Function zunionInterDiffGenericCommand

app/redis-6.2.6/src/t_zset.c:2575–2834

The zunionInterDiffGenericCommand() function is called in order to implement the * following commands: ZUNION, ZINTER, ZDIFF, ZUNIONSTORE, ZINTERSTORE, ZDIFFSTORE. * * 'numkeysIndex' parameter position of key number. for ZUNION/ZINTER/ZDIFF command, * this value is 1, for ZUNIONSTORE/ZINTERSTORE/ZDIFFSTORE command, this value is 2. * * 'op' SET_OP_INTER, SET_OP_UNION or SET_OP_DIFF. */

 * 'op' SET_OP_INTER, SET_OP_UNION or SET_OP_DIFF.
 */
void zunionInterDiffGenericCommand(client *c, robj *dstkey, int numkeysIndex, int op) {
    int i, j;
    long setnum;
    int aggregate = REDIS_AGGR_SUM;
    zsetopsrc *src;
    zsetopval zval;
    sds tmp;
    size_t maxelelen = 0, totelelen = 0;
    robj *dstobj;
    zset *dstzset;
    zskiplistNode *znode;
    int withscores = 0;

    /* expect setnum input keys to be given */
    if ((getLongFromObjectOrReply(c, c->argv[numkeysIndex], &setnum, NULL) != C_OK))
        return;

    if (setnum < 1) {
        addReplyErrorFormat(c,
            "at least 1 input key is needed for %s", c->cmd->name);
        return;
    }

    /* test if the expected number of keys would overflow */
    if (setnum > (c->argc-(numkeysIndex+1))) {
        addReplyErrorObject(c,shared.syntaxerr);
        return;
    }

    /* read keys to be used for input */
    src = zcalloc(sizeof(zsetopsrc) * setnum);
    for (i = 0, j = numkeysIndex+1; i < setnum; i++, j++) {
        robj *obj = dstkey ?
            lookupKeyWrite(c->db,c->argv[j]) :
            lookupKeyRead(c->db,c->argv[j]);
        if (obj != NULL) {
            if (obj->type != OBJ_ZSET && obj->type != OBJ_SET) {
                zfree(src);
                addReplyErrorObject(c,shared.wrongtypeerr);
                return;
            }

            src[i].subject = obj;
            src[i].type = obj->type;
            src[i].encoding = obj->encoding;
        } else {
            src[i].subject = NULL;
        }

        /* Default all weights to 1. */
        src[i].weight = 1.0;
    }

    /* parse optional extra arguments */
    if (j < c->argc) {
        int remaining = c->argc - j;

        while (remaining) {