More efficient introspection

Switches from a mutable locator to one based on tracked chains and optimizes query performance.

7 files changed, 49 insertions, 29 deletions

diff --git a/library/src/layout/mod.rs b/library/src/layout/mod.rs
index adfc433a..16ac46bb 100644
--- a/library/src/layout/mod.rs
+++ b/library/src/layout/mod.rs
@@ -75,11 +75,12 @@ impl LayoutRoot for Content {
             content: &Content,
             world: Tracked<dyn World + '_>,
             tracer: TrackedMut<Tracer>,
-            provider: TrackedMut<StabilityProvider>,
+            locator: Tracked<Locator>,
             introspector: Tracked<Introspector>,
             styles: StyleChain,
         ) -> SourceResult<Document> {
-            let mut vt = Vt { world, tracer, provider, introspector };
+            let mut locator = Locator::chained(locator);
+            let mut vt = Vt { world, tracer, locator: &mut locator, introspector };
             let scratch = Scratch::default();
             let (realized, styles) = realize_root(&mut vt, &scratch, content, styles)?;
             realized
@@ -94,7 +95,7 @@ impl LayoutRoot for Content {
             self,
             vt.world,
             TrackedMut::reborrow_mut(&mut vt.tracer),
-            TrackedMut::reborrow_mut(&mut vt.provider),
+            vt.locator.track(),
             vt.introspector,
             styles,
         )
@@ -121,10 +122,14 @@ pub trait Layout {
         styles: StyleChain,
         regions: Regions,
     ) -> SourceResult<Fragment> {
-        vt.provider.save();
-        let result = self.layout(vt, styles, regions);
-        vt.provider.restore();
-        result
+        let mut locator = Locator::chained(vt.locator.track());
+        let mut vt = Vt {
+            world: vt.world,
+            tracer: TrackedMut::reborrow_mut(&mut vt.tracer),
+            locator: &mut locator,
+            introspector: vt.introspector,
+        };
+        self.layout(&mut vt, styles, regions)
     }
 }
 
@@ -141,12 +146,13 @@ impl Layout for Content {
             content: &Content,
             world: Tracked<dyn World + '_>,
             tracer: TrackedMut<Tracer>,
-            provider: TrackedMut<StabilityProvider>,
+            locator: Tracked<Locator>,
             introspector: Tracked<Introspector>,
             styles: StyleChain,
             regions: Regions,
         ) -> SourceResult<Fragment> {
-            let mut vt = Vt { world, tracer, provider, introspector };
+            let mut locator = Locator::chained(locator);
+            let mut vt = Vt { world, tracer, locator: &mut locator, introspector };
             let scratch = Scratch::default();
             let (realized, styles) = realize_block(&mut vt, &scratch, content, styles)?;
             realized
@@ -157,15 +163,18 @@ impl Layout for Content {
 
         tracing::info!("Layouting `Content`");
 
-        cached(
+        let fragment = cached(
             self,
             vt.world,
             TrackedMut::reborrow_mut(&mut vt.tracer),
-            TrackedMut::reborrow_mut(&mut vt.provider),
+            vt.locator.track(),
             vt.introspector,
             styles,
             regions,
-        )
+        )?;
+
+        vt.locator.visit_frames(&fragment);
+        Ok(fragment)
     }
 }
 
diff --git a/library/src/layout/par.rs b/library/src/layout/par.rs
index c7bc5359..2edbd93d 100644
--- a/library/src/layout/par.rs
+++ b/library/src/layout/par.rs
@@ -141,14 +141,15 @@ impl ParElem {
             par: &ParElem,
             world: Tracked<dyn World + '_>,
             tracer: TrackedMut<Tracer>,
-            provider: TrackedMut<StabilityProvider>,
+            locator: Tracked<Locator>,
             introspector: Tracked<Introspector>,
             styles: StyleChain,
             consecutive: bool,
             region: Size,
             expand: bool,
         ) -> SourceResult<Fragment> {
-            let mut vt = Vt { world, tracer, provider, introspector };
+            let mut locator = Locator::chained(locator);
+            let mut vt = Vt { world, tracer, locator: &mut locator, introspector };
             let children = par.children();
 
             // Collect all text into one string for BiDi analysis.
@@ -166,17 +167,20 @@ impl ParElem {
             finalize(&mut vt, &p, &lines, region, expand)
         }
 
-        cached(
+        let fragment = cached(
             self,
             vt.world,
             TrackedMut::reborrow_mut(&mut vt.tracer),
-            TrackedMut::reborrow_mut(&mut vt.provider),
+            vt.locator.track(),
             vt.introspector,
             styles,
             consecutive,
             region,
             expand,
-        )
+        )?;
+
+        vt.locator.visit_frames(&fragment);
+        Ok(fragment)
     }
 }
 
diff --git a/library/src/meta/counter.rs b/library/src/meta/counter.rs
index 50a097af..5c23c536 100644
--- a/library/src/meta/counter.rs
+++ b/library/src/meta/counter.rs
@@ -396,7 +396,7 @@ impl Counter {
         self.sequence_impl(
             vt.world,
             TrackedMut::reborrow_mut(&mut vt.tracer),
-            TrackedMut::reborrow_mut(&mut vt.provider),
+            vt.locator.track(),
             vt.introspector,
         )
     }
@@ -407,10 +407,11 @@ impl Counter {
         &self,
         world: Tracked<dyn World + '_>,
         tracer: TrackedMut<Tracer>,
-        provider: TrackedMut<StabilityProvider>,
+        locator: Tracked<Locator>,
         introspector: Tracked<Introspector>,
     ) -> SourceResult<EcoVec<(CounterState, NonZeroUsize)>> {
-        let mut vt = Vt { world, tracer, provider, introspector };
+        let mut locator = Locator::chained(locator);
+        let mut vt = Vt { world, tracer, locator: &mut locator, introspector };
         let mut state = CounterState(match &self.0 {
             // special case, because pages always start at one.
             CounterKey::Page => smallvec![1],
diff --git a/library/src/meta/query.rs b/library/src/meta/query.rs
index 9488a964..4db658d7 100644
--- a/library/src/meta/query.rs
+++ b/library/src/meta/query.rs
@@ -122,7 +122,12 @@ pub fn query(
     location: Location,
 ) -> Value {
     let _ = location;
-    vm.vt.introspector.query(&target.0).into()
+    let vec = vm.vt.introspector.query(&target.0);
+    Value::Array(
+        vec.into_iter()
+            .map(|elem| Value::Content(elem.into_inner()))
+            .collect(),
+    )
 }
 
 /// Turns a value into a selector. The following values are accepted:
diff --git a/library/src/meta/reference.rs b/library/src/meta/reference.rs
index 68837b89..ceb1a3b2 100644
--- a/library/src/meta/reference.rs
+++ b/library/src/meta/reference.rs
@@ -130,7 +130,7 @@ impl Synthesize for RefElem {
         let target = self.target();
         if vt.introspector.init() && !BibliographyElem::has(vt, &target.0) {
             if let Ok(elem) = vt.introspector.query_label(&target) {
-                self.push_element(Some(elem));
+                self.push_element(Some(elem.into_inner()));
                 return Ok(());
             }
         }
@@ -173,7 +173,7 @@ impl Show for RefElem {
         let supplement = match self.supplement(styles) {
             Smart::Auto | Smart::Custom(None) => None,
             Smart::Custom(Some(supplement)) => {
-                Some(supplement.resolve(vt, [elem.clone().into()])?)
+                Some(supplement.resolve(vt, [(*elem).clone().into()])?)
             }
         };
 
diff --git a/library/src/meta/state.rs b/library/src/meta/state.rs
index b466bd66..33c3b595 100644
--- a/library/src/meta/state.rs
+++ b/library/src/meta/state.rs
@@ -311,7 +311,7 @@ impl State {
         self.sequence_impl(
             vt.world,
             TrackedMut::reborrow_mut(&mut vt.tracer),
-            TrackedMut::reborrow_mut(&mut vt.provider),
+            vt.locator.track(),
             vt.introspector,
         )
     }
@@ -322,10 +322,11 @@ impl State {
         &self,
         world: Tracked<dyn World + '_>,
         tracer: TrackedMut<Tracer>,
-        provider: TrackedMut<StabilityProvider>,
+        locator: Tracked<Locator>,
         introspector: Tracked<Introspector>,
     ) -> SourceResult<EcoVec<Value>> {
-        let mut vt = Vt { world, tracer, provider, introspector };
+        let mut locator = Locator::chained(locator);
+        let mut vt = Vt { world, tracer, locator: &mut locator, introspector };
         let mut state = self.init.clone();
         let mut stops = eco_vec![state.clone()];
 
diff --git a/library/src/prelude.rs b/library/src/prelude.rs
index cb21a732..a0cef491 100644
--- a/library/src/prelude.rs
+++ b/library/src/prelude.rs
@@ -23,9 +23,9 @@ pub use typst::geom::*;
 #[doc(no_inline)]
 pub use typst::model::{
     element, Behave, Behaviour, Construct, Content, ElemFunc, Element, Finalize, Fold,
-    Introspector, Label, Locatable, LocatableSelector, Location, MetaElem, PlainText,
-    Resolve, Selector, Set, Show, StabilityProvider, StyleChain, StyleVec, Styles,
-    Synthesize, Unlabellable, Vt,
+    Introspector, Label, Locatable, LocatableSelector, Location, Locator, MetaElem,
+    PlainText, Resolve, Selector, Set, Show, StyleChain, StyleVec, Styles, Synthesize,
+    Unlabellable, Vt,
 };
 #[doc(no_inline)]
 pub use typst::syntax::{Span, Spanned};