What bit(s) in a zonefile inventory does a zonefile hash correspond to?
    Return their indexes in the bit field.

def atlasdb_get_zonefile_bits( zonefile_hash, con=None, path=None ):
    """
    What bit(s) in a zonefile inventory does a zonefile hash correspond to?
    Return their indexes in the bit field.
    """
    with AtlasDBOpen(con=con, path=path) as dbcon:

        sql = "SELECT inv_index FROM zonefiles WHERE zonefile_hash = ?;"
        args = (zonefile_hash,)

        cur = dbcon.cursor()
        res = atlasdb_query_execute( cur, sql, args )

        # NOTE: zero-indexed
        ret = []
        for r in res:
            ret.append( r['inv_index'] - 1 )

    return ret