🔧 Use LRU cache for tile surfaces

render-wasm/Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "adler2"
@@ -8,6 +8,17 @@ version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "512761e0bb2578dd7380c6baaa0f4ce03e84f95e960231d1dec8bf4d7d6e2627"
 
+[[package]]
+name = "ahash"
+version = "0.7.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "891477e0c6a8957309ee5c45a6368af3ae14bb510732d2684ffa19af310920f9"
+dependencies = [
+ "getrandom",
+ "once_cell",
+ "version_check",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.20"
@@ -823,6 +834,15 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
+dependencies = [
+ "ahash",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.15.0"
@@ -901,7 +921,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8c9c992b02b5b4c94ea26e32fe5bccb7aa7d9f390ab5c1221ff895bc7ea8b652"
 dependencies = [
  "equivalent",
- "hashbrown",
+ "hashbrown 0.15.0",
 ]
 
 [[package]]
@@ -1036,6 +1056,15 @@ version = "0.4.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
 
+[[package]]
+name = "lru"
+version = "0.6.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ea2d928b485416e8908cff2d97d621db22b27f7b3b6729e438bcf42c671ba91"
+dependencies = [
+ "hashbrown 0.11.2",
+]
+
 [[package]]
 name = "mac-notification-sys"
 version = "0.6.2"
@@ -1511,6 +1540,7 @@ dependencies = [
  "cargo-watch",
  "gl",
  "indexmap",
+ "lru",
  "skia-safe",
  "uuid",
 ]

render-wasm/Cargo.toml

@@ -11,6 +11,7 @@ name = "render_wasm"
 path = "src/main.rs"
 
 [dependencies]
+lru = "0.6"
 base64 = "0.22.1"
 gl = "0.14.0"
 indexmap = "2.7.1"

render-wasm/src/render.rs

@@ -462,12 +462,10 @@ impl RenderState {
         ey + interest_delta
         */
         self.pending_tiles = vec![];
-        self.surfaces.cache_clear_visited();
         for y in sy..=ey {
             for x in sx..=ex {
                 let tile = (x, y);
                 self.pending_tiles.push(tile);
-                self.surfaces.cache_visit(tile);
             }
         }
         self.current_tile = None;

render-wasm/src/render/surfaces.rs

@@ -1,11 +1,11 @@
 use crate::shapes::Shape;
 use crate::view::Viewbox;
-use skia_safe::{self as skia, Paint, RRect};
+use skia_safe::{self as skia, Paint, RRect, Surface};
 
 use super::{gpu_state::GpuState, tiles::Tile};
 
 use base64::{engine::general_purpose, Engine as _};
-use std::collections::HashMap;
+use lru::LruCache;
 
 #[derive(Debug, PartialEq, Clone, Copy)]
 pub enum SurfaceId {
@@ -22,22 +22,22 @@ pub enum SurfaceId {
 
 pub struct Surfaces {
     // is the final destination surface, the one that it is represented in the canvas element.
-    target: skia::Surface,
+    target: Surface,
     // keeps the current render
-    current: skia::Surface,
+    current: Surface,
     // keeps the current shape's fills
-    shape_fills: skia::Surface,
+    shape_fills: Surface,
     // keeps the current shape's strokes
-    shape_strokes: skia::Surface,
+    shape_strokes: Surface,
     // used for rendering shadows
-    shadow: skia::Surface,
+    shadow: Surface,
     // used for new shadow rendering
-    drop_shadows: skia::Surface,
+    drop_shadows: Surface,
-    inner_shadows: skia::Surface,
+    inner_shadows: Surface,
     // for drawing the things that are over shadows.
-    overlay: skia::Surface,
+    overlay: Surface,
     // for drawing debug info.
-    debug: skia::Surface,
+    debug: Surface,
     // for drawing tiles.
     tiles: TileSurfaceCache,
     sampling_options: skia::SamplingOptions,
@@ -74,8 +74,11 @@ impl Surfaces {
         const POOL_CAPACITY_THRESHOLD: i32 = 4;
         let pool_capacity =
             (width / tile_dims.width) * (height / tile_dims.height) * POOL_CAPACITY_THRESHOLD;
-        let pool = SurfacePool::with_capacity(&mut target, tile_dims, pool_capacity as usize);
+        let tiles = TileSurfaceCache::new(
-        let tiles = TileSurfaceCache::new(pool);
+            pool_capacity as usize,
+            target.new_surface_with_dimensions(tile_dims).unwrap(),
+            tile_dims,
+        );
         Surfaces {
             target,
             current,
@@ -145,7 +148,7 @@ impl Surfaces {
             .draw(self.canvas(to), (0.0, 0.0), sampling_options, paint);
     }
 
-    pub fn apply_mut(&mut self, ids: &[SurfaceId], mut f: impl FnMut(&mut skia::Surface) -> ()) {
+    pub fn apply_mut(&mut self, ids: &[SurfaceId], mut f: impl FnMut(&mut Surface) -> ()) {
         for id in ids {
             let surface = self.get_mut(*id);
             f(surface);
@@ -172,7 +175,7 @@ impl Surfaces {
         );
     }
 
-    fn get_mut(&mut self, id: SurfaceId) -> &mut skia::Surface {
+    fn get_mut(&mut self, id: SurfaceId) -> &mut Surface {
         match id {
             SurfaceId::Target => &mut self.target,
             SurfaceId::Current => &mut self.current,
@@ -186,7 +189,7 @@ impl Surfaces {
         }
     }
 
-    fn reset_from_target(&mut self, target: skia::Surface) {
+    fn reset_from_target(&mut self, target: Surface) {
         let dim = (target.width(), target.height());
         self.target = target;
         self.debug = self.target.new_surface_with_dimensions(dim).unwrap();
@@ -238,18 +241,10 @@ impl Surfaces {
             .reset_matrix();
     }
 
-    pub fn cache_clear_visited(&mut self) {
-        self.tiles.clear_visited();
-    }
-
-    pub fn cache_visit(&mut self, tile: Tile) {
-        self.tiles.visit(tile);
-    }
-
     pub fn cache_tile_surface(&mut self, tile: Tile, id: SurfaceId, color: skia::Color) {
         let sampling_options = self.sampling_options;
-        let mut tile_surface = self.tiles.get_or_create(tile).unwrap();
         let margins = self.margins;
+        let mut tile_surface = self.tiles.get_or_create(tile);
         let surface = self.get_mut(id);
         tile_surface.canvas().clear(color);
         surface.draw(
@@ -280,148 +275,52 @@ impl Surfaces {
     }
 
     pub fn remove_cached_tiles(&mut self) {
-        self.tiles.clear_grid();
+        self.tiles.clear();
-    }
-}
-
-pub struct SurfaceRef {
-    pub index: usize,
-    pub in_use: bool,
-    pub surface: skia::Surface,
-}
-
-impl Clone for SurfaceRef {
-    fn clone(&self) -> Self {
-        Self {
-            index: self.index,
-            in_use: self.in_use,
-            surface: self.surface.clone(),
-        }
-    }
-}
-
-pub struct SurfacePool {
-    pub surfaces: Vec<SurfaceRef>,
-    pub index: usize,
-}
-
-impl SurfacePool {
-    pub fn with_capacity(surface: &mut skia::Surface, dims: skia::ISize, capacity: usize) -> Self {
-        let mut surfaces = Vec::with_capacity(capacity);
-        for _ in 0..capacity {
-            surfaces.push(surface.new_surface_with_dimensions(dims).unwrap())
-        }
-
-        Self {
-            index: 0,
-            surfaces: surfaces
-                .into_iter()
-                .enumerate()
-                .map(|(index, surface)| SurfaceRef {
-                    index,
-                    in_use: false,
-                    surface: surface,
-                })
-                .collect(),
-        }
-    }
-
-    pub fn clear(&mut self) {
-        for surface in self.surfaces.iter_mut() {
-            surface.in_use = false;
-        }
-    }
-
-    pub fn deallocate(&mut self, surface_ref_to_deallocate: &SurfaceRef) {
-        let surface_ref = self
-            .surfaces
-            .get_mut(surface_ref_to_deallocate.index)
-            .unwrap();
-        surface_ref.in_use = false;
-    }
-
-    pub fn allocate(&mut self) -> Option<SurfaceRef> {
-        let start = self.index;
-        let len = self.surfaces.len();
-        loop {
-            self.index = (self.index + 1) % len;
-            if self.index == start {
-                return None;
-            }
-            if let Some(surface_ref) = self.surfaces.get_mut(self.index) {
-                if !surface_ref.in_use {
-                    surface_ref.in_use = true;
-                    return Some(surface_ref.clone());
-                }
-            }
-        }
     }
 }
 
 pub struct TileSurfaceCache {
-    pool: SurfacePool,
+    surface: Surface,
-    grid: HashMap<Tile, SurfaceRef>,
+    dims: skia::ISize,
-    visited: HashMap<Tile, bool>,
+    lru_cache: LruCache<Tile, Surface>,
 }
 
 impl TileSurfaceCache {
-    pub fn new(pool: SurfacePool) -> Self {
+    pub fn new(pool_capacity: usize, surface: Surface, dims: skia::ISize) -> Self {
+        let lru_cache = LruCache::new(pool_capacity);
         Self {
-            pool,
+            surface,
-            grid: HashMap::new(),
+            dims,
-            visited: HashMap::new(),
+            lru_cache,
         }
     }
 
     pub fn has(&mut self, tile: Tile) -> bool {
-        return self.grid.contains_key(&tile);
+        self.lru_cache.contains(&tile)
     }
 
-    pub fn get_or_create(&mut self, tile: Tile) -> Result<skia::Surface, String> {
+    pub fn get_or_create(&mut self, tile: Tile) -> Surface {
-        if let Some(surface_ref) = self.pool.allocate() {
+        if let Some(surface) = self.lru_cache.get(&tile) {
-            self.grid.insert(tile, surface_ref.clone());
+            return surface.clone();
-            Ok(surface_ref.surface.clone())
-        } else {
-            // TODO: I don't know yet how to improve this but I don't like it. I think
-            // there should be a better solution.
-            for (tile, surface_ref) in self.grid.iter() {
-                if !self.visited.contains_key(tile) {
-                    continue;
-                }
-                if !self.visited.get(tile).unwrap() {
-                    self.pool.deallocate(surface_ref);
-                }
-            }
-            if let Some(surface_ref) = self.pool.allocate() {
-                self.grid.insert(tile, surface_ref.clone());
-                return Ok(surface_ref.surface.clone());
-            }
-            return Err("Not enough surfaces".into());
         }
+
+        let new_surface = self.surface.new_surface_with_dimensions(self.dims).unwrap();
+        self.lru_cache.put(tile, new_surface.clone());
+        new_surface
     }
 
-    pub fn get(&mut self, tile: Tile) -> Result<&mut skia::Surface, String> {
+    pub fn get(&mut self, tile: Tile) -> Result<&mut Surface, String> {
-        Ok(&mut self.grid.get_mut(&tile).unwrap().surface)
+        self.lru_cache
+            .get_mut(&tile)
+            .ok_or_else(|| "Tile not found".to_string())
     }
 
     pub fn remove(&mut self, tile: Tile) -> bool {
-        if !self.grid.contains_key(&tile) {
+        self.lru_cache.pop(&tile);
-            return false;
-        }
-        self.grid.remove(&tile);
         true
     }
 
-    pub fn clear_grid(&mut self) {
+    pub fn clear(&mut self) {
-        self.grid.clear();
+        self.lru_cache.clear();
-        self.pool.clear();
-    }
-
-    pub fn clear_visited(&mut self) {
-        self.visited.clear();
-    }
-
-    pub fn visit(&mut self, tile: Tile) {
-        self.visited.insert(tile, true);
     }
 }