umqtt.simple: Initial implementation of a simple MQTT client.

pull/81/head
Paul Sokolovsky 2016-07-02 01:13:06 +03:00
rodzic 0b524194a0
commit f44a33c1df
1 zmienionych plików z 147 dodań i 0 usunięć

Wyświetl plik

@ -0,0 +1,147 @@
import usocket as socket
import ustruct as struct
from ubinascii import hexlify
import time
class MQTTException(Exception):
pass
class MQTTClient:
def __init__(self, client_id, server, port=1883):
self.client_id = client_id
self.sock = None
self.addr = socket.getaddrinfo(server, port)[0][-1]
self.pid = 0
self.cb = None
def _send_str(self, s):
self.sock.write(struct.pack("!H", len(s)))
self.sock.write(s)
def _recv_len(self):
n = 0
sh = 0
while 1:
b = self.sock.read(1)[0]
n |= (b & 0x7f) << sh
if not b & 0x80:
return n
sh += 7
def set_callback(self, f):
self.cb = f
def connect(self, clean_session=True):
self.sock = socket.socket()
self.sock.connect(self.addr)
msg = bytearray(b"\x10\0\0\x04MQTT\x04\x02\0\0")
msg[1] = 10 + 2 + len(self.client_id)
msg[9] = clean_session << 1
self.sock.write(msg)
#print(hex(len(msg)), hexlify(msg, ":"))
self._send_str(self.client_id)
resp = self.sock.read(4)
assert resp[0] == 0x20 and resp[1] == 0x02
if resp[3] != 0:
raise MQTTException(resp[3])
return resp[2] & 1
def disconnect(self):
self.sock.write(b"\xe0\0")
self.sock.close()
def ping(self):
self.sock.write(b"\xc0\0")
self.sock.close()
def publish(self, topic, msg, retain=False, qos=0):
pkt = bytearray(b"\x30\0\0")
pkt[0] |= qos << 1 | retain
sz = 2 + len(topic) + len(msg)
if qos > 0:
sz += 2
assert sz <= 16383
pkt[1] = (sz & 0x7f) | 0x80
pkt[2] = sz >> 7
#print(hex(len(pkt)), hexlify(pkt, ":"))
self.sock.write(pkt)
self._send_str(topic)
if qos > 0:
self.pid += 1
pid = self.pid
buf = bytearray(b"\0\0")
struct.pack_into("!H", buf, 0, pid)
self.sock.write(buf)
self.sock.write(msg)
if qos == 1:
while 1:
op = self.wait_msg()
if op == 0x40:
sz = self.sock.read(1)
assert sz == b"\x02"
rcv_pid = self.sock.read(2)
rcv_pid = rcv_pid[0] << 8 | rcv_pid[1]
if pid == rcv_pid:
return
elif qos == 2:
assert 0
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, ":"))
self.sock.write(pkt)
self._send_str(topic)
self.sock.write(qos.to_bytes(1))
resp = self.sock.read(5)
#print(resp)
assert resp[0] == 0x90
assert resp[2] == pkt[2] and resp[3] == pkt[3]
if resp[4] == 0x80:
raise MQTTException(resp[4])
# 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.
def wait_msg(self):
res = self.sock.read(1)
if res is None:
return None
self.sock.setblocking(True)
if res == b"":
raise OSError(-1)
if res == b"\xd0": # PINGRESP
sz = self.sock.read(1)[0]
assert sz == 0
return None
op = res[0]
if op & 0xf0 != 0x30:
return op
sz = self._recv_len()
topic_len = self.sock.read(2)
topic_len = (topic_len[0] << 8) | topic_len[1]
topic = self.sock.read(topic_len)
sz -= topic_len + 2
if op & 6:
pid = self.sock.read(2)
pid = pid[0] << 8 | pid[1]
sz -= 2
msg = self.sock.read(sz)
self.cb(topic, msg)
if op & 6 == 2:
pkt = bytearray(b"\x40\x02\0\0")
struct.pack_into("!H", pkt, 2, pid)
self.sock.write(pkt)
elif op & 6 == 4:
assert 0
# Checks whether a pending message from server is available.
# If not, returns immediately with None. Otherwise, does
# the same processing as wait_msg.
def check_msg(self):
self.sock.setblocking(False)
return self.wait_msg()