Triggered before cache is created. You may perform some other stuff before cache is created.

<?php
function my_component_init(){
		ossn_register_callback('cache', 'before:create', 'my_component_cb');
}
function my_component_cb($callback, $type, $params){
		//$params['time'] contain the cache timestamp
}
ossn_register_callback('ossn', 'init', 'my_component_init');