Function wasmer_c_api::wasm_c_api::unstable::middlewares::metering::wasmer_metering_set_remaining_points

#[no_mangle]
pub unsafe extern "C" fn wasmer_metering_set_remaining_points(
    instance: &mut wasm_instance_t,
    new_limit: u64
)

Set a new amount of points for the given metering middleware.

Example

This example only illustrates the wasmer_metering_set_remaining_points function, as the number of points aren’t updated by the WebAssembly module execution

// Define a dummy “cost function”.
uint64_t cost_function(wasmer_parser_operator_t wasm_operator) {
    switch(wasm_operator) {
        default:
            return 0;
    }
}

int main() {
    // Set the initial amount of points to 7.
    wasmer_metering_t* metering = wasmer_metering_new(7, cost_function);

    // Consume `metering` to produce `middleware`.
    wasmer_middleware_t* middleware = wasmer_metering_as_middleware(metering);

    // Create the configuration (which consumes `middleware`),
    // the engine, and the store.
    wasm_config_t* config = wasm_config_new();
    wasm_config_push_middleware(config, middleware);
     
    wasm_engine_t* engine = wasm_engine_new_with_config(config);

    wasm_store_t* store = wasm_store_new(engine);
     
    // Create the module and instantiate it.
    wasm_byte_vec_t wat;
    wasmer_byte_vec_new_from_string(&wat, "(module)");
    wasm_byte_vec_t wasm;
    wat2wasm(&wat, &wasm);

    wasm_module_t* module = wasm_module_new(store, &wasm);
    assert(module);
     
    wasm_extern_vec_t imports = WASM_EMPTY_VEC;
    wasm_trap_t* trap = NULL;
    wasm_instance_t* instance = wasm_instance_new(store, module, &imports, &trap);
    assert(instance);

    // Read the number of points.
    assert(wasmer_metering_get_remaining_points(instance) == 7);

    // Set a new number of points.
    wasmer_metering_set_remaining_points(instance, 42);

    // Read the number of points.
    assert(wasmer_metering_get_remaining_points(instance) == 42);

    wasm_instance_delete(instance);
    wasm_module_delete(module);
    wasm_store_delete(store);
    wasm_engine_delete(engine);

    return 0;
}