Struct wasmi::MemoryInstance

pub struct MemoryInstance { /* fields omitted */ }

Runtime representation of a linear memory (or memory for short).

A memory is a contiguous, mutable array of raw bytes. Wasm code can load and store values from/to a linear memory at any byte address. A trap occurs if an access is not within the bounds of the current memory size.

A memory is created with an initial size but can be grown dynamically. The growth can be limited by specifying maximum size. The size of a memory is always a integer multiple of a page size - 64KiB.

At the moment, wasm doesn't provide any way to shrink the memory.

Methods

impl MemoryInstance

fn alloc(
    initial_pages: u32,
    maximum_pages: Option<u32>
) -> Result<MemoryRef, Error>

fn initial_pages(&self) -> u32

fn maximum_pages(&self) -> Option<u32>

fn size(&self) -> u32

Return linear memory size (in pages).

fn get(&self, offset: u32, size: usize) -> Result<Vec<u8>, Error>

Get data at given offset.

fn get_into(&self, offset: u32, target: &mut [u8]) -> Result<(), Error>

Write memory slice into another slice

fn set(&self, offset: u32, value: &[u8]) -> Result<(), Error>

Set data at given offset.

fn grow(&self, pages: u32) -> Result<u32, Error>

Increases the size of the linear memory by given number of pages. Returns previous memory size (in pages) if succeeds.

fn copy(
    &self,
    src_offset: usize,
    dst_offset: usize,
    len: usize
) -> Result<(), Error>

Copy memory region. Semantically equivalent to memmove.

fn copy_nonoverlapping(
    &self,
    src_offset: usize,
    dst_offset: usize,
    len: usize
) -> Result<(), Error>

Copy memory region, non-overlapping version. Semantically equivalent to memcpy, but returns Error if source overlaping with destination.

fn clear(&self, offset: usize, new_val: u8, len: usize) -> Result<(), Error>

Clear memory region with a specified value. Semantically equivalent to memset.

fn zero(&self, offset: usize, len: usize) -> Result<(), Error>

Zero memory region

Trait Implementations

impl Debug for MemoryInstance

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

Formats the value using the given formatter.