File Source for class.url

<?php
/**
* Class to shorten Urls
* @package url_shortener
* @author Julius Beckmann
* @link http://juliusbeckmann.de/classes/url_shortener/
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
* @filesource
*/
/*
* class.url_shortener.php
*
* Copyright 2009 Julius Beckmann
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
/*
MySQL Table for this Class:
CREATE TABLE IF NOT EXISTS `url_redirect` (
`id` bigint(20) unsigned NOT NULL auto_increment,
`url` varchar(255) NOT NULL,
`md5` char(32) NOT NULL,
`ts` int(10) unsigned NOT NULL,
`ip` int(10) unsigned NOT NULL,
PRIMARY KEY (`id`),
KEY `md5` (`md5`)
) ENGINE=MyISAM AUTO_INCREMENT=1000 ;
If you want to log number of hits, create such a table:
CREATE TABLE IF NOT EXISTS `url_hits` (
`id` BIGINT UNSIGNED NOT NULL ,
`hits` BIGINT UNSIGNED NOT NULL ,
PRIMARY KEY (`id`)
) ENGINE = MYISAM;
This database layout is abled to store more then 4 Billion links.
This limit is set by the MySQL BIGINT collumn used.
The md5 collumn is used for validating and searching duplicate Urls.
I did a short test and inserted about 100.000 Links and Hits
which needed only ~17 MB of space. => 180 Byte per Link (with index and hits)
The only limitation by the class is the convert method.
After 1.000.000.000.000.000.000 links there would be a overflow.
*/
/**
* Class for shortening urls
* The urls will be stored in a MySQL database, read doku for table Format.
* @name Url shorten class
* @version v0.1_2009.09.10
* @access public
* @package url_shortener
*/
class url_shortener {
/**
* Name of Database table for storing urls and keys
* @access public
* @var string
*/
var $db_table_redirect = 'url_redirect';
/**
* Name of Database table for storing redirect hits
* @access public
* @var string
*/
var $db_table_hits = 'url_hits';
/**
* Convertion basis for the key convert method.
* Default and maximum is 36 (36 => 0..9 and a..z)
* If you want to have hex keys set this to 16 (16 => 0..9 and a..f)
* @access public
* @var int
*/
var $key_base = 36;
/**
* Regex for URL validation
* This one is very simple and does only allow urls
* starting with http:// and https://
* @access public
* @var string
*/
var $regex_valid_url = '@http(s?):\/\/@';
/**
* List of forbidden URL parts
* Can be used to avoid making short links from short links
* @access public
* @var array
*/
var $url_parts_forbidden = array('http://www.example.com');
// --- PUBLIC Methods ---
// public means: You can _safely_ use this functions from outside.
// They will not change.
/**
* Method for creating a new redirect
* Will return data from database if url already shortened
* @access public
* @param string $url Url to shorten
* @return array Array with all available data inside, or empty one
*/
function new_redirect($url) {
$ret = array();
$url = trim($url);
if($url && $this->_valid_url($url) && !$this->_forbidden_url($url)) {
// Check if url is already in database
$get = $this->_get_redirect_by_url($url);
if($get)
$ret = $get;
else
// If not, insert
$ret = $this->_insert_url($url);
}
return $ret;
}
/**
* Method for selecting a redirect from database
* @access public
* @param string $key Redirect key to search
* @return array Array with all available data inside, or empty one
*/
function get_redirect($key) {
return $this->_get_redirect_by_key($key);
}
/**
* Logs a redirect hit by key
* @access public
* @param string $key Key of hitted link
* @return bool false on error
*/
function log_redirect($key) {
$ret = false;
$id = $this->_convert_id($key, false);
if($id) {
// Try to update first
// We will use LOW_PRIORITY/DELAYED here to smoothen the database IO.
$sql = 'UPDATE LOW_PRIORITY '.$this->db_table_hits.' SET hits=hits+1
WHERE id='.(int)$id.' LIMIT 1;';
if(mysql_query($sql))
$ret = (bool)mysql_affected_rows();
// Insert if update failed
if(!$ret) {
$sql = 'INSERT DELAYED INTO '.$this->db_table_hits
.' (id,hits)VALUES(\''.(int)$id.'\',\'1\');';
if(mysql_query($sql))
$ret = (bool)mysql_affected_rows();
}
}
return $ret;
}
/**
* Simply returns the number of current hits for this key
* @access public
* @param string $key Key of hitted link
* @return int|falsefalse on error
*/
function get_redirect_count($key) {
$ret = false;
$sql = 'SELECT count(*) AS count FROM '.$this->db_table_hits
.' WHERE id = '.$this->_convert_id($key, false).';';
$query = mysql_query($sql);
if($query) {
$r = mysql_fetch_assoc($query);
$ret = (int)$r['count'];
}
return $ret;
}
/**
* Simply returns the number of current urls
* @access public
* @return int|falsefalse on error
*/
function count_urls() {
$ret = false;
$sql = 'SELECT count(*) AS count FROM '.$this->db_table_redirect.';';
$query = mysql_query($sql);
if($query) {
$r = mysql_fetch_assoc($query);
$ret = (int)$r['count'];
}
return $ret;
}
// --- PRIVATE Methods ---
// "private" means: do _not_ use these functions from outside!
// It is very likely that they will get change or removed.
/**
* Validates a URL with global regex
* @access private
* @param strin $url URL to validate
* @return bool true if URL is ok
*/
function _valid_url($url) {
$ret = true;
// Only validate if regex is set
if($this->regex_valid_url)
$ret = (bool)preg_match($this->regex_valid_url, $url);
return $ret;
}
/**
* Checks if a URL contains forbidden parts
* @access private
* @param string $url URL to check
* @return bool True if URL is forbidden
*/
function _forbidden_url($url) {
$ret = false;
if(is_array($this->url_parts_forbidden)) {
$i = 0;
$count = count($this->url_parts_forbidden);
while(!$ret && $i < $count)
$ret = (strpos($url, $this->url_parts_forbidden[$i++]) !== false);
}
return $ret;
}
/**
* Inserts a URL to the database and returns the whole dataset
* @access private
* @param string $url Url to shorten
* @return array Array with all available data inside, or empty one
*/
function _insert_url($url) {
$ret = array();
// Clear unwanted chars from url
$url = str_ireplace(array("\n","\r","\t"), '', $url);
// We save timestamp and IP of submitter.
// MD5 is needed for verification and faster search on multiple insert
$sql = 'INSERT INTO '.$this->db_table_redirect.' (url,md5,ts,ip)
VALUES (
\''.mysql_real_escape_string($url).'\',
\''.md5($url).'\',
\''.time().'\',
INET_ATON(\''.$this->_get_ip().'\'));';
if(mysql_query($sql))
$ret = $this->get_redirect($this->_convert_id(mysql_insert_id()));
return $ret;
}
/**
* Searches a Key in the database and returns the whole dataset
* @access private
* @param string $key Key to search
* @return array Array with all available data inside, or empty one
*/
function _get_redirect_by_key($key) {
$ret = array();
// Search for the
$sql = 'SELECT *, INET_NTOA(ip) as ip_long FROM '.
$this->db_table_redirect.' WHERE id = \''.
$this->_convert_id($key, false).'\' LIMIT 1;';
$query = mysql_query($sql);
if($query && $r = mysql_fetch_assoc($query)) {
$ret = $r;
$ret['key'] = $this->_convert_id($ret['id']);
}
return $ret;
}
/**
* Searches a URL in the database and returns the whole dataset
* @access private
* @param string $url Url to search
* @return array Array with all available data inside, or empty one
*/
function _get_redirect_by_url($url) {
$ret = array();
// Search for MD5 of URL because it is a CHAR Collumn with a INDEX on it.
$sql = 'SELECT *, INET_NTOA(ip) as ip_long FROM '.
$this->db_table_redirect.' WHERE md5 = \''.md5($url).'\';';
$query = mysql_query($sql);
if($query) {
while($r = mysql_fetch_assoc($query))
if($r['url'] == $url) {
$ret = $r;
$ret['key'] = $this->_convert_id($ret['id']);
}
}
return $ret;
}
/**
* Converts a numeric id from decimal to alphanumeric.
* @access private
* @param int|string$id Integer to convert
* @param bool $dir Direction to convert, default=true => normal
* @return string Converted id
*/
function _convert_id($id, $dir=true) {
if($dir)
return base_convert($id, 10, $this->key_base);
else
return base_convert($id, $this->key_base, 10);
}
/**
* Returns the ip of current client
* Checks for clients behind proxys
* @access private
* @return string IP of current client
*/
function _get_ip() {
$ip = $_SERVER['REMOTE_ADDR'];
if($_SERVER['HTTP_X_FORWARDED_FOR'])
$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
if($_SERVER['HTTP_FORWARDED_FOR'])
$ip = $_SERVER['HTTP_FORWARDED_FOR'];
if($_SERVER['HTTP_FORWARDED'])
$ip = $_SERVER['HTTP_FORWARDED'];
return $ip;
}
}
?>

Source for file class.url_shortener.php