VLAN Ingress filtering process on switch

Question

I read and read the information and somehow it is inconsistent or incomplete. The specification of 802.1Q also read, but to me as a person who has not previously read the specification is difficult. I draw a diagram. The diagram shows an illustration of the included ingress filtering. Is this a correct opinion? What is mapped at all, what are the "variables", maybe there is some sort of VLAN memberset where multiple allowed VLANs can be entered. Need a direct understanding of how this works.

In pseudocode, it can be illustrated like this:

fvid = frame.tag8021q.VLAN
isUntagged = fvid == 0 
if isUntagged {
    if egressPort.Mode&ACCESS != 0 {
        if ingressPort.PVID() != egressPort.PVID() {
            return 0
        }
    }
    if egressPort.Mode&TRUNK != 0 {
        isMatched = egressPort.AllowedVlans().Contains(ingressPort.PVID())
        if !isMatched {
            return 0 
        }
    }
} else {
    if fvid != ingressPort.PVID() {
        return 0
    }
}

EDIT:

Unknown moment #1: We are searching in FDB, check frame source address and frame VID, if there is an entry and data match - we continue frame processing, otherwise - we discard. Is that correct?

Unknown moment #2: If ingress filtering is turned off on the egress port, so there will be no VLAN member set, what should we match the VID of the frame with? Completely scheme of three phases processing of frame:

Answer 1

Ingress PVID equals VID of frame? should really be current frame VLAN tag is member of PVIDs? as there can be many VLANs associated with a port. And you've skipped the test for the ingress frame's VLAN being allowed on the inbound port.

Also, I don't think it's practical to try doing the ingress and the egress processing in one step.

Actual hardware implementations are likely simpler than that. The VLAN ID from an ingress frame is stored in memory along with the frame. During MAC learning and where to forward, that tag is used to match the CAM entries. The only special cases is for untagged frames that are appended with a port-dependent VLID on ingress or stripped of their tag on egress. The other special case of a non-existant/non-associated VLID isn't really special as the frame's simply blackholed.