Struct SurbBalancer 

pub struct SurbBalancer<C, E, F> {
    session_id: SessionId,
    controller: C,
    surb_estimator: E,
    flow_control: F,
    state: Arc<BalancerStateValues>,
    last_estimator_state: SimpleSurbFlowEstimator,
    last_update: Instant,
    last_decay: Instant,
    was_below_target: bool,
}

Runs a continuous process that attempts to evaluate and regulate the flow of SURBs to the Session counterparty, to keep the number of SURBs locally or at the counterparty at a certain level.

Internally, the Balancer uses an implementation of SurbBalancerController to control the rate of SURBs consumed or sent to the counterparty each time the update method is called:

1. The size of the SURB buffer at locally or at the counterparty is estimated using SurbFlowEstimator.
2. Error against a set-point given in SurbBalancerConfig is evaluated in the SurbBalancerController.
3. The SurbBalancerController applies a new SURB flow rate value using the SurbFlowController.

In the local context, the SurbFlowController might simply regulate the egress traffic from the Session, slowing it down to avoid fast SURB drainage.

In the remote context, the SurbFlowController might regulate the flow of non-organic SURBs via Start protocol’s KeepAlive messages to deliver additional SURBs to the counterparty.

Fields

session_id: SessionId

controller: C

surb_estimator: E

flow_control: F

state: Arc<BalancerStateValues>

last_estimator_state: SimpleSurbFlowEstimator

last_update: Instant

last_decay: Instant

was_below_target: bool

Implementations

impl<C, E, F> SurbBalancer<C, E, F>

where C: SurbBalancerController + Send + Sync + 'static, E: SurbFlowEstimator + Send + Sync + 'static, F: SurbFlowController + Send + Sync + 'static,

pub fn new( session_id: SessionId, controller: C, surb_estimator: E, flow_control: F, state: Arc<BalancerStateValues>, ) -> Self

fn update(&mut self) -> u64

Computes the next control update and adjusts the SurbFlowController rate accordingly.

pub fn start_control_loop( self, sampling_interval: Duration, ) -> (impl Stream<Item = u64>, AbortHandle)

Spawns a new task that performs updates of the given SurbBalancer at the given sampling_interval.

If cfg_feedback is given, SurbBalancerConfig can be queried for updates and also updated if the underlying SurbBalancerController also does target updates.

Returns a stream of current estimated buffer levels, and also an AbortHandle to terminate the loop. If abort_reg was given, the returned AbortHandle corresponds to it.