Struct wasmer_ruby::Wasmer::Memory

pub struct Memory;

A WebAssembly memory instance.

A memory instance is the runtime representation of a linear memory. It consists of a vector of bytes and an optional maximum size.

The length of the vector always is a multiple of the WebAssembly page size, which is defined to be the constant 65536 – abbreviated 64Ki. Like in a memory type, the maximum size in a memory instance is given in units of this page size.

A memory created by the host or in WebAssembly code will be accessible and mutable from both host and WebAssembly.

Specification: https://webassembly.github.io/spec/core/exec/runtime.html#memory-instances

Example

Creates a Memory from scratch:

store = Wasmer::Store.new
memory_type = Wasmer::MemoryType.new 3, 10, true
memory = Wasmer::Memory.new store, memory_type

assert { memory.size == 3 }

Gets a memory from the exports of an instance:

module_ = Wasmer::Module.new Wasmer::Store.new, wasm_bytes
instance = Wasmer::Instance.new module, nil

memory = instance.exports.memory

Implementations

impl Memory

pub fn new(store: Store, memory_type: MemoryType) -> Self

Creates a new Memory.

pub fn type(&self) -> MemoryType

Returns the memory type.

pub fn size(&self) -> Integer

Returns the size (in pages) of the memory.

pub fn data_size(&self) -> Integer

Returns the size (in bytes) of the memory.

pub fn grow(&self, number_of_pages: Integer) -> Integer

Grows memory by the specified amount of WebAssembly pages.

Example

memory = instance.exports.memory
old_memory_size = memory.data_size

memory.grow 1

memory_size = memory.data_size

assert { memory_size == 1179648 }
assert { memory_size - old_memory_size == 65536 }

pub fn uint8_view(&self) -> Uint8View

Creates a read-and-write view over the memory data where elements are of kind uint8.

pub fn int8_view(&self) -> Int8View

Creates a read-and-write view over the memory data where elements are of kind int8.

pub fn uint16_view(&self) -> Uint16View

Creates a read-and-write view over the memory data where elements are of kind uint16.

pub fn int16_view(&self) -> Int16View

Creates a read-and-write view over the memory data where elements are of kind int16.

pub fn uint32_view(&self) -> Uint32View

Creates a read-and-write view over the memory data where elements are of kind uint32.

pub fn int32_view(&self) -> Int32View

Creates a read-and-write view over the memory data where elements are of kind int32.