"websocket" -- Websocket Server
*******************************

This module provides a simple way to create a websocket server.  It
works with a few tweaks in the "wsgi" module that allow websockets to
coexist with other WSGI applications.

To create a websocket server, simply decorate a handler method with
"WebSocketWSGI" and use it as a wsgi application:

   from eventlet import wsgi, websocket
   import eventlet

   @websocket.WebSocketWSGI
   def hello_world(ws):
       ws.send("hello world")

   wsgi.server(eventlet.listen(('', 8090)), hello_world)

Note: Please see graceful termination warning in "server()"
  documentation

You can find a slightly more elaborate version of this code in the
file "examples/websocket.py".

As of version 0.9.13, eventlet.websocket supports SSL websockets; all
that's necessary is to use an SSL wsgi server.

Note: The web socket spec is still under development, and it will be
  necessary to change the way that this module works in response to
  spec changes.

class eventlet.websocket.WebSocketWSGI(handler)

   Wraps a websocket handler function in a WSGI application.

   Use it like this:

      @websocket.WebSocketWSGI
      def my_handler(ws):
          from_browser = ws.wait()
          ws.send("from server")

   The single argument to the function will be an instance of
   "WebSocket".  To close the socket, simply return from the function.
   Note that the server will log the websocket request at the time of
   closure.

class eventlet.websocket.WebSocket(sock, environ, version=76)

   A websocket object that handles the details of
   serialization/deserialization to the socket.

   The primary way to interact with a "WebSocket" object is to call
   "send()" and "wait()" in order to pass messages back and forth with
   the browser.  Also available are the following properties:

   path
      The path value of the request.  This is the same as the WSGI
      PATH_INFO variable, but more convenient.

   protocol
      The value of the Websocket-Protocol header.

   origin
      The value of the 'Origin' header.

   environ
      The full WSGI environment for this request.

   close()

      Forcibly close the websocket; generally it is preferable to
      return from the handler method.

   send(message)

      Send a message to the browser.

      *message* should be convertable to a string; unicode objects
      should be encodable as utf-8.  Raises socket.error with errno of
      32 (broken pipe) if the socket has already been closed by the
      client.

   wait()

      Waits for and deserializes messages.

      Returns a single message; the oldest not yet processed. If the
      client has already closed the connection, returns None.  This is
      different from normal socket behavior because the empty string
      is a valid websocket message.
