Question

我一直在使用PyQt5的客户端和围绕asyncio构建的websockets模块。我认为类似下面的代码可以工作，但我发现输入的数据（来自服务器）没有在GUI中更新，直到我在行编辑框中单击输入。这些传入消息旨在为GUI的更新设置脉冲，并将携带用于更新的数据。 quamash是一个更好的方法来解决这个问题吗？顺便说一下，我将使用这个代码的其他一些方面的进程，所以我不认为它有点过分（在这一点上）。这是Python 3.6，PyQt5.6（或更高版本）以及当前使用pip安装的任何版本的websockets。 https://github.com/aaugustin/websockets

客户：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import asyncio
import websockets
import sys
import time
from multiprocessing import Process, Pipe, Queue
from PyQt5 import QtCore, QtGui, QtWidgets

class ComBox(QtWidgets.QDialog):
    def __init__(self):
        QtWidgets.QDialog.__init__(self)
        self.verticalLayout = QtWidgets.QVBoxLayout(self)
        self.groupBox = QtWidgets.QGroupBox(self)
        self.groupBox.setTitle( "messages from beyond" )
        self.gridLayout = QtWidgets.QGridLayout(self.groupBox)
        self.label = QtWidgets.QLabel(self.groupBox)
        self.gridLayout.addWidget(self.label, 0, 0, 1, 1)
        self.verticalLayout.addWidget(self.groupBox)
        self.lineEdit = QtWidgets.QLineEdit(self)
        self.verticalLayout.addWidget(self.lineEdit)
        self.lineEdit.editingFinished.connect(self.enterPress)

    @QtCore.pyqtSlot()
    def enterPress(self):
        mytext = str(self.lineEdit.text())
        self.inputqueue.put(mytext)

    @QtCore.pyqtSlot(str)
    def updategui(self, message):
        self.label.setText(message)

class Websocky(QtCore.QThread):
    updatemaingui = QtCore.pyqtSignal(str)
    def __init__(self):
        super(Websocky, self).__init__()
    def run(self):
        while True:
            time.sleep(.1)
            message = self.outputqueue.get()
            try:
                self.updatemaingui[str].emit(message)
            except Exception as e1:
                print("updatemaingui problem: {}".format(e1))

async def consumer_handler(websocket):
    while True:
        try:
            message = await websocket.recv()
            outputqueue.put(message)
        except Exception as e1:
            print(e1)

async def producer_handler(websocket):
    while True:
        message = inputqueue.get()
        await websocket.send(message)
        await asyncio.sleep(.1)

async def handler():
    async with websockets.connect('ws://localhost:8765') as websocket:
        consumer_task = asyncio.ensure_future(consumer_handler(websocket))
        producer_task = asyncio.ensure_future(producer_handler(websocket))
        done, pending = await asyncio.wait(
            [consumer_task, producer_task],
            return_when=asyncio.FIRST_COMPLETED, )
        for task in pending:
            task.cancel()

def start_websockets():
    loop = asyncio.get_event_loop()
    loop.run_until_complete(handler())

inputqueue = Queue()
outputqueue = Queue()

app = QtWidgets.QApplication(sys.argv)
comboxDialog = ComBox()
comboxDialog.inputqueue = inputqueue
comboxDialog.outputqueue = outputqueue
comboxDialog.show()

webster = Websocky()
webster.outputqueue = outputqueue
webster.updatemaingui[str].connect(comboxDialog.updategui)
webster.start()

p2 = Process(target=start_websockets)
p2.start()

sys.exit(app.exec_())

服务器：

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import asyncio
import time
import websockets

# here we'll store all active connections to use for sending periodic messages
connections = []


#@asyncio.coroutine
async def connection_handler(connection, path):
    connections.append(connection)  # add connection to pool
    while True:
        msg = await connection.recv()
        if msg is None:  # connection lost
            connections.remove(connection)  # remove connection from pool, when client disconnects
            break
        else:
            print('< {}'.format(msg))

#@asyncio.coroutine
async def send_periodically():
    while True:
        await asyncio.sleep(2)  # switch to other code and continue execution in 5 seconds
        for connection in connections:
            message = str(round(time.time()))
            print('> Periodic event happened.')
            await connection.send(message)  # send message to each connected client

start_server = websockets.serve(connection_handler, 'localhost', 8765)
asyncio.get_event_loop().run_until_complete(start_server)
asyncio.ensure_future(send_periodically())  # before blocking call we schedule our coroutine for sending periodic messages
asyncio.get_event_loop().run_forever()

Answer 1

发布此问题后不久，我意识到了这个问题。这条线

git commit -m "message here"

producer_handler函数中的

是阻塞的。这导致应该是异步函数挂起该进程中的所有内容，直到它看到队列中的某些内容。我的解决方法是使用提供asyncio兼容队列的aioprocessing模块。所以，它看起来更像是这样：

message = inputqueue.get()

aioprocessing模块提供了一些不错的选项和文档。在这种情况下，这个问题是一个相当简单的解决方案。 https://github.com/dano/aioprocessing 所以，回答我的问题：不，你不必使用quamash来做这种事情。

websockets，asyncio和PyQt5最后在一起。 Quamash有必要吗？

1 个答案: