php 缓存函数代码

** 
* @说明: 文件缓存输出 
* @参数: $cachefile => cache文件(绝对路径) 
* @参数: $pertime => 缓存输出的间隔时间 
* @参数: $sql => sql语句 
* @参数: $templatefile => 模板文件名称(绝对路径) 
* www.php100.com 来自 
**/ 
function __cache($cachefile,$pertime,$sql,$templatefile) { 
global $db; 
if(time() - @filemtime($cachefile) >= $pertime) { 
$query = $db->query($sql); 
while($r=$db->fetch($query)) { 
$cachelist[] = $r; 
} 
include $templatefile.'.php'; 
$cacheserialize = serialize($cachelist); 
file_put_contents($cachefile,$cacheserialize); 
}else{ 
$cachelist = unserialize(file_get_contents($cachefile)); 
include $templatefile.'.php'; 
} 
}