Simple php Cache class sharing php Cache mechanism

This article mainly introduces a php Cache class that uses md5 encryption for file names. The code is as follows:
Class Cache
{
Private $ dir = "data/cache/"; // defines the cache Directory
Private $ key = 'c _ a_sss '; // file name md5 encryption key

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 ('unable to create cache folders '. $ path );
}
}
Private function del_file ($ dir)
{
If (is_dir ($ dir ))
{
$ Dh = opendir ($ dir); // open the Directory // list all files in the directory and remove ..
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 ('a' => 1111, 'BB '=> 2222, 'date' => date ('Y-m-d H: I: s '));
$ Cache-> write ('sys ', $ data );
}
Print_r ($ data );