Method getRowKey

src/meta/Annotation.java:658–692

Calculates the row key based on the TSUID and the start time. If the TSUID is empty, the row key is a 0 filled byte array TSDB.metrics_width() wide plus the normalized start timestamp without any tag bytes. @param start_time The start time as a Unix epoch timestamp @param tsuid An optional T

(final long start_time, final byte[] tsuid)

   * @return The row key as a byte array
   */
  private static byte[] getRowKey(final long start_time, final byte[] tsuid) {
    if (start_time < 1) {
      throw new IllegalArgumentException("The start timestamp has not been set");
    }
    
    final long base_time;
    if ((start_time & Const.SECOND_MASK) != 0) {
      // drop the ms timestamp to seconds to calculate the base timestamp
      base_time = ((start_time / 1000) - 
          ((start_time / 1000) % Const.MAX_TIMESPAN));
    } else {
      base_time = (start_time - (start_time % Const.MAX_TIMESPAN));
    }
    
    // if the TSUID is empty, then we're a global annotation. The row key will 
    // just be an empty byte array of metric width plus the timestamp. We also 
    // don't salt the global row key (though it has space for salts)
    if (tsuid == null || tsuid.length < 1) {
      final byte[] row = new byte[Const.SALT_WIDTH() + 
                                  TSDB.metrics_width() + Const.TIMESTAMP_BYTES];
      Bytes.setInt(row, (int) base_time, Const.SALT_WIDTH() + TSDB.metrics_width());
      return row;
    }
    
    // otherwise we need to build the row key from the TSUID and start time
    final byte[] row = new byte[Const.SALT_WIDTH() + Const.TIMESTAMP_BYTES + 
                                tsuid.length];
    System.arraycopy(tsuid, 0, row, Const.SALT_WIDTH(), TSDB.metrics_width());
    Bytes.setInt(row, (int) base_time, Const.SALT_WIDTH() + TSDB.metrics_width());
    System.arraycopy(tsuid, TSDB.metrics_width(), row, 
        Const.SALT_WIDTH() + TSDB.metrics_width() + Const.TIMESTAMP_BYTES, 
        (tsuid.length - TSDB.metrics_width()));
    RowKey.prefixKeyWithSalt(row);
    return row;
  }
  
// Getters and Setters --------------