Add api for setting qos for pubmsg.

examples/mqttpub.py

@@ -22,6 +22,7 @@ async def main():
     pubmsg.set_packet_type(3) # 0x03 Publish
     pubmsg.set_publish_payload("Hello")
     pubmsg.set_publish_topic("topic")
+    pubmsg.set_publish_qos(1) # qos is 1
     await mqtt.asend_msg(pubmsg)
     print(f"Publish packet sent.")
 

examples/mqttsub.py

@@ -8,7 +8,7 @@
 import pynng
 import curio
 
-address = "mqtt-quic://54.75.171.11:14567"
+address = "mqtt-quic://127.0.0.1:14567"
 
 async def main():
   with pynng.Mqtt(address) as mqtt:
@@ -22,14 +22,15 @@ async def main():
     print(f"Connection packet sent.")
     submsg = pynng.Mqttmsg()
     submsg.set_packet_type(8) # 0x08 Subscribe
-    submsg.set_subscribe_topic("topic", 0)
+    submsg.set_subscribe_topic("topic", 1) # topic With Qos 1
     await mqtt.asend_msg(submsg)
     print(f"Subscribe packet sent.")
     while True:
       rmsg = await mqtt.arecv_msg()
       rmsg.__class__ = pynng.Mqttmsg # convert to mqttmsg
       print("msg", rmsg, "arrived.")
       print("type:   ", rmsg.packet_type())
+      print("qos:    ", rmsg.publish_qos())
       print("topic:  ", rmsg.publish_topic())
       print("payload:", rmsg.publish_payload())
 

pynng/nng.py

@@ -1666,6 +1666,12 @@ def publish_topic(self):
     data = ffi.cast('char *', lib.nng_mqtt_msg_get_publish_topic(self._nng_msg, tlenp))
     return bytes(ffi.buffer(data[0:tlenp[0]])).decode()
 
+  def set_publish_qos(self, qos):
+    lib.nng_mqtt_msg_set_publish_qos(self._nng_msg, qos)
+
+  def publish_qos(self):
+    return lib.nng_mqtt_msg_get_publish_qos(self._nng_msg)
+
   def set_subscribe_topic(self, topic, qos):
     topics = lib.nng_mqtt_topic_qos_array_create(1)
     lib.nng_mqtt_topic_qos_array_set(topics, 0, to_char(topic), qos)