caching - How to pass a callback function with parameters for ob_start in PHP? -

i've been following this tutorial on caching function. run problem of passing callback function cache_page() ob_start. how can pass cache_page() along 2 paramters $mid , $path ob_start, along lines of

  ob_start("cache_page($mid,$path)"); 

of course above won't work. here's example code:

$mid = $_get['mid'];  $path = "cachefile";  define('cache_time', 12);  function cache_file($p,$m) {     return "directory/{$p}/{$m}.html"; }  function cache_display($p,$m) {     $file = cache_file($p,$m);      // check cache file exists , not old     if(!file_exists($file)) return;      if(filemtime($file) < time() - cache_time * 3600) return;      header('content-encoding: gzip');      // if so, display cache file , stop processing     echo gzuncompress(file_get_contents($file));      exit; }    // write cache file function cache_page($content,$p,$m) {   if(false !== ($f = @fopen(cache_file($p,$m), 'w'))) {       fwrite($f, gzcompress($content));        fclose($f);   }   return $content; }  cache_display($path,$mid);  ob_start("cache_page"); ///// here's problem 

the signature of callback ob_start has be:

string handler ( string $buffer [, int $phase ] ) 

your cache_page method has incompatible signature:

cache_page($content, $p, $m) 

this means expecting different arguments ($p , $m) ob_start pass callback. there no way make ob_start change behavior. not send $p , $m.

in linked tutorial, cache file name derived request, e.g.

function cache_file() {     return cache_path . md5($_server['request_uri']); } 

from code take want define file path manually. can this:

$p = 'cache'; $m = 'foo';  ob_start(function($buffer) use ($p, $m) {     return cache_page($buffer, $p, $m); }); 

this passes compatible callback ob_start call cache_page function output buffer , closes on $p , $m callback.