Function NewJSFilter

access/jsfilter.go:28–83

(filename string, instances int, logger *clog.CondLogger, next Filter)

}

func NewJSFilter(filename string, instances int, logger *clog.CondLogger, next Filter) (*JSFilter, error) {
	script, err := os.ReadFile(filename)
	if err != nil {
		return nil, fmt.Errorf("unable to load JS script file %q: %w", filename, err)
	}

	instances = max(1, instances)
	pool := make(chan JSFilterFunc, instances)
	initGroup, _ := errgroup.WithContext(context.Background())

	for i := 0; i < instances; i++ {
		initGroup.Go(func() error {
			vm := goja.New()
			err := jsext.AddPrinter(vm, logger)
			if err != nil {
				return fmt.Errorf("can't add print function to runtime: %w", err)
			}
			err = jsext.ConfigureRuntime(vm)
			if err != nil {
				return fmt.Errorf("can't configure runtime: %w", err)
			}
			_, err = vm.RunString(string(script))
			if err != nil {
				return fmt.Errorf("script run failed: %w", err)
			}

			var f JSFilterFunc
			var accessFnJSVal goja.Value
			if ex := vm.Try(func() {
				accessFnJSVal = vm.Get("access")
			}); ex != nil {
				return fmt.Errorf("\"access\" function cannot be located in VM context: %w", err)
			}
			if accessFnJSVal == nil {
				return errors.New("\"access\" function is not defined")
			}
			err = vm.ExportTo(accessFnJSVal, &f)
			if err != nil {
				return fmt.Errorf("can't export \"access\" function from JS VM: %w", err)
			}

			pool <- f
			return nil
		})
	}

	err = initGroup.Wait()
	if err != nil {
		return nil, err
	}

	return &JSFilter{
		funcPool: pool,
		next:     next,
	}, nil
}

func (j *JSFilter) Access(ctx context.Context, req *http.Request, username, network, address string) error {