feat(rumqttc): declare rx batch size in event loop

This number shall be reused for the tx side as well.

rumqttc/src/v5/eventloop.rs

@@ -31,6 +31,9 @@ use {
 #[cfg(feature = "proxy")]
 use crate::proxy::ProxyError;
 
+/// Number of packets or requests processed before flusing the network
+const BATCH_SIZE: usize = 10;
+
 /// Critical errors during eventloop polling
 #[derive(Debug, thiserror::Error)]
 pub enum ConnectionError {
@@ -212,7 +215,7 @@ impl EventLoop {
                 Err(_) => Err(ConnectionError::RequestsDone),
             },
             // Pull a bunch of packets from network, reply in bunch and yield the first item
-            o = network.readb(&mut self.state) => {
+            o = network.readb(&mut self.state, BATCH_SIZE) => {
                 o?;
                 // flush all the acks and return first incoming packet
                 network.flush().await?;

rumqttc/src/v5/framed.rs

@@ -14,8 +14,6 @@ use super::{Incoming, StateError};
 pub struct Network {
     /// Frame MQTT packets from network connection
     framed: Framed<Box<dyn AsyncReadWrite>, Codec>,
-    /// Maximum readv count
-    max_readb_count: usize,
 }
 impl Network {
     pub fn new(socket: impl AsyncReadWrite + 'static, max_incoming_size: Option<u32>) -> Network {
@@ -26,10 +24,7 @@ impl Network {
         };
         let framed = Framed::new(socket, codec);
 
-        Network {
-            framed,
-            max_readb_count: 10,
-        }
+        Network { framed }
     }
 
     pub fn set_max_outgoing_size(&mut self, max_outgoing_size: Option<u32>) {
@@ -48,7 +43,11 @@ impl Network {
 
     /// Read packets in bulk. This allow replies to be in bulk. This method is used
     /// after the connection is established to read a bunch of incoming packets
-    pub async fn readb(&mut self, state: &mut MqttState) -> Result<(), StateError> {
+    pub async fn readb(
+        &mut self,
+        state: &mut MqttState,
+        batch_size: usize,
+    ) -> Result<(), StateError> {
         // wait for the first read
         let mut res = self.framed.next().await;
         let mut count = 1;
@@ -60,7 +59,7 @@ impl Network {
                     }
 
                     count += 1;
-                    if count >= self.max_readb_count {
+                    if count >= batch_size {
                         break;
                     }
                 }