Struct ImpactEstimate 

pub struct ImpactEstimate {
    pub savings_per_instance: usize,
    pub cache_line_size: usize,
    pub current_cache_lines: usize,
    pub optimal_cache_lines: usize,
    pub extra_bytes_1k: usize,
    pub extra_bytes_1m: usize,
    pub extra_cache_lines_1k: usize,
    pub extra_cache_lines_1m: usize,
}

Estimated impact of a struct layout inefficiency at various scales.

Built from estimate_impact. All “extra” figures are relative to the layout produced by reorder::reorder_savings (the optimal field order).

Fields

savings_per_instance: usize

Bytes saved per instance by applying the optimal field ordering.

cache_line_size: usize

Cache-line size used for this estimate (bytes).

current_cache_lines: usize

Cache lines occupied by the current layout per instance.

optimal_cache_lines: usize

Cache lines that would be occupied by the optimal layout per instance.

extra_bytes_1k: usize

Extra bytes across 1 000 instances (savings × 1 000).

extra_bytes_1m: usize

Extra bytes across 1 000 000 instances (savings × 1 000 000).

extra_cache_lines_1k: usize

Approximate extra cache lines loaded for a sequential scan of 1 000 instances.

extra_cache_lines_1m: usize

Approximate extra cache lines loaded for a sequential scan of 1 000 000 instances.

Implementations

impl ImpactEstimate

pub fn reduces_cache_line_crossings(&self) -> bool

Returns true when the current layout occupies more cache lines per instance than the optimal layout, meaning a reorder would reduce cache-line crossings on random access.

Trait Implementations

impl Clone for ImpactEstimate

fn clone(&self) -> ImpactEstimate

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ImpactEstimate

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

Formats the value using the given formatter.

impl PartialEq for ImpactEstimate

fn eq(&self, other: &ImpactEstimate) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ImpactEstimate