class Middleware(object):

"""WSGI middleware for Engine.IO.

This middleware dispatches traffic to an Engine.IO application, and

optionally forwards regular HTTP traffic to a WSGI application.

:param engineio_app: The Engine.IO server.

:param wsgi_app: The WSGI app that receives all other traffic.

:param engineio_path: The endpoint where the Engine.IO application should

be installed. The default value is appropriate for

most cases.

Example usage::

import engineio

import eventlet

from . import wsgi_app

eio = engineio.Server()

app = engineio.Middleware(eio, wsgi_app)

eventlet.wsgi.server(eventlet.listen(('', 8000)), app)

"""

def __init__(self, engineio_app, wsgi_app=None, engineio_path='engine.io'):

self.engineio_app = engineio_app

self.wsgi_app = wsgi_app

self.engineio_path = engineio_path.strip('/')

def __call__(self, environ, start_response):

if 'gunicorn.socket' in environ:

# gunicorn saves the socket under environ['gunicorn.socket'], while

# eventlet saves it under environ['eventlet.input']. Eventlet also

# stores the socket inside a wrapper class, while gunicon writes it

# directly into the environment. To give eventlet's WebSocket

# module access to this socket when running under gunicorn, here we

# copy the socket to the eventlet format.

class Input(object):

def __init__(self, socket):

self.socket = socket

def get_socket(self):

return self.socket

environ['eventlet.input'] = Input(environ['gunicorn.socket'])

path = environ['PATH_INFO']

if path is not None and \

path.startswith('/{0}/'.format(self.engineio_path)):

return self.engineio_app.handle_request(environ, start_response)

elif self.wsgi_app is not None:

return self.wsgi_app(environ, start_response)

else:

start_response("404 Not Found", [('Content-type', 'text/plain')])

return ['Not Found']