Use a wit resource for the ecs world and a slab to allow multiple worlds

Cargo.lock

@@ -1266,6 +1266,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "slab"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f92a496fb766b417c996b9c5e57daf2f7ad3b0bebe1ccfca4856390e3d3bb67"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "slice-group-by"
 version = "0.3.1"
@@ -2271,6 +2280,8 @@ version = "0.1.0"
 dependencies = [
  "async-trait",
  "lyra-ecs",
+ "slab",
+ "thiserror",
  "tokio",
  "wasmtime",
  "wasmtime-wasi",

Cargo.toml

@@ -12,3 +12,5 @@ tokio = { version = "1.37.0", features = ["full"] }
 wasmtime = "19.0.2"
 wasmtime-wasi = "19.0.2"
 lyra-ecs = { path = "./lyra-engine/lyra-ecs" }
+slab = "0.4.9"
+thiserror = "1.0.58"

src/main.rs

@@ -4,20 +4,20 @@ use std::mem;
 use std::ptr::NonNull;
 
 use async_trait::async_trait;
-use component::witguest::{ecs_world, math};
+use component::witguest::ecs::WasmTypeId;
+use component::witguest::{ecs as wasm_ecs, math};
 use ecs::query::dynamic::QueryDynamicType;
-use lyra_ecs::{Component, World};
+use lyra_ecs::Component;
 
 use lyra_ecs as ecs;
 
-use lyra_engine::ecs::component::witguest::ecs_world::WasmTypeId;
+use slab::Slab;
+use thiserror::Error;
 use wasmtime_wasi::WasiView;
 
 #[allow(unused_imports)]
 pub(crate) mod lyra_engine {
-    pub(crate) mod ecs {
+    pub use lyra_ecs as ecs;
-        pub use super::super::*;
-    }
 }
 
 wasmtime::component::bindgen!({
@@ -42,7 +42,7 @@ impl Into<ecs::DynTypeId> for WasmTypeId {
     }
 }
 
-impl Into<ecs::ComponentInfo> for ecs_world::ComponentInfo {
+impl Into<ecs::ComponentInfo> for wasm_ecs::ComponentInfo {
     fn into(self) -> ecs::ComponentInfo {
         ecs::ComponentInfo::new_unknown(
             None,
@@ -52,10 +52,10 @@ impl Into<ecs::ComponentInfo> for ecs_world::ComponentInfo {
     }
 }
 
-impl From<ecs::Entity> for ecs_world::Entity {
+impl From<ecs::Entity> for wasm_ecs::Entity {
     fn from(value: ecs::Entity) -> Self {
         Self {
-            id: ecs_world::EntityId { id: value.id().0 },
+            id: wasm_ecs::EntityId { id: value.id().0 },
             generation: value.generation(),
         }
     }
@@ -70,7 +70,7 @@ struct Vec3 {
 }
 
 struct Imports {
-    world: lyra_ecs::World,
+    world_slab: Slab<lyra_ecs::World>,
 }
 
 impl WasiView for Imports {
@@ -93,13 +93,23 @@ impl ExampleImports for Imports {
 
 impl math::Host for Imports {}
 
+#[derive(Error, Debug)]
+pub enum WasmError {
+    #[error("an invalid '{0}' resource handle was used by the guest")]
+    InvalidResourceHandle(&'static str)
+}
+
 #[async_trait]
-impl ecs_world::Host for Imports {
+impl wasm_ecs::HostEcsWorld for Imports {
-    async fn spawn(
+    async fn new(&mut self,) ->  wasmtime::Result<wasmtime::component::Resource<wasm_ecs::EcsWorld>> {
-        &mut self,
+        let world = self.world_slab.insert(lyra_ecs::World::new());
-        mut components: Vec<u8>,
+        Ok(wasmtime::component::Resource::new_own(world as _))
-        infos: Vec<ecs_world::ComponentInfo>,
+    }
-    ) -> wasmtime::Result<ecs_world::Entity> {
+
+    async fn spawn(&mut self, this: wasmtime::component::Resource<wasm_ecs::EcsWorld>, mut components: Vec<u8>, infos: Vec<wasm_ecs::ComponentInfo>) ->  wasmtime::Result<wasm_ecs::Entity> {
+        let world = self.world_slab.get_mut(this.rep() as _)
+            .ok_or(WasmError::InvalidResourceHandle("EcsWorld"))?;
+        
         // add the components in the tightly packed `components` buffer into the dynamic bundle
         let mut bundle = ecs::DynamicBundle::new();
         let mut offset = 0;
@@ -112,13 +122,16 @@ impl ecs_world::Host for Imports {
             offset += info.size as usize;
         }
 
-        let en = self.world.spawn(bundle);
+        let en = world.spawn(bundle);
         Ok(en.into())
     }
 
-    async fn view(&mut self, infos: Vec<ecs_world::ComponentInfo>) -> wasmtime::Result<Vec<u8>> {
+    async fn view(&mut self, this: wasmtime::component::Resource<wasm_ecs::EcsWorld>, infos: Vec<wasm_ecs::ComponentInfo>) -> wasmtime::Result<Vec<u8>> {
+        let world = self.world_slab.get_mut(this.rep() as _)
+            .ok_or(WasmError::InvalidResourceHandle("EcsWorld"))?;
+
         // Create a dynamic view for querying for the components
-        let mut view = self.world.dynamic_view();
+        let mut view = world.dynamic_view();
         for info in infos.clone() {
             view.push(QueryDynamicType::from_info(info.into()));
         }
@@ -145,6 +158,18 @@ impl ecs_world::Host for Imports {
 
         Ok(components)
     }
+
+    fn drop(&mut self, this: wasmtime::component::Resource<wasm_ecs::EcsWorld>) -> wasmtime::Result<()>  {
+        self.world_slab.try_remove(this.rep() as _)
+            .ok_or(WasmError::InvalidResourceHandle("EcsWorld"))?;
+
+        Ok(())
+    }
+}
+
+#[async_trait]
+impl wasm_ecs::Host for Imports {
+
 }
 
 #[tokio::main]
@@ -164,7 +189,9 @@ async fn main() -> wasmtime::Result<()> {
     let mut store = wasmtime::Store::new(
         &engine,
         Imports {
-            world: World::new(),
+            // There will likely be a world, but a slab is used in the case that the guest
+            // wants another world for some reason.
+            world_slab: Slab::with_capacity(1),
         },
     );
 

witguest/src/bindings.rs

@@ -82,7 +82,7 @@ pub mod component {
     
     
     #[allow(clippy::all)]
-    pub mod ecs_world {
+    pub mod ecs {
       #[used]
       #[doc(hidden)]
       #[cfg(target_arch = "wasm32")]
@@ -131,9 +131,72 @@ pub mod component {
           f.debug_struct("ComponentInfo").field("size", &self.size).field("alignment", &self.alignment).field("type-id", &self.type_id).finish()
         }
       }
+      
+      #[derive(Debug)]
+      #[repr(transparent)]
+      pub struct EcsWorld{
+        handle: wit_bindgen::rt::Resource<EcsWorld>,
+      }
+      
+      impl EcsWorld{
+        #[doc(hidden)]
+        pub unsafe fn from_handle(handle: u32) -> Self {
+          Self {
+            handle: wit_bindgen::rt::Resource::from_handle(handle),
+          }
+        }
+        
+        #[doc(hidden)]
+        pub fn handle(&self) -> u32 {
+          wit_bindgen::rt::Resource::handle(&self.handle)
+        }
+      }
+      
+      
+      unsafe impl wit_bindgen::rt::WasmResource for EcsWorld{
+        #[inline]
+        unsafe fn drop(_handle: u32) {
+          #[cfg(not(target_arch = "wasm32"))]
+          unreachable!();
+          
+          #[cfg(target_arch = "wasm32")]
+          {
+            #[link(wasm_import_module = "component:witguest/ecs")]
+            extern "C" {
+              #[link_name = "[resource-drop]ecs-world"]
+              fn drop(_: u32);
+            }
+            
+            drop(_handle);
+          }
+        }
+      }
+      
+      impl EcsWorld {
         #[allow(unused_unsafe, clippy::all)]
-      /// expects components to be tightly packed in the same order of component-infos
+        pub fn new() -> Self{
-      pub fn spawn(components: &[u8],component_infos: &[ComponentInfo],) -> Entity{
+          
+          #[allow(unused_imports)]
+          use wit_bindgen::rt::{alloc, vec::Vec, string::String};
+          unsafe {
+            
+            #[cfg(target_arch = "wasm32")]
+            #[link(wasm_import_module = "component:witguest/ecs")]
+            extern "C" {
+              #[link_name = "[constructor]ecs-world"]
+              fn wit_import() -> i32;
+            }
+            
+            #[cfg(not(target_arch = "wasm32"))]
+            fn wit_import() -> i32{ unreachable!() }
+            let ret = wit_import();
+            EcsWorld::from_handle(ret as u32)
+          }
+        }
+      }
+      impl EcsWorld {
+        #[allow(unused_unsafe, clippy::all)]
+        pub fn spawn(&self,components: &[u8],component_infos: &[ComponentInfo],) -> Entity{
           
           #[allow(unused_imports)]
           use wit_bindgen::rt::{alloc, vec::Vec, string::String};
@@ -150,15 +213,15 @@ pub mod component {
             let len1 = vec1.len() as i32;
             let ptr2 = ret_area.as_mut_ptr() as i32;
             #[cfg(target_arch = "wasm32")]
-          #[link(wasm_import_module = "component:witguest/ecs-world")]
+            #[link(wasm_import_module = "component:witguest/ecs")]
             extern "C" {
-            #[link_name = "spawn"]
+              #[link_name = "[method]ecs-world.spawn"]
-            fn wit_import(_: i32, _: i32, _: i32, _: i32, _: i32, );
+              fn wit_import(_: i32, _: i32, _: i32, _: i32, _: i32, _: i32, );
             }
             
             #[cfg(not(target_arch = "wasm32"))]
-          fn wit_import(_: i32, _: i32, _: i32, _: i32, _: i32, ){ unreachable!() }
+            fn wit_import(_: i32, _: i32, _: i32, _: i32, _: i32, _: i32, ){ unreachable!() }
-          wit_import(ptr0, len0, ptr1, len1, ptr2);
+            wit_import((self).handle() as i32, ptr0, len0, ptr1, len1, ptr2);
             let l3 = *((ptr2 + 0) as *const i64);
             let l4 = *((ptr2 + 8) as *const i64);
             Entity{
@@ -169,8 +232,10 @@ pub mod component {
             }
           }
         }
+      }
+      impl EcsWorld {
         #[allow(unused_unsafe, clippy::all)]
-      pub fn view(component_infos: &[ComponentInfo],) -> wit_bindgen::rt::vec::Vec::<u8>{
+        pub fn view(&self,component_infos: &[ComponentInfo],) -> wit_bindgen::rt::vec::Vec::<u8>{
           
           #[allow(unused_imports)]
           use wit_bindgen::rt::{alloc, vec::Vec, string::String};
@@ -184,21 +249,22 @@ pub mod component {
             let len0 = vec0.len() as i32;
             let ptr1 = ret_area.as_mut_ptr() as i32;
             #[cfg(target_arch = "wasm32")]
-          #[link(wasm_import_module = "component:witguest/ecs-world")]
+            #[link(wasm_import_module = "component:witguest/ecs")]
             extern "C" {
-            #[link_name = "view"]
+              #[link_name = "[method]ecs-world.view"]
-            fn wit_import(_: i32, _: i32, _: i32, );
+              fn wit_import(_: i32, _: i32, _: i32, _: i32, );
             }
             
             #[cfg(not(target_arch = "wasm32"))]
-          fn wit_import(_: i32, _: i32, _: i32, ){ unreachable!() }
+            fn wit_import(_: i32, _: i32, _: i32, _: i32, ){ unreachable!() }
-          wit_import(ptr0, len0, ptr1);
+            wit_import((self).handle() as i32, ptr0, len0, ptr1);
             let l2 = *((ptr1 + 0) as *const i32);
             let l3 = *((ptr1 + 4) as *const i32);
             let len4 = l3 as usize;
             Vec::from_raw_parts(l2 as *mut _, len4, len4)
           }
         }
+      }
       
     }
     
@@ -208,7 +274,7 @@ pub mod component {
 #[cfg(target_arch = "wasm32")]
 #[link_section = "component-type:example"]
 #[doc(hidden)]
-pub static __WIT_BINDGEN_COMPONENT_TYPE: [u8; 514] = [0, 97, 115, 109, 13, 0, 1, 0, 0, 25, 22, 119, 105, 116, 45, 99, 111, 109, 112, 111, 110, 101, 110, 116, 45, 101, 110, 99, 111, 100, 105, 110, 103, 4, 0, 7, 133, 3, 1, 65, 2, 1, 65, 9, 1, 66, 2, 1, 114, 3, 1, 120, 118, 1, 121, 118, 1, 122, 118, 4, 0, 4, 118, 101, 99, 51, 3, 0, 0, 3, 1, 23, 99, 111, 109, 112, 111, 110, 101, 110, 116, 58, 119, 105, 116, 103, 117, 101, 115, 116, 47, 109, 97, 116, 104, 5, 0, 1, 66, 15, 1, 114, 1, 2, 105, 100, 119, 4, 0, 9, 101, 110, 116, 105, 116, 121, 45, 105, 100, 3, 0, 0, 1, 114, 2, 2, 105, 100, 1, 10, 103, 101, 110, 101, 114, 97, 116, 105, 111, 110, 119, 4, 0, 6, 101, 110, 116, 105, 116, 121, 3, 0, 2, 1, 111, 2, 119, 119, 1, 114, 1, 5, 105, 110, 110, 101, 114, 4, 4, 0, 12, 119, 97, 115, 109, 45, 116, 121, 112, 101, 45, 105, 100, 3, 0, 5, 1, 114, 3, 4, 115, 105, 122, 101, 119, 9, 97, 108, 105, 103, 110, 109, 101, 110, 116, 119, 7, 116, 121, 112, 101, 45, 105, 100, 6, 4, 0, 14, 99, 111, 109, 112, 111, 110, 101, 110, 116, 45, 105, 110, 102, 111, 3, 0, 7, 1, 112, 125, 1, 112, 8, 1, 64, 2, 10, 99, 111, 109, 112, 111, 110, 101, 110, 116, 115, 9, 15, 99, 111, 109, 112, 111, 110, 101, 110, 116, 45, 105, 110, 102, 111, 115, 10, 0, 3, 4, 0, 5, 115, 112, 97, 119, 110, 1, 11, 1, 64, 1, 15, 99, 111, 109, 112, 111, 110, 101, 110, 116, 45, 105, 110, 102, 111, 115, 10, 0, 9, 4, 0, 4, 118, 105, 101, 119, 1, 12, 3, 1, 28, 99, 111, 109, 112, 111, 110, 101, 110, 116, 58, 119, 105, 116, 103, 117, 101, 115, 116, 47, 101, 99, 115, 45, 119, 111, 114, 108, 100, 5, 1, 1, 64, 1, 3, 109, 115, 103, 115, 1, 0, 3, 0, 10, 104, 111, 115, 116, 45, 112, 114, 105, 110, 116, 1, 2, 1, 106, 1, 125, 0, 1, 64, 0, 0, 3, 4, 0, 7, 111, 110, 45, 105, 110, 105, 116, 1, 4, 4, 1, 26, 99, 111, 109, 112, 111, 110, 101, 110, 116, 58, 119, 105, 116, 103, 117, 101, 115, 116, 47, 101, 120, 97, 109, 112, 108, 101, 4, 0, 11, 13, 1, 0, 7, 101, 120, 97, 109, 112, 108, 101, 3, 0, 0, 0, 70, 9, 112, 114, 111, 100, 117, 99, 101, 114, 115, 1, 12, 112, 114, 111, 99, 101, 115, 115, 101, 100, 45, 98, 121, 2, 13, 119, 105, 116, 45, 99, 111, 109, 112, 111, 110, 101, 110, 116, 6, 48, 46, 50, 49, 46, 48, 16, 119, 105, 116, 45, 98, 105, 110, 100, 103, 101, 110, 45, 114, 117, 115, 116, 6, 48, 46, 49, 56, 46, 48];
+pub static __WIT_BINDGEN_COMPONENT_TYPE: [u8; 608] = [0, 97, 115, 109, 13, 0, 1, 0, 0, 25, 22, 119, 105, 116, 45, 99, 111, 109, 112, 111, 110, 101, 110, 116, 45, 101, 110, 99, 111, 100, 105, 110, 103, 4, 0, 7, 227, 3, 1, 65, 2, 1, 65, 9, 1, 66, 2, 1, 114, 3, 1, 120, 118, 1, 121, 118, 1, 122, 118, 4, 0, 4, 118, 101, 99, 51, 3, 0, 0, 3, 1, 23, 99, 111, 109, 112, 111, 110, 101, 110, 116, 58, 119, 105, 116, 103, 117, 101, 115, 116, 47, 109, 97, 116, 104, 5, 0, 1, 66, 20, 1, 114, 1, 2, 105, 100, 119, 4, 0, 9, 101, 110, 116, 105, 116, 121, 45, 105, 100, 3, 0, 0, 1, 114, 2, 2, 105, 100, 1, 10, 103, 101, 110, 101, 114, 97, 116, 105, 111, 110, 119, 4, 0, 6, 101, 110, 116, 105, 116, 121, 3, 0, 2, 1, 111, 2, 119, 119, 1, 114, 1, 5, 105, 110, 110, 101, 114, 4, 4, 0, 12, 119, 97, 115, 109, 45, 116, 121, 112, 101, 45, 105, 100, 3, 0, 5, 1, 114, 3, 4, 115, 105, 122, 101, 119, 9, 97, 108, 105, 103, 110, 109, 101, 110, 116, 119, 7, 116, 121, 112, 101, 45, 105, 100, 6, 4, 0, 14, 99, 111, 109, 112, 111, 110, 101, 110, 116, 45, 105, 110, 102, 111, 3, 0, 7, 4, 0, 9, 101, 99, 115, 45, 119, 111, 114, 108, 100, 3, 1, 1, 105, 9, 1, 64, 0, 0, 10, 4, 0, 22, 91, 99, 111, 110, 115, 116, 114, 117, 99, 116, 111, 114, 93, 101, 99, 115, 45, 119, 111, 114, 108, 100, 1, 11, 1, 104, 9, 1, 112, 125, 1, 112, 8, 1, 64, 3, 4, 115, 101, 108, 102, 12, 10, 99, 111, 109, 112, 111, 110, 101, 110, 116, 115, 13, 15, 99, 111, 109, 112, 111, 110, 101, 110, 116, 45, 105, 110, 102, 111, 115, 14, 0, 3, 4, 0, 23, 91, 109, 101, 116, 104, 111, 100, 93, 101, 99, 115, 45, 119, 111, 114, 108, 100, 46, 115, 112, 97, 119, 110, 1, 15, 1, 64, 2, 4, 115, 101, 108, 102, 12, 15, 99, 111, 109, 112, 111, 110, 101, 110, 116, 45, 105, 110, 102, 111, 115, 14, 0, 13, 4, 0, 22, 91, 109, 101, 116, 104, 111, 100, 93, 101, 99, 115, 45, 119, 111, 114, 108, 100, 46, 118, 105, 101, 119, 1, 16, 3, 1, 22, 99, 111, 109, 112, 111, 110, 101, 110, 116, 58, 119, 105, 116, 103, 117, 101, 115, 116, 47, 101, 99, 115, 5, 1, 1, 64, 1, 3, 109, 115, 103, 115, 1, 0, 3, 0, 10, 104, 111, 115, 116, 45, 112, 114, 105, 110, 116, 1, 2, 1, 106, 1, 125, 0, 1, 64, 0, 0, 3, 4, 0, 7, 111, 110, 45, 105, 110, 105, 116, 1, 4, 4, 1, 26, 99, 111, 109, 112, 111, 110, 101, 110, 116, 58, 119, 105, 116, 103, 117, 101, 115, 116, 47, 101, 120, 97, 109, 112, 108, 101, 4, 0, 11, 13, 1, 0, 7, 101, 120, 97, 109, 112, 108, 101, 3, 0, 0, 0, 70, 9, 112, 114, 111, 100, 117, 99, 101, 114, 115, 1, 12, 112, 114, 111, 99, 101, 115, 115, 101, 100, 45, 98, 121, 2, 13, 119, 105, 116, 45, 99, 111, 109, 112, 111, 110, 101, 110, 116, 6, 48, 46, 50, 49, 46, 48, 16, 119, 105, 116, 45, 98, 105, 110, 100, 103, 101, 110, 45, 114, 117, 115, 116, 6, 48, 46, 49, 56, 46, 48];
 
 #[inline(never)]
 #[doc(hidden)]

witguest/src/lib.rs

@@ -1,7 +1,7 @@
 #[allow(warnings)]
 mod bindings;
 
-use bindings::{component::witguest::ecs_world::{self, ComponentInfo, WasmTypeId}, Guest};
+use bindings::{component::witguest::ecs::{ComponentInfo, EcsWorld, WasmTypeId}, Guest};
 
 use std::{alloc::Layout, any::TypeId, mem};
 
@@ -49,11 +49,14 @@ impl Guest for Component {
         let comps = comps.as_mut_ptr().cast::<u8>();
         let comps = unsafe { Vec::from_raw_parts(comps, mem::size_of::<Vec3>(), 1) };
 
-        let en = ecs_world::spawn(&comps, info);
+        let world = EcsWorld::new();
+        let en = world.spawn(&comps, info);
+
+        //let en = ecs_world::spawn(&comps, info);
 
         bindings::host_print(&format!("Spawned entity: {}", en.id.id));
 
-        let mut buffer = ecs_world::view(&[Vec3::component_info()]);
+        let mut buffer = world.view(&[Vec3::component_info()]);
         bindings::host_print(&format!("Retrieved vec3 of {} bytes long", buffer.len()));
         let fetched_vec = unsafe { std::ptr::read(buffer.as_mut_ptr().cast::<Vec3>()) };
         bindings::host_print(&format!("Retrieved vec3: {:?}", fetched_vec));

witguest/wit/world.wit

@@ -8,7 +8,7 @@ interface math {
     }
 }
 
-interface ecs-world {
+interface ecs {
     //use math.{vec3};
 
     record entity-id {
@@ -30,15 +30,19 @@ interface ecs-world {
         type-id: wasm-type-id, // a u128
     }
 
+    resource ecs-world {
+        constructor();
+
         // expects components to be tightly packed in the same order of component-infos
         spawn: func(components: list<u8>, component-infos: list<component-info>) -> entity;
         view: func(component-infos: list<component-info>) -> list<u8>;
     }
+}
 
 /// An example world for the component to target.
 world example {
     import math;
-    import ecs-world;
+    import ecs;
 
     import host-print: func(msg: string);
     export on-init: func() -> result<u8>;