Struct wasmedge_sys::Memory

pub struct Memory { /* private fields */ }

Defines a WebAssembly memory instance, which is a linear memory described by its type. Each memory instance consists of a vector of bytes and an optional maximum size, and its size is a multiple of the WebAssembly page size (64KiB of each page).

Implementations

impl Memory

pub fn create(ty: &MemType) -> WasmEdgeResult<Self>

Create a new Memory to be associated with the given capacity limit.

Arguments

• ty - The type of the new Memory instance.

Errors

• If fail to create the memory instance, then WasmEdgeError::Mem(MemError::Create) is returned.

Example

use wasmedge_sys::{MemType, Memory};

let ty = MemType::create(10, Some(20), false).expect("fail to create memory type");

let memory = Memory::create(&ty);

pub fn ty(&self) -> WasmEdgeResult<MemType>

Returns the type of the Memory.

Errors

If fail to get the type from the Memory, then an error is returned.

pub fn get_data(&self, offset: u32, len: u32) -> WasmEdgeResult<Vec<u8>>

Copies the data from the Memory to the output buffer.

Arguments

• offset - The data start offset in the Memory.

• len - The requested data length.

Errors

If the offset + len is larger than the data size in the Memory, then an error is returned.

pub fn set_data( &mut self, data: impl AsRef<[u8]>, offset: u32 ) -> WasmEdgeResult<()>

Copies the data from the given input buffer into the Memory.

Arguments

• data - The data buffer to copy.

• offset - The data start offset in the Memory.

Errors

If the sum of the offset and the data length is larger than the size of the Memory, then an error is returned.

use wasmedge_sys::{Memory, MemType};
use wasmedge_types::error::{CoreError, CoreExecutionError, WasmEdgeError};

// create a Memory: the min size 1 and the max size 2
let ty = MemType::create(1, Some(2), false).expect("fail to create a memory type");
let mut mem = Memory::create(&ty).expect("fail to create a Memory");

// set data and the data length is larger than the data size in the memory
let result = mem.set_data(vec![1; 10], u32::pow(2, 16) - 9);
assert!(result.is_err());
assert_eq!(result.unwrap_err(), Box::new(WasmEdgeError::Core(CoreError::Execution(CoreExecutionError::MemoryOutOfBounds))));

Example

use wasmedge_sys::{MemType, Memory};

// create a Memory: the min size 1 and the max size 2
let ty = MemType::create(1, Some(2), false).expect("fail to create a memory type");
let mut mem = Memory::create(&ty).expect("fail to create a Memory");
// page count
let count = mem.size();
assert_eq!(count, 1);

// set data
mem.set_data(vec![1; 10], 10).expect("fail to set data");

// get data
let data = mem.get_data(10, 10).expect("fail to get data");
assert_eq!(data, vec![1; 10]);

pub fn data_pointer(&self, offset: u32, len: u32) -> WasmEdgeResult<*const u8>

Returns the const data pointer to the Memory.

Arguments

• offset - The data start offset in the Memory.

• len - The requested data length. If the size of offset + len is larger than the data size in the Memory

Errors

If fail to get the data pointer, then an error is returned.

pub fn data_pointer_mut( &mut self, offset: u32, len: u32 ) -> WasmEdgeResult<*mut u8>

Returns the data pointer to the Memory.

Arguments

• offset - The data start offset in the Memory.

• len - The requested data length. If the size of offset + len is larger than the data size in the Memory

Errors

If fail to get the data pointer, then an error is returned.

pub fn size(&self) -> u32

Returns the size, in WebAssembly pages (64 KiB of each page), of this wasm memory.

pub fn grow(&mut self, count: u32) -> WasmEdgeResult<()>

Grows this WebAssembly memory by count pages.

Arguments

• count - The page counts to be extended to the Memory.

Errors

If fail to grow the page count, then an error is returned.

Example

use wasmedge_sys::{MemType, Memory};

// create a Memory with a limit range [10, 20]
let ty = MemType::create(10, Some(20), false).expect("fail to create a memory type");
let mut mem = Memory::create(&ty).expect("fail to create a Memory");
// check page count
let count = mem.size();
assert_eq!(count, 10);

// grow 5 pages
mem.grow(10).expect("fail to grow the page count");
assert_eq!(mem.size(), 20);

pub fn as_ptr(&self) -> *const WasmEdge_MemoryInstanceContext

Available on crate feature ffi only.

Provides a raw pointer to the inner memory context.

Trait Implementations

impl Clone for Memory

fn clone(&self) -> Self

Returns a copy 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 Drop for Memory

fn drop(&mut self)

Executes the destructor for this type.

impl Memory for Memory

Available on crate feature async and Linux only.

fn get_data<T: Sized>(&self, offset: WasmPtr<T>) -> Result<&T, Errno>

fn get_slice<T: Sized>( &self, offset: WasmPtr<T>, len: usize ) -> Result<&[T], Errno>

fn get_iovec<'a>( &self, iovec_ptr: WasmPtr<__wasi_ciovec_t>, iovec_len: __wasi_size_t ) -> Result<Vec<IoSlice<'a>>, Errno>

fn mut_data<T: Sized>(&mut self, offset: WasmPtr<T>) -> Result<&mut T, Errno>

fn mut_slice<T: Sized>( &mut self, offset: WasmPtr<T>, len: usize ) -> Result<&mut [T], Errno>

fn mut_iovec( &mut self, iovec_ptr: WasmPtr<__wasi_iovec_t>, iovec_len: __wasi_size_t ) -> Result<Vec<IoSliceMut<'_>>, Errno>

fn write_data<T: Sized>( &mut self, offset: WasmPtr<T>, data: T ) -> Result<(), Errno>