Method setupMultiColumnIncrementCoalescing

src/HBaseClient.java:1825–1863

Called the first time we get a buffered increment. Lazily creates the increment buffer and sets up a timer to regularly flush buffered increments.

()

   * flush buffered increments.
   */
  private synchronized void setupMultiColumnIncrementCoalescing() {
    // If multiple threads attempt to setup coalescing at the same time, the
    // first one to get here will make `increment_buffer' non-null, and thus
    // subsequent ones will return immediately.  This is important to avoid
    // creating more than one FlushBufferedIncrementsTimer below.
    if (multi_column_increment_buffer != null) {
      return;
    }
    makeMultiColumnIncrementBuffer();  // Volatile-write.

    // Start periodic buffered increment flushes.
    final class FlushBufferedMultiColumnIncrementsTimer implements TimerTask {
      public void run(final Timeout timeout) {
        try {
          flushBufferedMultiColumnIncrements(multi_column_increment_buffer);
        } finally {
          final short interval = flush_interval; // Volatile-read.
          // Even if we paused or disabled the client side buffer by calling
          // setFlushInterval(0), we will continue to schedule this timer
          // forever instead of pausing it.  Pausing it is troublesome because
          // we don't keep a reference to this timer, so we can't cancel it or
          // tell if it's running or not.  So let's just KISS and assume that
          // if we need the timer once, we'll need it forever.  If it's truly
          // not needed anymore, we'll just cause a bit of extra work to the
          // timer thread every 100ms, no big deal.
          newTimeout(this, interval > 0 ? interval : 100);
        }
      }
    }
    final short interval = flush_interval; // Volatile-read.
    // Handle the extremely unlikely yet possible racy case where:
    //   flush_interval was > 0
    //   A buffered increment came in
    //   It was the first one ever so we landed here
    //   Meanwhile setFlushInterval(0) to disable buffering
    // In which case we just flush whatever we have in 1ms.
    timer.newTimeout(new FlushBufferedMultiColumnIncrementsTimer(),
                     interval > 0 ? interval : 1, MILLISECONDS);
  }

  /**
   * Flushes all buffered increments.