Struct XonXoffFlowCtrl 

pub(crate) struct XonXoffFlowCtrl {
    params: Arc<FlowCtrlParameters>,
    rate_limit_updater: Sender<StreamRateLimit>,
    drain_rate_requester: NotifySender<DrainRateRequest>,
    last_sent_xon_xoff: Option<XonXoffMsg>,
    xoff_limit: CellCount<{ _ }>,
    sidechannel_mitigation: Option<SidechannelMitigation>,
}

State for XON/XOFF flow control.

Fields

params: Arc<FlowCtrlParameters>

Consensus parameters.

rate_limit_updater: Sender<StreamRateLimit>

How we communicate rate limit updates to the DataWriter.

drain_rate_requester: NotifySender<DrainRateRequest>

How we communicate requests for new drain rate updates to the XonXoffReader.

last_sent_xon_xoff: Option<XonXoffMsg>

The last rate limit we sent.

xoff_limit: CellCount<{ _ }>

The buffer limit at which we should send an XOFF.

In prop324 it says that this will be either cc_xoff_client or cc_xoff_exit depending on whether we’re a client/hs or exit, but we deviate from the spec here (see how it is set below).

sidechannel_mitigation: Option<SidechannelMitigation>

DropMark sidechannel mitigations.

This is only enabled if we are a client (including an onion service).

Implementations

impl XonXoffFlowCtrl

pub(crate) fn new( params: Arc<FlowCtrlParameters>, use_sidechannel_mitigations: bool, rate_limit_updater: Sender<StreamRateLimit>, drain_rate_requester: NotifySender<DrainRateRequest>, ) -> Self

Returns a new xon/xoff-based state.

Trait Implementations

impl Debug for XonXoffFlowCtrl

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

Formats the value using the given formatter.

impl FlowCtrlHooks for XonXoffFlowCtrl

fn can_send<M: RelayMsg>(&self, _msg: &M) -> bool

Whether this stream is ready to send msg.

fn about_to_send(&mut self, msg: &AnyRelayMsg) -> Result<()>

Inform the flow control code that we’re about to send msg. Returns an error if the message should not be sent, and the circuit should be closed.

fn put_for_incoming_sendme(&mut self, _msg: UnparsedRelayMsg) -> Result<()>

Handle an incoming sendme.

fn handle_incoming_xon(&mut self, msg: UnparsedRelayMsg) -> Result<()>

Handle an incoming XON message.

fn handle_incoming_xoff(&mut self, msg: UnparsedRelayMsg) -> Result<()>

Handle an incoming XOFF message.

fn maybe_send_xon( &mut self, rate: XonKbpsEwma, buffer_len: usize, ) -> Result<Option<Xon>>

Check if we should send an XON message.

fn maybe_send_xoff(&mut self, buffer_len: usize) -> Result<Option<Xoff>>

Check if we should send an XOFF message.

impl From<XonXoffFlowCtrl> for StreamFlowCtrlEnum

Available on crate feature flowctl-cc only.

fn from(v: XonXoffFlowCtrl) -> StreamFlowCtrlEnum

Converts to this type from the input type.

impl TryInto<XonXoffFlowCtrl> for StreamFlowCtrlEnum

Available on crate feature flowctl-cc only.

type Error = &'static str

The type returned in the event of a conversion error.

fn try_into( self, ) -> Result<XonXoffFlowCtrl, <Self as TryInto<XonXoffFlowCtrl>>::Error>

Performs the conversion.