NFD

Davide Pesavento wrote:

Teng Liang wrote:

Mapping UDP6 (142-bit) to EndpointId (64-bit) is challenging, so is the reverse mapping.

Why is it challenging?

I don't see a simple way to do reverse mapping.

However, if EndpointId is redefined as string, then we can define EndpointId with the following format:

I really dislike using strings unless absolutely necessary. Also keep in mind that this means converting the remote address to a string, converting the port number to a string, and combining the two strings, all of this for every packet received on a multicast face.

If we need to change EndpointId type, I suggest using a variant.

So how about variant<int64_t, int64_t*>, the former one is used for Ethernet and UDP4, and the latter one needs 3 64-bit for UDP6?

In most cases, EndpointId has empty value. How about defining it as variant<std::monostate, ethernet::Address, ip::udp::endpoint> to make it default constructible without values?

Teng Liang wrote:

In most cases, EndpointId has empty value.

I suppose these cases are remnants from our failed attempt at introducing EndpointId in forwarding and strategies?

In any case, adding monostate is fine with me.

Davide Pesavento wrote:

Teng Liang wrote:

In most cases, EndpointId has empty value.

I suppose these cases are remnants from our failed attempt at introducing EndpointId in forwarding and strategies?

The current EndpointId is 0 when a Face is not multicast. What's the equivalent value when using variant?

Why couldn't we have a valid endpoint for all faces, which can simply be interpreted as "remote" (almost equal to RemoveFaceUri, just programmatical, instead for human interpretation). Could this simplify things?..

Teng Liang wrote:

Davide Pesavento wrote:

Teng Liang wrote:

In most cases, EndpointId has empty value.

I suppose these cases are remnants from our failed attempt at introducing EndpointId in forwarding and strategies?

The current EndpointId is 0 when a Face is not multicast. What's the equivalent value when using variant?

For non-multicast faces, the EndpointId value is meaningless and should never be used. So you could literally use any invalid address, it doesn't matter. But as I said, monostate is fine and makes the "invalid case" more explicit.

Alex Afanasyev wrote:

Why couldn't we have a valid endpoint for all faces, which can simply be interpreted as "remote" (almost equal to RemoveFaceUri, just programmatical, instead for human interpretation). Could this simplify things?..

We could do that, given that the information is available at the socket layer. But it would be kind of useless, as the rest of NFD doesn't use that information. So I'd leave this extension for later, if we ever need it.

Agreed