<?php
/**
* Bastiaan Welmers - 20081013
* instataniate this class and use mysql_query_cache instead of mysql_query for slow queries
*
* php4 style class
*
*/

class memCacheDb
{
	var $memcache;
	
	// constructor
	function memCacheDb()
	{
		# Connect to memcache:
		$this->memcache = new Memcache;
		$this->memcache->connect('localhost', 11211) or die ("Could not connect to memcache");
	}
	
	# Gets key / value pair into memcache ... called by mysql_query_cache()
	function getCache($key) {
		return ($this->memcache) ? $this->memcache->get($key) : false;
	}

	# Puts key / value pair into memcache ... called by mysql_query_cache()
	function setCache($key,$object,$timeout = 60) {
		return ($this->memcache) ? $this->memcache->set($key,$object,MEMCACHE_COMPRESSED,$timeout) : false;
	}

	# Caching version of mysql_query()
	function mysql_query_cache($sql, $linkIdentifier = false, $timeout = 600 /* = 10 minutes expiration */) {
		if (!($cache = getCache(md5("mysql_query" . $sql)))) {
			$cache = false;
			$r = ($linkIdentifier !== false) ? mysql_query($sql,$linkIdentifier) : mysql_query($sql);
			if (is_resource($r) && (($rows = mysql_num_rows($r)) != 0)) {
				for ($i=0;$i<$rows;$i++) {
					$fields = mysql_num_fields($r);
					$row = mysql_fetch_array($r);
					for ($j=0;$j<$fields;$j++) {
						if ($i == 0) {
							$columns[$j] = mysql_field_name($r,$j);
						}
						$cache[$i][$columns[$j]] = $row[$j];
					}
				}
				if (!setCache(md5("mysql_query" . $sql),$cache,$timeout)) {
					die('Error trying to connect to memcache');
					# If we get here, there isn't a memcache daemon running or responding
				}
			}
		}
		return $cache;
	}
}