components/component_updater/update_checker.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/component_updater/update_checker.h"
   6
   7 #include "base/compiler_specific.h"
   8 #include "base/logging.h"
   9 #include "base/strings/stringprintf.h"
  10 #include "base/threading/thread_checker.h"
  11 #include "components/component_updater/component_updater_configurator.h"
  12 #include "components/component_updater/component_updater_utils.h"
  13 #include "components/component_updater/crx_update_item.h"
  14 #include "net/url_request/url_fetcher.h"
  15 #include "net/url_request/url_fetcher_delegate.h"
  16 #include "url/gurl.h"
  17
  18 namespace component_updater {
  19
  20 // Builds an update check request for |components|. |additional_attributes| is
  21 // serialized as part of the <request> element of the request to customize it
  22 // with data that is not platform or component specific. For each |item|, a
  23 // corresponding <app> element is created and inserted as a child node of
  24 // the <request>.
  25 //
  26 // An app element looks like this:
  27 //    <app appid="hnimpnehoodheedghdeeijklkeaacbdc"
  28 //         version="0.1.2.3" installsource="ondemand">
  29 //      <updatecheck />
  30 //      <packages>
  31 //        <package fp="abcd" />
  32 //      </packages>
  33 //    </app>
  34 std::string BuildUpdateCheckRequest(const Configurator& config,
  35                                     const std::vector<CrxUpdateItem*>& items,
  36                                     const std::string& additional_attributes) {
  37   std::string app_elements;
  38   for (size_t i = 0; i != items.size(); ++i) {
  39     const CrxUpdateItem* item = items[i];
  40     std::string app("<app ");
  41     base::StringAppendF(&app,
  42                         "appid=\"%s\" version=\"%s\"",
  43                         item->id.c_str(),
  44                         item->component.version.GetString().c_str());
  45     if (item->on_demand)
  46       base::StringAppendF(&app, " installsource=\"ondemand\"");
  47     base::StringAppendF(&app, ">");
  48     base::StringAppendF(&app, "<updatecheck />");
  49     if (!item->component.fingerprint.empty()) {
  50       base::StringAppendF(&app,
  51                           "<packages>"
  52                           "<package fp=\"%s\"/>"
  53                           "</packages>",
  54                           item->component.fingerprint.c_str());
  55     }
  56     base::StringAppendF(&app, "</app>");
  57     app_elements.append(app);
  58     VLOG(1) << "Appending to update request: " << app;
  59   }
  60
  61   return BuildProtocolRequest(config.GetBrowserVersion().GetString(),
  62                               config.GetChannel(),
  63                               config.GetLang(),
  64                               config.GetOSLongName(),
  65                               app_elements,
  66                               additional_attributes);
  67 }
  68
  69 class UpdateCheckerImpl : public UpdateChecker, public net::URLFetcherDelegate {
  70  public:
  71   UpdateCheckerImpl(const Configurator& config,
  72                     const UpdateCheckCallback& update_check_callback);
  73   virtual ~UpdateCheckerImpl();
  74
  75   // Overrides for UpdateChecker.
  76   virtual bool CheckForUpdates(
  77       const std::vector<CrxUpdateItem*>& items_to_check,
  78       const std::string& additional_attributes) OVERRIDE;
  79
  80   // Overrides for UrlFetcher.
  81   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
  82
  83  private:
  84   const Configurator& config_;
  85   const UpdateCheckCallback update_check_callback_;
  86
  87   scoped_ptr<net::URLFetcher> url_fetcher_;
  88
  89   base::ThreadChecker thread_checker_;
  90
  91   DISALLOW_COPY_AND_ASSIGN(UpdateCheckerImpl);
  92 };
  93
  94 scoped_ptr<UpdateChecker> UpdateChecker::Create(
  95     const Configurator& config,
  96     const UpdateCheckCallback& update_check_callback) {
  97   scoped_ptr<UpdateCheckerImpl> update_checker(
  98       new UpdateCheckerImpl(config, update_check_callback));
  99   return update_checker.PassAs<UpdateChecker>();
 100 }
 101
 102 UpdateCheckerImpl::UpdateCheckerImpl(
 103     const Configurator& config,
 104     const UpdateCheckCallback& update_check_callback)
 105     : config_(config), update_check_callback_(update_check_callback) {
 106 }
 107
 108 UpdateCheckerImpl::~UpdateCheckerImpl() {
 109   DCHECK(thread_checker_.CalledOnValidThread());
 110 }
 111
 112 bool UpdateCheckerImpl::CheckForUpdates(
 113     const std::vector<CrxUpdateItem*>& items_to_check,
 114     const std::string& additional_attributes) {
 115   DCHECK(thread_checker_.CalledOnValidThread());
 116
 117   if (url_fetcher_)
 118     return false;  // Another fetch is in progress.
 119
 120   url_fetcher_.reset(SendProtocolRequest(
 121       config_.UpdateUrl(),
 122       BuildUpdateCheckRequest(config_, items_to_check, additional_attributes),
 123       this,
 124       config_.RequestContext()));
 125
 126   return true;
 127 }
 128
 129 void UpdateCheckerImpl::OnURLFetchComplete(const net::URLFetcher* source) {
 130   DCHECK(thread_checker_.CalledOnValidThread());
 131   DCHECK(url_fetcher_.get() == source);
 132
 133   int error = 0;
 134   std::string error_message;
 135   UpdateResponse update_response;
 136
 137   if (FetchSuccess(*source)) {
 138     std::string xml;
 139     source->GetResponseAsString(&xml);
 140     if (!update_response.Parse(xml)) {
 141       error = -1;
 142       error_message = update_response.errors();
 143       VLOG(1) << "Update request failed: " << error_message;
 144     }
 145   } else {
 146     error = GetFetchError(*source);
 147     error_message.assign("network error");
 148     VLOG(1) << "Update request failed: network error";
 149   }
 150
 151   url_fetcher_.reset();
 152   update_check_callback_.Run(error, error_message, update_response.results());
 153 }
 154
 155 }  // namespace component_updater