synchronized IHistogramData getHourlyReads() {
   DcacheReadsHourly entry = new DcacheReadsHourly();
   entry.setCount(readCount);
   entry.setDate(timestamp);
   entry.setTransferred(bytesRead);
   return entry;
 }
 private void update(DcacheReadsHourly data) {
   readCount += data.getCount();
   bytesRead += data.getTransferred();
 }