package scripting import ( "errors" "fmt" "sync" "git.kirsle.net/SketchyMaze/doodle/pkg/log" "github.com/dop251/goja" ) // VM manages a single isolated JavaScript VM. type VM struct { Name string // Globals available to the scripts. Events *Events Self interface{} // Channels for inbound and outbound PubSub messages. // Each VM has a single Inbound channel that watches for received messages // and invokes the Message.Subscribe() handlers for relevant ones. // Each VM also has an array of Outbound channels which map to the Inbound // channel of the VMs it is linked to, for pushing out Message.Publish() // messages. Inbound chan Message Outbound []chan Message stop chan bool subscribe map[string][]goja.Value // Subscribed message handlers by name. muSubscribe sync.RWMutex muPublish sync.Mutex // serialize PubSub publishes vm *goja.Runtime // setTimeout and setInterval variables. timerLastID int // becomes 1 when first timer is set timers map[int]*Timer } // NewVM creates a new JavaScript VM. func NewVM(name string) *VM { vm := &VM{ Name: name, vm: goja.New(), timers: map[int]*Timer{}, // Pub/sub structs. Inbound: make(chan Message, 100), Outbound: []chan Message{}, stop: make(chan bool, 1), subscribe: map[string][]goja.Value{}, } vm.Events = NewEvents(vm.vm) return vm } // Run code in the VM. func (vm *VM) Run(src string) (goja.Value, error) { v, err := vm.vm.RunString(src) return v, err } // Set a value in the VM. func (vm *VM) Set(name string, v interface{}) error { return vm.vm.Set(name, v) } // RegisterLevelHooks registers accessors to the level hooks // and Doodad API for Play Mode. func (vm *VM) RegisterLevelHooks() error { bindings := NewJSProxy(vm) for name, v := range bindings { err := vm.vm.Set(name, v) if err != nil { return fmt.Errorf("RegisterLevelHooks(%s): %s", name, err, ) } } return nil } // Main calls the main function of the script. func (vm *VM) Main() error { function, ok := goja.AssertFunction(vm.vm.Get("main")) if !ok { return errors.New("didn't find function main()") } // Catch panics. defer func() { if err := recover(); err != nil { log.Error("Panic caught in JavaScript VM: %s", err) } }() _, err := function(goja.Undefined()) return err }