Enum IncomingState 

pub enum IncomingState {
    Idle(LastResponse),
    Received(bool),
    SendingAck,
    SendingRst,
    SendingPiggybacked,
    AwaitingResponse,
    SendingCon(RetransmissionState),
    SendingNon,
}

The state in which the incoming communication path is currently

Variants

Idle(LastResponse)

New requests can be handled

Received(bool)

A request was received and needs to be handled by the user. The contained bool determines if the request was confirmable (true) or non-confirmable (false).

In any case, the response may be sent with IncomingCommunication::schedule_response immediately. For CON requests, this will result in a piggybacked response. For NON requests, a NON response will be sent which is considered the default case for NON requests (see RFC 7252 5.2.3 Non-confirmable: “If the request message is Non-confirmable, then the response SHOULD be returned in a Non-confirmable message as well.”)

Furthermore, IncomingCommunication::schedule_rst may be called in both cases which will transmit a RST message.

If a different behavior is desired, the following different options exist:

• In Received(true), IncomingCommunication::schedule_empty_ack allows to send an empty ACK which will trigger a state transition via IncomingState::SendingAck into IncomingState::AwaitingResponse where separate responses may be sent. Additionally, IncomingCommunication::schedule_piggybacked_response may be called which is identical to IncomingCommunication::schedule_response in this case.
• In Received(false), IncomingCommunication::schedule_con_response and IncomingCommunication::schedule_non_response are available, the second being identical to IncomingCommunication::schedule_response in this case.

In this state, the message buffer contains the request message. Thus, the request message may be obtained by calling IncomingCommunication::request.

SendingAck

An ACK is being sent. Afterwards, we will go into the IncomingState::AwaitingResponse state.

SendingRst

A RST message is being sent. Afterwards, we will go back to the Idle state.

SendingPiggybacked

A piggybacked response is being sent. Afterwards, we will go into the Idle state.

AwaitingResponse

The request has been acknowledged, i.e. a separate response is expected. In this state, IncomingCommunication::schedule_con_response and IncomingCommunication::schedule_non_response are available and either of those must be called by the user.

In this state, the message buffer still contains the request message and may be obtained with IncomingCommunication::request.

SendingCon(RetransmissionState)

A separate CON response is being sent. We will stay in this state and try retransmissions until an ACK to this message is received or until the whole communication attempt (with retries) times out.

SendingNon

A separate NON response is being sent.

Trait Implementations

impl Clone for IncomingState

fn clone(&self) -> IncomingState

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for IncomingState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for IncomingState