Page Comparison

public void run() {
	Map<DatapathId, List<OFStatsReply>> replies = getSwitchStatistics(switchService.getAllSwitchDpids(), OFStatsType.PORT);
	for (Entry<DatapathId, List<OFStatsReply>> e : replies.entrySet()) {
		for (OFStatsReply r : e.getValue()) {
			OFPortStatsReply psr = (OFPortStatsReply) r;
			for (OFPortStatsEntry pse : psr.getEntries()) {
				NodePortTuple npt = new NodePortTuple(e.getKey(), pse.getPortNo());
				SwitchPortBandwidth spb;
				if (portStats.containsKey(npt) || tentativePortStats.containsKey(npt)) {
					if (portStats.containsKey(npt)) { /* update */
						spb = portStats.get(npt);
					} else if (tentativePortStats.containsKey(npt)) { /* finish */
						spb = tentativePortStats.get(npt);
						tentativePortStats.remove(npt);
					} else {
						log.error("Inconsistent state between tentative and official port stats lists.");
						return;
					}
					/* Get counted bytes over the elapsed period. Check for counter overflow. */
					U64 rxBytesCounted;
					U64 txBytesCounted;
					if (spb.getPriorByteValueRx().compareTo(pse.getRxBytes()) > 0) { /* overflow */
						U64 upper = U64.NO_MASK.subtract(spb.getPriorByteValueRx());
						U64 lower = pse.getRxBytes();
						rxBytesCounted = upper.add(lower);
					} else {
						rxBytesCounted = pse.getRxBytes().subtract(spb.getPriorByteValueRx());
					}
					if (spb.getPriorByteValueTx().compareTo(pse.getTxBytes()) > 0) { /* overflow */
						U64 upper = U64.NO_MASK.subtract(spb.getPriorByteValueTx());
						U64 lower = pse.getTxBytes();
						txBytesCounted = upper.add(lower);
					} else {
						txBytesCounted = pse.getTxBytes().subtract(spb.getPriorByteValueTx());
					}
					long timeDifSec = (System.currentTimeMillis() - spb.getUpdateTime()) / MILLIS_PER_SEC;
					portStats.put(npt, SwitchPortBandwidth.of(npt.getNodeId(), npt.getPortId(), 
							U64.ofRaw((rxBytesCounted.getValue() * BITS_PER_BYTE) / timeDifSec), 
							U64.ofRaw((txBytesCounted.getValue() * BITS_PER_BYTE) / timeDifSec), 
							pse.getRxBytes(), pse.getTxBytes())
							);
				} else { /* initialize */
					tentativePortStats.put( npt, 
                                            SwitchPortBandwidth.of(npt.getNodeId(), npt.getPortId(), U64.ZERO,                                                                   npt.getPortId(), 
                                                                   U64.ZERO, 
                                                                   U64.ZERO,
                                                                   pse.getRxBytes(),  
                                                                  U64.ZERO, pse.getRxBytes(), pse.getTxBytes()));
				}
			}
		}
	}
}