fine efficiency in PHP

[markjoe]

I am maintaining a large PHP app, and am trying to squeeze every last bit of performance out of it.

(as it is painfully slow as is)

I am looking for some efficiency tips, surprisingly google has turned up nothing for me, and I know there are good PHP'ers here.

Here's my contribution, I've done some simple benchmarks on a few common issues I know.

 

$x1=abcdefghijklmnopqrstuvwxyz

substr($x1,n,1): 0.7362 seconds (225.3%), value=t

$x1{n}: 0.326759 seconds (44.38%), value=t

 

$x2=123456abcdef

intval($x2): 0.572915 seconds (195.06%), value=123456

(int)$x2: 0.293719 seconds (51.27%), value=123456

 

$x3=array(a,b,c,d)

split(',',$x3): 2.54544 seconds (158.36%), value=Array ( [0] => a [1] => b [2] => c [3] => d )

explode(',',$x3): 1.607407 seconds (63.15%), value=Array ( [0] => a [1] => b [2] => c [3] => d )

 

I can further explain that if it doesn't make sense.

 

Anybody else have any suggestions or ideas?

[sKunKbad]

You'll probably find that a large app that is slow will need more than a little tweaking to become efficient. You may find yourself rewriting the whole thing.

[markjoe]

Unfortunately, a full rewrite isn't going to happen. for many reasons...

I'm looking at rewriting functions that get called thousands of times and optimizing all database joins.

Besides, even if I were to rewrite it, I would still want to know the most efficient way of doing things.

 

This topic isn't only about how I can shave a couple seconds off the load times for this project, it's about overall efficiency.

I don't just want code that works, I want code that works as well as it possibly can.