<?php 
/* SimpleCache v1.2
 * May 2010
 * Gilbert Pellegrom
 * http://gilbertpellegrom.co.uk
 *
 * Free to use and abuse under the MIT license.
 * http://www.opensource.org/licenses/mit-license.php
 */

class SimpleCache {

	//Path to cache folder (with trailing /)
	var $cache_path = 'cache/';
	//Length of time to cache a file in seconds
	var $cache_time = 3600;
	
	//This is just a functionality wrapper function
	function get_data($label, $url)
	{
		if($data = $this->get_cache($label)){
			return $data;
		} else {
			$data = $this->do_curl($url);
			$this->set_cache($label, $data);
			return $data;
		}
	}
	
	function set_cache($label, $data)
	{
		file_put_contents($this->cache_path . $this->safe_filename($label) .'.cache', $data);
	}
	
	function get_cache($label)
	{
		if($this->is_cached($label))
		{
            $filename = $this->cache_path . $this->safe_filename($label) .'.cache';
			return file_get_contents($filename);
		}
		
		return false;
	}
	
	function is_cached($label)
	{
		$filename = $this->cache_path . $this->safe_filename($label) .'.cache';
		
		if(file_exists($filename) && (filemtime($filename) + $this->cache_time >= time()))
		{
			return true;
		}
		
		return false;
	}
	
	//Helper function for retrieving data from url
	function do_curl($url)
	{
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $url);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
		curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 1);
		$content = curl_exec($ch);
		curl_close($ch);
		
		return $content;
	}
	
	//Helper function to validate filenames
	function safe_filename($filename) 
	{
		return preg_replace('/[^0-9a-z\.\_\-]/i','', strtolower($filename));
	}
}

?>