PHP短哈希像url缩短的网站

我正在寻找一个PHP函数来创build一个string或文件的短哈希,类似于那些URL缩短的网站,如tinyurl.com

散列不应超过8个字符。

URL缩短服务,而是使用一个自动递增的整数值(如补充数据库ID),并使用Base64或其他编码进行编码,以获得更多的每个字符的信息(64而不是像10位数字)。

TinyURL不散列任何东西,它使用Base 36整数(甚至是基数62,使用小写字母和大写字母)来指示要访问的logging。

基数36到整数:

 intval($str,36) 

整数到基数36:

 base_convert($val, 10, 36) 

那么,而不是redirect到像/url/1234这样的路线,它变成了/url/ax 。 这会给你一个比散列更多的用处,因为不会有冲突。 有了这个,你可以很容易地检查一个url是否存在,并返回适当的,现有的ID在基地36,用户不知道它已经在数据库中。

不要哈希,使用其他的基础这种事情。 (速度更快,可以防撞。)

我写了一个小的库来从整数生成混淆的哈希值。

http://web.archive.org/web/20130727034425/http://blog.kevburnsjr.com/php-unique-hash

 $ids = range(1,10); foreach($ids as $id) { echo PseudoCrypt::unhash($id) . "\n"; } 
  m8z2p
 8hy5e
 uqx83
 gzwas
 38vdh
 phug6
 bqtiv
 xzslk
 k8ro9
 6hqqy 

7/14/2015:添加下面的实际代码,因为它很难find:

 <?php /** * PseudoCrypt by KevBurns (http://blog.kevburnsjr.com/php-unique-hash) * Reference/source: http://stackoverflow.com/a/1464155/933782 * * I want a short alphanumeric hash that's unique and who's sequence is difficult to deduce. * I could run it out to md5 and trim the first n chars but that's not going to be very unique. * Storing a truncated checksum in a unique field means that the frequency of collisions will increase * geometrically as the number of unique keys for a base 62 encoded integer approaches 62^n. * I'd rather do it right than code myself a timebomb. So I came up with this. * * Sample Code: * * echo "<pre>"; * foreach(range(1, 10) as $n) { * echo $n." - "; * $hash = PseudoCrypt::hash($n, 6); * echo $hash." - "; * echo PseudoCrypt::unhash($hash)."<br/>"; * } * * Sample Results: * 1 - cJinsP - 1 * 2 - EdRbko - 2 * 3 - qxAPdD - 3 * 4 - TGtDVc - 4 * 5 - 5ac1O1 - 5 * 6 - huKpGQ - 6 * 7 - KE3d8p - 7 * 8 - wXmR1E - 8 * 9 - YrVEtd - 9 * 10 - BBE2m2 - 10 */ class PseudoCrypt { /* Key: Next prime greater than 62 ^ n / 1.618033988749894848 */ /* Value: modular multiplicative inverse */ private static $golden_primes = array( '1' => '1', '41' => '59', '2377' => '1677', '147299' => '187507', '9132313' => '5952585', '566201239' => '643566407', '35104476161' => '22071637057', '2176477521929' => '294289236153', '134941606358731' => '88879354792675', '8366379594239857' => '7275288500431249', '518715534842869223' => '280042546585394647' ); /* Ascii : 0 9, AZ, az */ /* $chars = array_merge(range(48,57), range(65,90), range(97,122)) */ private static $chars62 = array( 0=>48,1=>49,2=>50,3=>51,4=>52,5=>53,6=>54,7=>55,8=>56,9=>57,10=>65, 11=>66,12=>67,13=>68,14=>69,15=>70,16=>71,17=>72,18=>73,19=>74,20=>75, 21=>76,22=>77,23=>78,24=>79,25=>80,26=>81,27=>82,28=>83,29=>84,30=>85, 31=>86,32=>87,33=>88,34=>89,35=>90,36=>97,37=>98,38=>99,39=>100,40=>101, 41=>102,42=>103,43=>104,44=>105,45=>106,46=>107,47=>108,48=>109,49=>110, 50=>111,51=>112,52=>113,53=>114,54=>115,55=>116,56=>117,57=>118,58=>119, 59=>120,60=>121,61=>122 ); public static function base62($int) { $key = ""; while(bccomp($int, 0) > 0) { $mod = bcmod($int, 62); $key .= chr(self::$chars62[$mod]); $int = bcdiv($int, 62); } return strrev($key); } public static function hash($num, $len = 5) { $ceil = bcpow(62, $len); $primes = array_keys(self::$golden_primes); $prime = $primes[$len]; $dec = bcmod(bcmul($num, $prime), $ceil); $hash = self::base62($dec); return str_pad($hash, $len, "0", STR_PAD_LEFT); } public static function unbase62($key) { $int = 0; foreach(str_split(strrev($key)) as $i => $char) { $dec = array_search(ord($char), self::$chars62); $int = bcadd(bcmul($dec, bcpow(62, $i)), $int); } return $int; } public static function unhash($hash) { $len = strlen($hash); $ceil = bcpow(62, $len); $mmiprimes = array_values(self::$golden_primes); $mmi = $mmiprimes[$len]; $num = self::unbase62($hash); $dec = bcmod(bcmul($num, $mmi), $ceil); return $dec; } } 

最短的哈希是32个字符的长度,你可以使用md5哈希的前8个字符

 echo substr(md5('http://www.google.com'), 0, 8); 

更新 :这里是另一个类由Travell珀金斯写在这里 ,其中logging的数量和创build短散列它。 14位数字产生8位数字串。 到达这个数字的date,你比tinyurl更受欢迎;)

 class BaseIntEncoder { //const $codeset = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; //readable character set excluded (0,O,1,l) const codeset = "23456789abcdefghijkmnopqrstuvwxyzABCDEFGHIJKLMNPQRSTUVWXYZ"; static function encode($n){ $base = strlen(self::codeset); $converted = ''; while ($n > 0) { $converted = substr(self::codeset, bcmod($n,$base), 1) . $converted; $n = self::bcFloor(bcdiv($n, $base)); } return $converted ; } static function decode($code){ $base = strlen(self::codeset); $c = '0'; for ($i = strlen($code); $i; $i--) { $c = bcadd($c,bcmul(strpos(self::codeset, substr($code, (-1 * ( $i - strlen($code) )),1)) ,bcpow($base,$i-1))); } return bcmul($c, 1, 0); } static private function bcFloor($x) { return bcmul($x, '1', 0); } static private function bcCeil($x) { $floor = bcFloor($x); return bcadd($floor, ceil(bcsub($x, $floor))); } static private function bcRound($x) { $floor = bcFloor($x); return bcadd($floor, round(bcsub($x, $floor))); } } 

这里是如何使用它的例子:

 BaseIntEncoder::encode('1122344523');//result:3IcjVE BaseIntEncoder::decode('3IcjVE');//result:1122344523 

最佳答案然而: 最小的唯一“哈希像”string给予唯一的数据库ID – PHP解决scheme,没有第三方库的要求。

代码如下:

 <?php /* THE FOLLOWING CODE WILL PRINT: A database_id value of 200 maps to 5K A database_id value of 1 maps to 1 A database_id value of 1987645 maps to 16LOD */ $database_id = 200; $base36value = dec2string($database_id, 36); echo "A database_id value of $database_id maps to $base36value\n"; $database_id = 1; $base36value = dec2string($database_id, 36); echo "A database_id value of $database_id maps to $base36value\n"; $database_id = 1987645; $base36value = dec2string($database_id, 36); echo "A database_id value of $database_id maps to $base36value\n"; // HERE'S THE FUNCTION THAT DOES THE HEAVY LIFTING... function dec2string ($decimal, $base) // convert a decimal number into a string using $base { //DebugBreak(); global $error; $string = null; $base = (int)$base; if ($base < 2 | $base > 36 | $base == 10) { echo 'BASE must be in the range 2-9 or 11-36'; exit; } // if // maximum character string is 36 characters $charset = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'; // strip off excess characters (anything beyond $base) $charset = substr($charset, 0, $base); if (!ereg('(^[0-9]{1,50}$)', trim($decimal))) { $error['dec_input'] = 'Value must be a positive integer with < 50 digits'; return false; } // if do { // get remainder after dividing by BASE $remainder = bcmod($decimal, $base); $char = substr($charset, $remainder, 1); // get CHAR from array $string = "$char$string"; // prepend to output //$decimal = ($decimal - $remainder) / $base; $decimal = bcdiv(bcsub($decimal, $remainder), $base); } while ($decimal > 0); return $string; } ?> 

实际上,具有“随机”哈希值的最佳解决scheme是生成一个随机哈希列表,并将其放置在具有唯一索引的Mysql上(您可以编写一个简单的UDF在1个后缀中插入100 000行)。

我觉得像这样的结构ID | HASH | STATUS | URL | VIEWS | ……

状态表示这个散列是否空闲。