Use processors as a map, don't iterate them every line.

CHANGELOG

    * All events in a batch are buffered until the batch is finished
    * The events are then published together in a single `BatchReceived` event
  * Added support for CHGHOST messages
+ * (Internal) Improve performance when the MessageHandler is finding a processor for a message
  * (Internal) Introduced event mutators
    * Event mutators are now responsible for handling changing events in response to state
      e.g. ChannelFanOutMutator creates Channel* events for global quits/nick changes/etc

src/main/kotlin/com/dmdirc/ktirc/io/MessageHandler.kt

 }
 
 internal class MessageHandler(
-        private val processors: List<MessageProcessor>,
+        processors: List<MessageProcessor>,
         private val mutators: List<EventMutator>,
         private val handlers: List<EventHandler>) : MessageEmitter {
 
     private val log by logger()
 
     private val emitters = mutableListOf<(IrcEvent) -> Unit>()
+    private val processorMap = processors.flatMap { it.commands.map { c -> c to it } }.toMap()
 
     suspend fun processMessages(ircClient: IrcClient, messages: ReceiveChannel<IrcMessage>) {
         for (message in messages) {
     }
 
     private fun IrcMessage.toEvents() = this.getProcessor()?.process(this) ?: emptyList()
-    private fun IrcMessage.getProcessor() = processors.firstOrNull { it.commands.contains(command) } ?: run {
+    private fun IrcMessage.getProcessor() = processorMap[command] ?: run {
         log.warning { "No processor found for $command" }
         null
     }

src/main/kotlin/com/dmdirc/ktirc/model/CapabilitiesState.kt

     object AwayStateMessages : Capability("away-notify") // TODO: Add processor
 
     /** Receive a notification when a user's host changes, instead of a quit/join. */
-    object HostChangeMessages : Capability("chghost") // TODO: Add processor
+    object HostChangeMessages : Capability("chghost")
 
 }