components/update_client/crx_downloader.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/update_client/crx_downloader.h"
   6
   7 #include "base/logging.h"
   8 #include "base/sequenced_task_runner.h"
   9 #include "base/single_thread_task_runner.h"
  10 #include "components/update_client/url_fetcher_downloader.h"
  11
  12 #if defined(OS_WIN)
  13 #include "components/update_client/background_downloader_win.h"
  14 #endif
  15
  16 namespace update_client {
  17
  18 CrxDownloader::Result::Result()
  19     : error(0), downloaded_bytes(-1), total_bytes(-1) {
  20 }
  21
  22 CrxDownloader::DownloadMetrics::DownloadMetrics()
  23     : downloader(kNone),
  24       error(0),
  25       downloaded_bytes(-1),
  26       total_bytes(-1),
  27       download_time_ms(0) {
  28 }
  29
  30 // On Windows, the first downloader in the chain is a background downloader,
  31 // which uses the BITS service.
  32 CrxDownloader* CrxDownloader::Create(
  33     bool is_background_download,
  34     net::URLRequestContextGetter* context_getter,
  35     scoped_refptr<base::SequencedTaskRunner> url_fetcher_task_runner,
  36     scoped_refptr<base::SingleThreadTaskRunner> background_task_runner) {
  37   scoped_ptr<CrxDownloader> url_fetcher_downloader(
  38       new UrlFetcherDownloader(scoped_ptr<CrxDownloader>().Pass(),
  39                                context_getter, url_fetcher_task_runner));
  40 #if defined(OS_WIN)
  41   if (is_background_download) {
  42     return new BackgroundDownloader(url_fetcher_downloader.Pass(),
  43                                     context_getter, background_task_runner);
  44   }
  45 #endif
  46
  47   return url_fetcher_downloader.release();
  48 }
  49
  50 CrxDownloader::CrxDownloader(scoped_ptr<CrxDownloader> successor)
  51     : successor_(successor.Pass()) {
  52 }
  53
  54 CrxDownloader::~CrxDownloader() {
  55 }
  56
  57 void CrxDownloader::set_progress_callback(
  58     const ProgressCallback& progress_callback) {
  59   progress_callback_ = progress_callback;
  60 }
  61
  62 GURL CrxDownloader::url() const {
  63   return current_url_ != urls_.end() ? *current_url_ : GURL();
  64 }
  65
  66 const std::vector<CrxDownloader::DownloadMetrics>
  67 CrxDownloader::download_metrics() const {
  68   if (!successor_)
  69     return download_metrics_;
  70
  71   std::vector<DownloadMetrics> retval(successor_->download_metrics());
  72   retval.insert(retval.begin(), download_metrics_.begin(),
  73                 download_metrics_.end());
  74   return retval;
  75 }
  76
  77 void CrxDownloader::StartDownloadFromUrl(
  78     const GURL& url,
  79     const DownloadCallback& download_callback) {
  80   std::vector<GURL> urls;
  81   urls.push_back(url);
  82   StartDownload(urls, download_callback);
  83 }
  84
  85 void CrxDownloader::StartDownload(const std::vector<GURL>& urls,
  86                                   const DownloadCallback& download_callback) {
  87   DCHECK(thread_checker_.CalledOnValidThread());
  88
  89   if (urls.empty()) {
  90     // Make a result and complete the download with a generic error for now.
  91     Result result;
  92     result.error = -1;
  93     download_callback.Run(result);
  94     return;
  95   }
  96
  97   // If the urls are mutated while this downloader is active, then the
  98   // behavior is undefined in the sense that the outcome of the download could
  99   // be inconsistent for the list of urls. At any rate, the |current_url_| is
 100   // reset at this point, and the iterator will be valid in all conditions.
 101   urls_ = urls;
 102   current_url_ = urls_.begin();
 103   download_callback_ = download_callback;
 104
 105   DoStartDownload(*current_url_);
 106 }
 107
 108 void CrxDownloader::OnDownloadComplete(
 109     bool is_handled,
 110     const Result& result,
 111     const DownloadMetrics& download_metrics) {
 112   DCHECK(thread_checker_.CalledOnValidThread());
 113
 114   download_metrics_.push_back(download_metrics);
 115
 116   if (result.error) {
 117     // If an error has occured, in general try the next url if there is any,
 118     // then move on to the successor in the chain if there is any successor.
 119     // If this downloader has received a 5xx error for the current url,
 120     // as indicated by the |is_handled| flag, remove that url from the list of
 121     // urls so the url is never retried. In both cases, move on to the
 122     // next url.
 123     if (!is_handled) {
 124       ++current_url_;
 125     } else {
 126       current_url_ = urls_.erase(current_url_);
 127     }
 128
 129     // Try downloading from another url from the list.
 130     if (current_url_ != urls_.end()) {
 131       DoStartDownload(*current_url_);
 132       return;
 133     }
 134
 135     // If there is another downloader that can accept this request, then hand
 136     // the request over to it so that the successor can try the pruned list
 137     // of urls. Otherwise, the request ends here since the current downloader
 138     // has tried all urls and it can't fall back on any other downloader.
 139     if (successor_ && !urls_.empty()) {
 140       successor_->StartDownload(urls_, download_callback_);
 141       return;
 142     }
 143   }
 144
 145   download_callback_.Run(result);
 146 }
 147
 148 void CrxDownloader::OnDownloadProgress(const Result& result) {
 149   DCHECK(thread_checker_.CalledOnValidThread());
 150
 151   if (progress_callback_.is_null())
 152     return;
 153
 154   progress_callback_.Run(result);
 155 }
 156
 157 }  // namespace update_client