mongo short id

test_mongo_short_id.php

<?php

class Base62 {
    const CHARS_SYMBOLS = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-';
    /**
     * @param $id
     * @return string
     */
    public static function encode($id){

        $l = strlen(self::CHARS_SYMBOLS);
        $chars = self::CHARS_SYMBOLS;
        $hash='';
        while($id > 0) {
            $i = fmod($id,$l);
            $hash= ($chars[intval($i)]) . $hash;
            $id=floor($id/$l);
        }
        return $hash;
    }

    /**
     * @param $code
     * @return string
     */
    public static function decode($code)
    {
        $l = strlen(self::CHARS_SYMBOLS);
        $id=0;
        $arr = array_flip(str_split(self::CHARS_SYMBOLS));
        for($i=0,$len = strlen($code); $i < $len; ++$i) {
            $id += $arr[$code[$i]] * pow($l, $len-$i-1);
        }
        return (string)$id;
    }
}


class MongoIdShort
{
    /*
        a 4-byte timestamp,
        a 3-byte machine identifier,
        a 2-byte process id, and
        a 3-byte counter.
     */

    public static function encode($id)
    {

        $timestamp = hexdec(substr($id,0,8));
        $identifier = hexdec(substr($id,8,6));
        $pid = hexdec(substr($id,14,4));
        $counter = hexdec(substr($id,18,6));
        $hashsource = Base62::encode($timestamp) .   Base62::encode($identifier)  . '\\' . Base62::encode($pid) . '\\' . Base62::encode($counter);
        return $hashsource;
    }

    public static function createMongoIdFromTimestamp($timestamp) {
        $inc = 0;
        $ts = pack('N', $timestamp);
        $m = substr(md5(gethostname()), 0, 3);
        $pid = pack('n', getmypid());
        $trail = substr(pack('N', $inc++), 1, 3);
        $bin = sprintf('%s%s%s%s', $ts, $m, $pid, $trail);
        $id = '';
        for ($i = 0; $i < 12; $i++) {
            $id .= sprintf('%02X', ord($bin[$i]));
        }
        return new \MongoID($id);
}

    public static function decode($id)
    {
        $part = explode('\\',$id);
        $timestamp =  Base62::decode(substr($part[0],0,6));
        $identifier = Base62::decode(substr($part[0],6));
        $pid = Base62::decode($part[1]);
        $counter =  Base62::decode($part[2]);
        $len_identifier = strlen($identifier)-6;
        $len_pid = strlen($pid)-4;
        $len_counter = strlen($counter)-6;

        return $hash = dechex($timestamp)
            . ($len_identifier < 0 ? str_repeat('0',$len_identifier*-1) : '')
            . dechex($identifier)
            . ($len_pid < 0 ? str_repeat('0',$len_pid*-1) : '')
            . dechex($pid)
            . ($len_counter < 0 ? str_repeat('0',$len_counter*-1) : '')
            . dechex($counter);
    }
}

/***tests ***/

$ids  = [
    '5824736fcaec5460bbfdc489',
    '58357bf59d1f9d381a000029',
    '58357bf59d1f9d381a000030',
    '58357bf59d1f9d381a005031',
    '58357bf59d1f9d381a200033',
    '58357bf59d1f9d381a001034',
    strval( new MongoId()),
    strval( new MongoId()),
    strval( new MongoId()),
    strval( new MongoId()),
    strval( new MongoId()),
    strval( new MongoId()),
    strval( new MongoId()),
    strval( new MongoId()),
    strval( new MongoId()),
];

foreach($ids as $id){
    echo "mongoId_source {$id} \n";
    $encodeId = MongoIdShort::encode($id);
    $decodeId = MongoIdShort::decode($encodeId);
    $isTrue = $id == $decodeId;
    echo "$id\n$encodeId\n{$isTrue}\n$decodeId\n========\n\n";

}

compress mongoid 25%-40%