View file stat/_core/_class/cache_user.php

<?php
class cache_user {
	public static function get($CK) {
		$file = cache."_user/{$CK}.data";
		$cache = @file_get_contents($file);
		return unserialize($cache);
	}

	public static function save($CK) {
		$file = cache."_user/{$CK}.data";
		$cache = DB :: $dbh -> queryFetch("SELECT * FROM user WHERE CK = ? LIMIT 1;",[$CK]);        
		$cache = serialize($cache);	
		@file_put_contents($file, $cache);
	}

	public static function check($CK) {
		$file = cache."_user/{$CK}.data";
		if(!file_exists($file)):
			self::save($CK);
		endif;
		return self::get($CK);
	}

	public static function ch($CK) {
		$file = cache."_user/{$CK}.data";
		if(file_exists($file)):
			return true;
		else:	
			return false;
		endif;	
	}
}	
?>