Trait Caller

pub trait Caller {
    type Context;

    // Required methods
    fn context(&self) -> &Self::Context;
    fn context_mut(&mut self) -> &mut Self::Context;
    fn bytecode(&self) -> Bytes;
    fn has_export(&self, name: &str) -> bool;
    fn memory_read_into(&self, offset: u32, output: &mut [u8]) -> VMResult<()>;
    fn memory_write(&self, offset: u32, data: &[u8]) -> VMResult<()>;
    fn alloc(&mut self, idx: u32, size: usize, ctx: u32) -> VMResult<u32>;
    fn gas_consumed(&mut self) -> MeteringPoints;
    fn consume_gas(&mut self, value: u64) -> VMResult<()>;

    // Provided method
    fn memory_read(&self, offset: u32, size: usize) -> VMResult<Vec<u8>> { ... }
}

An abstraction over the ‘caller’ object of a host function that works for any Wasm VM.

This allows access for important instances such as the context object that was passed to the instance, wasm linear memory access, etc.

Required Associated Types

type Context

Required Methods

fn context(&self) -> &Self::Context

fn context_mut(&mut self) -> &mut Self::Context

fn bytecode(&self) -> Bytes

Returns currently running unmodified bytecode.

fn has_export(&self, name: &str) -> bool

Check if an export is present in the module.

fn memory_read_into(&self, offset: u32, output: &mut [u8]) -> VMResult<()>

fn memory_write(&self, offset: u32, data: &[u8]) -> VMResult<()>

fn alloc(&mut self, idx: u32, size: usize, ctx: u32) -> VMResult<u32>

Allocates memory inside the Wasm VM by calling an export.

Error is a type-erased error coming from the VM itself.

fn gas_consumed(&mut self) -> MeteringPoints

Returns the amount of gas used.

fn consume_gas(&mut self, value: u64) -> VMResult<()>

Set the amount of gas used.

Provided Methods

fn memory_read(&self, offset: u32, size: usize) -> VMResult<Vec<u8>>

Implementors