serializer.php

<?php

class Serializer
{

        /**
	 * Vstupni pole musi obsahovat
	 *  - pouze celociselne hodnoty
	 *  - pro oznaceni klicu pismena a-f
	 *
	 * Pri oznaceni klicu pismeny a-f je vysledkem hexadecimal string
	 * ten lze prevest na binary string
	 * uspora mista v Redisu je pak cca 25%
	 *
	 * @param array $data
	 *
	 * @return string
	 * @throws \RuntimeException
	 */
	public static function pack( $data )
	{
		$res = '';
		foreach ( $data as $key => $val ) {
			// pro zaporna cisla nahradit minus nulou
			if ( $val < 0 ) {
				$val = '0' . ( $val * -1 );
			}
			$res .= $key . $val;
		}
		if ( preg_match( '~[^0-9a-f]~', $res ) > 0 ) {
			throw new \RuntimeException( 'Unexpected data format.' );
		}
		// Pred retezec s lichym poctem znaku pridat nulu
		if ( strlen( $res ) % 2 == 1 ) $res = '0' . $res;

		return pack( 'H*', $res );
	}


	/**
	 * input: binary from "0a04b25c3d1371384703e1371384703f1371298342"
	 * output: array (
	 *     a => -4,
	 *     b => 25,
	 *     c => 3,
	 *     d => 1371384703,
	 *     e => 1371384703,
	 *     f => 1371298342
	 * }
	 *
	 * @param string $bin
	 *
	 * @return array
	 * @throws \RuntimeException
	 */
	public static function unpack( $bin )
	{
		$unpack = unpack( 'H*', $bin );
		$unpack = $unpack[1];
		// Odstranit uvodni nulu (doplnuje retezec na sudy pocet znaku)
		if ( $unpack[0] === '0' ) $unpack = substr( $unpack, 1 );

		$hits = preg_match_all( '~(\D+)(\d+)~', $unpack, $match );
		// Musi byt alespon jedna shoda
		if ( $hits == 0 ) {
			throw new \RuntimeException( 'Unexpected data format.' );
		}

		$res = array_combine( $match[1], $match[2] );
		foreach ( $res as &$val ) {
			// Nula na zacatku hodnoty oznacuje zaporne cislo
			$pos = ( $val[0] === '0' ) ? -1 : 1;
			$val = intval( $val ) * $pos;
		}

		return $res;
	}

}