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use crate::component::matching::InstanceType;
use crate::component::types;
use crate::component::InstanceExportLookup;
use crate::prelude::*;
use crate::runtime::vm::component::ComponentRuntimeInfo;
use crate::runtime::vm::{
CompiledModuleId, VMArrayCallFunction, VMFuncRef, VMFunctionBody, VMWasmCallFunction,
};
use crate::{
code::CodeObject, code_memory::CodeMemory, type_registry::TypeCollection, Engine, Module,
ResourcesRequired,
};
use crate::{FuncType, ValType};
use alloc::sync::Arc;
use core::any::Any;
use core::mem;
use core::ops::Range;
use core::ptr::NonNull;
#[cfg(feature = "std")]
use std::path::Path;
use wasmtime_environ::component::{
AllCallFunc, CompiledComponentInfo, ComponentArtifacts, ComponentTypes, Export, ExportIndex,
GlobalInitializer, InstantiateModule, NameMapNoIntern, StaticModuleIndex, TrampolineIndex,
TypeComponentIndex, TypeDef, VMComponentOffsets,
};
use wasmtime_environ::{FunctionLoc, HostPtr, ObjectKind, PrimaryMap};
/// A compiled WebAssembly Component.
///
/// This structure represents a compiled component that is ready to be
/// instantiated. This owns a region of virtual memory which contains executable
/// code compiled from a WebAssembly binary originally. This is the analog of
/// [`Module`](crate::Module) in the component embedding API.
///
/// A [`Component`] can be turned into an
/// [`Instance`](crate::component::Instance) through a
/// [`Linker`](crate::component::Linker). [`Component`]s are safe to share
/// across threads. The compilation model of a component is the same as that of
/// [a module](crate::Module) which is to say:
///
/// * Compilation happens synchronously during [`Component::new`].
/// * The result of compilation can be saved into storage with
/// [`Component::serialize`].
/// * A previously compiled artifact can be parsed with
/// [`Component::deserialize`].
/// * No compilation happens at runtime for a component — everything is done
/// by the time [`Component::new`] returns.
///
/// ## Components and `Clone`
///
/// Using `clone` on a `Component` is a cheap operation. It will not create an
/// entirely new component, but rather just a new reference to the existing
/// component. In other words it's a shallow copy, not a deep copy.
///
/// ## Examples
///
/// For example usage see the documentation of [`Module`](crate::Module) as
/// [`Component`] has the same high-level API.
#[derive(Clone)]
pub struct Component {
inner: Arc<ComponentInner>,
}
struct ComponentInner {
/// Unique id for this component within this process.
///
/// Note that this is repurposing ids for modules intentionally as there
/// shouldn't be an issue overlapping them.
id: CompiledModuleId,
/// The engine that this component belongs to.
engine: Engine,
/// Component type index
ty: TypeComponentIndex,
/// Core wasm modules that the component defined internally, indexed by the
/// compile-time-assigned `ModuleUpvarIndex`.
static_modules: PrimaryMap<StaticModuleIndex, Module>,
/// Code-related information such as the compiled artifact, type
/// information, etc.
///
/// Note that the `Arc` here is used to share this allocation with internal
/// modules.
code: Arc<CodeObject>,
/// Metadata produced during compilation.
info: CompiledComponentInfo,
/// A cached handle to the `wasmtime::FuncType` for the canonical ABI's
/// `realloc`, to avoid the need to look up types in the registry and take
/// locks when calling `realloc` via `TypedFunc::call_raw`.
realloc_func_type: Arc<dyn Any + Send + Sync>,
}
pub(crate) struct AllCallFuncPointers {
pub wasm_call: NonNull<VMWasmCallFunction>,
pub array_call: VMArrayCallFunction,
}
impl Component {
/// Compiles a new WebAssembly component from the in-memory list of bytes
/// provided.
///
/// The `bytes` provided can either be the binary or text format of a
/// [WebAssembly component]. Note that the text format requires the `wat`
/// feature of this crate to be enabled. This API does not support
/// streaming compilation.
///
/// This function will synchronously validate the entire component,
/// including all core modules, and then compile all components, modules,
/// etc., found within the provided bytes.
///
/// [WebAssembly component]: https://github.com/WebAssembly/component-model/blob/main/design/mvp/Binary.md
///
/// # Errors
///
/// This function may fail and return an error. Errors may include
/// situations such as:
///
/// * The binary provided could not be decoded because it's not a valid
/// WebAssembly binary
/// * The WebAssembly binary may not validate (e.g. contains type errors)
/// * Implementation-specific limits were exceeded with a valid binary (for
/// example too many locals)
/// * The wasm binary may use features that are not enabled in the
/// configuration of `engine`
/// * If the `wat` feature is enabled and the input is text, then it may be
/// rejected if it fails to parse.
///
/// The error returned should contain full information about why compilation
/// failed.
///
/// # Examples
///
/// The `new` function can be invoked with a in-memory array of bytes:
///
/// ```no_run
/// # use wasmtime::*;
/// # use wasmtime::component::Component;
/// # fn main() -> anyhow::Result<()> {
/// # let engine = Engine::default();
/// # let wasm_bytes: Vec<u8> = Vec::new();
/// let component = Component::new(&engine, &wasm_bytes)?;
/// # Ok(())
/// # }
/// ```
///
/// Or you can also pass in a string to be parsed as the wasm text
/// format:
///
/// ```
/// # use wasmtime::*;
/// # use wasmtime::component::Component;
/// # fn main() -> anyhow::Result<()> {
/// # let engine = Engine::default();
/// let component = Component::new(&engine, "(component (core module))")?;
/// # Ok(())
/// # }
#[cfg(any(feature = "cranelift", feature = "winch"))]
pub fn new(engine: &Engine, bytes: impl AsRef<[u8]>) -> Result<Component> {
crate::CodeBuilder::new(engine)
.wasm_binary_or_text(bytes.as_ref(), None)?
.compile_component()
}
/// Compiles a new WebAssembly component from a wasm file on disk pointed
/// to by `file`.
///
/// This is a convenience function for reading the contents of `file` on
/// disk and then calling [`Component::new`].
#[cfg(all(feature = "std", any(feature = "cranelift", feature = "winch")))]
pub fn from_file(engine: &Engine, file: impl AsRef<Path>) -> Result<Component> {
crate::CodeBuilder::new(engine)
.wasm_binary_or_text_file(file.as_ref())?
.compile_component()
}
/// Compiles a new WebAssembly component from the in-memory wasm image
/// provided.
///
/// This function is the same as [`Component::new`] except that it does not
/// accept the text format of WebAssembly. Even if the `wat` feature
/// is enabled an error will be returned here if `binary` is the text
/// format.
///
/// For more information on semantics and errors see [`Component::new`].
#[cfg(any(feature = "cranelift", feature = "winch"))]
pub fn from_binary(engine: &Engine, binary: &[u8]) -> Result<Component> {
crate::CodeBuilder::new(engine)
.wasm_binary(binary, None)?
.compile_component()
}
/// Same as [`Module::deserialize`], but for components.
///
/// Note that the bytes referenced here must contain contents previously
/// produced by [`Engine::precompile_component`] or
/// [`Component::serialize`].
///
/// For more information see the [`Module::deserialize`] method.
///
/// # Unsafety
///
/// The unsafety of this method is the same as that of the
/// [`Module::deserialize`] method.
///
/// [`Module::deserialize`]: crate::Module::deserialize
pub unsafe fn deserialize(engine: &Engine, bytes: impl AsRef<[u8]>) -> Result<Component> {
let code = engine.load_code_bytes(bytes.as_ref(), ObjectKind::Component)?;
Component::from_parts(engine, code, None)
}
/// Same as [`Module::deserialize_file`], but for components.
///
/// Note that the file referenced here must contain contents previously
/// produced by [`Engine::precompile_component`] or
/// [`Component::serialize`].
///
/// For more information see the [`Module::deserialize_file`] method.
///
/// # Unsafety
///
/// The unsafety of this method is the same as that of the
/// [`Module::deserialize_file`] method.
///
/// [`Module::deserialize_file`]: crate::Module::deserialize_file
#[cfg(feature = "std")]
pub unsafe fn deserialize_file(engine: &Engine, path: impl AsRef<Path>) -> Result<Component> {
let code = engine.load_code_file(path.as_ref(), ObjectKind::Component)?;
Component::from_parts(engine, code, None)
}
/// Returns the type of this component as a [`types::Component`].
///
/// This method enables runtime introspection of the type of a component
/// before instantiation, if necessary.
///
/// ## Component types and Resources
///
/// An important point to note here is that the precise type of imports and
/// exports of a component change when it is instantiated with respect to
/// resources. For example a [`Component`] represents an un-instantiated
/// component meaning that its imported resources are represented as abstract
/// resource types. These abstract types are not equal to any other
/// component's types.
///
/// For example:
///
/// ```
/// # use wasmtime::Engine;
/// # use wasmtime::component::Component;
/// # use wasmtime::component::types::ComponentItem;
/// # fn main() -> wasmtime::Result<()> {
/// # let engine = Engine::default();
/// let a = Component::new(&engine, r#"
/// (component (import "x" (type (sub resource))))
/// "#)?;
/// let b = Component::new(&engine, r#"
/// (component (import "x" (type (sub resource))))
/// "#)?;
///
/// let (_, a_ty) = a.component_type().imports(&engine).next().unwrap();
/// let (_, b_ty) = b.component_type().imports(&engine).next().unwrap();
///
/// let a_ty = match a_ty {
/// ComponentItem::Resource(ty) => ty,
/// _ => unreachable!(),
/// };
/// let b_ty = match b_ty {
/// ComponentItem::Resource(ty) => ty,
/// _ => unreachable!(),
/// };
/// assert!(a_ty != b_ty);
/// # Ok(())
/// # }
/// ```
///
/// Additionally, however, these abstract types are "substituted" during
/// instantiation meaning that a component type will appear to have changed
/// once it is instantiated.
///
/// ```
/// # use wasmtime::{Engine, Store};
/// # use wasmtime::component::{Component, Linker, ResourceType};
/// # use wasmtime::component::types::ComponentItem;
/// # fn main() -> wasmtime::Result<()> {
/// # let engine = Engine::default();
/// // Here this component imports a resource and then exports it as-is
/// // which means that the export is equal to the import.
/// let a = Component::new(&engine, r#"
/// (component
/// (import "x" (type $x (sub resource)))
/// (export "x" (type $x))
/// )
/// "#)?;
///
/// let (_, import) = a.component_type().imports(&engine).next().unwrap();
/// let (_, export) = a.component_type().exports(&engine).next().unwrap();
///
/// let import = match import {
/// ComponentItem::Resource(ty) => ty,
/// _ => unreachable!(),
/// };
/// let export = match export {
/// ComponentItem::Resource(ty) => ty,
/// _ => unreachable!(),
/// };
/// assert_eq!(import, export);
///
/// // However after instantiation the resource type "changes"
/// let mut store = Store::new(&engine, ());
/// let mut linker = Linker::new(&engine);
/// linker.root().resource("x", ResourceType::host::<()>(), |_, _| Ok(()))?;
/// let instance = linker.instantiate(&mut store, &a)?;
/// let instance_ty = instance.get_resource(&mut store, "x").unwrap();
///
/// // Here `instance_ty` is not the same as either `import` or `export`,
/// // but it is equal to what we provided as an import.
/// assert!(instance_ty != import);
/// assert!(instance_ty != export);
/// assert!(instance_ty == ResourceType::host::<()>());
/// # Ok(())
/// # }
/// ```
///
/// Finally, each instantiation of an exported resource from a component is
/// considered "fresh" for all instantiations meaning that different
/// instantiations will have different exported resource types:
///
/// ```
/// # use wasmtime::{Engine, Store};
/// # use wasmtime::component::{Component, Linker};
/// # fn main() -> wasmtime::Result<()> {
/// # let engine = Engine::default();
/// let a = Component::new(&engine, r#"
/// (component
/// (type $x (resource (rep i32)))
/// (export "x" (type $x))
/// )
/// "#)?;
///
/// let mut store = Store::new(&engine, ());
/// let linker = Linker::new(&engine);
/// let instance1 = linker.instantiate(&mut store, &a)?;
/// let instance2 = linker.instantiate(&mut store, &a)?;
///
/// let x1 = instance1.get_resource(&mut store, "x").unwrap();
/// let x2 = instance2.get_resource(&mut store, "x").unwrap();
///
/// // Despite these two resources being the same export of the same
/// // component they come from two different instances meaning that their
/// // types will be unique.
/// assert!(x1 != x2);
/// # Ok(())
/// # }
/// ```
pub fn component_type(&self) -> types::Component {
self.with_uninstantiated_instance_type(|ty| types::Component::from(self.inner.ty, ty))
}
fn with_uninstantiated_instance_type<R>(&self, f: impl FnOnce(&InstanceType<'_>) -> R) -> R {
let resources = Arc::new(PrimaryMap::new());
f(&InstanceType {
types: self.types(),
resources: &resources,
})
}
/// Final assembly step for a component from its in-memory representation.
///
/// If the `artifacts` are specified as `None` here then they will be
/// deserialized from `code_memory`.
pub(crate) fn from_parts(
engine: &Engine,
code_memory: Arc<CodeMemory>,
artifacts: Option<ComponentArtifacts>,
) -> Result<Component> {
let ComponentArtifacts {
ty,
info,
types,
static_modules,
} = match artifacts {
Some(artifacts) => artifacts,
None => postcard::from_bytes(code_memory.wasmtime_info()).err2anyhow()?,
};
// Validate that the component can be used with the current instance
// allocator.
engine.allocator().validate_component(
&info.component,
&VMComponentOffsets::new(HostPtr, &info.component),
&|module_index| &static_modules[module_index].module,
)?;
// Create a signature registration with the `Engine` for all trampolines
// and core wasm types found within this component, both for the
// component and for all included core wasm modules.
let signatures = TypeCollection::new_for_module(engine, types.module_types());
// Assemble the `CodeObject` artifact which is shared by all core wasm
// modules as well as the final component.
let types = Arc::new(types);
let code = Arc::new(CodeObject::new(code_memory, signatures, types.into()));
// Convert all information about static core wasm modules into actual
// `Module` instances by converting each `CompiledModuleInfo`, the
// `types` type information, and the code memory to a runtime object.
let static_modules = static_modules
.into_iter()
.map(|(_, info)| Module::from_parts_raw(engine, code.clone(), info, false))
.collect::<Result<_>>()?;
let realloc_func_type = Arc::new(FuncType::new(
engine,
[ValType::I32, ValType::I32, ValType::I32, ValType::I32],
[ValType::I32],
)) as _;
Ok(Component {
inner: Arc::new(ComponentInner {
id: CompiledModuleId::new(),
engine: engine.clone(),
ty,
static_modules,
code,
info,
realloc_func_type,
}),
})
}
pub(crate) fn ty(&self) -> TypeComponentIndex {
self.inner.ty
}
pub(crate) fn env_component(&self) -> &wasmtime_environ::component::Component {
&self.inner.info.component
}
pub(crate) fn static_module(&self, idx: StaticModuleIndex) -> &Module {
&self.inner.static_modules[idx]
}
#[inline]
pub(crate) fn types(&self) -> &Arc<ComponentTypes> {
self.inner.component_types()
}
pub(crate) fn signatures(&self) -> &TypeCollection {
self.inner.code.signatures()
}
pub(crate) fn text(&self) -> &[u8] {
self.inner.code.code_memory().text()
}
pub(crate) fn trampoline_ptrs(&self, index: TrampolineIndex) -> AllCallFuncPointers {
let AllCallFunc {
wasm_call,
array_call,
} = &self.inner.info.trampolines[index];
AllCallFuncPointers {
wasm_call: self.func(wasm_call).cast(),
array_call: unsafe {
mem::transmute::<NonNull<VMFunctionBody>, VMArrayCallFunction>(
self.func(array_call),
)
},
}
}
fn func(&self, loc: &FunctionLoc) -> NonNull<VMFunctionBody> {
let text = self.text();
let trampoline = &text[loc.start as usize..][..loc.length as usize];
NonNull::new(trampoline.as_ptr() as *mut VMFunctionBody).unwrap()
}
pub(crate) fn code_object(&self) -> &Arc<CodeObject> {
&self.inner.code
}
/// Same as [`Module::serialize`], except for a component.
///
/// Note that the artifact produced here must be passed to
/// [`Component::deserialize`] and is not compatible for use with
/// [`Module`].
///
/// [`Module::serialize`]: crate::Module::serialize
/// [`Module`]: crate::Module
pub fn serialize(&self) -> Result<Vec<u8>> {
Ok(self.code_object().code_memory().mmap().to_vec())
}
pub(crate) fn runtime_info(&self) -> Arc<dyn ComponentRuntimeInfo> {
self.inner.clone()
}
/// Creates a new `VMFuncRef` with all fields filled out for the destructor
/// specified.
///
/// The `dtor`'s own `VMFuncRef` won't have `wasm_call` filled out but this
/// component may have `resource_drop_wasm_to_native_trampoline` filled out
/// if necessary in which case it's filled in here.
pub(crate) fn resource_drop_func_ref(&self, dtor: &crate::func::HostFunc) -> VMFuncRef {
// Host functions never have their `wasm_call` filled in at this time.
assert!(dtor.func_ref().wasm_call.is_none());
// Note that if `resource_drop_wasm_to_native_trampoline` is not present
// then this can't be called by the component, so it's ok to leave it
// blank.
let wasm_call = self
.inner
.info
.resource_drop_wasm_to_array_trampoline
.as_ref()
.map(|i| self.func(i).cast());
VMFuncRef {
wasm_call,
..*dtor.func_ref()
}
}
/// Returns a summary of the resources required to instantiate this
/// [`Component`][crate::component::Component].
///
/// Note that when a component imports and instantiates another component or
/// core module, we cannot determine ahead of time how many resources
/// instantiating this component will require, and therefore this method
/// will return `None` in these scenarios.
///
/// Potential uses of the returned information:
///
/// * Determining whether your pooling allocator configuration supports
/// instantiating this component.
///
/// * Deciding how many of which `Component` you want to instantiate within
/// a fixed amount of resources, e.g. determining whether to create 5
/// instances of component X or 10 instances of component Y.
///
/// # Example
///
/// ```
/// # fn main() -> wasmtime::Result<()> {
/// use wasmtime::{Config, Engine, component::Component};
///
/// let mut config = Config::new();
/// config.wasm_multi_memory(true);
/// config.wasm_component_model(true);
/// let engine = Engine::new(&config)?;
///
/// let component = Component::new(&engine, &r#"
/// (component
/// ;; Define a core module that uses two memories.
/// (core module $m
/// (memory 1)
/// (memory 6)
/// )
///
/// ;; Instantiate that core module three times.
/// (core instance $i1 (instantiate (module $m)))
/// (core instance $i2 (instantiate (module $m)))
/// (core instance $i3 (instantiate (module $m)))
/// )
/// "#)?;
///
/// let resources = component.resources_required()
/// .expect("this component does not import any core modules or instances");
///
/// // Instantiating the component will require allocating two memories per
/// // core instance, and there are three instances, so six total memories.
/// assert_eq!(resources.num_memories, 6);
/// assert_eq!(resources.max_initial_memory_size, Some(6));
///
/// // The component doesn't need any tables.
/// assert_eq!(resources.num_tables, 0);
/// assert_eq!(resources.max_initial_table_size, None);
/// # Ok(()) }
/// ```
pub fn resources_required(&self) -> Option<ResourcesRequired> {
let mut resources = ResourcesRequired {
num_memories: 0,
max_initial_memory_size: None,
num_tables: 0,
max_initial_table_size: None,
};
for init in &self.env_component().initializers {
match init {
GlobalInitializer::InstantiateModule(inst) => match inst {
InstantiateModule::Static(index, _) => {
let module = self.static_module(*index);
resources.add(&module.resources_required());
}
InstantiateModule::Import(_, _) => {
// We can't statically determine the resources required
// to instantiate this component.
return None;
}
},
GlobalInitializer::LowerImport { .. }
| GlobalInitializer::ExtractMemory(_)
| GlobalInitializer::ExtractRealloc(_)
| GlobalInitializer::ExtractPostReturn(_)
| GlobalInitializer::Resource(_) => {}
}
}
Some(resources)
}
/// Returns the range, in the host's address space, that this module's
/// compiled code resides at.
///
/// For more information see
/// [`Module::image_range`](crate::Module::image_range).
pub fn image_range(&self) -> Range<*const u8> {
self.inner.code.code_memory().mmap().image_range()
}
/// Force initialization of copy-on-write images to happen here-and-now
/// instead of when they're requested during first instantiation.
///
/// When [copy-on-write memory
/// initialization](crate::Config::memory_init_cow) is enabled then Wasmtime
/// will lazily create the initialization image for a component. This method
/// can be used to explicitly dictate when this initialization happens.
///
/// Note that this largely only matters on Linux when memfd is used.
/// Otherwise the copy-on-write image typically comes from disk and in that
/// situation the creation of the image is trivial as the image is always
/// sourced from disk. On Linux, though, when memfd is used a memfd is
/// created and the initialization image is written to it.
///
/// Also note that this method is not required to be called, it's available
/// as a performance optimization if required but is otherwise handled
/// automatically.
pub fn initialize_copy_on_write_image(&self) -> Result<()> {
for (_, module) in self.inner.static_modules.iter() {
module.initialize_copy_on_write_image()?;
}
Ok(())
}
/// Looks up a specific export of this component by `name` optionally nested
/// within the `instance` provided.
///
/// This method is primarily used to acquire a [`ComponentExportIndex`]
/// which can be used with [`Instance`](crate::component::Instance) when
/// looking up exports. Export lookup with [`ComponentExportIndex`] can
/// skip string lookups at runtime and instead use a more efficient
/// index-based lookup.
///
/// This method takes a few arguments:
///
/// * `engine` - the engine that was used to compile this component.
/// * `instance` - an optional "parent instance" for the export being looked
/// up. If this is `None` then the export is looked up on the root of the
/// component itself, and otherwise the export is looked up on the
/// `instance` specified. Note that `instance` must have come from a
/// previous invocation of this method.
/// * `name` - the name of the export that's being looked up.
///
/// If the export is located then two values are returned: a
/// [`types::ComponentItem`] which enables introspection about the type of
/// the export and a [`ComponentExportIndex`]. The index returned notably
/// implements the [`InstanceExportLookup`] trait which enables using it
/// with [`Instance::get_func`](crate::component::Instance::get_func) for
/// example.
///
/// # Examples
///
/// ```
/// use wasmtime::{Engine, Store};
/// use wasmtime::component::{Component, Linker};
/// use wasmtime::component::types::ComponentItem;
///
/// # fn main() -> wasmtime::Result<()> {
/// let engine = Engine::default();
/// let component = Component::new(
/// &engine,
/// r#"
/// (component
/// (core module $m
/// (func (export "f"))
/// )
/// (core instance $i (instantiate $m))
/// (func (export "f")
/// (canon lift (core func $i "f")))
/// )
/// "#,
/// )?;
///
/// // Perform a lookup of the function "f" before instantiaton.
/// let (ty, export) = component.export_index(None, "f").unwrap();
/// assert!(matches!(ty, ComponentItem::ComponentFunc(_)));
///
/// // After instantiation use `export` to lookup the function in question
/// // which notably does not do a string lookup at runtime.
/// let mut store = Store::new(&engine, ());
/// let instance = Linker::new(&engine).instantiate(&mut store, &component)?;
/// let func = instance.get_typed_func::<(), ()>(&mut store, &export)?;
/// // ...
/// # Ok(())
/// # }
/// ```
pub fn export_index(
&self,
instance: Option<&ComponentExportIndex>,
name: &str,
) -> Option<(types::ComponentItem, ComponentExportIndex)> {
let info = self.env_component();
let index = self.lookup_export_index(instance, name)?;
let ty = match info.export_items[index] {
Export::Instance { ty, .. } => TypeDef::ComponentInstance(ty),
Export::LiftedFunction { ty, .. } => TypeDef::ComponentFunc(ty),
Export::ModuleStatic { ty, .. } | Export::ModuleImport { ty, .. } => {
TypeDef::Module(ty)
}
Export::Type(ty) => ty,
};
let item = self.with_uninstantiated_instance_type(|instance| {
types::ComponentItem::from(&self.inner.engine, &ty, instance)
});
Some((
item,
ComponentExportIndex {
id: self.inner.id,
index,
},
))
}
pub(crate) fn lookup_export_index(
&self,
instance: Option<&ComponentExportIndex>,
name: &str,
) -> Option<ExportIndex> {
let info = self.env_component();
let exports = match instance {
Some(idx) => {
if idx.id != self.inner.id {
return None;
}
match &info.export_items[idx.index] {
Export::Instance { exports, .. } => exports,
_ => return None,
}
}
None => &info.exports,
};
exports.get(name, &NameMapNoIntern).copied()
}
pub(crate) fn id(&self) -> CompiledModuleId {
self.inner.id
}
/// Returns the [`Engine`] that this [`Component`] was compiled by.
pub fn engine(&self) -> &Engine {
&self.inner.engine
}
}
/// A value which represents a known export of a component.
///
/// This is the return value of [`Component::export_index`] and implements the
/// [`InstanceExportLookup`] trait to work with lookups like
/// [`Instance::get_func`](crate::component::Instance::get_func).
#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq)]
pub struct ComponentExportIndex {
pub(crate) id: CompiledModuleId,
pub(crate) index: ExportIndex,
}
impl InstanceExportLookup for ComponentExportIndex {
fn lookup(&self, component: &Component) -> Option<ExportIndex> {
if component.inner.id == self.id {
Some(self.index)
} else {
None
}
}
}
impl ComponentRuntimeInfo for ComponentInner {
fn component(&self) -> &wasmtime_environ::component::Component {
&self.info.component
}
fn component_types(&self) -> &Arc<ComponentTypes> {
match self.code.types() {
crate::code::Types::Component(types) => types,
// The only creator of a `Component` is itself which uses the other
// variant, so this shouldn't be possible.
crate::code::Types::Module(_) => unreachable!(),
}
}
fn realloc_func_type(&self) -> &Arc<dyn Any + Send + Sync> {
&self.realloc_func_type
}
}
#[cfg(test)]
mod tests {
use crate::component::Component;
use crate::{Config, Engine};
use wasmtime_environ::MemoryInitialization;
#[test]
fn cow_on_by_default() {
let mut config = Config::new();
config.wasm_component_model(true);
let engine = Engine::new(&config).unwrap();
let component = Component::new(
&engine,
r#"
(component
(core module
(memory 1)
(data (i32.const 100) "abcd")
)
)
"#,
)
.unwrap();
for (_, module) in component.inner.static_modules.iter() {
let init = &module.env_module().memory_initialization;
assert!(matches!(init, MemoryInitialization::Static { .. }));
}
}
}