ClientStats.java

/*
 * This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that
 * it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If
 * not, see <http://www.gnu.org/licenses/>.
 */
package silentium.gameserver.network;

import silentium.gameserver.configs.MainConfig;

public class ClientStats
{
	public int processedPackets = 0;
	public int droppedPackets = 0;
	public int unknownPackets = 0;
	public int totalQueueSize = 0;
	public int maxQueueSize = 0;
	public int totalBursts = 0;
	public int maxBurstSize = 0;
	public int shortFloods = 0;
	public int longFloods = 0;
	public int totalQueueOverflows = 0;
	public int totalUnderflowExceptions = 0;

	private final int[] _packetsInSecond;
	private long _packetCountStartTick = 0;
	private int _head;
	private int _totalCount = 0;

	private int _floodsInMin = 0;
	private long _floodStartTick = 0;
	private int _unknownPacketsInMin = 0;
	private long _unknownPacketStartTick = 0;
	private int _overflowsInMin = 0;
	private long _overflowStartTick = 0;
	private int _underflowReadsInMin = 0;
	private long _underflowReadStartTick = 0;

	private volatile boolean _floodDetected = false;
	private volatile boolean _queueOverflowDetected = false;

	private final int BUFFER_SIZE;

	public ClientStats()
	{
		BUFFER_SIZE = MainConfig.CLIENT_PACKET_QUEUE_MEASURE_INTERVAL;
		_packetsInSecond = new int[BUFFER_SIZE];
		_head = BUFFER_SIZE - 1;
	}

	/**
	 * @return true if incoming packet need to be dropped.
	 */
	protected final boolean dropPacket()
	{
		final boolean result = _floodDetected || _queueOverflowDetected;
		if (result)
			droppedPackets++;
		return result;
	}

	/**
	 * @param queueSize
	 * @return true if flood detected first and ActionFailed packet need to be sent. Later during flood returns true (and send ActionFailed) once
	 *         per second.
	 */
	protected final boolean countPacket(int queueSize)
	{
		processedPackets++;
		totalQueueSize += queueSize;
		if (maxQueueSize < queueSize)
			maxQueueSize = queueSize;
		if (_queueOverflowDetected && queueSize < 2)
			_queueOverflowDetected = false;

		return countPacket();
	}

	/**
	 * Counts unknown packets.
	 * 
	 * @return true if threshold is reached.
	 */
	protected final boolean countUnknownPacket()
	{
		unknownPackets++;

		final long tick = System.currentTimeMillis();
		if (tick - _unknownPacketStartTick > 60000)
		{
			_unknownPacketStartTick = tick;
			_unknownPacketsInMin = 1;
			return false;
		}

		_unknownPacketsInMin++;
		return _unknownPacketsInMin > MainConfig.CLIENT_PACKET_QUEUE_MAX_UNKNOWN_PER_MIN;
	}

	/**
	 * Counts burst length.
	 * 
	 * @param count
	 *            - current number of processed packets in burst
	 * @return true if execution of the queue need to be aborted.
	 */
	protected final boolean countBurst(int count)
	{
		if (count > maxBurstSize)
			maxBurstSize = count;

		if (count < MainConfig.CLIENT_PACKET_QUEUE_MAX_BURST_SIZE)
			return false;

		totalBursts++;
		return true;
	}

	/**
	 * Counts queue overflows.
	 * 
	 * @return true if threshold is reached.
	 */
	protected final boolean countQueueOverflow()
	{
		_queueOverflowDetected = true;
		totalQueueOverflows++;

		final long tick = System.currentTimeMillis();
		if (tick - _overflowStartTick > 60000)
		{
			_overflowStartTick = tick;
			_overflowsInMin = 1;
			return false;
		}

		_overflowsInMin++;
		return _overflowsInMin > MainConfig.CLIENT_PACKET_QUEUE_MAX_OVERFLOWS_PER_MIN;
	}

	/**
	 * Counts underflow exceptions.
	 * 
	 * @return true if threshold is reached.
	 */
	protected final boolean countUnderflowException()
	{
		totalUnderflowExceptions++;

		final long tick = System.currentTimeMillis();
		if (tick - _underflowReadStartTick > 60000)
		{
			_underflowReadStartTick = tick;
			_underflowReadsInMin = 1;
			return false;
		}

		_underflowReadsInMin++;
		return _underflowReadsInMin > MainConfig.CLIENT_PACKET_QUEUE_MAX_UNDERFLOWS_PER_MIN;
	}

	/**
	 * @return true if maximum number of floods per minute is reached.
	 */
	protected final boolean countFloods()
	{
		return _floodsInMin > MainConfig.CLIENT_PACKET_QUEUE_MAX_FLOODS_PER_MIN;
	}

	private final boolean longFloodDetected()
	{
		return (_totalCount / BUFFER_SIZE) > MainConfig.CLIENT_PACKET_QUEUE_MAX_AVERAGE_PACKETS_PER_SECOND;
	}

	/**
	 * @return true if flood detected first and ActionFailed packet need to be sent. Later during flood returns true (and send ActionFailed) once
	 *         per second.
	 */
	private final synchronized boolean countPacket()
	{
		_totalCount++;
		final long tick = System.currentTimeMillis();
		if (tick - _packetCountStartTick > 1000)
		{
			_packetCountStartTick = tick;

			// clear flag if no more flooding during last seconds
			if (_floodDetected && !longFloodDetected() && _packetsInSecond[_head] < MainConfig.CLIENT_PACKET_QUEUE_MAX_PACKETS_PER_SECOND / 2)
				_floodDetected = false;

			// wrap head of the buffer around the tail
			if (_head <= 0)
				_head = BUFFER_SIZE;
			_head--;

			_totalCount -= _packetsInSecond[_head];
			_packetsInSecond[_head] = 1;
			return _floodDetected;
		}

		final int count = ++_packetsInSecond[_head];
		if (!_floodDetected)
		{
			if (count > MainConfig.CLIENT_PACKET_QUEUE_MAX_PACKETS_PER_SECOND)
				shortFloods++;
			else if (longFloodDetected())
				longFloods++;
			else
				return false;

			_floodDetected = true;
			if (tick - _floodStartTick > 60000)
			{
				_floodStartTick = tick;
				_floodsInMin = 1;
			}
			else
				_floodsInMin++;

			return true; // Return true only in the beginning of the flood
		}

		return false;
	}
}