Function spopCommand

app/redis-6.2.6/src/t_set.c:600–649

}

void spopCommand(client *c) {
    robj *set, *ele;
    sds sdsele;
    int64_t llele;
    int encoding;

    if (c->argc == 3) {
        spopWithCountCommand(c);
        return;
    } else if (c->argc > 3) {
        addReplyErrorObject(c,shared.syntaxerr);
        return;
    }

    /* Make sure a key with the name inputted exists, and that it's type is
     * indeed a set */
    if ((set = lookupKeyWriteOrReply(c,c->argv[1],shared.null[c->resp]))
         == NULL || checkType(c,set,OBJ_SET)) return;

    /* Get a random element from the set */
    encoding = setTypeRandomElement(set,&sdsele,&llele);

    /* Remove the element from the set */
    if (encoding == OBJ_ENCODING_INTSET) {
        ele = createStringObjectFromLongLong(llele);
        set->ptr = intsetRemove(set->ptr,llele,NULL);
    } else {
        ele = createStringObject(sdsele,sdslen(sdsele));
        setTypeRemove(set,ele->ptr);
    }

    notifyKeyspaceEvent(NOTIFY_SET,"spop",c->argv[1],c->db->id);

    /* Replicate/AOF this command as an SREM operation */
    rewriteClientCommandVector(c,3,shared.srem,c->argv[1],ele);

    /* Add the element to the reply */
    addReplyBulk(c,ele);
    decrRefCount(ele);

    /* Delete the set if it's empty */
    if (setTypeSize(set) == 0) {
        dbDelete(c->db,c->argv[1]);
        notifyKeyspaceEvent(NOTIFY_GENERIC,"del",c->argv[1],c->db->id);
    }

    /* Set has been modified */
    signalModifiedKey(c,c->db,c->argv[1]);
    server.dirty++;
}

/* handle the "SRANDMEMBER key <count>" variant. The normal version of the
 * command is handled by the srandmemberCommand() function itself. */