BaschtDotCom: Optimizing PHP Code

Optimizing PHP Code

Diving into zval @ z core.
Dough: "Working by reference will usually make you waste memory as it can trigger more easily the copy on write."
Hash Tables: Quick access by key or table traversal. But: Not way to get by value.

Be efficient, optimize tight loops, one line functions.
Highly covered source code (profile your app!).

Use tools

Have a look at the PHP Opcode: Vulcan Logic Dumper (pecl VLD)
Profile your apps: XDebug / Zend Debug Profilers.

Zend Op

Kind of the "maschine language" of ZE. OpCode, Op1, Op2, Metas (line n°, handler, result)

Live hacking Optimization Example

Slow

$array = array();

while($val = $res->fetch())  {

 $array[] = $val;

}

$arr = array_unique($array);

Faster

$array = array();

$dedup = array()

while($val = $res->fetch())  {

  if(isset($dedup[$val])) {

    $dedup[$val] = true;

    $array[] = $val;

  }

}

Other ways

Use built_in functions (except array_* and in_array())
Use opcode caching! (APC, eAcc, XCache, Zend Server)
Use data Caching! (Memcached)
Optimize your SQL
Acces your data in batches!
Create PHP Extensions (HP!)
Use other implementations: Facebooks HipHop, phc, Quercus, RoadSend PHP

Talk of Xavier De Cock auf der SymfonyLive2010

BaschtDotCom : XavierDeCockOptimizingPHP