Trait ProgressObserver 

pub trait ProgressObserver {
    // Required methods
    fn step_began(&mut self, step: &Step<'_>);
    fn step_advanced(&mut self, completed: u64);
    fn step_ended(&mut self);

    // Provided methods
    fn step_total_resolved(&mut self, total: u64) { ... }
    fn step_concluded(&mut self, conclusion: &str) { ... }
}

Receives the steps of a long-running operation.

An operation calls Self::step_began, then Self::step_advanced zero or more times, then Self::step_ended. Steps are sequential: implementations need not handle nesting, and both edges are forgiving so no caller can leave an implementation in a broken state — step_began while a step is active ends that step first, and step_ended without an active step does nothing.

Counts passed to step_advanced are cumulative completed items within the current step, never deltas, and never decrease.

Required Methods

fn step_began(&mut self, step: &Step<'_>)

A new step began.

fn step_advanced(&mut self, completed: u64)

completed items of the current step are done, cumulatively.

fn step_ended(&mut self)

The current step finished. An operation that fails mid-step still ends the step before returning its error.

Provided Methods

fn step_total_resolved(&mut self, total: u64)

The current step’s total became known after it began. The default implementation ignores it.

fn step_concluded(&mut self, conclusion: &str)

The current step’s result, as one short factual clause a renderer may append to the step’s completion line — for example "73,967 pre-existing bulk segments (15.0 GiB) will be shared in place and retained". Reported at most once per step, after the step’s counting is complete and before Self::step_ended. The default implementation ignores it: a conclusion is a courtesy to the reader, never something an operation depends on.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl<Observer: ProgressObserver + ?Sized> ProgressObserver for &mut Observer

Forwards to a borrowed observer, so &mut dyn ProgressObserver can be passed on where an impl ProgressObserver is expected.

fn step_began(&mut self, step: &Step<'_>)

fn step_advanced(&mut self, completed: u64)

fn step_total_resolved(&mut self, total: u64)

fn step_concluded(&mut self, conclusion: &str)

fn step_ended(&mut self)

Implementors

impl ProgressObserver for DiscardedProgress