Made network message type bound to a specific channel, this should give compile-time errors for sending messages on the wrong channel. Messages should now inherit from YourChannelObject.Message

build.gradle

@@ -21,7 +21,7 @@ buildscript {
 apply plugin: 'scala'
 apply plugin: 'forge'
 
-version = "1.4.4"
+version = "1.4.5"
 
 if (project.hasProperty('buildnum')) {
     project.version = project.version + '.' + project.buildnum

src/net/bdew/lib/multiblock/network/MsgOutputCfg.scala

@@ -9,8 +9,8 @@
 
 package net.bdew.lib.multiblock.network
 
-import net.bdew.lib.network.Message
+import net.bdew.lib.network.BaseMessage
 
-abstract class MsgOutputCfg extends Message {
+abstract class MsgOutputCfg extends BaseMessage[NetHandler.type] {
   val output: Int
 }

src/net/bdew/lib/network/BaseMessage.scala

@@ -9,4 +9,4 @@
 
 package net.bdew.lib.network
 
-abstract class Message extends Serializable
+abstract class BaseMessage[CH <: NetChannel] extends Serializable

src/net/bdew/lib/network/NetChannel.scala

@@ -13,18 +13,49 @@ import java.util
 
 import cpw.mods.fml.common.network.{FMLEmbeddedChannel, FMLOutboundHandler, NetworkRegistry}
 import cpw.mods.fml.relauncher.Side
-import io.netty.channel.{ChannelFutureListener, ChannelHandler}
+import io.netty.channel.{ChannelFutureListener, ChannelHandler, ChannelHandlerContext, SimpleChannelInboundHandler}
 import net.bdew.lib.{BdLib, Misc}
 import net.minecraft.entity.player.EntityPlayerMP
+import net.minecraft.network.NetHandlerPlayServer
 
 class NetChannel(val name: String) {
   var channels: util.EnumMap[Side, FMLEmbeddedChannel] = null
 
+  type Message = BaseMessage[this.type]
+
+  object ServerHandler extends SimpleChannelInboundHandler[Message] {
+    def channelRead0(ctx: ChannelHandlerContext, msg: Message) {
+      try {
+        val player = ctx.channel().attr(NetworkRegistry.NET_HANDLER).get.asInstanceOf[NetHandlerPlayServer].playerEntity
+        if (serverChain.isDefinedAt(msg, player))
+          serverChain(msg, player)
+        else
+          BdLib.logWarn("Unable to handle message from user %s: %s", player.getDisplayName, msg)
+      } catch {
+        case e: Throwable => BdLib.logErrorException("Error handling packet", e)
+      }
+    }
+  }
+
+  object ClientHandler extends SimpleChannelInboundHandler[Message] {
+    def channelRead0(ctx: ChannelHandlerContext, msg: Message) {
+      try {
+        if (clientChain.isDefinedAt(msg))
+          clientChain(msg)
+        else
+          BdLib.logWarn("Unable to handle message from server: %s", msg)
+      } catch {
+        case e: Throwable => BdLib.logErrorException("Error handling packet", e)
+      }
+    }
+  }
+
   def init() {
+    if (channels != null) sys.error("Attempted to initalize a channel twice (%s)".format(name))
     channels = NetworkRegistry.INSTANCE.newChannel(name, new SerializedMessageCodec)
     BdLib.logInfo("Initialized network channel '%s' for mod '%s'", name, Misc.getActiveModId)
-    addHandler(Side.SERVER, new NetChannelServerHandler(this))
-    addHandler(Side.CLIENT, new NetChannelClientHandler(this))
+    addHandler(Side.SERVER, ServerHandler)
+    addHandler(Side.CLIENT, ClientHandler)
   }
 
   var clientChain = PartialFunction.empty[Message, Unit]
@@ -38,7 +69,7 @@ class NetChannel(val name: String) {
 
   private def addHandler(side: Side, handler: ChannelHandler) {
     val ch = channels.get(side)
-    val name = ch.findChannelHandlerNameForType(classOf[SerializedMessageCodec])
+    val name = ch.findChannelHandlerNameForType(classOf[SerializedMessageCodec[this.type]])
     ch.pipeline().addAfter(name, side + "Handler", handler)
   }
 

src/net/bdew/lib/network/NetChannelClientHandler.scala

@@ -1,26 +0,0 @@
-/*
- * Copyright (c) bdew, 2013 - 2014
- * https://github.com/bdew/bdlib
- *
- * This mod is distributed under the terms of the Minecraft Mod Public
- * License 1.0, or MMPL. Please check the contents of the license located in
- * https://raw.github.com/bdew/bdlib/master/MMPL-1.0.txt
- */
-
-package net.bdew.lib.network
-
-import io.netty.channel.{ChannelHandlerContext, SimpleChannelInboundHandler}
-import net.bdew.lib.BdLib
-
-class NetChannelClientHandler(ch: NetChannel) extends SimpleChannelInboundHandler[Message] {
-  def channelRead0(ctx: ChannelHandlerContext, msg: Message) {
-    try {
-      if (ch.clientChain.isDefinedAt(msg))
-        ch.clientChain(msg)
-      else
-        BdLib.logWarn("Unable to handle message from server: %s", msg)
-    } catch {
-      case e: Throwable => BdLib.logErrorException("Error handling packet", e)
-    }
-  }
-}

src/net/bdew/lib/network/NetChannelServerHandler.scala

@@ -1,29 +0,0 @@
-/*
- * Copyright (c) bdew, 2013 - 2014
- * https://github.com/bdew/bdlib
- *
- * This mod is distributed under the terms of the Minecraft Mod Public
- * License 1.0, or MMPL. Please check the contents of the license located in
- * https://raw.github.com/bdew/bdlib/master/MMPL-1.0.txt
- */
-
-package net.bdew.lib.network
-
-import cpw.mods.fml.common.network.NetworkRegistry
-import io.netty.channel.{ChannelHandlerContext, SimpleChannelInboundHandler}
-import net.bdew.lib.BdLib
-import net.minecraft.network.NetHandlerPlayServer
-
-class NetChannelServerHandler(ch: NetChannel) extends SimpleChannelInboundHandler[Message] {
-  def channelRead0(ctx: ChannelHandlerContext, msg: Message) {
-    try {
-      val player = ctx.channel().attr(NetworkRegistry.NET_HANDLER).get.asInstanceOf[NetHandlerPlayServer].playerEntity
-      if (ch.serverChain.isDefinedAt(msg, player))
-        ch.serverChain(msg, player)
-      else
-        BdLib.logWarn("Unable to handle message from user %s: %s", player.getDisplayName, msg)
-    } catch {
-      case e: Throwable => BdLib.logErrorException("Error handling packet", e)
-    }
-  }
-}

src/net/bdew/lib/network/SerializedMessageCodec.scala

@@ -21,8 +21,8 @@ import io.netty.handler.codec.MessageToMessageCodec
 import net.bdew.lib.BdLib
 
 @Sharable
-class SerializedMessageCodec extends MessageToMessageCodec[FMLProxyPacket, Message] {
-  def encode(ctx: ChannelHandlerContext, msg: Message, out: util.List[AnyRef]) {
+class SerializedMessageCodec[T <: NetChannel] extends MessageToMessageCodec[FMLProxyPacket, BaseMessage[T]] {
+  def encode(ctx: ChannelHandlerContext, msg: BaseMessage[T], out: util.List[AnyRef]) {
     val buff = Unpooled.buffer()
     val writer = new ObjectOutputStream(new ByteBufOutputStream(buff))
     writer.writeObject(msg)