thinkphp one-click clear cache method code

//Get the directory you want to know and the absolute path where the directory is located
 public function cache(){
 ////The front desk uses ajax get to submit, judge it
 if($_POST['type' ]){
 //Get the passed value
 $type=$_POST['type'];
 //Cut the passed value. I used "-" to cut it
 $name=explode(' -', $type);
 //Get the number of cuts to facilitate the following loop
 $count=count($name);
 //Call the above method in a loop
 for ($i=0;$i<$count ;$i++){
 //Get the absolute path of the file
 $abs_dir=dirname(dirname(dirname(dirname(__FILE__)))));
 //Combined path
 $pa=$abs_dir.'indexRuntime';
 $runtime =$abs_dir.'indexRuntime~runtime.php';
 if(file_exists($runtime))//Determine whether the file exists
 {
 unlink($runtime);//Delete the file
 }
 //Call to delete the folder Method to download all files
 $this->rmFile($pa,$name[$i]);
 }
 //Give prompt information
 $this->ajaxReturn(1,'clear successfully',1) ;
 }else{
 $this->display();
 }
 }
 public function rmFile($path,$fileName){//Delete execution method
 //Remove spaces
 $path = preg_replace('/ (/){2,}|{}{1,}/','/',$path);
 //Get the complete directory
 $path.= $fileName;
 //Determine whether this file is a file directory
 if(is_dir($path)){
 //Open the file
 if ($dh = opendir($path)){
 //Traverse the file directory name
 while (($file = readdir($dh)) != false){
 //Delete one by one
 unlink($path.''.$file);
 }
 //Close the file
 closedir($dh);
 }
 }
 }

Part of the code on the front page: