Try to fix network when sending lots of packets

mirai-core/src/commonMain/kotlin/network/impl/netty/NettyNetworkHandler.kt

@@ -18,8 +18,6 @@ import io.netty.channel.socket.nio.NioSocketChannel
 import io.netty.handler.codec.LengthFieldBasedFrameDecoder
 import io.netty.handler.codec.MessageToByteEncoder
 import kotlinx.coroutines.*
-import kotlinx.coroutines.channels.Channel
-import kotlinx.coroutines.channels.trySendBlocking
 import net.mamoe.mirai.internal.network.components.*
 import net.mamoe.mirai.internal.network.handler.NetworkHandler.State
 import net.mamoe.mirai.internal.network.handler.NetworkHandlerContext
@@ -165,31 +163,17 @@ internal open class NettyNetworkHandler(
 
     protected inner class PacketDecodePipeline(parentContext: CoroutineContext) :
         CoroutineScope by parentContext.childScope() {
-        private val channel: Channel<RawIncomingPacket> = Channel(Channel.BUFFERED)
         private val packetCodec: PacketCodec by lazy { context[PacketCodec] }
 
-        init {
-            coroutineContext.job.invokeOnCompletion {
-                channel.close() // normally close
+        fun send(raw: RawIncomingPacket) {
+            launch {
+                packetLogger.debug { "Packet Handling Processor: receive packet ${raw.commandName}" }
+                val result = packetCodec.processBody(context.bot, raw)
+                if (result == null) {
+                    collectUnknownPacket(raw)
+                } else collectReceived(result)
             }
         }
-
-        init {
-            repeat(4) { processorId ->
-                launch(CoroutineName("PacketDecodePipeline processor #$processorId")) {
-                    while (isActive) {
-                        val raw = channel.receiveCatching().getOrNull() ?: return@launch
-                        packetLogger.debug { "Packet Handling Processor #$processorId: receive packet ${raw.commandName}" }
-                        val result = packetCodec.processBody(context.bot, raw)
-                        if (result == null) {
-                            collectUnknownPacket(raw)
-                        } else collectReceived(result)
-                    }
-                }
-            }
-        }
-
-        fun send(raw: RawIncomingPacket) = channel.trySendBlocking(raw)
     }