From 365d2db571fdde96fa9f32ce83b10ce5a9fd71de Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Sat, 2 Nov 2024 19:08:15 -0400
Subject: [PATCH] Make InvalidationSignal not generic over synchronicity

---
 crates/compute_graph/src/builder.rs | 49 +++++++++++++++--------------
 crates/compute_graph/src/lib.rs     | 42 +++++++++++--------------
 2 files changed, 44 insertions(+), 47 deletions(-)

diff --git a/crates/compute_graph/src/builder.rs b/crates/compute_graph/src/builder.rs
index 3c14bb4..d1a0bcb 100644
--- a/crates/compute_graph/src/builder.rs
+++ b/crates/compute_graph/src/builder.rs
@@ -103,13 +103,11 @@ impl<O: 'static, S: Synchronicity> GraphBuilder<O, S> {
     pub fn add_invalidatable_value<V: NodeValue>(
         &mut self,
         value: V,
-    ) -> (Input<V>, ValueInvalidationSignal<V, S>) {
+    ) -> (Input<V>, ValueInvalidationSignal<V>) {
         let input = self.add_node(InvalidatableConstNode::new(value));
         let signal = ValueInvalidationSignal {
-            node_idx: input.node_idx,
             value: Rc::clone(&input.value),
-            graph: Rc::clone(&self.node_graph),
-            graph_is_valid: Rc::clone(&self.is_valid),
+            signal: self.make_invalidation_signal(&input),
         };
         (input, signal)
     }
@@ -162,16 +160,26 @@ impl<O: 'static, S: Synchronicity> GraphBuilder<O, S> {
     pub fn add_invalidatable_rule<R: Rule>(
         &mut self,
         rule: R,
-    ) -> (Input<R::Output>, InvalidationSignal<S>) {
+    ) -> (Input<R::Output>, InvalidationSignal) {
         let input = self.add_rule(rule);
-        let signal = InvalidationSignal {
-            node_idx: Rc::new(Cell::new(Some(input.node_idx))),
-            graph: Rc::clone(&self.node_graph),
-            graph_is_valid: Rc::clone(&self.is_valid),
-        };
+        let signal = self.make_invalidation_signal(&input);
         (input, signal)
     }
 
+    fn make_invalidation_signal<V>(&self, input: &Input<V>) -> InvalidationSignal {
+        let node_idx = input.node_idx;
+        let graph = Rc::clone(&self.node_graph);
+        let graph_is_valid = Rc::clone(&self.is_valid);
+        InvalidationSignal {
+            do_invalidate: Rc::new(Box::new(move || {
+                graph_is_valid.set(false);
+                let mut graph = graph.borrow_mut();
+                let node = &mut graph[node_idx];
+                node.invalidate();
+            })),
+        }
+    }
+
     /// Creates a graph from this builder, consuming the builder.
     ///
     /// To successfully build a graph, there must be an output node set (using either
@@ -259,20 +267,13 @@ impl<O: 'static> GraphBuilder<O, Asynchronous> {
     ///
     /// Returns an [`Input`] representing the newly-added node, which can be used to construct further rules,
     /// as well as an [`InvalidationSignal`] which can be used to indicate that the node has been invalidated.
-    pub fn add_invalidatable_async_rule<R, F>(&mut self, mut f: F) -> Input<R::Output>
-    where
-        R: AsyncRule,
-        F: FnMut(InvalidationSignal<Asynchronous>) -> R,
-    {
-        let node_idx = Rc::new(Cell::new(None));
-        let signal = InvalidationSignal {
-            node_idx: Rc::clone(&node_idx),
-            graph: Rc::clone(&self.node_graph),
-            graph_is_valid: Rc::clone(&self.is_valid),
-        };
-        let input = self.add_async_rule(f(signal));
-        node_idx.set(Some(input.node_idx));
-        input
+    pub fn add_invalidatable_async_rule<R: AsyncRule>(
+        &mut self,
+        rule: R,
+    ) -> (Input<R::Output>, InvalidationSignal) {
+        let input = self.add_async_rule(rule);
+        let signal = self.make_invalidation_signal(&input);
+        (input, signal)
     }
 }
 
diff --git a/crates/compute_graph/src/lib.rs b/crates/compute_graph/src/lib.rs
index 0fbeb63..455a926 100644
--- a/crates/compute_graph/src/lib.rs
+++ b/crates/compute_graph/src/lib.rs
@@ -298,33 +298,25 @@ impl<O: 'static> Graph<O, Asynchronous> {
 ///
 /// `InvalidationSignal` implements `Clone`, so the signal can be cloned and used from multiple places.
 // TODO: there's a lot happening here, make sure this doesn't create a reference cycle
-// TODO: would be better if this didn't have to be generic over Synchronicity
-pub struct InvalidationSignal<Synch: Synchronicity> {
-    node_idx: Rc<Cell<Option<NodeId>>>,
-    graph: Rc<RefCell<NodeGraph<Synch>>>,
-    graph_is_valid: Rc<Cell<bool>>,
+pub struct InvalidationSignal {
+    do_invalidate: Rc<Box<dyn Fn() -> ()>>,
 }
 
-impl<S: Synchronicity> InvalidationSignal<S> {
+impl InvalidationSignal {
     /// Tell the graph that the node corresponding to this signal is now invalid.
     ///
     /// Note: Calling this method does not trigger a graph evaluation, it merely marks the corresponding
     /// node as invalid. The graph will not be re-evaluated until [`Graph::evaluate`] or
     /// [`Graph::evaluate_async`] is next called.
     pub fn invalidate(&self) {
-        self.graph_is_valid.set(false);
-        let mut graph = self.graph.borrow_mut();
-        let node = &mut graph[self.node_idx.get().unwrap()];
-        node.invalidate();
+        (self.do_invalidate)();
     }
 }
 
-impl<S: Synchronicity> Clone for InvalidationSignal<S> {
+impl Clone for InvalidationSignal {
     fn clone(&self) -> Self {
         Self {
-            node_idx: Rc::clone(&self.node_idx),
-            graph: Rc::clone(&self.graph),
-            graph_is_valid: Rc::clone(&self.graph_is_valid),
+            do_invalidate: Rc::clone(&self.do_invalidate),
         }
     }
 }
@@ -332,14 +324,12 @@ impl<S: Synchronicity> Clone for InvalidationSignal<S> {
 /// A type representing a node with an externally injected value.
 ///
 /// See [`GraphBuilder::add_invalidatable_value`].
-pub struct ValueInvalidationSignal<V, Synch: Synchronicity> {
-    node_idx: NodeId,
+pub struct ValueInvalidationSignal<V> {
     value: Rc<RefCell<Option<V>>>,
-    graph: Rc<RefCell<NodeGraph<Synch>>>,
-    graph_is_valid: Rc<Cell<bool>>,
+    signal: InvalidationSignal,
 }
 
-impl<V: NodeValue, S: Synchronicity> ValueInvalidationSignal<V, S> {
+impl<V: NodeValue> ValueInvalidationSignal<V> {
     /// Get a reference to current value for the node corresponding to this signal.
     pub fn value(&self) -> impl Deref<Target = V> + '_ {
         Ref::map(self.value.borrow(), |opt| {
@@ -361,10 +351,16 @@ impl<V: NodeValue, S: Synchronicity> ValueInvalidationSignal<V, S> {
             .node_value_eq(&value)
         {
             *current_value = Some(value);
-            self.graph_is_valid.set(false);
-            let mut graph = self.graph.borrow_mut();
-            let node = &mut graph[self.node_idx];
-            node.invalidate();
+            self.signal.invalidate();
+        }
+    }
+}
+
+impl<V> Clone for ValueInvalidationSignal<V> {
+    fn clone(&self) -> Self {
+        Self {
+            value: Rc::clone(&self.value),
+            signal: self.signal.clone(),
         }
     }
 }