使用sendMessage進行CouchDB更改使用Autobahn WebSocket庫

Question

到目前爲止，我有基本代碼將我的websocket服務器連接到websocket客戶端。我使用Autobahn作爲服務器代碼，而高級REST客戶端作爲客戶端。在DBAlertProtocol類中的一個單獨的方法中，我長時間輪詢CouchDB中的數據庫以瞭解發生的任何更改，即添加，刪除，更新等。此方法在websocket連接打開5秒後獲取調用。

使用sendMessage時出現問題，其中數據未顯示在客戶端，或者有時需要很長時間才能到達。

有沒有辦法改變通訊選項？數據可能太大而無法發送？我想弄清楚爲什麼我的其他示例可以成功發送數據，但couchdb更改通知不能。

下面是我到目前爲止的代碼。

在此先感謝！

server.py

import sys 
import logging 
import couchdb 
from twisted.python import log 
from twisted.internet import reactor 

from autobahn.twisted.websocket import WebSocketServerFactory, \ 
         WebSocketServerProtocol, listenWS 
from autobahn.twisted.resource import WebSocketResource 

couch = couchdb.Server("http://localhost:5984/") 
db = couch['event_db'] 

class DBAlertProtocol(WebSocketServerProtocol): 

    def onConnect(self, request): 
    print("Connection made on server side") 

    def onOpen(self): 
    print("WebSocket connection open.") 
    reactor.callLater(5, self.check_db_changes) 

    def check_db_changes(self): 
    since = 1 
    print("\nstart loop\n") 
    while True: 
     changes = db.changes(since=since, include_docs=True) 
     since = changes['last_seq'] 
     no_docs_changed = len(changes) 
     counter = 0 
     for changeset in changes['results']: 
     print("\nChange detected!\n") 
     try: 
      doc = db[changeset['id']] 
     except couchdb.http.ResourceNotFound: 
      print("Resource not found, or was deleted.") 
     else: 
      counter += 1 
      print("Number of docs effected: {}".format(str(counter))) 
      # Send change data to MW 
      self.sendMessage(str(changeset)) 

    def onClose(self, wasClean, code, reason): 
    print("WebSocket closed on server side: {}".format(reason)) 

    def onMessage(self, payload, isBinary): 
    print("Data received from database: {}".format(payload)) 
    self.sendMessage("Message received.") 


class DBAlertFactory(WebSocketServerFactory): 
    protocol = DBAlertProtocol 


def main(): 
    log.startLogging(sys.stdout) 

    port = 8000 

    factory = DBAlertFactory(u"ws://127.0.0.1:8000") 

    listenWS(factory) 
    print("Listening on port: {}".format(str(port))) 
    print("Starting reactor...") 
    reactor.run() 


if __name__ == "__main__": 
    main() 

Answer 1

check_db_changes從未放棄控制，使你的程序的任何其他部分都不能運行：

while True: 

相反，你可以試試twisted.internet.task.LoopingCall。