public void initTableDownloadWorkItems()

in odps-console-dship/src/main/java/com/aliyun/odps/ship/download/DshipDownload.java [104:160]
50 lines of code
10 McCabe index (conditional complexity)

  public void initTableDownloadWorkItems(Odps odps)
      throws IOException, ODPSConsoleException, OdpsException {

    PartitionHelper helper = new PartitionHelper(odps, projectName, schemaName, tableName);

    if (!helper.isPartitioned()) {
      if (partitonSpecLiteral != null) {
        throw new OdpsException(
            Constants.ERROR_INDICATOR + "can not specify partition for an unpartitioned table");
      }
      splitDataByThreads(new TunnelDownloadSession(tableName, null), null);
    } else {
      List<PartitionSpec> parSpecs = helper.inferPartitionSpecs(partitonSpecLiteral);
      if (parSpecs.size() == 0) {
        throw new OdpsException(Constants.ERROR_INDICATOR + "can not infer any partitions from: "
                                + partitonSpecLiteral);
      } else if (parSpecs.size() == 1) {
        // 对于指定分区数为 1 的表，退化为下载整个表的情况，分片数量等于使用线程的数量
        PartitionSpec ps = parSpecs.get(0);
        splitDataByThreads(new TunnelDownloadSession(tableName, ps), ps);
      } else {
        // 对于指定分区数大于 2 的表，分片数量等于下载分区的数量
        slices = parSpecs.size();
        long sliceId = 0;
        long start = 0;
        for (PartitionSpec ps : parSpecs) {
          if (limit != null && start == limit) {
            break;
          }

          TunnelDownloadSession tds = new TunnelDownloadSession(tableName, ps);
          SessionHistory sh = tds.getSessionHistory();
          String
              msg =
              ps.toString() + "\tnew session: " + tds.getDownloadId() + "\ttotal lines: " + Util
                  .toReadableNumber(tds.getTotalLines());
          System.err.println(sim.format(new Date()) + "  -  " + msg);
          sh.log(msg);

          long
              step =
              (limit == null) ? tds.getTotalLines() : Math.min(tds.getTotalLines(), limit - start);

          String sliceFileName = filename + PartitionHelper.buildSuffix(ps);
          if (StringUtils.isNotEmpty(ext)) {
            sliceFileName = sliceFileName + "." + ext;
          }
          path = parentDir + sliceFileName;
          FileDownloader sd = new FileDownloader(path, sliceId, 0L, step, tds, sh, isCsv, ps);
          workItems.add(sd);
          sliceId++;
          start += step;
        }
        totalLines = start;
      }
    }
  }