| 5 | use wasmtime::*; |
| 6 | |
| 7 | fn main() -> Result<()> { |
| 8 | let mut config = Config::new(); |
| 9 | config.consume_fuel(true); |
| 10 | let engine = Engine::new(&config)?; |
| 11 | let mut store = Store::new(&engine, ()); |
| 12 | store.set_fuel(10_000)?; |
| 13 | let module = Module::from_file(store.engine(), "examples/fuel.wat")?; |
| 14 | let instance = Instance::new(&mut store, &module, &[])?; |
| 15 | |
| 16 | // Invoke `fibonacci` export with higher and higher numbers until we exhaust our fuel. |
| 17 | let fibonacci = instance.get_typed_func::<i32, i32>(&mut store, "fibonacci")?; |
| 18 | for n in 1.. { |
| 19 | let fuel_before = store.get_fuel().unwrap(); |
| 20 | let output = match fibonacci.call(&mut store, n) { |
| 21 | Ok(v) => v, |
| 22 | Err(e) => { |
| 23 | assert_eq!(e.downcast::<Trap>()?, Trap::OutOfFuel); |
| 24 | println!("Exhausted fuel computing fib({n})"); |
| 25 | break; |
| 26 | } |
| 27 | }; |
| 28 | let fuel_consumed = fuel_before - store.get_fuel().unwrap(); |
| 29 | println!("fib({n}) = {output} [consumed {fuel_consumed} fuel]"); |
| 30 | store.set_fuel(10_000)?; |
| 31 | } |
| 32 | Ok(()) |
| 33 | } |