Trait WasmInstance 

pub trait WasmInstance: 'static {
    // Required methods
    fn call(
        &mut self,
        func: &str,
        args: &[WasmVal],
    ) -> Result<Vec<WasmVal>, WasmError>;
    fn memory_read(&self, offset: u32, len: u32) -> Result<Vec<u8>, WasmError>;
    fn memory_write(
        &mut self,
        offset: u32,
        data: &[u8],
    ) -> Result<(), WasmError>;
    fn set_fuel(&mut self, fuel: u64) -> Result<(), WasmError>;
    fn fuel_consumed(&self) -> Option<u64>;
}

A fully instantiated WASM module, ready to execute exported functions.

Created by WasmHost::instantiate.

Required Methods

fn call( &mut self, func: &str, args: &[WasmVal], ) -> Result<Vec<WasmVal>, WasmError>

Call an exported function by name.

Returns Err(WasmError::FuelExhausted) if the module ran out of fuel, Err(WasmError::Trap(…)) for other traps, and Err(WasmError::Call(…)) for missing exports or type errors.

fn memory_read(&self, offset: u32, len: u32) -> Result<Vec<u8>, WasmError>

Read len bytes from WASM linear memory at offset.

Returns Err(WasmError::MemoryAccess) on bounds violation.

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

Write data into WASM linear memory starting at offset.

Returns Err(WasmError::MemoryAccess) on bounds violation.

fn set_fuel(&mut self, fuel: u64) -> Result<(), WasmError>

Set the fuel budget for subsequent calls.

Has no effect if the runtime was not configured with fuel consumption enabled; in that case returns Ok(()) silently.

fn fuel_consumed(&self) -> Option<u64>

Return the number of fuel units consumed so far by this instance.

Returns None if the runtime was not configured with fuel tracking.

Implementors