Struct RateCalculator 

pub struct RateCalculator { /* private fields */ }

The rate the far end is receiving, from acknowledged bytes over a sliding window.

Why the controller needs this and not the target

On a decrease, AIMD backs off to a fraction of what the path is delivering, not of what the sender was aiming for. Those differ exactly when it matters: a sender aiming at 2 Mb/s over a path carrying 600 kb/s must drop to about 500 kb/s, not to 1.7 Mb/s. Backing off from the target would take several rounds to reach the same place, queueing the whole way down.

Implementations

impl RateCalculator

pub fn new(window: Duration) -> Self

A calculator over window.

pub fn add(&mut self, now: Instant, size: usize)

Record size bytes acknowledged at now.

pub fn rate_bits_per_second(&mut self, now: Instant) -> Option<f64>

The received rate in bits per second, or None when the window holds too little to say.

None rather than zero: a controller that reads an empty window as “the path is delivering nothing” would back off to its floor on the first feedback gap.

Trait Implementations

impl Clone for RateCalculator

fn clone(&self) -> RateCalculator

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RateCalculator

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

Formats the value using the given formatter.

impl Default for RateCalculator

fn default() -> Self

Returns the “default value” for a type.