public Reader()

in tajo-storage/src/main/java/org/apache/tajo/storage/v2/RCFile.java [1123:1216]
83 lines of code
17 McCabe index (conditional complexity)

    public Reader(Path file, ScheduledInputStream sin, int bufferSize, Configuration conf,
        long start, long length) throws IOException {
      tolerateCorruptions = conf.getBoolean(
        TOLERATE_CORRUPTIONS_CONF_STR, false);
      conf.setInt("io.file.buffer.size", bufferSize);
//      in = openFile(fs, file, bufferSize, length);
      this.file = file;
      this.sin = sin;
      this.conf = conf;
      end = start + length;
      boolean succeed = false;
      try {
        if (start > 0) {
          seek(0);
          init();
          seek(start);
        } else {
          seek(0);
          init();
        }
        succeed = true;
      } finally {
        if (!succeed) {
          if (sin != null) {
            try {
              sin.close();
            } catch(IOException e) {
              if (LOG != null && LOG.isDebugEnabled()) {
                LOG.debug("Exception in closing " + sin, e);
              }
            }
          }
        }
      }

      columnNumber = Integer.parseInt(metadata.get(
          new Text(COLUMN_NUMBER_METADATA_STR)).toString());

      java.util.ArrayList<Integer> notSkipIDs = ColumnProjectionUtils
          .getReadColumnIDs(conf);
      boolean[] skippedColIDs = new boolean[columnNumber];
      if (notSkipIDs.size() > 0) {
        for (int i = 0; i < skippedColIDs.length; i++) {
          skippedColIDs[i] = true;
        }
        for (int read : notSkipIDs) {
          if (read < columnNumber) {
            skippedColIDs[read] = false;
          }
        }
      } else {
        // TODO: if no column name is specified e.g, in select count(1) from tt;
        // skip all columns, this should be distinguished from the case:
        // select * from tt;
        for (int i = 0; i < skippedColIDs.length; i++) {
          skippedColIDs[i] = false;
        }
      }

      loadColumnNum = columnNumber;
      if (skippedColIDs.length > 0) {
        for (boolean skippedColID : skippedColIDs) {
          if (skippedColID) {
            loadColumnNum -= 1;
          }
        }
      }


      revPrjColIDs = new int[columnNumber];
      // get list of selected column IDs
      selectedColumns = new SelectedColumn[loadColumnNum];
      colValLenBufferReadIn = new NonSyncDataInputBuffer[loadColumnNum];
      for (int i = 0, j = 0; i < columnNumber; ++i) {
        if (!skippedColIDs[i]) {
          SelectedColumn col = new SelectedColumn();
          col.colIndex = i;
          col.runLength = 0;
          col.prvLength = -1;
          col.rowReadIndex = 0;
          selectedColumns[j] = col;
          colValLenBufferReadIn[j] = new NonSyncDataInputBuffer();
          revPrjColIDs[i] = j;
          j++;
        } else {
          revPrjColIDs[i] = -1;
        }
      }

      currentKey = createKeyBuffer();
      boolean lazyDecompress = !tolerateCorruptions;
      currentValue = new ValueBuffer(
        null, columnNumber, skippedColIDs, codec, lazyDecompress);
    }