (logo_dict->GetString("data", &encoded_image_base64)) {
  77     // Data is optional, since we may be revalidating a cached logo.
  78     base::RefCountedString* encoded_image_string = new base::RefCountedString();
  79     if (!base::Base64Decode(encoded_image_base64,
  80                             &encoded_image_string->data()))
  81       return scoped_ptr<EncodedLogo>();
  82     logo->encoded_image = encoded_image_string;
  83     if (!logo_dict->GetString("mime_type", &logo->metadata.mime_type))
  84       return scoped_ptr<EncodedLogo>();
  85   }
  86
  87   // Don't check return values since these fields are optional.
  88   logo_dict->GetString("target", &logo->metadata.on_click_url);
  89   logo_dict->GetString("fingerprint", &logo->metadata.fingerprint);
  90   logo_dict->GetString("alt", &logo->metadata.alt_text);
  91
  92   base::TimeDelta time_to_live;
  93   int time_to_live_ms;
  94   if (logo_dict->GetInteger("time_to_live", &time_to_live_ms)) {
  95     time_to_live = base::TimeDelta::FromMilliseconds(
  96         std::min(static_cast<int64>(time_to_live_ms), kMaxTimeToLiveMS));
  97     logo->metadata.can_show_after_expiration = false;
  98   } else {
  99     time_to_live = base::TimeDelta::FromMilliseconds(kMaxTimeToLiveMS);
 100     logo->metadata.can_show_after_expiration = true;
 101   }
 102   logo->metadata.expiration_time = response_time + time_to_live;
 103
 104   return logo.Pass();
 105 }
 106
 107 }  // namespace search_provider_logos