Function pfaddCommand

app/redis-6.2.6/src/hyperloglog.c:1180–1217

PFADD var ele ele ele ... ele => :0 or :1 */

/* PFADD var ele ele ele ... ele => :0 or :1 */
void pfaddCommand(client *c) {
    robj *o = lookupKeyWrite(c->db,c->argv[1]);
    struct hllhdr *hdr;
    int updated = 0, j;

    if (o == NULL) {
        /* Create the key with a string value of the exact length to
         * hold our HLL data structure. sdsnewlen() when NULL is passed
         * is guaranteed to return bytes initialized to zero. */
        o = createHLLObject();
        dbAdd(c->db,c->argv[1],o);
        updated++;
    } else {
        if (isHLLObjectOrReply(c,o) != C_OK) return;
        o = dbUnshareStringValue(c->db,c->argv[1],o);
    }
    /* Perform the low level ADD operation for every element. */
    for (j = 2; j < c->argc; j++) {
        int retval = hllAdd(o, (unsigned char*)c->argv[j]->ptr,
                               sdslen(c->argv[j]->ptr));
        switch(retval) {
        case 1:
            updated++;
            break;
        case -1:
            addReplyError(c,invalid_hll_err);
            return;
        }
    }
    hdr = o->ptr;
    if (updated) {
        signalModifiedKey(c,c->db,c->argv[1]);
        notifyKeyspaceEvent(NOTIFY_STRING,"pfadd",c->argv[1],c->db->id);
        server.dirty += updated;
        HLL_INVALIDATE_CACHE(hdr);
    }
    addReply(c, updated ? shared.cone : shared.czero);
}

/* PFCOUNT var -> approximated cardinality of set. */
void pfcountCommand(client *c) {