Classe: Cache_Output  - X-Ref

Class to cache the output of a script using the output buffering functions

Simple output cache. Some pages require lots of time to compute. Caching the
output can increase the overall speed dramatically, especially if you use
a Shared Memory storage container.

As you can see in the example the usage is extemely simple. To cache a script
simple put some few lines of code in front of your script and some at the end.
A preferrable place for this are the auto_prepend and auto_append files (=> php.ini).

Usage example:

// place this somewhere in a central config file
define(CACHE_STORAGE_CLASS, 'file');
// file storage needs a dir to put the cache files
define(CACHE_DIR, '/var/tmp/');

// get a cache object
$cache = new Cache_Output(CACHE_STORAGE_CLASS, array('cache_dir' => CACHE_DIR));

// compute the unique handle.
// if your script depends on Cookie and HTTP Post data as well
// you should use:
// $cache_handle = array(
//                       'file' => $REQUEST_URI,
//                       'post' => $HTTP_POST_VARS,
//                       'cookie'  => $HTTP_COOKIE_VARS
//                    );
// But be warned, using all GET or POST Variables as a seed
// can be used for a DOS attack. Calling http://www.example.com/example.php?whatever
// where whatever is a random text might be used to flood your cache.
$cache_handle = $cache->generateID($REQUEST_URI);

// now the magic happens: if cached call die()
// to end the time consumptiong script script execution and use the cached value!
if ($content = $cache->start($cache_handle)) {
print $content;
print '<p>Cache hit</p>';
die();
}

// time consumption script goes here.

// store the output of the cache into the cache and print the output.
print $cache->end();
print "<p>Cache miss, stored using the ID '$id'.</p>";

If you do not want to cache a whole page - no problem:

if (!($content = $cache->start($cache_handle))) {
// do the computation here
print $cache->end()
} else {
print $content;
}

If you need an example script check the (auto_)prepend and (auto_)append
files of my homepage:

http://www.ulf-wendel.de/php/show_source.php?file=prepend
http://www.ulf-wendel.de/php/show_source.php?file=append

Don't know how to use it or you need profiling informations?`
Ask Christian he was patient with me and he'll be so with your questions ;).

Have fun!