Testing for incremental

Also, constraint bugfixes.

src/geom/length.rs

@@ -108,6 +108,11 @@ impl Length {
         self.raw + 1e-6 >= other.raw
     }
 
+    /// Compares to lengths for whether they are approximately equal.
+    pub fn approx_eq(self, other: Self) -> bool {
+        self == other || (self - other).to_raw().abs() < 1e-6
+    }
+
     /// Whether the length is zero.
     pub fn is_zero(self) -> bool {
         self.raw == 0.0

src/layout/grid.rs

@@ -64,6 +64,8 @@ struct GridLayouter<'a> {
     children: &'a [AnyNode],
     /// The region to layout into.
     regions: Regions,
+    /// The original expand state of the target region.
+    original_expand: Spec<bool>,
     /// Resolved column sizes.
     rcols: Vec<Length>,
     /// The full main size of the current region.
@@ -135,7 +137,8 @@ impl<'a> GridLayouter<'a> {
         let full = regions.current.get(main);
         let rcols = vec![Length::zero(); cols.len()];
 
-        // We use the regions only for auto row measurement.
+        // We use the regions only for auto row measurement and constraints.
+        let original_expand = regions.expand;
         regions.expand = Gen::new(true, false).to_spec(main);
 
         Self {
@@ -144,8 +147,9 @@ impl<'a> GridLayouter<'a> {
             cols,
             rows,
             children: &grid.children,
-            constraints: Constraints::new(regions.expand),
+            constraints: Constraints::new(original_expand),
             regions,
+            original_expand,
             rcols,
             lrows: vec![],
             full,
@@ -506,7 +510,7 @@ impl<'a> GridLayouter<'a> {
         self.used.main = Length::zero();
         self.fr = Fractional::zero();
         self.finished.push(output.constrain(self.constraints));
-        self.constraints = Constraints::new(self.regions.expand);
+        self.constraints = Constraints::new(self.original_expand);
     }
 
     /// Get the node in the cell in column `x` and row `y`.

src/layout/incremental.rs

@@ -7,13 +7,15 @@ use super::*;
 pub struct LayoutCache {
     /// Maps from node hashes to the resulting frames and regions in which the
     /// frames are valid.
-    pub frames: HashMap<u64, FramesEntry>,
+    pub frames: HashMap<u64, Vec<FramesEntry>>,
+    /// In how many compilations this cache has been used.
+    age: usize,
 }
 
 impl LayoutCache {
     /// Create a new, empty layout cache.
     pub fn new() -> Self {
-        Self { frames: HashMap::new() }
+        Self { frames: HashMap::new(), age: 0 }
     }
 
     /// Clear the cache.
@@ -26,12 +28,68 @@ impl LayoutCache {
     where
         F: FnMut(usize) -> bool,
     {
-        self.frames.retain(|_, entry| f(entry.level));
+        for (_, hash_ident) in self.frames.iter_mut() {
+            hash_ident.retain(|entry| f(entry.level));
+        }
     }
 
     /// Amount of items in the cache.
     pub fn len(&self) -> usize {
-        self.frames.len()
+        self.frames.iter().map(|(_, e)| e.len()).sum()
+    }
+
+    /// Prepare the cache for the next round of compilation
+    pub fn turnaround(&mut self) {
+        self.age += 1;
+        for entry in self.frames.iter_mut().flat_map(|(_, x)| x.iter_mut()) {
+            for i in 0 .. (entry.temperature.len() - 1) {
+                entry.temperature[i] = entry.temperature[i + 1];
+            }
+            *entry.temperature.last_mut().unwrap() = Some(0);
+        }
+    }
+
+    /// What is the deepest level in the cache?
+    pub fn levels(&self) -> usize {
+        self.frames
+            .iter()
+            .flat_map(|(_, x)| x)
+            .map(|entry| entry.level + 1)
+            .max()
+            .unwrap_or(0)
+    }
+
+    /// Fetches the appropriate entry from the cache if there is any.
+    pub fn get(
+        &mut self,
+        hash: u64,
+        regions: Regions,
+    ) -> Option<Vec<Constrained<Rc<Frame>>>> {
+        self.frames.get_mut(&hash).and_then(|frames| {
+            for frame in frames {
+                let res = frame.check(regions.clone());
+                if res.is_some() {
+                    return res;
+                }
+            }
+
+            None
+        })
+    }
+
+    /// Inserts a new frame set into the cache.
+    pub fn insert(
+        &mut self,
+        hash: u64,
+        frames: Vec<Constrained<Rc<Frame>>>,
+        level: usize,
+    ) {
+        let entry = FramesEntry::new(frames, level);
+        if let Some(variants) = self.frames.get_mut(&hash) {
+            variants.push(entry);
+        } else {
+            self.frames.insert(hash, vec![entry]);
+        }
     }
 }
 
@@ -42,19 +100,72 @@ pub struct FramesEntry {
     pub frames: Vec<Constrained<Rc<Frame>>>,
     /// How nested the frame was in the context is was originally appearing in.
     pub level: usize,
+    /// How much the element was accessed during the last five compilations, the
+    /// most current one being the last element. `None` variants indicate that
+    /// the element is younger than five compilations.
+    temperature: [Option<usize>; 5],
 }
 
 impl FramesEntry {
+    /// Construct a new instance.
+    pub fn new(frames: Vec<Constrained<Rc<Frame>>>, level: usize) -> Self {
+        let mut temperature = [None; 5];
+        temperature[4] = Some(0);
+        Self { frames, level, temperature }
+    }
+
     /// Checks if the cached [`Frame`] is valid for the given regions.
-    pub fn check(&self, mut regions: Regions) -> Option<Vec<Constrained<Rc<Frame>>>> {
+    pub fn check(&mut self, mut regions: Regions) -> Option<Vec<Constrained<Rc<Frame>>>> {
         for (i, frame) in self.frames.iter().enumerate() {
             if (i != 0 && !regions.next()) || !frame.constraints.check(&regions) {
                 return None;
             }
         }
 
+        let tmp = self.temperature.get_mut(4).unwrap();
+        *tmp = Some(tmp.map_or(1, |x| x + 1));
+
         Some(self.frames.clone())
     }
+
+    /// Get the amount of compilation cycles this item has remained in the
+    /// cache.
+    pub fn age(&self) -> usize {
+        let mut age = 0;
+        for &temp in self.temperature.iter().rev() {
+            if temp.is_none() {
+                break;
+            }
+            age += 1;
+        }
+        age
+    }
+
+    /// Get the amount of consecutive cycles in which this item has not
+    /// been used.
+    pub fn cooldown(&self) -> usize {
+        let mut age = 0;
+        for (i, &temp) in self.temperature.iter().enumerate().rev() {
+            match temp {
+                Some(temp) => {
+                    if temp > 0 {
+                        return self.temperature.len() - 1 - i;
+                    }
+                }
+                None => {
+                    return age;
+                }
+            }
+            age += 1
+        }
+
+        age
+    }
+
+    /// Whether this element was used in the last compilation cycle.
+    pub fn hit(&self) -> bool {
+        self.temperature.last().unwrap().unwrap_or(0) != 0
+    }
 }
 
 #[derive(Debug, Copy, Clone, PartialEq)]
@@ -107,15 +218,22 @@ impl Constraints {
         let base = regions.base.to_spec();
         let current = regions.current.to_spec();
 
-        current.eq_by(&self.min, |x, y| y.map_or(true, |y| x >= &y))
+        let res = current.eq_by(&self.min, |&x, y| y.map_or(true, |y| x.fits(y)))
             && current.eq_by(&self.max, |x, y| y.map_or(true, |y| x < &y))
-            && current.eq_by(&self.exact, |x, y| y.map_or(true, |y| x == &y))
-            && base.eq_by(&self.base, |x, y| y.map_or(true, |y| x == &y))
+            && current.eq_by(&self.exact, |&x, y| y.map_or(true, |y| x.approx_eq(y)))
+            && base.eq_by(&self.base, |&x, y| y.map_or(true, |y| x.approx_eq(y)));
+
+        res
     }
 
     /// Changes all constraints by adding the argument to them if they are set.
-    pub fn mutate(&mut self, size: Size) {
-        for x in &mut [self.min, self.max, self.exact, self.base] {
+    pub fn mutate(&mut self, size: Size, regions: &Regions) {
+        for x in std::array::IntoIter::new([
+            &mut self.min,
+            &mut self.max,
+            &mut self.exact,
+            &mut self.base,
+        ]) {
             if let Some(horizontal) = x.horizontal.as_mut() {
                 *horizontal += size.width;
             }
@@ -123,6 +241,23 @@ impl Constraints {
                 *vertical += size.height;
             }
         }
+
+        self.exact = zip(self.exact, regions.current.to_spec(), |_, o| o);
+        self.base = zip(self.base, regions.base.to_spec(), |_, o| o);
+    }
+}
+
+fn zip<F>(
+    one: Spec<Option<Length>>,
+    other: Spec<Length>,
+    mut f: F,
+) -> Spec<Option<Length>>
+where
+    F: FnMut(Length, Length) -> Length,
+{
+    Spec {
+        vertical: one.vertical.map(|r| f(r, other.vertical)),
+        horizontal: one.horizontal.map(|r| f(r, other.horizontal)),
     }
 }
 

src/layout/mod.rs

@@ -102,18 +102,10 @@ impl Layout for AnyNode {
         regions: &Regions,
     ) -> Vec<Constrained<Rc<Frame>>> {
         ctx.level += 1;
-        let frames = ctx
-            .cache
-            .layout
-            .frames
-            .get(&self.hash)
-            .and_then(|x| x.check(regions.clone()))
-            .unwrap_or_else(|| {
+        let frames =
+            ctx.cache.layout.get(self.hash, regions.clone()).unwrap_or_else(|| {
                 let frames = self.node.layout(ctx, regions);
-                ctx.cache.layout.frames.insert(self.hash, FramesEntry {
-                    frames: frames.clone(),
-                    level: ctx.level - 1,
-                });
+                ctx.cache.layout.insert(self.hash, frames.clone(), ctx.level - 1);
                 frames
             });
         ctx.level -= 1;

src/layout/pad.rs

@@ -15,6 +15,7 @@ impl Layout for PadNode {
         ctx: &mut LayoutContext,
         regions: &Regions,
     ) -> Vec<Constrained<Rc<Frame>>> {
+        let original = regions.clone();
         let mut regions = regions.map(|size| size - self.padding.resolve(size).size());
 
         let mut frames = self.child.layout(ctx, &regions);
@@ -28,13 +29,13 @@ impl Layout for PadNode {
             let prev = std::mem::take(&mut frame.item);
             new.push_frame(origin, prev);
 
-            frame.constraints.mutate(padding.size() * -1.0);
+            frame.constraints.mutate(padding.size(), &original);
 
             if self.padding.left.is_relative() || self.padding.right.is_relative() {
-                frame.constraints.base.horizontal = Some(regions.base.width);
+                frame.constraints.base.horizontal = Some(original.base.width);
             }
             if self.padding.top.is_relative() || self.padding.bottom.is_relative() {
-                frame.constraints.base.vertical = Some(regions.base.height);
+                frame.constraints.base.vertical = Some(original.base.height);
             }
 
             regions.next();

src/layout/par.rs

@@ -213,10 +213,18 @@ impl<'a> ParLayouter<'a> {
             while !stack.regions.current.height.fits(line.size.height)
                 && !stack.regions.in_full_last()
             {
-                stack.constraints.max.vertical.set_min(line.size.height);
+                stack.constraints.max.vertical.set_min(
+                    stack.full.height - stack.regions.current.height + line.size.height,
+                );
                 stack.finish_region(ctx);
             }
 
+            if !stack.regions.current.height.fits(line.size.height)
+                && stack.regions.in_full_last()
+            {
+                stack.overflowing = true;
+            }
+
             // If the line does not fit horizontally or we have a mandatory
             // line break (i.e. due to "\n"), we push the line into the
             // stack.
@@ -303,11 +311,13 @@ impl ParItem<'_> {
 /// Stacks lines on top of each other.
 struct LineStack<'a> {
     line_spacing: Length,
+    full: Size,
     regions: Regions,
     size: Size,
     lines: Vec<LineLayout<'a>>,
     finished: Vec<Constrained<Rc<Frame>>>,
     constraints: Constraints,
+    overflowing: bool,
 }
 
 impl<'a> LineStack<'a> {
@@ -316,10 +326,12 @@ impl<'a> LineStack<'a> {
         Self {
             line_spacing,
             constraints: Constraints::new(regions.expand),
+            full: regions.current,
             regions,
             size: Size::zero(),
             lines: vec![],
             finished: vec![],
+            overflowing: false,
         }
     }
 
@@ -343,6 +355,12 @@ impl<'a> LineStack<'a> {
             self.constraints.exact.horizontal = Some(self.regions.current.width);
         }
 
+        if self.overflowing {
+            self.constraints.min.vertical = None;
+            self.constraints.max.vertical = None;
+            self.constraints.exact = self.full.to_spec().map(Some);
+        }
+
         let mut output = Frame::new(self.size, self.size.height);
         let mut offset = Length::zero();
         let mut first = true;
@@ -362,6 +380,7 @@ impl<'a> LineStack<'a> {
 
         self.finished.push(output.constrain(self.constraints));
         self.regions.next();
+        self.full = self.regions.current;
         self.constraints = Constraints::new(self.regions.expand);
         self.size = Size::zero();
     }

src/layout/stack.rs

@@ -86,8 +86,8 @@ impl<'a> StackLayouter<'a> {
         Self {
             stack,
             main,
+            constraints: Constraints::new(expand),
             expand,
-            constraints: Constraints::new(regions.expand),
             regions,
             full,
             used: Gen::zero(),
@@ -145,7 +145,10 @@ impl<'a> StackLayouter<'a> {
         while !self.regions.current.get(self.main).fits(size.main)
             && !self.regions.in_full_last()
         {
-            self.constraints.max.get_mut(self.main).set_min(size.main);
+            self.constraints
+                .max
+                .get_mut(self.main)
+                .set_min(size.main + self.used.main);
             self.finish_region();
         }
 
@@ -188,7 +191,9 @@ impl<'a> StackLayouter<'a> {
 
         // Make sure the stack's size satisfies the aspect ratio.
         if let Some(aspect) = self.stack.aspect {
-            self.constraints.exact = self.regions.current.to_spec().map(Some);
+            self.constraints.exact = self.full.to_spec().map(Some);
+            self.constraints.min = Spec::splat(None);
+            self.constraints.max = Spec::splat(None);
             let width = size
                 .width
                 .max(aspect.into_inner() * size.height)
@@ -244,6 +249,6 @@ impl<'a> StackLayouter<'a> {
         self.used = Gen::zero();
         self.ruler = Align::Start;
         self.finished.push(output.constrain(self.constraints));
-        self.constraints = Constraints::new(self.regions.expand);
+        self.constraints = Constraints::new(expand);
     }
 }

tests/typeset.rs

@@ -224,10 +224,8 @@ fn test_part(
     state.page.size = Size::new(Length::pt(120.0), Length::inf());
     state.page.margins = Sides::splat(Some(Length::pt(10.0).into()));
 
-    // Clear cache between tests (for now).
-    cache.layout.clear();
-
-    let mut pass = typst::typeset(loader, cache, Some(src_path), &src, &scope, state);
+    let mut pass =
+        typst::typeset(loader, cache, Some(src_path), &src, &scope, state.clone());
 
     if !compare_ref {
         pass.output.clear();
@@ -266,6 +264,56 @@ fn test_part(
         }
     }
 
+    let reference_cache = cache.layout.clone();
+    for level in 0 .. reference_cache.levels() {
+        cache.layout = reference_cache.clone();
+        cache.layout.retain(|x| x == level);
+        if cache.layout.frames.is_empty() {
+            continue;
+        }
+
+        cache.layout.turnaround();
+
+        let mut cached_result =
+            typst::typeset(loader, cache, Some(src_path), &src, &scope, state.clone());
+
+        if !compare_ref {
+            cached_result.output.clear();
+        }
+
+        let misses: Vec<_> = cache
+            .layout
+            .frames
+            .iter()
+            .flat_map(|(_, e)| e)
+            .filter(|e| e.level == level && !e.hit() && e.age() == 2)
+            .collect();
+
+        if !misses.is_empty() {
+            ok = false;
+            let mut miss_count = 0;
+            for miss in misses {
+                dbg!(miss.frames.iter().map(|f| f.constraints).collect::<Vec<_>>());
+                miss_count += 1;
+            }
+            println!(
+                "    Recompilation had {} cache misses on level {} (Subtest {}) ❌",
+                miss_count, level, i
+            );
+        }
+
+        if cached_result != pass {
+            ok = false;
+            println!(
+                "    Recompilation of subtest {} differs from clean pass ❌",
+                i
+            );
+        }
+    }
+
+    cache.layout = reference_cache;
+    cache.layout.turnaround();
+
     (ok, compare_ref, pass.output)
 }