一个简单至极的PHP缓存类代码

//从缓存从读取键值 $key 的数据
$values = $cache->get($key);

//如果没有缓存数据
if ($values == false) {
//insert code here...
//写入键值 $key 的数据
$cache->put($key,$values);
} else {
//insert code here...
}

//cache constructor,optional expiring time and cache path
public function Cache($exp_time=3600,$path="cache/"){
$this->cache_expire=$exp_time;
$this->cache_path=$path;
}

//returns the filename for the cache
private function fileName($key){
return $this->cache_path.md5($key);
}

//creates new cache files with the given data,$key== name of the cache,data the info/values to store
public function put($key,$data){
$values = serialize($data);
$filename = $this->fileName($key);
$file = fopen($filename,'w');
if ($file){//able to create the file
fwrite($file,$values);
fclose($file);
}
else return false;
}

//returns cache for the given key
public function get($key){
$filename = $this->fileName($key);
if (!file_exists($filename) || !is_readable($filename)){//can't read the cache
return false;
}
if ( time() < (filemtime($filename) + $this->cache_expire) ) {//cache for the key not expired
$file = fopen($filename,"r");// read data file
if ($file){//able to open the file
$data = fread($file,filesize($filename));
fclose($file);
return unserialize($data);//return the values
}
else return false;
}
else return false;//was expired you need to create new
}
}
?>