message relayer

this repo implements a message relayer and a message relayer server with the interfaces:

type MessageRelayer interface {
	SubscribeToMessage(msgType domain.MessageType, ch chan<- domain.Message)
}

type MessageRelayerServer interface {
	MessageRelayer
	ReadAndRelay() // serve
}

the default implementation of the MessageRelayerServer relays messages to its subscribers as messages are read from the network.

app.go provides a sample use of the api. in the example a relayer server runs until it's network crashes (simulated by an empty set of responses).

> cd ./src
> go run main.go

there are test cases agains the DefaultMessageRelayer which can be run via:

> cd ./src/relayer
> go test -run "_default"

by default debug logging is off. debug out put can be included by flipping the flag in ./src/utils/utils.go.

priority message relayer

the priority message relayer limits the number of messages that it keeps queued locally to avoid runaway memory consumption, but the protocol imposes some rules about the priority of these messages:

• We must always ensure that we broadcast the 2 most recent StartNewRound messages
• We only need to ensure that we broadcast only the most recent ReceivedAnswer message
• Any time that both a “StartNewRound” and a “ReceivedAnswer” are queued, the “StartNewRound” message should be broadcasted first
• Any time that one of the subscribers of this system is busy and cannot receive a message immediately, we should just skip broadcasting to that subscriber

the priority message relayer achieves these goals by first Enqueueing each message from the network onto a priority queue and then Dequeueing and Broadcasting the messages from the queue.

there are test cases agains the PriorityMessageRelayer which can be run via:

> cd ./src/relayer
> go test -run "_priority"