python消息队列snakemq使用总结

Python 消息队列snakemq总结

最近学习消息总线zeromq，在网上搜了python实现的消息总线模块，意外发现有个消息队列snakemq，于是拿来研究一下，感觉还是很不错的，入手简单使用也简单（比ice强多了），就是资料太少了，只能自己抠。

一、关于snakemq的官方介绍

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()

6symmetrical -- 单个TCP连接可用于双工通讯

7多数据库支持 -- SQLite、MongoDB……

8brokerless - 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

from common import nxlogger

import snakemqlogger as logger

可替换成logging的。

 

回调类（callbacks.py）：

 

# -*- coding:utf-8 -*-

#*********************************************************#

# @@FileName: callbacks.py

# @@Author:
Shelwinnee<Shelwinnee@163.com>

# @@Create Date: 2016-04-14 22:24:14

# @@Modify Date: 2016-04-14 22:24:34

# @@Description: simple synchronized
callbacks helper

#*********************************************************#

 

'''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）：

# -*- coding:utf-8 -*-

#*********************************************************#

# @@FileName: snakemqConnector.py

# @@Author:
Shelwinnee<Shelwinnee@163.com>

# @@Create Date: 2016-04-14 22:24:14

# @@Modify Date: 2016-04-14 22:24:34

# @@Description: 

# note:if message persistent is
necessary, please make sure you know the following instruction meaning,

# 'sqlite object created in a thread can
only be used in that same thread'

# this problem's solution: modify the
connection method of sqlite3, open file ('snakemq\storage\sqlite.py') ,and
modify the following code:

# self.conn =
sqlite3.connect(filename,check_same_thread = False)

#*********************************************************#

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）：

# -*- coding:utf-8 -*-

#*********************************************************#

# @@FileName: snakemqListener.py

# @@Author:
Shelwinnee<Shelwinnee@163.com>

# @@Create Date: 2016-04-14 22:24:14

# @@Modify Date: 2016-04-14 22:24:34

# @@Description: 

# note:if message persistent is
necessary, please make sure you know the following instruction meaning,

# 'sqlite object created in a thread can
only be used in that same thread'

# this problem's solution: modify the
connection method of sqlite3, open file ('snakemq\storage\sqlite.py') ,and
modify the following code:

# self.conn =
sqlite3.connect(filename,check_same_thread = False)

#*********************************************************#

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。

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...")

 

四、测试结果

 应该与其它消息类组件对比后出结论。应付一个小项目绝对杠杠滴。