49 lines
1.4 KiB
Rust
49 lines
1.4 KiB
Rust
#[cfg(not(feature = "std"))]
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use alloc::{string::String, vec::Vec};
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use core::ops::Range;
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use crate::{AttrsOwned, HashMap, ShapeGlyph};
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/// Key for caching shape runs.
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#[derive(Clone, Debug, Hash, PartialEq, Eq)]
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pub struct ShapeRunKey {
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pub text: String,
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pub default_attrs: AttrsOwned,
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pub attrs_spans: Vec<(Range<usize>, AttrsOwned)>,
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}
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/// A helper structure for caching shape runs.
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#[derive(Clone, Default)]
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pub struct ShapeRunCache {
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age: u64,
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cache: HashMap<ShapeRunKey, (u64, Vec<ShapeGlyph>)>,
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}
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impl ShapeRunCache {
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/// Get cache item, updating age if found
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pub fn get(&mut self, key: &ShapeRunKey) -> Option<&Vec<ShapeGlyph>> {
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self.cache.get_mut(key).map(|(age, glyphs)| {
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*age = self.age;
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&*glyphs
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})
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}
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/// Insert cache item with current age
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pub fn insert(&mut self, key: ShapeRunKey, glyphs: Vec<ShapeGlyph>) {
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self.cache.insert(key, (self.age, glyphs));
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}
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/// Remove anything in the cache with an age older than keep_ages
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pub fn trim(&mut self, keep_ages: u64) {
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self.cache
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.retain(|_key, (age, _glyphs)| *age + keep_ages >= self.age);
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// Increase age
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self.age += 1;
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}
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}
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impl core::fmt::Debug for ShapeRunCache {
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fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
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f.debug_tuple("ShapeRunCache").finish()
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}
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}
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