public String downloadUrlTo()

in agent/src/main/java/jetbrains/buildServer/torrent/TorrentTransportFactory.java [178:268]
79 lines of code
11 McCabe index (conditional complexity)

    public String downloadUrlTo(@NotNull String url, @NotNull File target, @NotNull final FileProgress fileDownloadProgress) throws IOException {
      if (url.endsWith(TEAMCITY_IVY)) {
        // downloading teamcity-ivy.xml and parsing it:
        return parseArtifactsList(url, target);
      }
      final String decodedUrl = URLDecoder.decode(url, "UTF-8");
      ParsedArtifactPath parsedArtifactUrl = new ParsedArtifactPath(decodedUrl);

      long start = System.currentTimeMillis();

      TorrentMetadata torrent = downloadTorrent(parsedArtifactUrl);
      if (torrent == null) {
        return null;
      }

      long maxTimeForDownloadTorrentMs = 1000;
      final long downloadTime = System.currentTimeMillis() - start;
      if (downloadTime > maxTimeForDownloadTorrentMs) {
        LOG.info("torrent " + parsedArtifactUrl + " was downloaded in " + downloadTime + " ms");
      }

      File torrentFile = myTorrentFilesFactory.getTorrentFile();
      TorrentUtil.saveTorrentToFile(torrent, torrentFile);
      String hexInfoHash = torrent.getHexInfoHash();
      String name = torrent.getDirectoryName();
      List<String> fileNames = TorrentUtils.getTorrentFileNames(torrent);
      long size = 0;
      for (TorrentFile file : torrent.getFiles()) {
        size += file.size;
      }
      fileDownloadProgress.setExpectedLength(size);
      torrent = null;

      try {
        LOG.info(String.format("trying to download %s via bittorrent", url));
        final String message = "Downloading " + target.getName() + " via BitTorrent protocol.";
        myBuildLogger.logMessage(DefaultMessagesInfo.createProgressMessage(message));

        final int minSeedersForDownload = myLeechSettings.getMinSeedersForDownload();

        final int timeoutForConnectToPeersMs = 5000;

        final AtomicReference<Exception> exceptionHolder = new AtomicReference<Exception>();
        Loggers.AGENT.debug("start download file " + target.getName());

        Thread th = myClient.downloadAndShareOrFailAsync(
                torrentFile,
                fileNames,
                hexInfoHash,
                target,
                target.getParentFile(),
                fileDownloadProgress,
                myLeechSettings.getMaxPieceDownloadTime() * 1000,
                minSeedersForDownload,
                timeoutForConnectToPeersMs,
                exceptionHolder);
        myCurrentDownload.set(Thread.currentThread());
        th.join();
        myCurrentDownload.set(null);
        if (exceptionHolder.get() != null) {
          myTorrentsDownloadStatistic.fileDownloadFailed();
          Loggers.AGENT.warnAndDebugDetails("unable to download file " + name + " "
                  + exceptionHolder.get().getMessage(), exceptionHolder.get());
          throw exceptionHolder.get();
        }

        if (size != target.length()) {
          myTorrentsDownloadStatistic.fileDownloadFailed();
          log2Build(String.format("Failed to download file completely via BitTorrent protocol. Expected file size: %s, actual file size: %s", String.valueOf(size), String.valueOf(target.length())));
          return null;
        }
      } catch (InterruptedException e) {
        throw new IOException("Torrent download has been interrupted " + url, e);
      } catch (RuntimeException ex) {
        log2Build(String.format("Unable to download artifact %s: %s", url, ex.getMessage()));
        throw ex;
      } catch (Exception ex) {
        log2Build(String.format("Unable to download artifact %s: %s", url, ex.getMessage()));
        throw new IOException(ex);
      }
      // return standard digest
      String digest;
      try {
        digest = getDigest(url);
      } catch (IOException e) {
        Loggers.AGENT.warnAndDebugDetails("Unable to execute digest request by URL " + url, e);
        throw e;
      }
      myTorrentsDownloadStatistic.fileDownloaded();
      return digest;
    }