/** Method to assign the burst states. */
  private void analyzeBursts() {
    List<UserEvent> userEvents = analysis.getUserEvents();
    List<CpuActivity> cpuEvents = analysis.getCpuActivityList();
    int userEventsSize = userEvents.size();
    int cpuEventsSize = cpuEvents.size();
    int userEventPointer = 0;
    int cpuPointer = 0;
    // Analyze each burst
    Burst b = null;
    Burst lastBurst;
    for (Iterator<Burst> i = burstCollection.iterator(); i.hasNext(); ) {
      lastBurst = b;
      b = i.next();
      // Step 1: Remove background packets
      List<PacketInfo> pktIdx = new ArrayList<PacketInfo>(b.getPackets().size());
      int payloadLen = 0;
      Set<TcpInfo> tcpInfo = new HashSet<TcpInfo>();
      for (PacketInfo p : b.getPackets()) {
        if (p.getAppName() != null) {
          payloadLen += p.getPayloadLen();
          pktIdx.add(p);
          TcpInfo tcp = p.getTcpInfo();
          if (tcp != null) {
            tcpInfo.add(tcp);
          }
        }
      }
      if (pktIdx.size() == 0) {
        assert (payloadLen == 0);
        b.addBurstInfo(BurstInfo.BURST_BKG);
        continue;
      }
      PacketInfo pkt0 = pktIdx.get(0);
      TcpInfo info0 = pkt0.getTcpInfo();
      double time0 = pkt0.getTimeStamp();

      // Step 2: a long burst?
      if (b.getEndTime() - b.getBeginTime() > profile.getLargeBurstDuration()
          && payloadLen > profile.getLargeBurstSize()) {
        b.addBurstInfo(BurstInfo.BURST_LONG);
        ++longBurstCount;
        continue;
      }

      // Step 3: Contains no payload?
      if (payloadLen == 0) {
        if (tcpInfo.contains(TcpInfo.TCP_CLOSE)) {
          b.addBurstInfo(BurstInfo.BURST_FIN);
        }
        if (tcpInfo.contains(TcpInfo.TCP_ESTABLISH)) {
          b.addBurstInfo(BurstInfo.BURST_SYN);
        }
        if (tcpInfo.contains(TcpInfo.TCP_RESET)) {
          b.addBurstInfo(BurstInfo.BURST_RST);
        }
        if (tcpInfo.contains(TcpInfo.TCP_KEEP_ALIVE)
            || tcpInfo.contains(TcpInfo.TCP_KEEP_ALIVE_ACK)) {
          b.addBurstInfo(BurstInfo.BURST_KEEPALIVE);
        }
        if (tcpInfo.contains(TcpInfo.TCP_ZERO_WINDOW)) {
          b.addBurstInfo(BurstInfo.BURST_ZEROWIN);
        }
        if (tcpInfo.contains(TcpInfo.TCP_WINDOW_UPDATE)) {
          b.addBurstInfo(BurstInfo.BURST_WINUPDATE);
        }
        if (b.getBurstInfos().size() == 0
            && (info0 == TcpInfo.TCP_ACK_RECOVER || info0 == TcpInfo.TCP_ACK_DUP)) {
          b.addBurstInfo(BurstInfo.BURST_LOSS_RECOVER);
        }
        if (b.getBurstInfos().size() > 0) continue;
      }

      // Step 4: Server delay
      if (pkt0.getDir() == PacketInfo.Direction.DOWNLINK
          && (info0 == TcpInfo.TCP_DATA || info0 == TcpInfo.TCP_ACK)) {
        b.addBurstInfo(BurstInfo.BURST_SERVER_DELAY);
        continue;
      }

      // Step 5: Loss recover
      if (info0 == TcpInfo.TCP_ACK_DUP || info0 == TcpInfo.TCP_DATA_DUP) {
        b.addBurstInfo(BurstInfo.BURST_LOSS_DUP);
        continue;
      }

      if (info0 == TcpInfo.TCP_DATA_RECOVER || info0 == TcpInfo.TCP_ACK_RECOVER) {
        b.addBurstInfo(BurstInfo.BURST_LOSS_RECOVER);
        continue;
      }

      // Step 6: User triggered
      final double USER_EVENT_SMALL_TOLERATE = profile.getUserInputTh();
      if (payloadLen > 0) {
        UserEvent ue = null;
        while ((userEventPointer < userEventsSize)
            && ((ue = userEvents.get(userEventPointer)).getReleaseTime()
                < (time0 - USER_EVENT_TOLERATE))) ++userEventPointer;
        BurstInfo bi =
            ue != null
                ? ((ue.getEventType() == UserEventType.SCREEN_LANDSCAPE
                        || ue.getEventType() == UserEventType.SCREEN_PORTRAIT)
                    ? BurstInfo.BURST_SCREEN_ROTATION_INPUT
                    : BurstInfo.BURST_USER_INPUT)
                : null;
        int j = userEventPointer;
        double minGap = Double.MAX_VALUE;
        while (j < userEventsSize) {
          UserEvent uEvent = userEvents.get(j);
          if (withinTolerate(uEvent.getPressTime(), time0)) {
            double gap = time0 - uEvent.getPressTime();
            if (gap < minGap) {
              minGap = gap;
            }
          }
          if (withinTolerate(uEvent.getReleaseTime(), time0)) {
            double gap = time0 - uEvent.getReleaseTime();
            if (gap < minGap) {
              minGap = gap;
            }
          }
          if (uEvent.getPressTime() > time0) {
            break;
          }
          j++;
        }
        if (minGap < USER_EVENT_SMALL_TOLERATE) {
          b.addBurstInfo(bi);
          continue;
        } else if (minGap < USER_EVENT_TOLERATE
            && (lastBurst == null || lastBurst.getEndTime() < b.getBeginTime() - minGap)) {
          double cpuBegin = time0 - minGap;
          double cpuEnd = time0;
          // Check CPU usage
          while (cpuPointer < cpuEventsSize) {
            double t = cpuEvents.get(cpuPointer).getBeginTimeStamp();
            if (t < b.getBeginTime() - USER_EVENT_TOLERATE) {
              ++cpuPointer;
            } else {
              break;
            }
          }
          int k = cpuPointer;
          double s = 0.0f;
          int ns = 0;
          while (k < cpuEventsSize) {
            CpuActivity cpuAct = cpuEvents.get(k);
            double t = cpuAct.getBeginTimeStamp();
            if (t > cpuBegin && t < cpuEnd) {
              s += cpuAct.getUsage();
              ns++;
            }
            if (t >= cpuEnd) {
              break;
            }
            k++;
          }
          if (ns > 0 && (s / ns) > AVG_CPU_USAGE_THRESHOLD) {
            b.addBurstInfo(bi);
            b.addBurstInfo(BurstInfo.BURST_CPU_BUSY);
            continue;
          }
        }
      }

      // Step 7: Client delay
      if (b.getBurstInfos().size() == 0 && payloadLen == 0) {
        b.addBurstInfo(BurstInfo.BURST_UNKNOWN);
      } else {
        b.addBurstInfo(BurstInfo.BURST_CLIENT_DELAY);
      }
    }
  }