Function pubsubCommand

app/redis-6.2.6/src/pubsub.c:415–469

PUBSUB command for Pub/Sub introspection. */

/* PUBSUB command for Pub/Sub introspection. */
void pubsubCommand(client *c) {
    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
        const char *help[] = {
"CHANNELS [<pattern>]",
"    Return the currently active channels matching a <pattern> (default: '*').",
"NUMPAT",
"    Return number of subscriptions to patterns.",
"NUMSUB [<channel> ...]",
"    Return the number of subscribers for the specified channels, excluding",
"    pattern subscriptions(default: no channels).",
NULL
        };
        addReplyHelp(c, help);
    } else if (!strcasecmp(c->argv[1]->ptr,"channels") &&
        (c->argc == 2 || c->argc == 3))
    {
        /* PUBSUB CHANNELS [<pattern>] */
        sds pat = (c->argc == 2) ? NULL : c->argv[2]->ptr;
        dictIterator *di = dictGetIterator(server.pubsub_channels);
        dictEntry *de;
        long mblen = 0;
        void *replylen;

        replylen = addReplyDeferredLen(c);
        while((de = dictNext(di)) != NULL) {
            robj *cobj = dictGetKey(de);
            sds channel = cobj->ptr;

            if (!pat || stringmatchlen(pat, sdslen(pat),
                                       channel, sdslen(channel),0))
            {
                addReplyBulk(c,cobj);
                mblen++;
            }
        }
        dictReleaseIterator(di);
        setDeferredArrayLen(c,replylen,mblen);
    } else if (!strcasecmp(c->argv[1]->ptr,"numsub") && c->argc >= 2) {
        /* PUBSUB NUMSUB [Channel_1 ... Channel_N] */
        int j;

        addReplyArrayLen(c,(c->argc-2)*2);
        for (j = 2; j < c->argc; j++) {
            list *l = dictFetchValue(server.pubsub_channels,c->argv[j]);

            addReplyBulk(c,c->argv[j]);
            addReplyLongLong(c,l ? listLength(l) : 0);
        }
    } else if (!strcasecmp(c->argv[1]->ptr,"numpat") && c->argc == 2) {
        /* PUBSUB NUMPAT */
        addReplyLongLong(c,dictSize(server.pubsub_patterns));
    } else {
        addReplySubcommandSyntaxError(c);
    }
}