Archangel
=========
Archangel is a webserver designed to be fast and easy to use for personal 
usage. It was created to replace an internal webserver based off of flup for 
fcgi and wsgiref for http serving (basically anything would be an improvement) as 
well as explore the new pep-3156_/Tulip_ based library by Guido van Rossum

Archangel is designed to be 'fast'. This does not mean however that archangel 
is fast, Archangel is instead intended to explore how fast a server using an 
event loop based of tulip can be made to go and what is needed to get it there.

As an additional side effect it should serve as a light house in the fog as to 
what you should or should not do with Tulip_ (Of course it is still yet to be 
determine on which side of the divide Archangel ends up)

Tenets:
--------
Only do things when we need to:
    Do things "Just in Time"
Only do things we have to:
    Be lazy
Do it quickly:
    Go back to sleep as fast as possible

What Archangel provides
------------------------
* Pre-forking Webserver
* WSGI connector
* The ability to run multiple dissimilar WSGI apps in the same process and 
  route requests to them individually based off of PATH_INFO or HOST headers

What Archangel does not provide
--------------------------------
* 'Cron' like functionality, this is now implemented via Tulip_. get a copy of 
  the mainloop with ``loop = tulip.get_event_loop()``, then attach your cron 
  function with ``loop.call_repeatably(15.0, my_cron)`` which will call your 
  ``my_cron`` function every 15 seconds
* Unix Signal support, this functionality is already provided by Tulip_ via the 
  ``add_signal_handler`` functionality
* Long running background tasks. Tulip_ can be used to launch background 
  contexts via ``call_soon``. note that CPU bound tasks should ``yield`` 
  periodically to prevent blocking of other tasks or use ``run_in_executor`` 
  provided by the main loop.

Possible Future Features
-------------------------
* Internal 'signalling' allowing applications to signal each other and respond 
  accordingly

Compatibility Notes
--------------------
* For performance, any 3rd party library you use will need to be 
  tulip_/pep-3156_ compatible and return a future on blocking calls so that it 
  may be ``yield from``'d. libraries using open() and socket.socket or other 
  blocking calls will still work without issue but will prevent other requests 
  from being handled while the system call is blocked
* To use traditional style locks and events, use the implementations in tulip_ 
  rather than the ``threading`` library

TWIG: Tulipe Webservices Gateway Interface
------------------------------------------
Archangel provides a test-bed for developing a new protocol loosely based 
off of pep-3333_/WSGI, Designed for use with Tulip_ and providing a more 
'stream' like interface. This can be used to implement long polling clients as 
well as support traditional WSGI like request/response through the use of 
middleware that will be bundled with Archangel.

An inital draft of the TWIG spec can be found here__

__ http://code.pocketnix.org/archangel/file/tip/TWIG

Requirements
------------
* Python 3.3 or greater
* Distutils2 (to replace setup.py, a fallback is provided)
* A copy of the Tulip_ library
* PyYaml for parsing the config files

Getting the Latest version
---------------------------
The latest version of Archangel can be obtained with mercurial/hg using the 
following command:

    hg clone http://code.pocketnix.org/archangel

Links
-----
* `Design Notes`_

.. _pep-3333: http://www.python.org/dev/peps/pep-3333/
.. _pep-3156: http://www.python.org/dev/peps/pep-3156/
.. _Tulip: https://code.google.com/p/tulip/
.. _Design Notes: http://www.pocketnix.org/posts/Archangel%20Design%20Notes%3A%20Part%201

Change Log
-----------

0.3
++++
* Added twig module
* Added Request object
* Added Response object
* Expand on TWIG PEP

0.2.1
++++++
* Minor bump to update filenames (WSGI-STREAM => TWIG)

0.2: Fresh Breeze
++++++++++++++++++
* Split code into modules
* Name changes to WSGIProtocol and friends, now split along 'FCGI' and
  'HTTP' lines
* Framework can make requests with to a special function using a
  'looks like wsgi if you squint hard enough' protocol
    
0.1.2
++++++
* Added WSGI-STREAM spec
* Refined documentation and links
* Added Changelog

0.1.1
++++++
* Inital code
* README file
