umqtt.async: Initial implementation based on umqtt.simple

Author: dketov

micropython/umqtt.async/manifest.py

@@ -0,0 +1,7 @@
+metadata(description="Lightweight async MQTT client for MicroPython.", version="1.7.0")
+
+# Originally written by Paul Sokolovsky, adapted by Dmitry Ketov
+
+require("ssl")
+
+package("umqtt")

micropython/umqtt.async/umqtt/async.py

@@ -0,0 +1,238 @@
+import socket
+import struct
+from binascii import hexlify
+import uasyncio as aio
+
+
+class MQTTException(Exception):
+    pass
+
+
+class MQTTClient:
+    def __init__(
+        self,
+        client_id,
+        server,
+        port=0,
+        user=None,
+        password=None,
+        keepalive=0,
+        ssl=None,
+        ssl_params={},
+    ):
+        if port == 0:
+            port = 8883 if ssl else 1883
+        self.client_id = client_id
+        self.r, self.w = None, None
+        self.server = server
+        self.port = port
+        self.ssl = ssl
+        self.ssl_params = ssl_params
+        self.pid = 0
+        self.cb = None
+        self.user = user
+        self.pswd = password
+        self.keepalive = keepalive
+        self.lw_topic = None
+        self.lw_msg = None
+        self.lw_qos = 0
+        self.lw_retain = False
+
+    async def _send_str(self, s):
+        await self.w.awrite(struct.pack("!H", len(s)))
+        await self.w.awrite(s)
+
+    async def _recv_len(self):
+        n = 0
+        sh = 0
+        while 1:
+            b = (await self.r.read(1))[0]
+            n |= (b & 0x7F) << sh
+            if not b & 0x80:
+                return n
+            sh += 7
+
+    def set_callback(self, f):
+        self.cb = f
+
+    def set_last_will(self, topic, msg, retain=False, qos=0):
+        assert 0 <= qos <= 2
+        assert topic
+        self.lw_topic = topic
+        self.lw_msg = msg
+        self.lw_qos = qos
+        self.lw_retain = retain
+
+    async def connect(self, clean_session=True, timeout=None):
+	self.r, self.w = await aio.open_connection(self.server, self.port)
+        premsg = bytearray(b"\x10\0\0\0\0\0")
+        msg = bytearray(b"\x04MQTT\x04\x02\0\0")
+
+        sz = 10 + 2 + len(self.client_id)
+        msg[6] = clean_session << 1
+        if self.user:
+            sz += 2 + len(self.user) + 2 + len(self.pswd)
+            msg[6] |= 0xC0
+        if self.keepalive:
+            assert self.keepalive < 65536
+            msg[7] |= self.keepalive >> 8
+            msg[8] |= self.keepalive & 0x00FF
+        if self.lw_topic:
+            sz += 2 + len(self.lw_topic) + 2 + len(self.lw_msg)
+            msg[6] |= 0x4 | (self.lw_qos & 0x1) << 3 | (self.lw_qos & 0x2) << 3
+            msg[6] |= self.lw_retain << 5
+
+        i = 1
+        while sz > 0x7F:
+            premsg[i] = (sz & 0x7F) | 0x80
+            sz >>= 7
+            i += 1
+        premsg[i] = sz
+
+        await self.w.awrite(premsg[:i + 2])
+        await self.w.awrite(msg)
+        # print(hex(len(msg)), hexlify(msg, ":"))
+        await self._send_str(self.client_id)
+        if self.lw_topic:
+            await self._send_str(self.lw_topic)
+            await self._send_str(self.lw_msg)
+        if self.user:
+            await self._send_str(self.user)
+            await self._send_str(self.pswd)
+        resp = await self.r.read(4)
+        assert resp[0] == 0x20 and resp[1] == 0x02
+        if resp[3] != 0:
+            raise MQTTException(resp[3])
+        return resp[2] & 1
+
+    async def disconnect(self):
+        await self.w.awrite(b"\xe0\0")
+        await self.w.close()
+        await self.r.close()
+
+    async def ping(self):
+        await self.w.awrite(b"\xc0\0")
+
+    async def publish(self, topic, msg, retain=False, qos=0):
+        pkt = bytearray(b"\x30\0\0\0")
+        pkt[0] |= qos << 1 | retain
+        sz = 2 + len(topic) + len(msg)
+        if qos > 0:
+            sz += 2
+        assert sz < 2097152
+        i = 1
+        while sz > 0x7F:
+            pkt[i] = (sz & 0x7F) | 0x80
+            sz >>= 7
+            i += 1
+        pkt[i] = sz
+        # print(hex(len(pkt)), hexlify(pkt, ":"))
+        await self.w.awrite(pkt[:i + 1])
+        await self._send_str(topic)
+        if qos > 0:
+            self.pid += 1
+            pid = self.pid
+            struct.pack_into("!H", pkt, 0, pid)
+            await self.w.awrite(pkt, 2)
+        await self.w.awrite(msg)
+        if qos == 1:
+            while 1:
+                op = await self.wait_msg()
+                if op == 0x40:
+                    sz = await self.r.read(1)
+                    assert sz == b"\x02"
+                    rcv_pid = await self.r.read(2)
+                    rcv_pid = rcv_pid[0] << 8 | rcv_pid[1]
+                    if pid == rcv_pid:
+                        return
+        elif qos == 2:
+            assert 0
+
+    async def subscribe(self, topic, qos=0):
+        assert self.cb is not None, "Subscribe callback is not set"
+        pkt = bytearray(b"\x82\0\0\0")
+        self.pid += 1
+        struct.pack_into("!BH", pkt, 1, 2 + 2 + len(topic) + 1, self.pid)
+        # print(hex(len(pkt)), hexlify(pkt, ":"))
+        await self.w.awrite(pkt)
+        await self._send_str(topic)
+        await self.w.awrite(qos.to_bytes(1, "little"))
+        while 1:
+            op = await self.wait_msg()
+            if op == 0x90:
+                resp = await self.r.read(4)
+                # print(resp)
+                assert resp[1] == pkt[2] and resp[2] == pkt[3]
+                if resp[3] == 0x80:
+                    raise MQTTException(resp[3])
+                return
+
+    async def unsubscribe(self, topic):
+        pkt = bytearray(b"\xa2\0\0\0")
+        self.pid += 1
+        struct.pack_into("!BH", pkt, 1, 2 + 2 + len(topic), self.pid)
+        await self.w.awrite(pkt)
+        await self._send_str(topic)
+        while 1:
+            op = await self.wait_msg()
+            if op == 0xB0:
+                resp = await self.r.read(3)
+                assert resp[1] == pkt[2] and resp[2] == pkt[3]
+                return
+
+    # Wait for a single incoming MQTT message and process it.
+    # Subscribed messages are delivered to a callback previously
+    # set by .set_callback() method. Other (internal) MQTT
+    # messages processed internally.
+    async def wait_msg(self):
+        res = await self.r.read(1)
+        if res is None:
+            return None
+        if res == b"":
+            raise OSError(-1)
+        if res == b"\xd0":  # PINGRESP
+            sz = await self.r.read(1)[0]
+            assert sz == 0
+            return None
+        op = res[0]
+        if op & 0xF0 != 0x30:
+            return op
+        sz = await self._recv_len()
+        topic_len = await self.r.read(2)
+        topic_len = (topic_len[0] << 8) | topic_len[1]
+        topic = await self.r.read(topic_len)
+        sz -= topic_len + 2
+        if op & 6:
+            pid = await self.r.read(2)
+            pid = pid[0] << 8 | pid[1]
+            sz -= 2
+        msg = await self.r.read(sz)
+        self.cb(topic, msg)
+        if op & 6 == 2:
+            pkt = bytearray(b"\x40\x02\0\0")
+            struct.pack_into("!H", pkt, 2, pid)
+            await self.w.awrite(pkt)
+        elif op & 6 == 4:
+            assert 0
+        return op
+
+if __name__ == "__main__":
+    import uasyncio as aio
+
+    async def test(name):
+        c = MQTTClient(name, "localhost")
+        await c.connect()
+        c.set_callback(lambda t, m: print(t, m))
+        await c.subscribe("#")
+        await c.publish(name, name)
+        for i in range(100):
+            print("!", await c.wait_msg())
+        c.disconnect()
+
+    async def main():
+        await aio.gather(
+            aio.create_task(test("c1")),
+            aio.create_task(test("c2"))
+	)
+
+    aio.run(main())