<?
/*
questions, contact me:
dietrich ayala
dietricha@subpop.com
todo:
* add expiration functionality - a time/date var that indicates a maximum age for a cache_file
* actually benchmark the class. see how much it decreases script execution time
my *basic* performance test:
(benchmarked with Dirks Webstress - http://www.paessler.com)
server: pentiumII 400 256mb RAM
webserver: apache 1.3.12
php: version 4.02 w/ Zend Optimizer
mysql: version 3.21.33b
script: hit mysql once for 700 rows of 12 fields each
and formatted results into nested tables, one per row.
avg request time w/o caching:
880 milleseconds
avg request time w/ caching:
594 milleseconds
usage:
$cache = new cache;
$args = array_merge($HTTP_POST_VARS,$HTTP_GET_VARS);
$args[] = $PHP_SELF;
$buffer = $cache->check_cache($args);
if(!$buffer){
// normal script execution here
// but instead of printing, load all
// output into a buffer var ($buffer).
// load buffer var into cache file
if(!$cache->set_cache($buffer)){
print "couldn't create cache file";
}
}
print $buffer;
*/
class cache {
function cache(){
$this->cache_name = "";
$this->debug_flag = true;
$this->cache_dir = "/home/www/scripts/cache";
}
function check_cache($args){
if($args["PHPSESSID"]){
$this->debug("found a session id");
unset($args["PHPSESSID"]);
}
$this->cache_name = strtolower(ereg_replace("[\"\'\-\;\:\,\\\/]","_",str_replace(" ","",join("_",$args)))).".cache";
$this->debug("cache_name: $this->cache_name");
clearstatcache();
if(file_exists("$this->cache_dir/$this->cache_name")){
$this->debug("and cache file exists!");
return join("",file("$this->cache_dir/$this->cache_name"));
}
return false;
}
function set_cache($buffer){
// write buffer to cache file
if($fp = @fopen("$this->cache_dir/$this->cache_name","w")){
fputs($fp,$buffer);
fclose($fp);
if(!$cache = fopen("$this->cache_dir/$this->cache_name","r")){
return false;
}
}
return true;
}
function debug($string){
if($this->debug_flag == true){
print "$string<br>";
}
}
}
?>
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