Function enableTracking

app/redis-6.2.6/src/tracking.c:180–209

Enable the tracking state for the client 'c', and as a side effect allocates * the tracking table if needed. If the 'redirect_to' argument is non zero, the * invalidation messages for this client will be sent to the client ID * specified by the 'redirect_to' argument. Note that if such client will * eventually get freed, we'll send a message to the original client to * inform it of the condit

 * inform it of the condition. Multiple clients can redirect the invalidation
 * messages to the same client ID. */
void enableTracking(client *c, uint64_t redirect_to, uint64_t options, robj **prefix, size_t numprefix) {
    if (!(c->flags & CLIENT_TRACKING)) server.tracking_clients++;
    c->flags |= CLIENT_TRACKING;
    c->flags &= ~(CLIENT_TRACKING_BROKEN_REDIR|CLIENT_TRACKING_BCAST|
                  CLIENT_TRACKING_OPTIN|CLIENT_TRACKING_OPTOUT|
                  CLIENT_TRACKING_NOLOOP);
    c->client_tracking_redirection = redirect_to;

    /* This may be the first client we ever enable. Create the tracking
     * table if it does not exist. */
    if (TrackingTable == NULL) {
        TrackingTable = raxNew();
        PrefixTable = raxNew();
        TrackingChannelName = createStringObject("__redis__:invalidate",20);
    }

    /* For broadcasting, set the list of prefixes in the client. */
    if (options & CLIENT_TRACKING_BCAST) {
        c->flags |= CLIENT_TRACKING_BCAST;
        if (numprefix == 0) enableBcastTrackingForPrefix(c,"",0);
        for (size_t j = 0; j < numprefix; j++) {
            sds sdsprefix = prefix[j]->ptr;
            enableBcastTrackingForPrefix(c,sdsprefix,sdslen(sdsprefix));
        }
    }

    /* Set the remaining flags that don't need any special handling. */
    c->flags |= options & (CLIENT_TRACKING_OPTIN|CLIENT_TRACKING_OPTOUT|
                           CLIENT_TRACKING_NOLOOP);
}

/* This function is called after the execution of a readonly command in the
 * case the client 'c' has keys tracking enabled and the tracking is not