In this new post to his site Kevin Schroeder thinks out loud and wonders if an idea of his is "a dumb idea" to be included into the PHP core - engine state caching.

I was consulting and I would see significant server resources consumed by bootstrapping the apps. Loading config files, loading dependent classes, setting up dependencies, initializing ACL’s, and the list goes on and on. One of the ways to negate the effect would be to cache a bootstrap object and then pull that object from the cache at the start of the request. However, the problem is that unserialization can actually end up taking more time than the bootstrap process itself.

He wonders if, after the initial bootstrapping happened, a method could be called (his example is "init_engine_state") that would cache the Zend Engine's current state and pass that to a callback function. This would cache everything - objects, variables, classes, etc - all pre-interpreted into memory and make them easy to reuse on future executions. What do you think? Share your thoughts in the comments of the post.