Struct frame_support::weights::WeightMeter

pub struct WeightMeter {
    pub consumed: Weight,
    pub limit: Weight,
}

Meters consumed weight and a hard limit for the maximal consumable weight.

Can be used to check if enough weight for an operation is available before committing to it.

Example

use sp_weights::{Weight, WeightMeter};

// The weight is limited to (10, 0).
let mut meter = WeightMeter::from_limit(Weight::from_parts(10, 0));
// There is enough weight remaining for an operation with (5, 0) weight.
assert!(meter.check_accrue(Weight::from_parts(5, 0)));
// There is not enough weight remaining for an operation with (6, 0) weight.
assert!(!meter.check_accrue(Weight::from_parts(6, 0)));

Fields

consumed: Weight

The already consumed weight.

limit: Weight

The maximal consumable weight.

Implementations

impl WeightMeter

pub fn from_limit(limit: Weight) -> WeightMeter

Creates Self from a limit for the maximal consumable weight.

pub fn max_limit() -> WeightMeter

Creates Self with the maximal possible limit for the consumable weight.

pub fn remaining(&self) -> Weight

The remaining weight that can still be consumed.

pub fn consumed_ratio(&self) -> Perbill

The ratio of consumed weight to the limit.

Calculates one ratio per component and returns the largest.

pub fn defensive_saturating_accrue(&mut self, w: Weight)

Consume some weight and defensively fail if it is over the limit. Saturate in any case.

pub fn check_accrue(&mut self, w: Weight) -> bool

Consume the given weight after checking that it can be consumed. Otherwise do nothing.

pub fn can_accrue(&self, w: Weight) -> bool

Check if the given weight can be consumed.

Trait Implementations

impl Clone for WeightMeter

fn clone(&self) -> WeightMeter

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for WeightMeter

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

Formats the value using the given formatter.