Channels

Lightyear introduces the concept of a Channel to handle reliability.

A Channel is a way to send packets with specific reliability, ordering and priority guarantees.

You can add a channel to your protocol like so:

#[derive(Channel)]
struct MyChannel;

pub fn protocol() -> MyProtocol {
    let mut p = MyProtocol::default();
    p.add_channel::<MyChannel>(ChannelSettings {
        mode: ChannelMode::OrderedReliable(ReliableSettings::default()),
        direction: ChannelDirection::Bidirectional,
    });
    p
}

Mode

The mode field of ChannelSettings defines the reliability/ordering guarantees of the channel.

Reliability:

• Unreliable: packets are not guaranteed to arrive
• Reliable: packets are guaranteed to arrive. We will resend the packet until we receive an acknowledgement from the remote. You can define how often we resend the packet via the ReliableSettings field.

Ordering:

• Ordered: packets are guaranteed to arrive in the order they were sent (client sends 1,2,3,4,5, server receives 1,2,3,4,5)
• Unordered: packets are not guaranteed to arrive in the order they were sent (client sends 1,2,3,4,5, server receives 1,3,2,5,4)
• Sequenced: packets are not guaranteed to arrive in the order they were sent, but we will discard packets that are older than the last received packet (client sends 1,2,3,4,5, server receives 1,3,5 (2 and 4 are discarded))

Direction

The direction field can be used to restrict a Channel from sending packets from client->server or server->client.