python-gevent/examples/webchat/chat/views.py

66 lines
2.2 KiB
Python

import uuid
import simplejson
from django.shortcuts import render_to_response
from django.template.loader import render_to_string
from django.http import HttpResponse
from gevent.event import Event
from webchat import settings
class ChatRoom(object):
cache_size = 200
def __init__(self):
self.cache = []
self.new_message_event = Event()
def main(self, request):
if self.cache:
request.session['cursor'] = self.cache[-1]['id']
return render_to_response('index.html', {'MEDIA_URL': settings.MEDIA_URL, 'messages': self.cache})
def message_new(self, request):
name = request.META.get('REMOTE_ADDR') or 'Anonymous'
forwarded_for = request.META.get('HTTP_X_FORWARDED_FOR')
if forwarded_for and name == '127.0.0.1':
name = forwarded_for
msg = create_message(name, request.POST['body'])
self.cache.append(msg)
if len(self.cache) > self.cache_size:
self.cache = self.cache[-self.cache_size:]
self.new_message_event.set()
self.new_message_event.clear()
return json_response(msg)
def message_updates(self, request):
cursor = request.session.get('cursor')
if not self.cache or cursor == self.cache[-1]['id']:
self.new_message_event.wait()
assert cursor != self.cache[-1]['id'], cursor
try:
for index, m in enumerate(self.cache):
if m['id'] == cursor:
return json_response({'messages': self.cache[index + 1:]})
return json_response({'messages': self.cache})
finally:
if self.cache:
request.session['cursor'] = self.cache[-1]['id']
else:
request.session.pop('cursor', None)
room = ChatRoom()
main = room.main
message_new = room.message_new
message_updates = room.message_updates
def create_message(from_, body):
data = {'id': str(uuid.uuid4()), 'from': from_, 'body': body}
data['html'] = render_to_string('message.html', dictionary={'message': data})
return data
def json_response(value, **kwargs):
kwargs.setdefault('content_type', 'text/javascript; charset=UTF-8')
return HttpResponse(simplejson.dumps(value), **kwargs)