/*
* ProtocolLib - Bukkit server library that allows access to the Minecraft protocol.
* Copyright (C) 2012 Kristian S. Stangeland
*
* 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 2 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
* 02111-1307 USA
*/
package com.comphenix.protocol.async;
import java.io.IOException;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.Executor;
import java.util.concurrent.PriorityBlockingQueue;
import org.bukkit.entity.Player;
import com.comphenix.protocol.PacketType;
import com.comphenix.protocol.ProtocolLibrary;
import com.comphenix.protocol.error.Report;
import com.comphenix.protocol.error.ReportType;
import com.comphenix.protocol.events.PacketEvent;
import com.comphenix.protocol.injector.PlayerLoggedOutException;
import com.comphenix.protocol.reflect.FieldAccessException;
/**
* Represents packets ready to be transmitted to a client.
* @author Kristian
*/
abstract class PacketSendingQueue {
public static final ReportType REPORT_DROPPED_PACKET = new ReportType("Warning: Dropped packet index %s of type %s.");
public static final int INITIAL_CAPACITY = 10;
private PriorityBlockingQueue<PacketEventHolder> sendingQueue;
// Asynchronous packet sending
private Executor asynchronousSender;
// Whether or not packet transmission must occur on a specific thread
private final boolean notThreadSafe;
// Whether or not we've run the cleanup procedure
private boolean cleanedUp = false;
/**
* Create a packet sending queue.
* @param notThreadSafe - whether or not to synchronize with the main thread or a background thread.
*/
public PacketSendingQueue(boolean notThreadSafe, Executor asynchronousSender) {
this.sendingQueue = new PriorityBlockingQueue<PacketEventHolder>(INITIAL_CAPACITY);
this.notThreadSafe = notThreadSafe;
this.asynchronousSender = asynchronousSender;
}
/**
* Number of packet events in the queue.
* @return The number of packet events in the queue.
*/
public int size() {
return sendingQueue.size();
}
/**
* Enqueue a packet for sending.
* @param packet - packet to queue.
*/
public void enqueue(PacketEvent packet) {
sendingQueue.add(new PacketEventHolder(packet));
}
/**
* Invoked when one of the packets have finished processing.
* @param packetUpdated - the packet that has now been updated.
* @param onMainThread - whether or not this is occuring on the main thread.
*/
public synchronized void signalPacketUpdate(PacketEvent packetUpdated, boolean onMainThread) {
AsyncMarker marker = packetUpdated.getAsyncMarker();
// Should we reorder the event?
if (marker.getQueuedSendingIndex() != marker.getNewSendingIndex() && !marker.hasExpired()) {
PacketEvent copy = PacketEvent.fromSynchronous(packetUpdated, marker);
// "Cancel" the original event
packetUpdated.setReadOnly(false);
packetUpdated.setCancelled(true);
// Enqueue the copy with the new sending index
enqueue(copy);
}
// Mark this packet as finished
marker.setProcessed(true);
trySendPackets(onMainThread);
}
/***
* Invoked when a list of packet IDs are no longer associated with any listeners.
* @param packetsRemoved - packets that no longer have any listeners.
* @param onMainThread - whether or not this is occuring on the main thread.
*/
public synchronized void signalPacketUpdate(List<PacketType> packetsRemoved, boolean onMainThread) {
Set<PacketType> lookup = new HashSet<PacketType>(packetsRemoved);
// Note that this is O(n), so it might be expensive
for (PacketEventHolder holder : sendingQueue) {
PacketEvent event = holder.getEvent();
if (lookup.contains(event.getPacketType())) {
event.getAsyncMarker().setProcessed(true);
}
}
// This is likely to have changed the situation a bit
trySendPackets(onMainThread);
}
/**
* Attempt to send any remaining packets.
* @param onMainThread - whether or not this is occuring on the main thread.
*/
public void trySendPackets(boolean onMainThread) {
// Whether or not to continue sending packets
boolean sending = true;
// Transmit as many packets as we can
while (sending) {
PacketEventHolder holder = sendingQueue.poll();
if (holder != null) {
sending = processPacketHolder(onMainThread, holder);
if (!sending) {
// Add it back again
sendingQueue.add(holder);
}
} else {
// No more packets to send
sending = false;
}
}
}
/**
* Invoked when a packet might be ready for transmission.
* @param onMainThread - TRUE if we're on the main thread, FALSE otherwise.
* @param holder - packet container.
* @return TRUE to continue sending packets, FALSE otherwise.
*/
private boolean processPacketHolder(boolean onMainThread, final PacketEventHolder holder) {
PacketEvent current = holder.getEvent();
AsyncMarker marker = current.getAsyncMarker();
boolean hasExpired = marker.hasExpired();
// Guard in cause the queue is closed
if (cleanedUp) {
return true;
}
// End condition?
if (marker.isProcessed() || hasExpired) {
if (hasExpired) {
// Notify timeout listeners
onPacketTimeout(current);
// Recompute
marker = current.getAsyncMarker();
hasExpired = marker.hasExpired();
// Could happen due to the timeout listeners
if (!marker.isProcessed() && !hasExpired) {
return false;
}
}
// Is it okay to send the packet?
if (!current.isCancelled() && !hasExpired) {
// Make sure we're on the main thread
if (notThreadSafe) {
try {
boolean wantAsync = marker.isMinecraftAsync(current);
boolean wantSync = !wantAsync;
// Wait for the next main thread heartbeat if we haven't fulfilled our promise
if (!onMainThread && wantSync) {
return false;
}
// Let's give it what it wants
if (onMainThread && wantAsync) {
asynchronousSender.execute(new Runnable() {
@Override
public void run() {
// We know this isn't on the main thread
processPacketHolder(false, holder);
}
});
// Scheduler will do the rest
return true;
}
} catch (FieldAccessException e) {
e.printStackTrace();
// Just drop the packet
return true;
}
}
// Silently skip players that have logged out
if (isOnline(current.getPlayer())) {
sendPacket(current);
}
}
// Drop the packet
return true;
}
// Add it back and stop sending
return false;
}
/**
* Invoked when a packet has timed out.
* @param event - the timed out packet.
*/
protected abstract void onPacketTimeout(PacketEvent event);
private boolean isOnline(Player player) {
return player != null && player.isOnline();
}
/**
* Send every packet, regardless of the processing state.
*/
private void forceSend() {
while (true) {
PacketEventHolder holder = sendingQueue.poll();
if (holder != null) {
sendPacket(holder.getEvent());
} else {
break;
}
}
}
/**
* Whether or not the packet transmission must synchronize with the main thread.
* @return TRUE if it must, FALSE otherwise.
*/
public boolean isSynchronizeMain() {
return notThreadSafe;
}
/**
* Transmit a packet, if it hasn't already.
* @param event - the packet to transmit.
*/
private void sendPacket(PacketEvent event) {
AsyncMarker marker = event.getAsyncMarker();
try {
// Don't send a packet twice
if (marker != null && !marker.isTransmitted()) {
marker.sendPacket(event);
}
} catch (PlayerLoggedOutException e) {
ProtocolLibrary.getErrorReporter().reportDebug(this, Report.newBuilder(REPORT_DROPPED_PACKET).
messageParam(marker.getOriginalSendingIndex(), event.getPacketType()).
callerParam(event)
);
} catch (IOException e) {
// Just print the error
e.printStackTrace();
}
}
/**
* Automatically transmits every delayed packet.
*/
public void cleanupAll() {
if (!cleanedUp) {
// Note that the cleanup itself will always occur on the main thread
forceSend();
// And we're done
cleanedUp = true;
}
}
}