rpc

type Endpoint interface {
	broker.Endpoint

	DispatchRequest(receiver []byte, msg Request) error
	DispatchInterrupt(receiver []byte, msg Interrupt) error
	DispatchProgress(msg Progress) error
	DispatchStreamFrame(msg StreamFrame) error
	DispatchReply(msg Reply) error
}

type Exchange interface {
	// RegisterMethod tells the handler that the app can start processing
	// requests to the method specified.
	RegisterMethod(app string, endpoint Endpoint, method string) error

	// UnregisterMethod is the opposite of RegisterMethod.
	UnregisterMethod(app string, method string)

	// UnregisterApp unregisters the app. This should be called by the endpoint
	// one the application has disconnected.
	UnregisterApp(app string)

	// UnregisterEndpoint is invoked when the relevant endpoint is closed so
	// that the handler can perform some cleanup if necessary.
	UnregisterEndpoint(endpoint Endpoint)

	HandleRequest(msg Request, srcEndpoint Endpoint)
	HandleInterrupt(msg Interrupt)
	HandleProgress(msg Progress)
	HandleStreamFrame(msg StreamFrame)
	HandleReply(msg Reply)
}

type Interrupt interface {

	// Sender is the application that sent the interrupt.
	Sender() []byte

	// TargetRequestId returns ID of the request that is supposed to be
	// interrupted. It always contains uint16 (BE).
	TargetRequestId() []byte
}

type Progress interface {
	Sender() []byte
	Receiver() []byte
	TargetRequestId() []byte
}

type Reply interface {
	Sender() []byte
	Receiver() []byte
	TargetRequestId() []byte
	ReturnCode() []byte
	ReturnValue() []byte
}

type Request interface {

	// Sender is the application that sent the request.
	Sender() []byte

	// Id must be unique for the given sender. It always contains a uint16 (BE).
	Id() []byte

	// Method returns the remote method requested.
	Method() []byte

	// Args returns the arguments for the method call, marshalled.
	Args() []byte

	// StdoutTag returns the stream tag identifying this request's stdout stream.
	// If no stream is requested, this method returns an empty slice.
	StdoutTag() []byte

	// StderrTag is the same as StdoutTag, just for stderr instead of stdout.
	StderrTag() []byte

	// A utility function for the RPC handler to be able to reject requests
	// for methods that nobody really exported more easily.
	Reject(code byte, reason string) error
}

type StreamFrame interface {
	Sender() []byte
	Receiver() []byte
	TargetStreamTag() []byte
	Body() []byte
}