Enum DeferredEstimate 

pub enum DeferredEstimate {
    Sample,
    Callback(Box<EstimateFn>),
}

Deferred work that can resolve to a terminal EstimateVerdict.

Variants

Sample

The scheme cannot cheaply estimate its ratio, so the compressor should compress a small sample to determine effectiveness.

Callback(Box<EstimateFn>)

A fallible estimation requiring a custom expensive computation.

Use this only when the scheme needs to perform trial encoding or other costly checks to determine its compression ratio. The callback returns an EstimateVerdict directly, so it cannot request more sampling or another deferred callback.

The compressor evaluates all immediate CompressionEstimate::Verdict results before invoking any deferred callback, and passes the best EstimateScore observed so far to the callback. This lets the callback return EstimateVerdict::Skip without performing expensive work when its maximum achievable ratio cannot beat the current best. See EstimateFn for the full contract.

Trait Implementations

impl Debug for DeferredEstimate

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

Formats the value using the given formatter.