Django SSE 高并发分析与解决

from django.http import HttpResponse
from django.views.generic import View
​
class ServerSentEventView(View):
    def get(self, request, *args, **kwargs):
        response = HttpResponse(content_type='text/event-stream')
        response['Cache-Control'] = 'no-cache'
        response['Content-Encoding'] = 'none'
        response['Connection'] = 'keep-alive'
​
        # Limit the number of SSE connections to 5
        if len(response.streaming) >= 5:
            response.close()
        else:
            response.streaming.append(self.send_event())
​
        return response
​
    def send_event(self):
        """
        Send an SSE event.
        """
        return 'data: {}\n\n'.format(json.dumps({'message': 'Hello, world!'}))

from django.http import HttpResponse
from django.views.generic import View
​
class ServerSentEventView(View):
    def get(self, request, *args, **kwargs):
        response = HttpResponse(content_type='text/event-stream')
        response['Cache-Control'] = 'no-cache'
        response['Content-Encoding'] = 'none'
        response['Connection'] = 'keep-alive'
​
        # Only send updates when there is new data
        if self.has_new_data():
            response.streaming.append(self.send_event())
​
        return response
​
    def has_new_data(self):
        """
        Check if there is new data to send.
        """
        return True
​
    def send_event(self):
        """
        Send an SSE event.
        """
        return 'data: {}\n\n'.format(json.dumps({'message': 'Hello, world!'}))

from django.contrib.auth.decorators import login_required
from django.shortcuts import render
from django.utils.decorators import method_decorator
from channels.layers import get_channel_layer
from asgiref.sync import async_to_sync
​
@login_required
def index(request):
    """
    Render the index page.
    """
    return render(request, 'chat/index.html')
​
@method_decorator(login_required, name='dispatch')
class WebSocketConsumer(WebsocketConsumer):
    def connect(self):
        """
        Accept the WebSocket connection.
        """
        self.accept()
​
    def disconnect(self, close_code):
        """
        Close the WebSocket connection.
        """
        pass
​
    def receive(self, text_data=None, bytes_data=None):
        """
        Receive a message from the client.
        """
        message = text_data
        channel_layer = get_channel_layer()
        async_to_sync(channel_layer.group_send)(
            'chat',
            {
                'type': 'chat.message',
                'message': message,
                'user': self.scope['user'].username,
            }
        )
​
    def chat_message(self, event):
        """
        Send a message to the client.
        """
        message = event['message']
        user = event['user']
        self.send(text_data=json.dumps({'message': message, 'user': user}))