wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\DataModel\Internal;

use InvalidArgumentException;
use Traversable;

/**
 * Generates hashes for associative arrays based on the values of their elements.
 *
 * @since 0.1
 *
 * @license GPL-2.0-or-later
 * @author Jeroen De Dauw < jeroendedauw@gmail.com >
 */
class MapValueHasher {

    /** @var bool */
    private $isOrdered;

    public function __construct( $holdOrderIntoAccount = false ) {
        $this->isOrdered = $holdOrderIntoAccount;
    }

    /**
     * Computes and returns the hash of the provided map.
     *
     * @since 0.1
     *
     * @param Traversable $map
     *
     * @return string
     * @throws InvalidArgumentException
     */
    public function hash( $map ) {
        if ( !is_iterable( $map ) ) {
            throw new InvalidArgumentException( '$map must be an array or an instance of Traversable' );
        }

        $hashes = [];

        foreach ( $map as $hashable ) {
            $hashes[] = $hashable->getHash();
        }

        if ( !$this->isOrdered ) {
            sort( $hashes );
        }

        return sha1( implode( '|', $hashes ) );
    }

}