use crate::{ DrawCommand, LayoutBox, MeasureResult };
use std::collections::{ HashMap, HashSet };
struct CachedEntry {
layout_box: LayoutBox,
commands: Vec<DrawCommand>,
}
#[derive(Default)]
pub struct RenderCache {
entries: HashMap<String, CachedEntry>,
measured: HashMap<String, MeasureResult>,
}
impl RenderCache {
pub fn new() -> Self {
Self::default()
}
pub fn cached_size(&self, key: &str) -> Option<(f32, f32)> {
self.entries.get(key).map(|e| (e.layout_box.width, e.layout_box.height))
}
pub fn try_reuse(
&self,
key: &str,
layout_box: LayoutBox,
dirty: bool
) -> Option<&[DrawCommand]> {
if dirty {
return None;
}
self.entries
.get(key)
.and_then(|entry| (entry.layout_box == layout_box).then_some(entry.commands.as_slice()))
}
pub fn store(&mut self, key: &str, layout_box: LayoutBox, commands: Vec<DrawCommand>) {
self.entries.insert(key.to_string(), CachedEntry {
layout_box,
commands,
});
}
pub fn cached_measure(&self, key: &str) -> Option<MeasureResult> {
self.measured.get(key).copied()
}
pub fn store_measure(&mut self, key: &str, size: MeasureResult) {
self.measured.insert(key.to_string(), size);
}
pub fn retain_keys(&mut self, live_keys: &HashSet<String>) {
self.entries.retain(|k, _| live_keys.contains(k));
self.measured.retain(|k, _| live_keys.contains(k));
}
}