[UPHPU] require_once vs. class_exists

[Alvaro Carrasco]

Sean wrote:
> That's wrong, if you install apc and use it's we interface, you can 
> use autoload and it will show that the all the files are getting cached.
>
> ...
>>
>
Thinks may have changed since I last profiled my scripts, but I remember 
this comment from Rasmus:

|<arnaud_> does autoload have a performance impact when using apc ?
<Rasmus_> it is slow both with and without apc
<Rasmus_> but yes, moreso with apc because anything that is autoloaded is pushed down into the executor
<Rasmus_> so nothing can be cached
<Rasmus_> the script itself is cached of course, but no functions or classes
<Rasmus_> Well, there is no way around that
<Rasmus_> autoload is runtime dependent
<Rasmus_> we have no idea if any autoloaded class should be loaded until the script is executed
<Rasmus_> top-level clean deps would speed things up a lot
<Rasmus_> it's not just autoload
<Rasmus_> it is any sort of class or function declaration that depends on some runtime context
<Rasmus_> if(cond) function foo...
<Rasmus_> if(cond) include file
<Rasmus_> where file has functions and classes 
<Rasmus_> or heaven forbid: function foo() { class bar { } }|

I'll profile them again when i get some time.

Alvaro