Struct GlyphOutlineCache 

pub struct GlyphOutlineCache { /* private fields */ }

Bounded least-recently-used cache of glyph outlines.

Keys are opaque u128s combining font identity and glyph id (the renderer passes identifier().cache_key()); values are the outlines in glyph space. When the cache is full, inserting a new outline evicts the least-recently-used one. Eviction is always output-neutral — it only decides which outlines get rebuilt.

A disabled cache (set_enabled) never hits and stores nothing; every lookup counts as a miss. Already-stored entries are kept while disabled, so re-enabling resumes from them.

Implementations

impl GlyphOutlineCache

pub const DEFAULT_CAPACITY: usize = 4096

Default entry bound.

A typical Latin page uses well under 256 distinct glyphs and a whole Latin/Cyrillic/Greek document stays in the hundreds, so 4096 serves common documents with zero evictions. Long CJK documents can reach a few thousand distinct glyphs overall, but the per-page working set is in the hundreds, which stays resident. Memory stays modest: a Latin outline is typically hundreds of bytes to ~2KB and a complex CJK outline up to ~10KB, so a full cache holds single-digit megabytes — small next to the page pixmaps (tens of MB).

pub fn new() -> Self

An empty cache with DEFAULT_CAPACITY entries.

pub fn with_capacity(capacity: usize) -> Self

An empty cache holding at most capacity entries.

A capacity of zero is allowed: lookups always build and nothing is ever stored (every call counts as a miss).

pub fn set_enabled(&mut self, enabled: bool)

Enable or disable the cache. A disabled cache rebuilds every outline (each build counts as a miss) and stores nothing; re-enabling resumes from the entries stored before.

pub fn is_enabled(&self) -> bool

Whether lookups can hit.

pub fn hits(&self) -> u64

Outlines served from the cache.

pub fn misses(&self) -> u64

Outlines built because the cache was disabled, empty of the key, or had evicted it. Equal to the number of outline builds through this cache.

pub fn len(&self) -> usize

Entries currently stored. Always within capacity.

pub fn is_empty(&self) -> bool

Whether no outline is stored.

pub fn capacity(&self) -> usize

Maximum entries stored.

pub fn clear(&mut self)

Drop all entries and reset the hit/miss counters.

Trait Implementations

impl Debug for GlyphOutlineCache

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

Formats the value using the given formatter.

impl Default for GlyphOutlineCache

fn default() -> Self

Returns the “default value” for a type.