rounds

type Comms interface {
	GetHost(hostId *id.ID) (*connect.Host, bool)
	RequestHistoricalRounds(host *connect.Host, message *pb.HistoricalRounds) (
		*pb.HistoricalRoundsResponse, error)
}

type Params struct {
	// MaxHistoricalRounds is the number of historical rounds required to
	// automatically send a historical rounds query.
	MaxHistoricalRounds uint

	// HistoricalRoundsPeriod is the maximum period of time a pending historical
	// round query will wait before it is transmitted.
	HistoricalRoundsPeriod time.Duration

	// HistoricalRoundsBufferLen is the length of historical rounds channel
	// buffer.
	HistoricalRoundsBufferLen uint

	// MaxHistoricalRoundsRetries is the maximum number of times a historical
	// round lookup will be attempted.
	MaxHistoricalRoundsRetries uint
}

type Retriever interface {
	StartProcesses() *stoppable.Single
	LookupHistoricalRound(rid id.Round, callback RoundResultCallback) error
}

type Round struct {
	// ID of the round. IDs are sequential and monotonic.
	ID id.Round

	// State is the last known state of the round. Possible states are:
	//   PENDING - not started yet
	//   PRECOMPUTING - In the process of preparing to process messages
	//   STANDBY - Completed precomputing but not yet scheduled to run
	//	 QUEUED - Scheduled to run at a set time
	//	 REALTIME - Running, actively handing messages
	//	 COMPLETED - Successfully deleted messages
	//	 FAILED - Failed to deliver messages
	State states.Round

	// Topology contains the list of nodes in the round.
	Topology *connect.Circuit

	// Timestamps of all events that have occurred in the round (see the above
	// states).
	// The QUEUED state's timestamp is different; it denotes when Realtime
	// was/is scheduled to start, not whe the QUEUED state is entered.
	Timestamps map[states.Round]time.Time

	// Errors that occurred in the round. Will only be present in the failed
	// state.
	Errors []RoundError

	// BatchSize is the max number of messages the round can process.
	BatchSize uint32

	// AddressSpaceSize is the ephemeral address space size used in the round.
	AddressSpaceSize uint8

	// UpdateID is a monotonic counter between all round updates denoting when
	// this updated occurred in the queue.
	UpdateID uint64

	// Raw is raw round data, including signatures.
	Raw *pb.RoundInfo
}

type RoundError struct {
	NodeID *id.ID
	Error  string
}

type RoundResultCallback func(round Round, success bool)