Struct metered_wasmi::ModuleRef

pub struct ModuleRef(_);

Reference to a ModuleInstance.

This reference has a reference-counting semantics.

All ModuleInstance have strong references to it's components (i.e. globals, memories, funcs, tables), however, this components have weak references to it's containing module. This might be a problem at execution time.

So if have to make sure that all modules which might be needed at execution time should be retained.

Methods from Deref<Target = ModuleInstance>

pub fn func_by_index(&self, idx: u32) -> Option<FuncRef>

pub fn globals<'a>(&self) -> Ref<Vec<GlobalRef>>

Access all globals. This is a non-standard API so it's unlikely to be portable to other engines.

pub fn invoke_export<E: Externals>(
    &self,
    func_name: &str,
    args: &[RuntimeValue],
    externals: &mut E
) -> Result<Option<RuntimeValue>, Error>

Invoke exported function by a name.

This function finds exported function by a name, and calls it with provided arguments and external state.

Errors

Returns Err if:

• there are no export with a given name or this export is not a function,
• given arguments doesn't match to function signature,
• trap occurred at the execution time,

Examples

Invoke a function that takes two numbers and returns sum of them.

assert_eq!(
    instance.invoke_export(
        "add",
        &[RuntimeValue::I32(5), RuntimeValue::I32(3)],
        &mut NopExternals,
    )
    .expect("failed to execute export"),
    Some(RuntimeValue::I32(8)),
);

pub fn invoke_export_with_stack<E: Externals>(
    &self,
    func_name: &str,
    args: &[RuntimeValue],
    externals: &mut E,
    stack_recycler: &mut StackRecycler
) -> Result<Option<RuntimeValue>, Error>

Invoke exported function by a name using recycled stacks.

Errors

Same as invoke_export.

pub fn export_by_name(&self, name: &str) -> Option<ExternVal>

Find export by a name.

Returns None if there is no export with such name.

Trait Implementations

impl ModuleImportResolver for ModuleRef

fn resolve_func(
    &self,
    field_name: &str,
    _signature: &Signature
) -> Result<FuncRef, Error>

Resolve a function.

fn resolve_global(
    &self,
    field_name: &str,
    _global_type: &GlobalDescriptor
) -> Result<GlobalRef, Error>

Resolve a global variable.

fn resolve_memory(
    &self,
    field_name: &str,
    _memory_type: &MemoryDescriptor
) -> Result<MemoryRef, Error>

Resolve a memory.

fn resolve_table(
    &self,
    field_name: &str,
    _table_type: &TableDescriptor
) -> Result<TableRef, Error>

Resolve a table.

impl Clone for ModuleRef

fn clone(&self) -> ModuleRef

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Deref for ModuleRef

type Target = ModuleInstance

The resulting type after dereferencing.

fn deref(&self) -> &ModuleInstance

Dereferences the value.