Struct SizeClassInfo 

pub struct SizeClassInfo {
    pub block_size: usize,
    pub max_blocks: usize,
    pub div_mult: u32,
    pub class: usize,
}

Bundles all the per-class constants that are computed separately in the individual lookup functions — convenient when a consumer needs multiple fields for the same class without repeated calls.

Fields

block_size: usize

Block size in bytes for this class.

max_blocks: usize

Maximum blocks per 64 KiB page.

div_mult: u32

Lemire reciprocal multiplier for block_index_in_page.

class: usize

0-based class index.

Implementations

impl SizeClassInfo

pub const fn for_class(class: usize) -> Option<SizeClassInfo>

Returns the metadata for class class, or None if out of range.

pub const fn for_size(size: usize) -> Option<SizeClassInfo>

Returns the metadata for the class that serves size, or None when size > MAX_SMALL_ALLOC_SIZE.

pub const fn block_index(&self, offset: usize) -> usize

Computes the block index for a page offset using the pre-computed Lemire multiplier.

pub fn fragmentation_for(&self, requested: usize) -> f64

Internal fragmentation for a request of requested bytes served by this class: (block_size - requested) / block_size, in [0.0, 1.0].

Trait Implementations

impl Clone for SizeClassInfo

fn clone(&self) -> SizeClassInfo

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SizeClassInfo

impl Debug for SizeClassInfo

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

Formats the value using the given formatter.

impl Eq for SizeClassInfo

impl PartialEq for SizeClassInfo

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SizeClassInfo