Function zrangeGenericCommand

app/redis-6.2.6/src/t_zset.c:3571–3719

* This function handles ZRANGE and ZRANGESTORE, and also the deprecated * Z[REV]RANGE[BYPOS|BYLEX] commands. * * The simple ZRANGE and ZRANGESTORE can take _AUTO in rangetype and direction, * other command pass explicit value. * * The argc_start points to the src key argument, so following syntax is like: * [BYSCORE | BYLEX] [REV] [WITHSCORES] [LIMIT offset count] */

 * <src> <min> <max> [BYSCORE | BYLEX] [REV] [WITHSCORES] [LIMIT offset count]
 */
void zrangeGenericCommand(zrange_result_handler *handler, int argc_start, int store,
                          zrange_type rangetype, zrange_direction direction)
{
    client *c = handler->client;
    robj *key = c->argv[argc_start];
    robj *zobj;
    zrangespec range;
    zlexrangespec lexrange;
    int minidx = argc_start + 1;
    int maxidx = argc_start + 2;

    /* Options common to all */
    long opt_start = 0;
    long opt_end = 0;
    int opt_withscores = 0;
    long opt_offset = 0;
    long opt_limit = -1;

    /* Step 1: Skip the <src> <min> <max> args and parse remaining optional arguments. */
    for (int j=argc_start + 3; j < c->argc; j++) {
        int leftargs = c->argc-j-1;
        if (!store && !strcasecmp(c->argv[j]->ptr,"withscores")) {
            opt_withscores = 1;
        } else if (!strcasecmp(c->argv[j]->ptr,"limit") && leftargs >= 2) {
            if ((getLongFromObjectOrReply(c, c->argv[j+1], &opt_offset, NULL) != C_OK) ||
                (getLongFromObjectOrReply(c, c->argv[j+2], &opt_limit, NULL) != C_OK))
            {
                return;
            }
            j += 2;
        } else if (direction == ZRANGE_DIRECTION_AUTO &&
                   !strcasecmp(c->argv[j]->ptr,"rev"))
        {
            direction = ZRANGE_DIRECTION_REVERSE;
        } else if (rangetype == ZRANGE_AUTO &&
                   !strcasecmp(c->argv[j]->ptr,"bylex"))
        {
            rangetype = ZRANGE_LEX;
        } else if (rangetype == ZRANGE_AUTO &&
                   !strcasecmp(c->argv[j]->ptr,"byscore"))
        {
            rangetype = ZRANGE_SCORE;
        } else {
            addReplyErrorObject(c,shared.syntaxerr);
            return;
        }
    }

    /* Use defaults if not overriden by arguments. */
    if (direction == ZRANGE_DIRECTION_AUTO)
        direction = ZRANGE_DIRECTION_FORWARD;
    if (rangetype == ZRANGE_AUTO)
        rangetype = ZRANGE_RANK;

    /* Check for conflicting arguments. */
    if (opt_limit != -1 && rangetype == ZRANGE_RANK) {
        addReplyError(c,"syntax error, LIMIT is only supported in combination with either BYSCORE or BYLEX");
        return;