Profiling support in PHP4b

Hey guys, here to bug u with another question... Would it be posible / easy to build a profiling extention to PHP4 ? with this i mean build hooks into PHP that measure the amount of time spent (in Ms?) in each function of your scripts, and dumps the results in a profile.log in a format like function my_function() : 10.3 Ms function my_other_function() : 5.1 Ms etc... I would be more then willing to take a shot @ this project (i also believe in the shutup-and-code(Tm) open source method), but i have no clue if there's one place where the function is entered and left, or several etc .... So if u could point me in the right direction or help me realise this, i would be more then greatfull... Background for this question: Im creating Yet-Another-Content-Management-System, with dynamic php module loaders, templates, etc etc, and im looking for some usefull stats on what functions take up the most time to execute ... optimizing the whole bunch of code would be very time consuming, but basic programming would dictate that 80% of your time is mostly spent in one loop, and thats the place one would want to optimize, for the best performance / coding time curve .... for this kind of work a profiling tool is more then vital ;/ -- Chris Chabot