Implement a "downcastable" wasm resource for ecs resources, cleanup code for exposing asset manager

guests/csharp/dotnet-guest-test/ExampleWorldImpl.cs

@@ -24,9 +24,8 @@ public class ExampleWorldImpl : IExampleWorld
             Console.WriteLine($"C#:   Delta time: {dt?.Seconds:0.##}");
         } */
 
-        AssetManager? man = world.GetAssetManager();
-        if (man != null)
-        {
+        AssetManager? man = world.GetResource<AssetManager>();
+        if (man != null) {
             Handle<ImageHandle> han = man.Request<ImageHandle>("test_assets/white.png");
             Console.WriteLine($"C#:   Asset uuid: {han.Uuid}");
 

guests/csharp/dotnet-guest-test/LyraApi/Asset/AssetManager.cs

@@ -1,5 +1,6 @@
 using LyraApi.Ecs;
 using ExampleWorld.wit.imports.lyra.api;
+using System.Numerics;
 
 namespace LyraApi.Asset;
 
@@ -15,11 +16,9 @@ public class AssetManager(IAsset.AssetManager assetManager) : IResource
         {
             case IEcs.WorldResourceResult.NONE:
                 return null;
-            case IEcs.WorldResourceResult.WASM_RESOURCE_REP:
-                Console.WriteLine($"Got the resource rep: {result.AsWasmResourceRep}");
-                var handle = new IAsset.AssetManager.THandle((int)result.AsWasmResourceRep);
-                var inner = new IAsset.AssetManager(handle);
-                return new AssetManager(inner);
+            case IEcs.WorldResourceResult.WASM_RESOURCE:
+                var handle = IAsset.AssetManager.FromEcsResource(result.AsWasmResource) ?? throw new MismatchedResourceResultException();
+                return new AssetManager(handle);
             case IEcs.WorldResourceResult.BYTES:
                 return null;
             default:

guests/csharp/dotnet-guest-test/LyraApi/Asset/Handle.cs

@@ -4,10 +4,10 @@ public class Handle<T>(UntypedHandle handle) where T : IAssetHandle
 {
     internal UntypedHandle inner = handle;
 
-    public bool Watched { get => inner.Watched; set => inner.Watched = value; }
+    public bool Watched { get => inner.Watched; }
     public ulong Version { get => inner.Version; }
     public Guid Uuid { get => inner.Uuid; }
-    public string Path { get => inner.Path; }
+    public string? Path { get => inner.Path; }
     public bool IsLoaded { get => inner.IsLoaded; }
 
     public void WaitForLoad()

guests/csharp/dotnet-guest-test/LyraApi/Asset/UntypedHandle.cs

@@ -6,10 +6,10 @@ public class UntypedHandle(IAsset.AssetHandle handle)
 {
     internal IAsset.AssetHandle inner = handle;
 
-    public bool Watched { get => inner.IsWatched(); set => inner.SetWatched(value); }
+    public bool Watched { get => inner.IsWatched(); }
     public ulong Version { get => inner.Version(); }
     public Guid Uuid { get => Guid.Parse(inner.Uuid()); }
-    public string Path { get => inner.Path(); }
+    public string? Path { get => inner.Path(); }
     public bool IsLoaded { get => inner.IsLoaded(); }
 
     public void WaitForLoad()

guests/csharp/dotnet-guest-test/LyraApi/Ecs/IResource.cs

@@ -8,3 +8,5 @@ public interface IResource
 
     public abstract static object? FromWasmResult(WorldResourceResult result);
 }
+
+public class MismatchedResourceResultException : Exception {}

guests/csharp/dotnet-guest-test/LyraApi/Ecs/World.cs

@@ -35,7 +35,7 @@ public class World(IEcs.EcsWorld world)
         return (T?)T.FromWasmResult(result);
     }
 
-    public AssetManager? GetAssetManager()
+    /* public AssetManager? GetAssetManager()
     {
         IAsset.AssetManager? assetManager = IAsset.AssetManager.FromWorld(inner);
 
@@ -47,5 +47,5 @@ public class World(IEcs.EcsWorld world)
         {
             return null;
         }
-    }
+    } */
 }

guests/csharp/dotnet-guest-test/LyraApi/Engine/DeltaTime.cs

@@ -15,7 +15,7 @@ public struct DeltaTime : IResource {
     {
         return result.Tag switch
         {
-            WorldResourceResult.NONE | WorldResourceResult.WASM_RESOURCE_REP => null,
+            WorldResourceResult.NONE | WorldResourceResult.WASM_RESOURCE => null,
             WorldResourceResult.BYTES => MarshalUtils.FromBytes<DeltaTime>(result.AsBytes),
             _ => null,
         };

guests/csharp/dotnet-guest-test/wit/deps/lyraapi/asset.wit

@@ -1,6 +1,7 @@
 interface asset {
+    use ecs.{ecs-world, ecs-resource};
+
     resource asset-handle {
-        set-watched: func(watched: bool);
         version: func() -> u64;
         uuid: func() -> string;
         path: func() -> option<string>;
@@ -18,10 +19,8 @@ interface asset {
         get-bytes: func() -> option<list<u8>>;
     }
 
-    use ecs.{ecs-world};
-
     resource asset-manager {
-        from-world: static func(w: borrow<ecs-world>) -> option<asset-manager>;
+        from-ecs-resource: static func(w: borrow<ecs-resource>) -> option<asset-manager>;
         request: func(path: string) -> asset-handle;
     }
 }

guests/csharp/dotnet-guest-test/wit/deps/lyraapi/ecs.wit

@@ -37,9 +37,16 @@ interface ecs {
         next: func() -> option<tuple<entity, list<u8>>>;
     }
 
+    /// An resource that can be "downcasted" to a specific type.
+    /// 
+    /// You can use `T.from-ecs-resource` to "downcast" the type
+    resource ecs-resource {
+
+    }
+
     variant world-resource-result {
         none,
-        wasm-resource-rep(u32),
+        wasm-resource(ecs-resource),
         bytes(list<u8>),
     }
 

guests/rust/common-api/src/resource/dt.rs

@@ -20,7 +20,7 @@ impl EcsResource for DeltaTime {
     fn from_wasm_result(result: &WorldResourceResult) -> Option<Self> {
         match result {
             WorldResourceResult::None => None,
-            WorldResourceResult::WasmResourceRep(_) => None,
+            WorldResourceResult::WasmResource(_) => None,
             WorldResourceResult::Bytes(vec) => Some(Self(*bytemuck::from_bytes::<f32>(&vec))),
         }
     }

guests/rust/common-api/wit/asset.wit

@@ -1,6 +1,7 @@
 interface asset {
+    use ecs.{ecs-world, ecs-resource};
+
     resource asset-handle {
-        set-watched: func(watched: bool);
         version: func() -> u64;
         uuid: func() -> string;
         path: func() -> option<string>;
@@ -18,10 +19,8 @@ interface asset {
         get-bytes: func() -> option<list<u8>>;
     }
 
-    use ecs.{ecs-world};
-
     resource asset-manager {
-        from-world: static func(w: borrow<ecs-world>) -> option<asset-manager>;
+        from-ecs-resource: static func(w: borrow<ecs-resource>) -> option<asset-manager>;
         request: func(path: string) -> asset-handle;
     }
 }

guests/rust/common-api/wit/ecs.wit

@@ -37,9 +37,16 @@ interface ecs {
         next: func() -> option<tuple<entity, list<u8>>>;
     }
 
+    /// An resource that can be "downcasted" to a specific type.
+    /// 
+    /// You can use `T.from-ecs-resource` to "downcast" the type
+    resource ecs-resource {
+
+    }
+
     variant world-resource-result {
         none,
-        wasm-resource-rep(u32),
+        wasm-resource(ecs-resource),
         bytes(list<u8>),
     }
 

guests/rust/witguest/wit/deps/lyraapi/asset.wit

@@ -1,6 +1,7 @@
 interface asset {
+    use ecs.{ecs-world, ecs-resource};
+
     resource asset-handle {
-        set-watched: func(watched: bool);
         version: func() -> u64;
         uuid: func() -> string;
         path: func() -> option<string>;
@@ -18,10 +19,8 @@ interface asset {
         get-bytes: func() -> option<list<u8>>;
     }
 
-    use ecs.{ecs-world};
-
     resource asset-manager {
-        from-world: static func(w: borrow<ecs-world>) -> option<asset-manager>;
+        from-ecs-resource: static func(w: borrow<ecs-resource>) -> option<asset-manager>;
         request: func(path: string) -> asset-handle;
     }
 }

guests/rust/witguest/wit/deps/lyraapi/ecs.wit

@@ -37,9 +37,16 @@ interface ecs {
         next: func() -> option<tuple<entity, list<u8>>>;
     }
 
+    /// An resource that can be "downcasted" to a specific type.
+    /// 
+    /// You can use `T.from-ecs-resource` to "downcast" the type
+    resource ecs-resource {
+
+    }
+
     variant world-resource-result {
         none,
-        wasm-resource-rep(u32),
+        wasm-resource(ecs-resource),
         bytes(list<u8>),
     }
 

src/asset.rs

@@ -1,10 +1,6 @@
-use std::any::TypeId;
-
 use async_trait::async_trait;
-use tokio::task;
 use wasmtime::component::Resource as WasmResource;
 
-use crate::WasmError;
 use crate::{lyra, Imports};
 
 use lyra::api::asset as wasm_asset;
@@ -14,17 +10,17 @@ impl wasm_asset::Host for Imports {}
 
 #[async_trait]
 impl wasm_asset::HostAssetManager for Imports {
-    async fn from_world(&mut self, world: WasmResource<wasm_ecs::EcsWorld>) -> Option<WasmResource<wasm_asset::AssetManager>> {
-        let world_entry = self
-            .world_slab
-            .get(world.rep() as _)
-            .ok_or(WasmError::InvalidResourceHandle("EcsWorld")).unwrap();
-        let world = &world_entry.world;
+    async fn from_ecs_resource(&mut self, res: WasmResource<wasm_ecs::EcsResource>) -> Option<WasmResource<wasm_asset::AssetManager>> {
+        let res_rep = res.rep() as u32;
+        let res = self.resource_data_slab.get_mut(res_rep as _)?;
+        res.borrow += 1;
 
-        let man = world.get_resource_data::<lyra_engine::assets::ResourceManager>()?;
-        let man_rep = self.asset_manager_slab.insert(man);
+        // ensure that the 
+        if !res.data.is::<lyra_engine::assets::ResourceManager>() {
+            return None;
+        }
         
-        Some(WasmResource::new_own(man_rep as _))
+        Some(WasmResource::new_own(res_rep as _))
     }
 
     async fn request(
@@ -32,33 +28,22 @@ impl wasm_asset::HostAssetManager for Imports {
         this: WasmResource<wasm_asset::AssetManager>,
         path: String,
     ) -> WasmResource<wasm_asset::AssetHandle> {
-        let man = self.asset_manager_slab.get(this.rep() as _)
+        let man = self.resource_data_slab.get(this.rep() as _)
             .unwrap()
-            .get::<lyra_engine::assets::ResourceManager>();
+            .data.get::<lyra_engine::assets::ResourceManager>();
         let res = man.request_raw(&path).unwrap();
         let rep = self.asset_handles_slab.insert(res);
         WasmResource::new_own(rep as _)
     }
 
     async fn drop(&mut self, this: WasmResource<wasm_asset::AssetManager>) -> wasmtime::Result<()> {
-        let rep = this.rep() as usize;
-        if self.asset_handles_slab.contains(rep) {
-            self.asset_manager_slab.remove(rep);
-        }
-
+        self.resource_data_slab.drop_ref(this.rep() as _);
         Ok(())
     }
 }
 
 #[async_trait]
 impl wasm_asset::HostAssetHandle for Imports {
-    async fn set_watched(&mut self, this: WasmResource<wasm_asset::AssetHandle>, watched: bool) {
-        let han = self.asset_handles_slab.get(this.rep() as _)
-            .unwrap();
-
-        todo!()
-    }
-
     async fn version(&mut self, this: WasmResource<wasm_asset::AssetHandle>) -> u64 {
         let han = self.asset_handles_slab.get(this.rep() as _)
             .unwrap();
@@ -111,7 +96,8 @@ impl wasm_asset::HostAssetHandle for Imports {
     }
 
     async fn drop(&mut self, this: WasmResource<wasm_asset::AssetHandle>) -> wasmtime::Result<()> {
-        todo!()
+        self.asset_handles_slab.drop_ref(this.rep() as _);
+        Ok(())
     }
 }
 
@@ -122,7 +108,10 @@ impl wasm_asset::HostImageHandle for Imports {
         // image will be none if the asset is not an image asset
         let image = untyped.as_typed::<lyra_engine::assets::Image>();
         if image.is_some() {
-            Some(WasmResource::new_own(raw_handle.rep()))
+            let rep = raw_handle.rep();
+            self.asset_handles_slab.increment_ref(rep as _);
+
+            Some(WasmResource::new_own(rep))
         } else {
             None
         }
@@ -150,6 +139,7 @@ impl wasm_asset::HostImageHandle for Imports {
     }
 
     async fn drop(&mut self, this: WasmResource<wasm_asset::ImageHandle>) -> wasmtime::Result<()> {
-        todo!()
+        self.asset_handles_slab.drop_ref(this.rep() as _);
+        Ok(())
     }
 }

src/main.rs

@@ -9,22 +9,23 @@ use async_trait::async_trait;
 use common_api::math::Vec3;
 use component::witguest::math;
 use ecs::query::dynamic::{DynamicViewState, DynamicViewStateIter, QueryDynamicType};
-use lyra_ecs::{query::dynamic::DynamicViewOne, DynTypeId, World};
+use lyra_ecs::{query::dynamic::DynamicViewOne, World};
 
 use lyra_ecs as ecs;
 
 use lyra_engine::DeltaTime;
-use lyra_reflect::{FromType, ReflectedResource, RegisteredType, TypeRegistry};
+use lyra_reflect::{ReflectedResource, TypeRegistry};
 use slab::Slab;
 use thiserror::Error;
 use wasmtime_wasi::{ResourceTable, WasiCtx, WasiCtxBuilder, WasiView};
 
-use wasmtime::component::{Resource as WasmResource, ResourceAny};
+use wasmtime::component::Resource as WasmResource;
 
 mod proxy;
 pub use proxy::*;
 
 mod asset;
+#[allow(unused_imports)]
 pub use asset::*;
 
 /* #[allow(unused_imports)]
@@ -85,13 +86,84 @@ struct DynamicViewEntry {
     view: DynamicViewStateIter,
 }
 
+#[derive(Clone)]
+pub(crate) struct RefCountedData<T> {
+    pub borrow: u64,
+    pub data: T,
+}
+
+impl<T> std::ops::Deref for RefCountedData<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.data
+    }
+}
+
+impl<T> std::ops::DerefMut for RefCountedData<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.data
+    }
+}
+
+/// A Slab of reference counted data.
+pub(crate) struct SlabRcData<T>(Slab<RefCountedData<T>>);
+
+impl<T> From<Slab<RefCountedData<T>>> for SlabRcData<T> {
+    fn from(value: Slab<RefCountedData<T>>) -> Self {
+        Self(value)
+    }
+}
+
+impl<T> std::ops::Deref for SlabRcData<T> {
+    type Target = Slab<RefCountedData<T>>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<T> std::ops::DerefMut for SlabRcData<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl<T> SlabRcData<T> {
+    pub fn with_capacity(capacity: usize) -> Self {
+        Self(Slab::with_capacity(capacity))
+    }
+
+    pub fn increment_ref(&mut self, r: usize) {
+        if let Some(count) = self.0.get_mut(r) {
+            count.borrow += 1;
+        }
+    }
+
+    pub fn drop_ref(&mut self, r: usize) {
+        if let Some(count) = self.0.get_mut(r) {
+            // only remove the data from the slab if this is the only borrow
+            if count.borrow == 1 {
+                self.0.remove(r);
+            } else {
+                count.borrow -= 1;
+            }
+        }
+    }
+
+    /// Insert a new reference counted element into the slab.
+    pub fn insert(&mut self, data: T) -> usize {
+        self.0.insert(RefCountedData { borrow: 1, data, })
+    }
+}
+
 unsafe impl Send for DynamicViewEntry {}
 
-pub(crate) struct Imports {
+pub struct Imports {
     pub(crate) world_slab: Slab<WorldEntry>,
     pub(crate) world_views_slab: Slab<DynamicViewEntry>,
-    pub(crate) asset_manager_slab: Slab<lyra_ecs::ResourceData>,
-    pub(crate) asset_handles_slab: Slab<lyra_engine::assets::UntypedResHandle>,
+    pub(crate) resource_data_slab: SlabRcData<lyra_ecs::ResourceData>,
+    pub(crate) asset_handles_slab: SlabRcData<lyra_engine::assets::UntypedResHandle>,
 
     pub(crate) ctx: WasiCtx,
     pub(crate) table: ResourceTable,
@@ -279,9 +351,16 @@ impl wasm_ecs::HostEcsWorld for Imports {
         let w = NonNull::from(world);
         let world = unsafe { w.as_ref() };
         let refl = refl.reflect(world).unwrap();
-        let res = proxy.marshal_to_bytes(self, refl.deref());
+        let res = proxy.marshal_to_bytes(self, this.rep(), refl.deref());
 
-        res
+        match res {
+            ProxyResult::None => wasm_ecs::WorldResourceResult::None,
+            ProxyResult::Bytes(bytes) => wasm_ecs::WorldResourceResult::Bytes(bytes),
+            ProxyResult::WasmResource(data) => {
+                let rep = self.resource_data_slab.insert(data);
+                wasm_ecs::WorldResourceResult::WasmResource(WasmResource::new_own(rep as _))
+            }
+        }
     }
 
     async fn drop(
@@ -439,6 +518,18 @@ impl GuestTypeLookup {
     }
 }
 
+#[async_trait]
+impl wasm_ecs::HostEcsResource for Imports {
+    async fn drop(
+        &mut self,
+        this: wasmtime::component::Resource<wasm_ecs::EcsResource>,
+    ) -> wasmtime::Result<()> {
+        self.resource_data_slab.drop_ref(this.rep() as _);
+
+        Ok(())
+    }
+}
+
 #[async_trait]
 impl wasm_ecs::Host for Imports {}
 
@@ -466,8 +557,8 @@ async fn main() -> wasmtime::Result<()> {
             // wants another world for some reason.
             world_slab: Slab::with_capacity(1),
             world_views_slab: Slab::with_capacity(10),
-            asset_manager_slab: Slab::with_capacity(1),
-            asset_handles_slab: Slab::with_capacity(25),
+            resource_data_slab: SlabRcData::with_capacity(25),
+            asset_handles_slab: SlabRcData::with_capacity(25),
             ctx: builder.build(),
             table: ResourceTable::new(),
         },
@@ -478,7 +569,7 @@ async fn main() -> wasmtime::Result<()> {
     let bytes = std::fs::read("guests/csharp/dotnet-guest-test/bin/Debug/net9.0/wasi-wasm/native/dotnet-guest-test.wasm")?;
     let component = wasmtime::component::Component::new(&engine, bytes)?;
 
-    let (script_en, (world_res_a, world_res_b)) = {
+    let (script_en, (world_res_a, _)) = {
         let mut world = World::new();
 
         world.add_resource(DeltaTime::from(100.00));
@@ -492,12 +583,8 @@ async fn main() -> wasmtime::Result<()> {
 
         {
             let mut reg = world.get_resource_or_default::<TypeRegistry>();
-
-            let mut dt_type = RegisteredType::new();
-            dt_type.add_data(<ReflectedResource as FromType::<DeltaTime>>::from_type());
-            dt_type.add_data(<WasmProxied as FromType::<DeltaTime>>::from_type());
-
-            reg.add_registered_type(TypeId::of::<DeltaTime>(), dt_type);
+            add_proxy_type_data::<DeltaTime>(&mut reg);
+            add_proxy_type_data::<lyra_engine::assets::ResourceManager>(&mut reg);
         }
 
         let script_en = world.spawn(());

src/proxy.rs

@@ -1,20 +1,28 @@
-use crate::{lyra::api::ecs as wasm_ecs, Imports};
+use std::any::TypeId;
+
+use crate::Imports;
 use common_api::bytemuck;
 use lyra_engine::DeltaTime;
-use lyra_reflect::{FromType, Reflect};
+use lyra_reflect::{FromType, Reflect, ReflectedResource, TypeRegistry};
+
+pub enum ProxyResult {
+    None,
+    WasmResource(lyra_ecs::ResourceData),
+    Bytes(Vec<u8>)
+}
 
 pub trait WasmProxy {
-    fn marshal_to_bytes(&self, imports: &mut Imports) -> wasm_ecs::WorldResourceResult;
+    fn marshal_to_bytes(&self, imports: &mut Imports, world_idx: u32) -> ProxyResult;
 }
 
 #[derive(Clone)]
 pub struct WasmProxied {
-    fn_marshal: for<'a> fn (&mut Imports, &'a dyn Reflect) -> wasm_ecs::WorldResourceResult,
+    fn_marshal: for<'a> fn (&mut Imports, world_idx: u32, &'a dyn Reflect) -> ProxyResult,
 }
 
 impl WasmProxied {
-    pub fn marshal_to_bytes(&self, imports: &mut Imports, reflected: &dyn Reflect) -> wasm_ecs::WorldResourceResult {
-        (self.fn_marshal)(imports, reflected)
+    pub fn marshal_to_bytes(&self, imports: &mut Imports, world_idx: u32, reflected: &dyn Reflect) -> ProxyResult {
+        (self.fn_marshal)(imports, world_idx, reflected)
     }
 }
 
@@ -24,25 +32,33 @@ where
 {
     fn from_type() -> Self {
         WasmProxied {
-            fn_marshal: |imports, reflect| {
+            fn_marshal: |imports, world_idx: u32, reflect| {
                 let this: &T = reflect.as_any().downcast_ref().unwrap();
-                this.marshal_to_bytes(imports)
+                this.marshal_to_bytes(imports, world_idx)
             }
         }
     }
 }
 
+pub fn add_proxy_type_data<T: WasmProxy + lyra_ecs::ResourceObject + lyra_reflect::Reflect>(reg: &mut TypeRegistry) {
+    let ty = reg.get_type_or_default(TypeId::of::<T>());
+    ty.add_data(<ReflectedResource as FromType::<T>>::from_type());
+    ty.add_data(<WasmProxied as FromType::<T>>::from_type());
+}
+
 impl WasmProxy for DeltaTime {
-    fn marshal_to_bytes(&self, _: &mut Imports) -> wasm_ecs::WorldResourceResult {
-        wasm_ecs::WorldResourceResult::Bytes(bytemuck::bytes_of(&**self).to_vec())
+    fn marshal_to_bytes(&self, _: &mut Imports, _: u32) -> ProxyResult {
+        ProxyResult::Bytes(bytemuck::bytes_of(&**self).to_vec())
     }
 }
 
 impl WasmProxy for lyra_engine::assets::ResourceManager {
-    fn marshal_to_bytes(&self, imports: &mut Imports) -> wasm_ecs::WorldResourceResult {
-        //imports.
-
-        todo!()
-        //imports.asset_manager_slab.insert(val)
+    fn marshal_to_bytes(&self, imports: &mut Imports, world_idx: u32) -> ProxyResult {
+        let world = &imports.world_slab.get(world_idx as _)
+            .unwrap().world;
+        match world.get_resource_data::<Self>() {
+            Some(data) => ProxyResult::WasmResource(data),
+            None => ProxyResult::None,
+        }
     }
 }