如何在 tornado websocket 中向客户端发送永久数据？

Question

我正在尝试使用 tornado 运行服务器 websocket，并且我想在循环中而不是在我想要的时候而不是 onmessage 时向客户端发送消息。

这是我现在的代码：

import tornado.httpserver
import tornado.websocket
import tornado.ioloop
import tornado.web


class WSHandler(tornado.websocket.WebSocketHandler):

    def open(self):
        print 'new connection'

    def on_message(self, message):
        print 'message received:  %s' % message
        if message == "data":
            self.write_message("message")
            # here i want when i receive data from the client, to continue sending data for it until the connection is closed, and in the some time keep accepting other connections


    def on_close(self):
        print 'connection closed'


    def check_origin(self, origin):
        return True


application = tornado.web.Application([
    (r'/ws', WSHandler),
])


if __name__ == "__main__":
    http_server = tornado.httpserver.HTTPServer(application)
    http_server.listen(8888)
    myIP = socket.gethostbyname(socket.gethostname())
    print '*** Websocket Server Started at %s***' % myIP
    tornado.ioloop.IOLoop.instance().start()

Answer 1

这是执行此操作的一种方法，循环每秒发送一条消息，直到关闭。其中最棘手的部分是在连接关闭时取消循环。本版本使用Event.wait的超时参数；其他选择包括gen.with_timeout 和gen.sleep。

def open(self):
    self.close_event = tornado.locks.Event()
    IOLoop.current().spawn_callback(self.loop)

def on_close(self):
    self.close_event.set()

@gen.coroutine
def loop(self):
    while True:
        if (yield self.close_event.wait(1.0)):
            # yield event.wait returns true if the event has
            # been set, or false if the timeout has been reached.
            return
        self.write_message("abc")