Function trackingInvalidateKeyRaw

app/redis-6.2.6/src/tracking.c:350–395

This function is called from signalModifiedKey() or other places in Redis * when a key changes value. In the context of keys tracking, our task here is * to send a notification to every client that may have keys about such caching * slot. * * Note that 'c' may be NULL in case the operation was performed outside the * context of a client modifying the database (for instance when we delete a

 * just to notify the clients that are in the table for this key, that would
 * otherwise miss the fact we are no longer tracking the key for them. */
void trackingInvalidateKeyRaw(client *c, char *key, size_t keylen, int bcast) {
    if (TrackingTable == NULL) return;

    if (bcast && raxSize(PrefixTable) > 0)
        trackingRememberKeyToBroadcast(c,key,keylen);

    rax *ids = raxFind(TrackingTable,(unsigned char*)key,keylen);
    if (ids == raxNotFound) return;

    raxIterator ri;
    raxStart(&ri,ids);
    raxSeek(&ri,"^",NULL,0);
    while(raxNext(&ri)) {
        uint64_t id;
        memcpy(&id,ri.key,sizeof(id));
        client *target = lookupClientByID(id);
        /* Note that if the client is in BCAST mode, we don't want to
         * send invalidation messages that were pending in the case
         * previously the client was not in BCAST mode. This can happen if
         * TRACKING is enabled normally, and then the client switches to
         * BCAST mode. */
        if (target == NULL ||
            !(target->flags & CLIENT_TRACKING)||
            target->flags & CLIENT_TRACKING_BCAST)
        {
            continue;
        }

        /* If the client enabled the NOLOOP mode, don't send notifications
         * about keys changed by the client itself. */
        if (target->flags & CLIENT_TRACKING_NOLOOP &&
            target == c)
        {
            continue;
        }

        sendTrackingMessage(target,key,keylen,0);
    }
    raxStop(&ri);

    /* Free the tracking table: we'll create the radix tree and populate it
     * again if more keys will be modified in this caching slot. */
    TrackingTableTotalItems -= raxSize(ids);
    raxFree(ids);
    raxRemove(TrackingTable,(unsigned char*)key,keylen,NULL);
}

/* Wrapper (the one actually called across the core) to pass the key
 * as object. */