Struct wasmtime_runtime::Memory

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pub struct Memory(_);

Expand description

Representation of a runtime wasm linear memory.

Implementations

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impl Memory

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pub fn new_dynamic(
 plan: &MemoryPlan,
 creator: &dyn RuntimeMemoryCreator,
 store: &mut dyn Store,
 memory_image: Option<&Arc<MemoryImage>>
) -> Result<Self>

Create a new dynamic (movable) memory instance for the specified plan.

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pub fn new_static(
 plan: &MemoryPlan,
 base: &'static mut [u8],
 make_accessible: Option<fn(_: *mut u8, _: usize) -> Result<()>>,
 memory_image: Option<MemoryImageSlot>,
 store: &mut dyn Store
) -> Result<Self>

Create a new static (immovable) memory instance for the specified plan.

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pub fn byte_size(&self) -> usize

Returns the number of allocated wasm pages.

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pub fn maximum_byte_size(&self) -> Option<usize>

Returns the maximum number of pages the memory can grow to at runtime.

Returns None if the memory is unbounded.

The runtime maximum may not be equal to the maximum from the linear memory’s Wasm type when it is being constrained by an instance allocator.

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pub unsafe fn grow(
 &mut self,
 delta_pages: u64,
 store: Option<&mut dyn Store>
) -> Result<Option<usize>, Error>

Grow memory by the specified amount of wasm pages.

Returns None if memory can’t be grown by the specified amount of wasm pages. Returns Some with the old size of memory, in bytes, on successful growth.

Safety

Resizing the memory can reallocate the memory buffer for dynamic memories. An instance’s VMContext may have pointers to the memory’s base and will need to be fixed up after growing the memory.

Generally, prefer using InstanceHandle::memory_grow, which encapsulates this unsafety.

Ensure that the provided Store is not used to get access any Memory which lives inside it.

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