From 7c554f731ab16a10e703279f311e48573168a3ed Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Thu, 31 Oct 2024 11:00:48 -0400
Subject: [PATCH] Remove Synchronicity::AnyStorage indirection

---
 crates/graph/src/lib.rs | 77 +++++++++++------------------------------
 1 file changed, 21 insertions(+), 56 deletions(-)

diff --git a/crates/graph/src/lib.rs b/crates/graph/src/lib.rs
index 42d281c..a7b36c5 100644
--- a/crates/graph/src/lib.rs
+++ b/crates/graph/src/lib.rs
@@ -6,11 +6,11 @@ mod util;
 use petgraph::visit::{IntoEdgeReferences, NodeIndexable};
 use petgraph::{graph::NodeIndex, stable_graph::StableDiGraph, visit::EdgeRef};
 use std::any::Any;
-use std::cell::{Cell, Ref, RefCell, RefMut};
+use std::cell::{Cell, RefCell};
 use std::collections::HashMap;
 use std::collections::VecDeque;
 use std::future::Future;
-use std::ops::{Deref, DerefMut};
+use std::ops::Deref;
 use std::pin::Pin;
 use std::rc::Rc;
 
@@ -18,13 +18,6 @@ use std::rc::Rc;
 type NodeGraph<S: Synchronicity> = StableDiGraph<ErasedNode<S>, (), u32>;
 
 pub trait Synchronicity: 'static {
-    type AnyStorage;
-    fn make_any_storage<T: Any>(value: T) -> Self::AnyStorage;
-    fn unbox_any_storage<T: 'static>(storage: &Self::AnyStorage) -> impl Deref<Target = T>;
-    fn unbox_any_storage_mut<T: 'static>(
-        storage: &mut Self::AnyStorage,
-    ) -> impl DerefMut<Target = T>;
-
     type UpdateFn;
     fn make_update_fn<V: 'static>() -> Self::UpdateFn;
 
@@ -35,22 +28,6 @@ pub trait Synchronicity: 'static {
 pub enum Synchronous {}
 
 impl Synchronicity for Synchronous {
-    type AnyStorage = Box<dyn Any>;
-
-    fn make_any_storage<T: Any>(value: T) -> Self::AnyStorage {
-        Box::new(value)
-    }
-
-    fn unbox_any_storage<T: 'static>(storage: &Self::AnyStorage) -> impl Deref<Target = T> {
-        storage.downcast_ref().unwrap()
-    }
-
-    fn unbox_any_storage_mut<T: 'static>(
-        storage: &mut Self::AnyStorage,
-    ) -> impl DerefMut<Target = T> {
-        storage.downcast_mut().unwrap()
-    }
-
     type UpdateFn = Box<dyn Fn(&mut Box<dyn Any>) -> ()>;
 
     fn make_update_fn<V: 'static>() -> Self::UpdateFn {
@@ -68,23 +45,8 @@ impl Synchronicity for Synchronous {
 pub enum Asynchronous {}
 
 impl Synchronicity for Asynchronous {
-    type AnyStorage = Rc<RefCell<Box<dyn Any>>>;
-
-    fn make_any_storage<T: Any>(value: T) -> Self::AnyStorage {
-        Rc::new(RefCell::new(Box::new(value)))
-    }
-
-    fn unbox_any_storage<T: 'static>(storage: &Self::AnyStorage) -> impl Deref<Target = T> {
-        Ref::map(storage.borrow(), |any| any.downcast_ref().unwrap())
-    }
-
-    fn unbox_any_storage_mut<T: 'static>(
-        storage: &mut Self::AnyStorage,
-    ) -> impl DerefMut<Target = T> {
-        RefMut::map(storage.borrow_mut(), |any| any.downcast_mut().unwrap())
-    }
-
-    type UpdateFn = Box<dyn Fn(Rc<RefCell<Box<dyn Any>>>) -> Pin<Box<dyn Future<Output = ()>>>>;
+    type UpdateFn =
+        Box<dyn for<'a> Fn(&'a mut Box<dyn Any>) -> Pin<Box<dyn Future<Output = ()> + 'a>>>;
 
     fn make_update_fn<V: 'static>() -> Self::UpdateFn {
         Box::new(|any| Box::pin(Asynchronous::do_async_update::<V>(any)))
@@ -98,9 +60,8 @@ impl Synchronicity for Asynchronous {
 }
 
 impl Asynchronous {
-    async fn do_async_update<V: 'static>(any: Rc<RefCell<Box<dyn Any>>>) {
-        let mut any_ = any.borrow_mut();
-        let x = any_.downcast_mut::<Box<dyn Node<V, Self>>>().unwrap();
+    async fn do_async_update<V: 'static>(any: &mut Box<dyn Any>) {
+        let x = any.downcast_mut::<Box<dyn Node<V, Self>>>().unwrap();
         x.update().await;
     }
 }
@@ -362,8 +323,9 @@ impl<Output: Clone + 'static> FrozenGraph<Output, Asynchronous> {
                 Box::pin(self.update_node_async(source)).await;
             }
 
-            let node = &self.node_graph.borrow()[idx];
-            (node.update)(Rc::clone(&node.any)).await;
+            let mut graph = self.node_graph.borrow_mut();
+            let node = &mut graph[idx];
+            (node.update)(&mut node.any).await;
         }
     }
 
@@ -424,10 +386,10 @@ fn invalidate_nodes<S: Synchronicity>(
 // TODO: i really want Input to be able to implement Deref somehow
 
 pub struct ErasedNode<Synch: Synchronicity> {
-    any: Synch::AnyStorage,
-    is_valid: Box<dyn Fn(&Synch::AnyStorage) -> bool>,
-    invalidate: Box<dyn Fn(&mut Synch::AnyStorage) -> ()>,
-    visit_inputs: Box<dyn Fn(&mut Synch::AnyStorage, &mut dyn FnMut(NodeIndex<u32>) -> ()) -> ()>,
+    any: Box<dyn Any>,
+    is_valid: Box<dyn Fn(&Box<dyn Any>) -> bool>,
+    invalidate: Box<dyn Fn(&mut Box<dyn Any>) -> ()>,
+    visit_inputs: Box<dyn Fn(&mut Box<dyn Any>, &mut dyn FnMut(NodeIndex<u32>) -> ()) -> ()>,
     update: Synch::UpdateFn,
 }
 
@@ -435,18 +397,19 @@ impl<S: Synchronicity> ErasedNode<S> {
     fn new<N: Node<V, S> + 'static, V: 'static>(base: N) -> Self {
         // i don't love the double boxing, but i'm not sure how else to do this
         let thing: Box<dyn Node<V, S>> = Box::new(base);
+        let any: Box<dyn Any> = Box::new(thing);
         Self {
-            any: S::make_any_storage(thing),
+            any,
             is_valid: Box::new(|any| {
-                let x = S::unbox_any_storage::<Box<dyn Node<V, S>>>(any);
+                let x = any.downcast_ref::<Box<dyn Node<V, S>>>().unwrap();
                 x.is_valid()
             }),
             invalidate: Box::new(|any| {
-                let mut x = S::unbox_any_storage_mut::<Box<dyn Node<V, S>>>(any);
+                let x = any.downcast_mut::<Box<dyn Node<V, S>>>().unwrap();
                 x.invalidate();
             }),
             visit_inputs: Box::new(|any, visitor| {
-                let mut x = S::unbox_any_storage_mut::<Box<dyn Node<V, S>>>(any);
+                let x = any.downcast_mut::<Box<dyn Node<V, S>>>().unwrap();
                 x.visit_inputs(visitor);
             }),
             update: S::make_update_fn::<V>(),
@@ -454,7 +417,9 @@ impl<S: Synchronicity> ErasedNode<S> {
     }
 
     fn expect_type<'a, V: 'static>(&'a self) -> impl Deref<Target = Box<dyn Node<V, S>>> + 'a {
-        S::unbox_any_storage::<Box<dyn Node<V, S>>>(&self.any)
+        self.any
+            .downcast_ref::<Box<dyn Node<V, S>>>()
+            .expect("node should match expected type")
     }
 
     fn is_valid(&self) -> bool {