Function zrandmemberCommand

app/redis-6.2.6/src/t_zset.c:4208–4233

ZRANDMEMBER key [ [WITHSCORES]] */

/* ZRANDMEMBER key [<count> [WITHSCORES]] */
void zrandmemberCommand(client *c) {
    long l;
    int withscores = 0;
    robj *zset;
    ziplistEntry ele;

    if (c->argc >= 3) {
        if (getLongFromObjectOrReply(c,c->argv[2],&l,NULL) != C_OK) return;
        if (c->argc > 4 || (c->argc == 4 && strcasecmp(c->argv[3]->ptr,"withscores"))) {
            addReplyErrorObject(c,shared.syntaxerr);
            return;
        } else if (c->argc == 4)
            withscores = 1;
        zrandmemberWithCountCommand(c, l, withscores);
        return;
    }

    /* Handle variant without <count> argument. Reply with simple bulk string */
    if ((zset = lookupKeyReadOrReply(c,c->argv[1],shared.null[c->resp]))== NULL ||
        checkType(c,zset,OBJ_ZSET)) {
        return;
    }

    zsetTypeRandomElement(zset, zsetLength(zset), &ele,NULL);
    zsetReplyFromZiplistEntry(c,&ele);
}