/// Auto-generated bindings for a pre-instantiated version of a /// component which implements the world `foo`. /// /// This structure is created through [`FooPre::new`] which /// takes a [`InstancePre`](wasmtime::component::InstancePre) that /// has been created through a [`Linker`](wasmtime::component::Linker). /// /// For more information see [`Foo`] as well. pub struct FooPre { instance_pre: wasmtime::component::InstancePre, indices: FooIndices, } impl Clone for FooPre { fn clone(&self) -> Self { Self { instance_pre: self.instance_pre.clone(), indices: self.indices.clone(), } } } impl<_T: 'static> FooPre<_T> { /// Creates a new copy of `FooPre` bindings which can then /// be used to instantiate into a particular store. /// /// This method may fail if the component behind `instance_pre` /// does not have the required exports. pub fn new( instance_pre: wasmtime::component::InstancePre<_T>, ) -> wasmtime::Result { let indices = FooIndices::new(&instance_pre)?; Ok(Self { instance_pre, indices }) } pub fn engine(&self) -> &wasmtime::Engine { self.instance_pre.engine() } pub fn instance_pre(&self) -> &wasmtime::component::InstancePre<_T> { &self.instance_pre } /// Instantiates a new instance of [`Foo`] within the /// `store` provided. /// /// This function will use `self` as the pre-instantiated /// instance to perform instantiation. Afterwards the preloaded /// indices in `self` are used to lookup all exports on the /// resulting instance. pub fn instantiate( &self, mut store: impl wasmtime::AsContextMut, ) -> wasmtime::Result { let mut store = store.as_context_mut(); let instance = self.instance_pre.instantiate(&mut store)?; self.indices.load(&mut store, &instance) } } impl<_T: Send + 'static> FooPre<_T> { /// Same as [`Self::instantiate`], except with `async`. pub async fn instantiate_async( &self, mut store: impl wasmtime::AsContextMut, ) -> wasmtime::Result { let mut store = store.as_context_mut(); let instance = self.instance_pre.instantiate_async(&mut store).await?; self.indices.load(&mut store, &instance) } } /// Auto-generated bindings for index of the exports of /// `foo`. /// /// This is an implementation detail of [`FooPre`] and can /// be constructed if needed as well. /// /// For more information see [`Foo`] as well. #[derive(Clone)] pub struct FooIndices { new: wasmtime::component::ComponentExportIndex, } /// Auto-generated bindings for an instance a component which /// implements the world `foo`. /// /// This structure can be created through a number of means /// depending on your requirements and what you have on hand: /// /// * The most convenient way is to use /// [`Foo::instantiate`] which only needs a /// [`Store`], [`Component`], and [`Linker`]. /// /// * Alternatively you can create a [`FooPre`] ahead of /// time with a [`Component`] to front-load string lookups /// of exports once instead of per-instantiation. This /// method then uses [`FooPre::instantiate`] to /// create a [`Foo`]. /// /// * If you've instantiated the instance yourself already /// then you can use [`Foo::new`]. /// /// These methods are all equivalent to one another and move /// around the tradeoff of what work is performed when. /// /// [`Store`]: wasmtime::Store /// [`Component`]: wasmtime::component::Component /// [`Linker`]: wasmtime::component::Linker pub struct Foo { new: wasmtime::component::Func, } const _: () = { impl FooIndices { /// Creates a new copy of `FooIndices` bindings which can then /// be used to instantiate into a particular store. /// /// This method may fail if the component does not have the /// required exports. pub fn new<_T>( _instance_pre: &wasmtime::component::InstancePre<_T>, ) -> wasmtime::Result { let _component = _instance_pre.component(); let _instance_type = _instance_pre.instance_type(); let new = { let (item, index) = _component .get_export(None, "new") .ok_or_else(|| wasmtime::format_err!("no export `new` found"))?; match item { wasmtime::component::types::ComponentItem::ComponentFunc(func) => { wasmtime::error::Context::context( func.typecheck::<(), ()>(&_instance_type), "type-checking export func `new`", )?; index } _ => Err(wasmtime::format_err!("export `new` is not a function"))?, } }; Ok(FooIndices { new }) } /// Uses the indices stored in `self` to load an instance /// of [`Foo`] from the instance provided. /// /// Note that at this time this method will additionally /// perform type-checks of all exports. pub fn load( &self, mut store: impl wasmtime::AsContextMut, instance: &wasmtime::component::Instance, ) -> wasmtime::Result { let _ = &mut store; let _instance = instance; let new = *_instance.get_typed_func::<(), ()>(&mut store, &self.new)?.func(); Ok(Foo { new }) } } impl Foo { /// Convenience wrapper around [`FooPre::new`] and /// [`FooPre::instantiate`]. pub fn instantiate<_T>( store: impl wasmtime::AsContextMut, component: &wasmtime::component::Component, linker: &wasmtime::component::Linker<_T>, ) -> wasmtime::Result { let pre = linker.instantiate_pre(component)?; FooPre::new(pre)?.instantiate(store) } /// Convenience wrapper around [`FooIndices::new`] and /// [`FooIndices::load`]. pub fn new( mut store: impl wasmtime::AsContextMut, instance: &wasmtime::component::Instance, ) -> wasmtime::Result { let indices = FooIndices::new(&instance.instance_pre(&store))?; indices.load(&mut store, instance) } /// Convenience wrapper around [`FooPre::new`] and /// [`FooPre::instantiate_async`]. pub async fn instantiate_async<_T>( store: impl wasmtime::AsContextMut, component: &wasmtime::component::Component, linker: &wasmtime::component::Linker<_T>, ) -> wasmtime::Result where _T: Send, { let pre = linker.instantiate_pre(component)?; FooPre::new(pre)?.instantiate_async(store).await } pub fn call_new( &self, mut store: S, ) -> wasmtime::Result<()> { let callee = unsafe { wasmtime::component::TypedFunc::<(), ()>::new_unchecked(self.new) }; let () = callee.call(store.as_context_mut(), ())?; Ok(()) } } };