简单的php缓存类分享 php缓存机制

代码如下:

PHP
class Cache
{
private $dir = "data/cache/";//定义缓存目录
private $key='c_a_sss';// 文件名md5加密密钥function set_dir($dirpath)
{
$this->dir=$dirpath;
$this->make_dir($this->dir);
}
function read($key,$minutes=1)
{
$filename=$this->get_filename($key);
if($datas = @file_get_contents($filename))
{
$datas = unserialize($datas);
if(time() - $datas['time'] < $minutes*60)
{
return $datas['data'];
}
}
return false;
}function write($key,$data)
{
$filename=$this->get_filename($key);
if($handle = fopen($filename,'w+'))
{
$datas = array('data'=>$data,'time'=>time());
flock($handle,LOCK_EX);
$rs = fputs($handle,serialize($datas));
flock($handle,LOCK_UN);
fclose($handle);
if($rs!==false){return true; }
}
return false;
}
function clear_all()
{
$dir=$this->dir;
$this->del_file($dir);
}private function get_filename($key)
{
return $this->dir.$key.'_'.md5($key.$this->key);
}
private function make_dir($path)
{
if (! file_exists ( $path ))
{
$this->make_dir ( dirname ( $path ) );
if (! mkdir ( $path,0777 ))
die ( '无法创建缓存文件夹' . $path );
}
}
private function del_file($dir)
{
if (is_dir($dir))
{
$dh=opendir($dir);//打开目录 //列出目录中的所有文件并去掉 . 和 ..
while (false !== ( $file = readdir ($dh))) {
if($file!="." && $file!="..") {
$fullpath=$dir."/".$file;
if(!is_dir($fullpath)) {
unlink($fullpath);
} else {
$this->del_file($fullpath);
}
}
}
closedir($dh);
}
}
}

$cache = new cache();
$cache->set_dir('data/cache_dir/');
$data=$cache->read('sys',1);
if(empty($data))
{
$data=array('aa'=>1111,'bb'=>2222,'date'=>date('Y-m-d H:i:s'));
$cache->write('sys',$data);
}
print_r($data);