Compatible DJB2 Hash implementation in JS and SQL

djb2.js

function djb2Hash(str, seed) {
    for (var counter = 0, len = str.length; counter < len; counter++) {
        seed ^= (seed << 5);
        seed ^= str.charCodeAt(counter);
    }

    // We discard the sign-bit for compatibility with the DB implementation
    // and "always positive integers"
    return seed & ~(1 << 31);
}

djb2.sql

CREATE OR REPLACE FUNCTION djb2_hash(string text)
 RETURNS bigint
 LANGUAGE sql
AS $$
WITH RECURSIVE t(seed, string) AS (
    VALUES (
        87049::bigint,
        $1
    )
UNION ALL
    SELECT
        (
            (
                (t.seed << 5) #
                t.seed #
                ascii (
                    substr (
                        t.string,
                        1,
                        1
                    )
                )
            )
        ),
        substr (
            t.string,
            2
        )
    FROM t
)
SELECT seed & ~(1 << 31)::bigint
FROM t
WHERE string = ''
$$;

WITH v(s) AS (
    VALUES
        ('foo'),
        ('bar'),
        ('disqus'),
        ('bazinga')
)
SELECT s, djb2_hash(s)
FROM v;