sessions database manager - php

DB_Sessions.php

<?php

/**
 * Initial Setup of file
 * Garbage collection sucks, we should have a time check during read and auto destroy/not recover old sessions
 */
class DB_Sessions
{
	var $session_life = 300;
	var $sessiontable = 'sessions';
	var $recordtable = 'sessions_loginrecord';
	/**
	 * @var DB_Wrapper
	 */
	var $dbhost;
	var $sessionhash;
	var $write_callback;
	var $memcache;

	function __construct(&$dbhost)
	{
		$this->dbhost =& $dbhost;
		ini_set('session.save_handler', 'user');
		session_set_save_handler(
			array($this, 'sess_open'),
			array($this, 'sess_close'),
			array($this, 'sess_read'),
			array($this, 'sess_write'),
			array($this, 'sess_destroy'),
			array($this, 'sess_gc')
		);

		if(function_exists('memcache_pconnect')) {
			$this->memcache = @memcache_pconnect($_SERVER['MEMCACHE_SERVER'], $_SERVER['MEMCACHE_PORT']);
		}
	}

	/**************************************
	 * sess_open
	 ***************************************
	 * Notes:
	 ***************************************
	 * Used In
	 ***************************************
	 * @author Richard Thomas
	 *
	 * @param $save_path    STRING
	 * @param $session_name STRING
	 *
	 * @return BOOL
	 */
	function sess_open($save_path, $session_name)
	{
		return true;
	}

	/**************************************
	 * sess_close
	 ***************************************
	 * Notes:
	 ***************************************
	 * Used In
	 ***************************************
	 * @author Richard Thomas
	 * @return BOOL
	 */
	function sess_close()
	{
		return true;
	}

	/**************************************
	 * sess_read
	 ***************************************
	 * Notes:
	 ***************************************
	 * Used In
	 ***************************************
	 * @author Richard Thomas
	 *
	 * @param $key STRING
	 *
	 * @return BOOL
	 */
	function sess_read($key)
	{
		if (!is_object($this->memcache) OR (!$value = $this->memcache->get('sess_key_' . $key)))
		{
			$qry = "SELECT `value` FROM " . $this->sessiontable . " WHERE `sesskey` = '$key'";
			$qid = $this->dbhost->query($qry);
			if (list($value) = $qid->fetch_row())
			{
				$this->sessionhash = md5($value);
				if (is_object($this->memcache) AND $value)
				{
					$this->memcache->set('sess_key_' . $key, $value, COMPRESS_CACHE);
				}

				return (String) $value;
			}
		}
		else
		{
			$this->sessionhash = md5($value);

			return (String) $value;
		}

		return '';
	}

	/**************************************
	 * sess_write
	 ***************************************
	 * Notes:
	 ***************************************
	 * Used In
	 ***************************************
	 * @author Richard Thomas
	 *
	 * @param $key STRING
	 * @param $val STRING
	 *
	 * @return BOOL
	 */
	function sess_write($key, $val)
	{
		$expiry = time() + $this->session_life;
		$value  = addslashes($val);
		if (md5($val) == $this->sessionhash)
		{
			$qry = "UPDATE " . $this->sessiontable . " SET expiry = $expiry, userkey = '" . @$_SESSION['login'] . "' WHERE sesskey = '$key'";
		}
		else
		{
			if (is_object($this->memcache))
			{
				$this->memcache->delete('sess_key_' . $key);
			}
			$qry = "UPDATE " . $this->sessiontable . " SET expiry = $expiry, value = '$value', userkey = '" . @$_SESSION['login'] . "' WHERE sesskey = '$key'";
			if ($this->write_callback)
			{
				call_user_func($this->write_callback, $val);
			}
		}
		$qid = $this->dbhost->query($qry);
		if (!$this->dbhost->affected_rows())
		{
			if (!empty($_SERVER['REMOTE_ADDR']))
			{
				$qry = "INSERT INTO " . $this->sessiontable . " VALUES ('$key', $expiry, '$value','" . @$_SESSION['login'] . "','$expiry','" . $_SERVER['REMOTE_ADDR'] . "','" . $_SERVER['HTTP_HOST'] . "')";
			}
			else
			{
				$qry = "INSERT INTO " . $this->sessiontable . " VALUES ('$key', $expiry, '$value','" . @$_SESSION['login'] . "','$expiry','\"\"','" . $_SERVER['HTTP_HOST'] . "')";
			}
			$qid = $this->dbhost->query($qry);
		}

		return $qid;
	}

	/**************************************
	 * sess_destroy
	 ***************************************
	 * Notes:
	 ***************************************
	 * Used In
	 ***************************************
	 * @author Richard Thomas
	 *
	 * @param $key STRING
	 *
	 * @return BOOL
	 */
	function sess_destroy($key)
	{
		$temp = time();
		if (is_object($this->memcache))
		{
			$this->memcache->delete('sess_key_' . $key);
		}
		$qry     = "SELECT userkey,started,ip,host FROM " . $this->sessiontable . " WHERE sesskey = '$key'";
		$qid     = $this->dbhost->query($qry);
		$row     = $qid->fetch_assoc();
		$userkey = $row['userkey'];
		$started = $row['started'];
		$ip      = $row['ip'];
		$host    = $row['host'];
		if ($userkey <> "" AND $this->recordtable)
		{
			$qry = "INSERT INTO " . $this->recordtable . " VALUES ('$userkey','$started','$temp','$ip','$host')";
			$qid = $this->dbhost->query($qry);
		}
		$qry = "DELETE FROM " . $this->sessiontable . " WHERE sesskey = '$key'";
		$qid = $this->dbhost->query($qry);

		return $qid;
	}

	/**************************************
	 * sess_gc
	 ***************************************
	 * Notes:
	 ***************************************
	 * Used In
	 ***************************************
	 * @author Richard Thomas
	 *
	 * @param $maxlifetime INT
	 *
	 * @return BOOL
	 */
	function sess_gc($maxlifetime)
	{
		$temp   = time();
		$qry    = "SELECT sesskey FROM " . $this->sessiontable . " WHERE expiry < " . $temp;
		$result = $this->dbhost->query($qry);
		for ($i = 0; $i < $result->num_rows(); $i++)
		{
			$row = $result->fetch_assoc();
			$key = $row['sesskey'];
			if (is_object($this->memcache))
			{
				$this->memcache->delete('sess_key_' . $key);
			}
			$qry = "SELECT userkey,started,ip,host FROM " . $this->sessiontable . " WHERE sesskey = '$key'";
			$qid = $this->dbhost->query($qry);
			if ($qid)
			{
				$row     = $qid->fetch_assoc();
				$userkey = $row['userkey'];
				$started = $row['started'];
				$ip      = $row['ip'];
				$host    = $row['host'];
				if ($userkey <> "" AND $this->recordtable)
				{
					$qry = "INSERT INTO " . $this->recordtable . " VALUES ('$userkey','$started','$temp','$ip','$host')";
					$qid = $this->dbhost->query($qry);
				}
			}
		}
		$qry = "DELETE FROM " . $this->sessiontable . " WHERE expiry < " . $temp;
		$qid = $this->dbhost->query($qry);

		return $this->dbhost->affected_rows();
	}

	/**************************************
	 * sess_isonline
	 ***************************************
	 * Notes:
	 ***************************************
	 * Used In
	 ***************************************
	 * @author Richard Thomas
	 *
	 * @param $login STRING
	 *
	 * @return BOOL
	 */
	function session_isonline($login)
	{
		$temp   = time();
		$query  = "SELECT userkey FROM " . $this->sessiontable . " WHERE userkey = '$login' AND expiry > $temp";
		$result = $this->dbhost->query($query);

		return $result->num_rows();
	}

}