Struct Meter 

pub struct Meter<'a> { /* private fields */ }

The counter an algorithm ticks: a Control and the steps taken.

tick is the step: it asks the budget, then the poll, and counts the step only if neither stops it. A parallel pass gives each item a split and afterwards charges the items’ steps in the sequential order, so both builds stop on the same item with the same count (ADR-0030 §4).

Implementations

impl<'a> Meter<'a>

pub fn new(control: &Control<'a>) -> Self

A meter at zero steps under control.

pub fn tick(&mut self) -> Result<(), Interrupted>

One step. Err when the budget is spent (checked first, and the poll is then not asked) or the poll answers true; the step is not counted, so Interrupted::steps is the steps completed.

pub fn stopped(&self) -> Option<Interrupted>

The first stop tick reported, if any. A caller that runs code which may turn a failed step into a failure of its own (an attempt that falls back to another) asks this at its end: an operation that saw a stop is stopped, whatever else it returned.

pub fn steps(&self) -> u64

The steps taken so far.

pub fn split(&self) -> Meter<'a>

The meter for one item of a parallel pass: the same poll, no steps yet, capped at the budget this meter has left.

pub fn charge(&mut self, steps: u64) -> Result<(), Interrupted>

Takes the steps of one item of a pass this meter was split for. Items are charged in the sequential order; the first whose running total crosses the budget is Err(Interrupted { by: Stop::Budget, steps: budget }), which is what the sequential build’s own tick reports there.

pub fn charge_stop(&mut self, item: Interrupted) -> Interrupted

The Interrupted of an item that stopped itself, as this meter reports it: the item’s steps added to the ones already charged (and no more than the budget), so the count is the sequential build’s. An item that finished is charged; one that stopped is charged here instead, never both.

Trait Implementations

impl<'a> Clone for Meter<'a>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for Meter<'a>

impl Debug for Meter<'_>

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

Formats the value using the given formatter.

impl Default for Meter<'_>

fn default() -> Self

A meter that never stops: Control::NONE’s.