Struct Memory

pub struct Memory { /* private fields */ }

A shared or unshared wasm linear memory.

A Memory represents the memory used by a wasm instance.

Implementations

impl Memory

pub fn new(desc: MemoryDescriptor) -> Result<Self, CreationError>

Create a new Memory from a MemoryDescriptor

Usage:

fn create_memory() -> Result<()> {
    let descriptor = MemoryDescriptor::new(Pages(10), None, false).unwrap();

    let memory = Memory::new(descriptor)?;
    Ok(())
}

pub fn descriptor(&self) -> MemoryDescriptor

Return the MemoryDescriptor that this memory was created with.

pub fn grow(&self, delta: Pages) -> Result<Pages, GrowError>

Grow this memory by the specified number of pages.

pub fn size(&self) -> Pages

The size, in wasm pages, of this memory.

pub fn view<T: ValueType>(&self) -> MemoryView<'_, T>

Return a “view” of the currently accessible memory. By default, the view is unsynchronized, using regular memory accesses. You can force a memory view to use atomic accesses by calling the atomically method.

Notes:

This method is safe (as in, it won’t cause the host to crash or have UB), but it doesn’t obey rust’s rules involving data races, especially concurrent ones. Therefore, if this memory is shared between multiple threads, a single memory location can be mutated concurrently without synchronization.

Usage:

// Without synchronization.
let view: MemoryView<u8> = memory.view();
for byte in view[0x1000 .. 0x1010].iter().map(Cell::get) {
    println!("byte: {}", byte);
}

// With synchronization.
let atomic_view = view.atomically();
for byte in atomic_view[0x1000 .. 0x1010].iter().map(|atom| atom.load(Ordering::SeqCst)) {
    println!("byte: {}", byte);
}

Trait Implementations

impl Clone for Memory

fn clone(&self) -> Memory

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Memory

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Exportable<'a> for Memory

fn get_self(exports: &'a Exports, name: &str) -> ResolveResult<Self>

Implementation of how to get the export corresponding to the implementing type from an [Instance] by name.

impl IsExport for Memory

fn to_export(&self) -> Export

Gets self as Export.