Python的消息队列包SnakeMQ使用初探

时间:2022-11-15 11:50:17

一、关于snakemq的官方介绍
SnakeMQ的GitHub项目页:https://github.com/dsiroky/snakemq
1.纯python实现,跨平台

2.自动重连接

3.可靠发送--可配置的消息方式与消息超时方式

4.持久化/临时 两种队列

5.支持异步 -- poll()

6.symmetrical -- 单个TCP连接可用于双工通讯

7.多数据库支持 -- SQLite、MongoDB……

8.brokerless - 类似ZeroMQ的实现原理

9.扩展模块:RPC, bandwidth throttling

以上都是官话,需要自己验证,动手封装了一下,感觉萌萌哒。

 

二、几个主要问题说明

1.支持自动重连,不需要自己动手写心跳逻辑,你只需要关注发送和接收就行

2.支持数据持久化,如果开始持久化,在重连之后会自动发送数据。

3.数据的接收,snakemq通过提供回调实现,你只需要写个接收方法添加到回调列表里去。

4.数据的发送,在此发送的都是bytes类型(二进制),因此需要转换。我在程序中测试的都是文本字符串,使用str.encode(‘utf-8')转换成bytes,接收时再转换回来。

5.术语解释,Connector:类似于socket的TcpClient,Lisenter:类似于socket的TcpServer,每个connector或者listener都一个一个ident标识,发送和接收数据时就知道是谁的数据了。

6.使用sqlite持久化时,需要修改源码,sqlite3.connect(filename,check_same_thread = False),用于解决多线程访问sqlite的问题。(会不会死锁?)

7.启动持久化时,如果重新连上,则会自动发送,保证可靠。

8.为了封装的需要,数据接收以后,我通过callback方式传送出去。

 

三、代码

说明代码中使用了自定义的日志模块

?
1
2
3
from common import nxlogger
 
import snakemqlogger as logger

可替换成logging的。

回调类(callbacks.py):

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
# -*- coding:utf-8 -*-
 
'''synchronized callback'''
 
class Callback(object):
 
  def __init__(self):
 
    self.callbacks = []
 
 
 
  def add(self, func):
 
    self.callbacks.append(func)
 
 
 
  def remove(self, func):
 
    self.callbacks.remove(func)
 
 
 
  def __call__(self, *args, **kwargs):
 
    for callback in self.callbacks:
 
      callback(*args, **kwargs)

Connector类(snakemqConnector.py):

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
# -*- coding:utf-8 -*-
 
import threading
 
import snakemq
 
import snakemq.link
 
import snakemq.packeter
 
import snakemq.messaging
 
import snakemq.message
 
from snakemq.storage.sqlite import SqliteQueuesStorage
 
from snakemq.message import FLAG_PERSISTENT
 
from common.callbacks import Callback
 
 
 
from common import nxlogger
 
import snakemqlogger as logger
 
 
 
class SnakemqConnector(threading.Thread):
 
     def __init__(self, snakemqident = None, remoteIp = "localhost", remotePort = 9090, persistent = False):
 
         super(SnakemqConnector,self).__init__()
 
         self.messaging = None
 
         self.link = None
 
         self.snakemqident = snakemqident
 
         self.pktr = None
 
         self.remoteIp = remoteIp
 
         self.remotePort = remotePort
 
         self.persistent = persistent
 
         self.on_recv = Callback()
 
         self._initConnector()
 
 
 
     def run(self):
 
         logger.info("connector start...")
 
         
 
         if self.link != None:
 
              self.link.loop()
 
 
 
         logger.info("connector end...")
 
    
 
     def terminate(self):
 
         logger.info("connetor terminating...")
 
         if self.link != None:
 
              self.link.stop()
 
              self.link.cleanup()
 
         logger.info("connetor terminated")
 
 
 
     def on_recv_message(self, conn, ident, message):
 
         try:
 
              self.on_recv(ident, message.data.decode('utf-8'))#dispatch received data
 
         except Exception as e:
 
              logger.error("connector recv:{0}".format(e))
 
              print(e)
 
 
 
     '''send message to dest host named destIdent'''
 
     def sendMsg(self, destIdent, byteseq):
 
         msg = None
 
         if self.persistent:
 
              msg = snakemq.message.Message(byteseq, ttl=60, flags=FLAG_PERSISTENT)
 
         else:
 
              msg = snakemq.message.Message(byteseq, ttl=60)
 
         if self.messaging == None:
 
              logger.error("connector:messaging is not initialized, send message failed")
 
              return
 
         self.messaging.send_message(destIdent, msg)
 
 
 
     '''
 
    
 
     '''
 
     def _initConnector(self):
 
         try:
 
              self.link = snakemq.link.Link()
 
              self.link.add_connector((self.remoteIp, self.remotePort))
 
 
 
              self.pktr = snakemq.packeter.Packeter(self.link)
 
 
 
              if self.persistent:
 
                  storage = SqliteQueuesStorage("SnakemqStorage.db")
 
                  self.messaging = snakemq.messaging.Messaging(self.snakemqident, "", self.pktr, storage)
 
              else:
 
                  self.messaging = snakemq.messaging.Messaging(self.snakemqident, "", self.pktr)
 
             
 
              self.messaging.on_message_recv.add(self.on_recv_message)
 
             
 
         except Exception as e:
 
              logger.error("connector:{0}".format(e))
 
         finally:
 
              logger.info("connector[{0}] loop ended...".format(self.snakemqident))

 Listener类(snakemqListener.py):

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
# -*- coding:utf-8 -*-
 
import threading
 
import snakemq
 
import snakemq.link
 
import snakemq.packeter
 
import snakemq.messaging
 
import snakemq.message
 
from common import nxlogger
 
import snakemqlogger as logger
 
from common.callbacks import Callback
 
class SnakemqListener(threading.Thread):
 
     def __init__(self, snakemqident = None, ip = "localhost", port = 9090, persistent = False):
 
         super(SnakemqListener,self).__init__()
 
         self.messaging = None
 
         self.link = None
 
         self.pktr = None
 
         self.snakemqident = snakemqident
 
         self.ip = ip;
 
         self.port = port
 
         self.connectors = {}
 
         self.on_recv = Callback()
 
         self.persistent = persistent
 
         self._initlistener()
 
 
 
     '''
 
     thread run
 
     '''
 
     def run(self):
 
         logger.info("listener start...")
 
         
 
         if self.link != None:
 
              self.link.loop()
 
 
 
         logger.info("listener end...")
 
 
 
     '''
 
     terminate snakemq listener thread
 
     '''
 
     def terminate(self):
 
         logger.info("listener terminating...")
 
         if self.link != None:
 
              self.link.stop()
 
              self.link.cleanup()
 
         logger.info("listener terminated")
 
 
 
     '''
 
     receive message from host named ident
 
     '''
 
     def on_recv_message(self, conn, ident, message):
 
         try:
 
              self.on_recv(ident, message.data.decode('utf-8'))#dispatch received data
 
              self.sendMsg('bob','hello,{0}'.format(ident).encode('utf-8'))
 
         except Exception as e:
 
              logger.error("listener recv:{0}".format(e))
 
              print(e)
 
 
 
     def on_drop_message(self, ident, message):
 
         print("message dropped", ident, message)
 
         logger.debug("listener:message dropped,ident:{0},message:{1}".format(ident, message))
 
 
 
     '''client connect'''
 
     def on_connect(self, ident):
 
         logger.debug("listener:{0} connected".format(ident))
 
         self.connectors[ident] = ident
 
         self.sendMsg(ident, "hello".encode('utf-8'))
 
 
 
     '''client disconnect'''
 
     def on_disconnect(self, ident):
 
         logger.debug("listener:{0} disconnected".format(ident))
 
         if ident in self.connectors:
 
              self.connectors.pop(ident)
 
 
 
     '''
 
     listen start loop
 
     '''
 
     def _initlistener(self):
 
         try:
 
              self.link = snakemq.link.Link()
 
              self.link.add_listener((self.ip, self.port))
 
 
 
              self.pktr = snakemq.packeter.Packeter(self.link)
 
              self.pktr.on_connect.add(self.on_connect)
 
              self.pktr.on_disconnect.add(self.on_disconnect)
 
 
 
              if self.persistent:
 
                  storage = SqliteQueuesStorage("SnakemqStorage.db")
 
                  self.messaging = snakemq.messaging.Messaging(self.snakemqident, "", self.pktr, storage)
 
              else:
 
                  self.messaging = snakemq.messaging.Messaging(self.snakemqident, "", self.pktr)
 
             
 
              self.messaging.on_message_recv.add(self.on_recv_message)
 
              self.messaging.on_message_drop.add(self.on_drop_message)
 
 
 
         except Exception as e:
 
              logger.error("listener:{0}".format(e))
 
         finally:
 
              logger.info("listener:loop ended...")
 
     '''send message to dest host named destIdent'''
 
     def sendMsg(self, destIdent, byteseq):
 
         msg = None
 
         if self.persistent:
 
              msg = snakemq.message.Message(byteseq, ttl=60, flags=FLAG_PERSISTENT)
 
         else:
 
              msg = snakemq.message.Message(byteseq, ttl=60)
 
         if self.messaging == None:
 
              logger.error("listener:messaging is not initialized, send message failed")
 
              return
 
         self.messaging.send_message(destIdent, msg)

测试代码connector(testSnakeConnector.py):

读取本地一个1M的文件,然后发送给listener,然后listener发回一个hello的信息。

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
from netComm.snakemq import snakemqConnector
 
import time
 
import sys
 
import os
 
def received(ident, data):
 
     print(data)
 
 
 
if __name__ == "__main__":
 
     bob = snakemqConnector.SnakemqConnector('bob',"10.16.5.45",4002,True)
 
     bob.on_recv.add(received)
 
     bob.start()
 
     try:
 
         with open("testfile.txt",encoding='utf-8') as f:
 
              txt = f.read()
 
              for i in range(100):
 
                  bob.sendMsg("niess",txt.encode('utf-8'))
 
                  time.sleep(0.1)
 
     except Exception as e:
 
         print(e)
 
     time.sleep(5)
 
     bob.terminate()  
 
 
 
测试代码listener(testSnakeListener.py):
 
from netComm.snakemq import snakemqListener
 
import time
 
 
 
def received(ident, data):
 
     filename = "log/recFile{0}.txt".format(time.strftime('%S',time.localtime()))
 
     file = open(filename,'w')
 
     file.writelines(data)
 
     file.close()
 
 
 
if __name__ == "__main__":
 
     niess = snakemqListener.SnakemqListener("niess","10.16.5.45",4002)
 
     niess.on_recv.add(received)
 
     niess.start()
 
     print("niess start...")
 
     time.sleep(60)
 
     niess.terminate() 
 
     print("niess end...")