Feature: PacketDelay

Author: emyfops

common/src/main/java/com/lambda/mixin/ClientConnectionMixin.java

@@ -35,7 +35,7 @@ private void sendingPacketPost(Packet<?> packet, final CallbackInfo callbackInfo
         EventFlow.post(new PacketEvent.Send.Post(packet));
     }
 
-    @Inject(method = "channelRead0(Lio/netty/channel/ChannelHandlerContext;Lnet/minecraft/network/packet/Packet;)V", at = @At("HEAD"), cancellable = true, require = 1)
+    @Inject(method = "channelRead0(Lio/netty/channel/ChannelHandlerContext;Lnet/minecraft/network/packet/Packet;)V", at = @At(value = "INVOKE", target = "Lnet/minecraft/network/ClientConnection;handlePacket(Lnet/minecraft/network/packet/Packet;Lnet/minecraft/network/listener/PacketListener;)V", shift = At.Shift.BEFORE), cancellable = true, require = 1)
     private void receivingPacket(
             ChannelHandlerContext channelHandlerContext,
             Packet<?> packet,

common/src/main/kotlin/com/lambda/module/modules/network/PacketDelay.kt

@@ -0,0 +1,66 @@
+package com.lambda.module.modules.network
+
+import com.lambda.event.events.PacketEvent
+import com.lambda.event.listener.SafeListener.Companion.listener
+import com.lambda.module.Module
+import com.lambda.module.tag.ModuleTag
+import com.lambda.threading.runConcurrent
+import com.lambda.threading.runGameScheduled
+import kotlinx.coroutines.delay
+import net.minecraft.network.ClientConnection
+import net.minecraft.network.packet.Packet
+import net.minecraft.network.packet.c2s.common.KeepAliveC2SPacket
+
+object PacketDelay : Module(
+    name = "PacketDelay",
+    description = "Delays packets client-side & server-side.",
+    defaultTags = setOf(ModuleTag.NETWORK),
+) {
+    private val networkScope by setting("Network Scope", Direction.BOTH)
+    private val packetScope by setting("Packet Scope", PacketType.ANY)
+    private val inboundDelay by setting("Inbound Delay", 250L, 0L..5000L, 10L, unit = "ms") { networkScope != Direction.OUTBOUND }
+    private val outboundDelay by setting("Outbound Delay", 250L, 0L..5000L, 10L, unit = "ms") { networkScope != Direction.INBOUND }
+
+    enum class Direction {
+        BOTH,
+        INBOUND,
+        OUTBOUND
+    }
+
+    enum class PacketType(val filter: (Packet<*>) -> Boolean) {
+        ANY({ true }),
+        KEEP_ALIVE({ it is KeepAliveC2SPacket })
+    }
+
+    init {
+        listener<PacketEvent.Receive.Pre>(Int.MIN_VALUE) { event ->
+            if (!connection.connection.isOpen) return@listener
+            if (!packetScope.filter(event.packet)) return@listener
+            event.cancel()
+
+            runConcurrent {
+                delay(inboundDelay)
+                runGameScheduled {
+                    if (connection.connection.packetListener?.accepts(event.packet) == false) return@runGameScheduled
+
+                    ClientConnection.handlePacket(event.packet, connection.connection.packetListener)
+                    connection.connection.packetsReceivedCounter++
+                }
+            }
+        }
+
+        listener<PacketEvent.Send.Pre>(Int.MIN_VALUE) { event ->
+            if (!connection.connection.isOpen) return@listener
+            if (!packetScope.filter(event.packet)) return@listener
+            event.cancel()
+
+            runConcurrent {
+                delay(outboundDelay)
+                runGameScheduled {
+                    connection.connection.send(event.packet, null)
+                    connection.connection.packetsSentCounter++
+                }
+            }
+        }
+    }
+}

common/src/main/resources/lambda.accesswidener

@@ -44,9 +44,12 @@ accessible field net/minecraft/network/packet/c2s/play/PlayerInteractEntityC2SPa
 accessible field net/minecraft/network/packet/c2s/play/PlayerInteractEntityC2SPacket type Lnet/minecraft/network/packet/c2s/play/PlayerInteractEntityC2SPacket$InteractTypeHandler;
 accessible class net/minecraft/network/packet/c2s/play/PlayerInteractEntityC2SPacket$InteractTypeHandler
 accessible class net/minecraft/network/packet/c2s/play/PlayerInteractEntityC2SPacket$InteractAtHandler
+accessible method net/minecraft/network/ClientConnection handlePacket (Lnet/minecraft/network/packet/Packet;Lnet/minecraft/network/listener/PacketListener;)V
+accessible field net/minecraft/network/ClientConnection packetsReceivedCounter I
+accessible field net/minecraft/network/ClientConnection packetsSentCounter I
 
 # Other
 accessible field net/minecraft/world/explosion/Explosion behavior Lnet/minecraft/world/explosion/ExplosionBehavior;
 accessible field net/minecraft/structure/StructureTemplate blockInfoLists Ljava/util/List;
 accessible method net/minecraft/item/BlockItem getPlacementState (Lnet/minecraft/item/ItemPlacementContext;)Lnet/minecraft/block/BlockState;
-accessible field net/minecraft/client/network/ClientPlayerInteractionManager blockBreakingCooldown I
+accessible field net/minecraft/client/network/ClientPlayerInteractionManager blockBreakingCooldown I