Trait Memory 

pub trait Memory {
    // Required methods
    fn size(&self) -> u64;
    fn grow(&self, pages: u64) -> i64;
    fn read(&self, offset: u64, dst: &mut [u8]);
    fn write(&self, offset: u64, src: &[u8]);

    // Provided method
    unsafe fn read_unsafe(&self, offset: u64, dst: *mut u8, count: usize) { ... }
}

Abstraction over a WebAssembly-style linear memory (e.g., stable memory).

Implementations are expected to mirror WebAssembly semantics: out-of-bounds accesses will cause a panic (in native) or trap (in Wasm).

Required Methods

fn size(&self) -> u64

Returns the current size of the memory in WebAssembly pages.

One WebAssembly page is 64 KiB.

fn grow(&self, pages: u64) -> i64

Grows the memory by pages pages filled with zeroes.

Returns the previous size in pages on success, or -1 if the memory could not be grown.

fn read(&self, offset: u64, dst: &mut [u8])

Copies dst.len() bytes from memory starting at offset into dst.

Panics or traps if the read would go out of bounds.

fn write(&self, offset: u64, src: &[u8])

Copies src.len() bytes from src into memory starting at offset.

Panics or traps if the write would go out of bounds.

Provided Methods

unsafe fn read_unsafe(&self, offset: u64, dst: *mut u8, count: usize)

Unsafe variant of read for advanced use.

Copies count bytes from memory starting at offset into the raw pointer dst. Initializes the destination before reading.

Safety

Caller must ensure:

• dst points to valid writable memory of at least count bytes.
• The memory range dst..dst+count does not overlap with self.

Panics or traps if the read would go out of bounds.

Implementations on Foreign Types

impl Memory for RefCell<Vec<u8>>

fn size(&self) -> u64

fn grow(&self, pages: u64) -> i64

fn read(&self, offset: u64, dst: &mut [u8])

unsafe fn read_unsafe(&self, offset: u64, dst: *mut u8, count: usize)

fn write(&self, offset: u64, src: &[u8])

impl<M> Memory for Rc<M>

where M: Memory,

fn size(&self) -> u64

fn grow(&self, pages: u64) -> i64

fn read(&self, offset: u64, dst: &mut [u8])

unsafe fn read_unsafe(&self, offset: u64, dst: *mut u8, count: usize)

fn write(&self, offset: u64, src: &[u8])

Implementors

impl Memory for FileMemory

impl<M> Memory for VirtualMemory<M>

where M: Memory,

impl<M> Memory for RestrictedMemory<M>

where M: Memory,