Trait wasmtime_runtime::ModuleRuntimeInfo

pub trait ModuleRuntimeInfo: Send + Sync + 'static {
    fn module(&self) -> &Arc<Module>;
    fn function(&self, index: DefinedFuncIndex) -> *mut VMFunctionBody;
    fn memory_image(
        &self,
        memory: DefinedMemoryIndex
    ) -> Result<Option<&Arc<MemoryImage>>>;
    fn unique_id(&self) -> Option<CompiledModuleId>;
    fn wasm_data(&self) -> &[u8] ;
    fn signature_ids(&self) -> &[VMSharedSignatureIndex];
    fn offsets(&self) -> &VMOffsets<HostPtr>;
}

Functionality required by this crate for a particular module. This is chiefly needed for lazy initialization of various bits of instance state.

When an instance is created, it holds an Arc<dyn ModuleRuntimeInfo> so that it can get to signatures, metadata on functions, memory and funcref-table images, etc. All of these things are ordinarily known by the higher-level layers of Wasmtime. Specifically, the main implementation of this trait is provided by wasmtime::module::ModuleInner. Since the runtime crate sits at the bottom of the dependence DAG though, we don’t know or care about that; we just need some implementor of this trait for each allocation request.

Required Methods

fn module(&self) -> &Arc<Module>

The underlying Module.

fn function(&self, index: DefinedFuncIndex) -> *mut VMFunctionBody

Returns the address, in memory, that the function index resides at.

fn memory_image(
    &self,
    memory: DefinedMemoryIndex
) -> Result<Option<&Arc<MemoryImage>>>

Returns the MemoryImage structure used for copy-on-write initialization of the memory, if it’s applicable.

fn unique_id(&self) -> Option<CompiledModuleId>

A unique ID for this particular module. This can be used to allow for fastpaths to optimize a “re-instantiate the same module again” case.

fn wasm_data(&self) -> &[u8]

A slice pointing to all data that is referenced by this instance.

fn signature_ids(&self) -> &[VMSharedSignatureIndex]

Returns an array, indexed by SignatureIndex of all VMSharedSignatureIndex entries corresponding to the SignatureIndex.

fn offsets(&self) -> &VMOffsets<HostPtr>

Offset information for the current host.

Implementors