You can further speed up static file serving by exploiting client-side caching.
The idea is to send the client a version-specific URL for static files, and
tell the client that it may cache that data forever.
When the underlying file changes, your Webware app generates a new URL.
This reduces traffic to the server, but more importantly,
it can result in noticeably faster response at the client end.

This requires co-operation from Apache version 2.
Here's the details:

Configure apache-2 so that urls like ``/@X/...`` are mapped to ``/...``,
and the client is told it may cache the result for a long time::

    RewriteRule ^/@[^/]+/(.+)$        /$1      [L,E=VERSIONED_FILE:1]
    Header add "Expires" "Thu, 10 Nov 2016 23:30:00 GMT" env=VERSIONED_FILE
    Header add "Cache-Control" "max-age=315360000" env=VERSIONED_FILE

Modify your webware app to prefix version info to your static URLs.
For example, for data that almost never changes, like images,
return URLs like ``/@0/images/foo.gif``::

    # Apache serves image data out of /images.
    # Put this in an app-wide config file:
    images_url = '/@0/images'
    ...
    self.write('<img src="%s/foo.gif" ... >' % images_url)

If such an object really does change, change images_url to ``/@1/images``
and restart webkit.

For files that occasionally do change, like CSS and javascript,
set the version prefix to the underlying file's modification time.
A function like this is useful::

    # Let's assume the URL /static contains
    # static file data served by Apache 2.
    static_dir = '/var/www/myapp/static'  # filesystem path to /static

    def static_url(thing):
        path = '%s/%s' % (static_dir, thing)
        modtime = os.path.getmtime(path)
        return '/@%x/static/%s' % (modtime, thing)

    # Use it like so:
    self.write('<script type="text/javascript" src="%s"></script>' % static_url('foo.js'))

Thanks to `Cal Henderson`_ for the original idea.

.. _Cal Henderson: http://www.thinkvitamin.com/features/webapps/serving-javascript-fast


-- KenLalonde_ - 20 November 2006