replace unnecessary Task interface with struct

internal/config/config.go

@@ -27,7 +27,7 @@ type Config struct {
 	value            *types.Config
 	providers        F.Map[string, *proxy.Provider]
 	autocertProvider *autocert.Provider
-	task             task.Task
+	task             *task.Task
 }
 
 var (
@@ -88,7 +88,7 @@ func WatchChanges() {
 	eventQueue.Start(cfgWatcher.Events(task.Context()))
 }
 
-func OnConfigChange(flushTask task.Task, ev []events.Event) {
+func OnConfigChange(flushTask *task.Task, ev []events.Event) {
 	defer flushTask.Finish("config reload complete")
 
 	// no matter how many events during the interval
@@ -136,7 +136,7 @@ func GetAutoCertProvider() *autocert.Provider {
 	return instance.autocertProvider
 }
 
-func (cfg *Config) Task() task.Task {
+func (cfg *Config) Task() *task.Task {
 	return cfg.task
 }
 

internal/docker/idlewatcher/waker.go

@@ -39,7 +39,7 @@ const (
 
 // TODO: support stream
 
-func newWaker(providerSubTask task.Task, entry route.Entry, rp *gphttp.ReverseProxy, stream net.Stream) (Waker, E.Error) {
+func newWaker(providerSubTask *task.Task, entry route.Entry, rp *gphttp.ReverseProxy, stream net.Stream) (Waker, E.Error) {
 	hcCfg := entry.HealthCheckConfig()
 	hcCfg.Timeout = idleWakerCheckTimeout
 
@@ -72,16 +72,16 @@ func newWaker(providerSubTask task.Task, entry route.Entry, rp *gphttp.ReversePr
 }
 
 // lifetime should follow route provider.
-func NewHTTPWaker(providerSubTask task.Task, entry route.Entry, rp *gphttp.ReverseProxy) (Waker, E.Error) {
+func NewHTTPWaker(providerSubTask *task.Task, entry route.Entry, rp *gphttp.ReverseProxy) (Waker, E.Error) {
 	return newWaker(providerSubTask, entry, rp, nil)
 }
 
-func NewStreamWaker(providerSubTask task.Task, entry route.Entry, stream net.Stream) (Waker, E.Error) {
+func NewStreamWaker(providerSubTask *task.Task, entry route.Entry, stream net.Stream) (Waker, E.Error) {
 	return newWaker(providerSubTask, entry, nil, stream)
 }
 
 // Start implements health.HealthMonitor.
-func (w *Watcher) Start(routeSubTask task.Task) E.Error {
+func (w *Watcher) Start(routeSubTask *task.Task) E.Error {
 	routeSubTask.Finish("ignored")
 	w.task.OnCancel("stop route and cleanup", func() {
 		routeSubTask.Parent().Finish(w.task.FinishCause())

internal/docker/idlewatcher/watcher.go

@@ -32,7 +32,7 @@ type (
 		client       D.Client
 		stopByMethod StopCallback // send a docker command w.r.t. `stop_method`
 		ticker       *time.Ticker
-		task         task.Task
+		task         *task.Task
 	}
 
 	WakeDone     <-chan error
@@ -51,7 +51,7 @@ var (
 
 const dockerReqTimeout = 3 * time.Second
 
-func registerWatcher(providerSubtask task.Task, entry route.Entry, waker *waker) (*Watcher, error) {
+func registerWatcher(providerSubtask *task.Task, entry route.Entry, waker *waker) (*Watcher, error) {
 	cfg := entry.IdlewatcherConfig()
 
 	if cfg.IdleTimeout == 0 {
@@ -209,7 +209,7 @@ func (w *Watcher) resetIdleTimer() {
 	w.ticker.Reset(w.IdleTimeout)
 }
 
-func (w *Watcher) getEventCh(dockerWatcher watcher.DockerWatcher) (eventTask task.Task, eventCh <-chan events.Event, errCh <-chan E.Error) {
+func (w *Watcher) getEventCh(dockerWatcher watcher.DockerWatcher) (eventTask *task.Task, eventCh <-chan events.Event, errCh <-chan E.Error) {
 	eventTask = w.task.Subtask("docker event watcher")
 	eventCh, errCh = dockerWatcher.EventsWithOptions(eventTask.Context(), watcher.DockerListOptions{
 		Filters: watcher.NewDockerFilter(

internal/net/http/loadbalancer/loadbalancer.go

@@ -27,7 +27,7 @@ type (
 		impl
 		*Config
 
-		task task.Task
+		task *task.Task
 
 		pool   Pool
 		poolMu sync.Mutex
@@ -52,7 +52,7 @@ func New(cfg *Config) *LoadBalancer {
 }
 
 // Start implements task.TaskStarter.
-func (lb *LoadBalancer) Start(routeSubtask task.Task) E.Error {
+func (lb *LoadBalancer) Start(routeSubtask *task.Task) E.Error {
 	lb.startTime = time.Now()
 	lb.task = routeSubtask
 	lb.task.OnFinished("loadbalancer cleanup", func() {

internal/net/http/middleware/errorpage/error_page.go

@@ -73,7 +73,7 @@ func loadContent() {
 	}
 }
 
-func watchDir(task task.Task) {
+func watchDir(task *task.Task) {
 	eventCh, errCh := dirWatcher.Events(task.Context())
 	for {
 		select {

internal/net/http/server/server.go

@@ -24,7 +24,7 @@ type Server struct {
 	httpsStarted bool
 	startTime    time.Time
 
-	task task.Task
+	task *task.Task
 
 	l zerolog.Logger
 }

internal/notif/dispatcher.go

@@ -13,7 +13,7 @@ import (
 
 type (
 	Dispatcher struct {
-		task      task.Task
+		task      *task.Task
 		logCh     chan *LogMessage
 		providers F.Set[Provider]
 	}
@@ -35,7 +35,7 @@ var (
 
 const dispatchErr = "notification dispatch error"
 
-func StartNotifDispatcher(parent task.Task) *Dispatcher {
+func StartNotifDispatcher(parent *task.Task) *Dispatcher {
 	dispatcher = &Dispatcher{
 		task:      parent.Subtask("notification dispatcher"),
 		logCh:     make(chan *LogMessage),

internal/route/http.go

@@ -31,7 +31,7 @@ type (
 		handler      http.Handler
 		rp           *gphttp.ReverseProxy
 
-		task task.Task
+		task *task.Task
 
 		l zerolog.Logger
 	}
@@ -74,8 +74,8 @@ func (r *HTTPRoute) String() string {
 	return string(r.Alias)
 }
 
-// Start implements task.TaskStarter.
+// Start implements*task.TaskStarter.
-func (r *HTTPRoute) Start(providerSubtask task.Task) E.Error {
+func (r *HTTPRoute) Start(providerSubtask *task.Task) E.Error {
 	if entry.ShouldNotServe(r) {
 		providerSubtask.Finish("should not serve")
 		return nil
@@ -148,7 +148,7 @@ func (r *HTTPRoute) Start(providerSubtask task.Task) E.Error {
 	return nil
 }
 
-// Finish implements task.TaskFinisher.
+// Finish implements*task.TaskFinisher.
 func (r *HTTPRoute) Finish(reason any) {
 	r.task.Finish(reason)
 }

internal/route/provider/event_handler.go

@@ -28,7 +28,7 @@ func (p *Provider) newEventHandler() *EventHandler {
 	}
 }
 
-func (handler *EventHandler) Handle(parent task.Task, events []watcher.Event) {
+func (handler *EventHandler) Handle(parent *task.Task, events []watcher.Event) {
 	oldRoutes := handler.provider.routes
 	newRoutes, err := handler.provider.loadRoutesImpl()
 	if err != nil {
@@ -97,7 +97,7 @@ func (handler *EventHandler) match(event watcher.Event, route *route.Route) bool
 	return false
 }
 
-func (handler *EventHandler) Add(parent task.Task, route *route.Route) {
+func (handler *EventHandler) Add(parent *task.Task, route *route.Route) {
 	err := handler.provider.startRoute(parent, route)
 	if err != nil {
 		handler.errs.Add(err.Subject("add"))
@@ -112,7 +112,7 @@ func (handler *EventHandler) Remove(route *route.Route) {
 	handler.removed.Adds(route.Entry.Alias)
 }
 
-func (handler *EventHandler) Update(parent task.Task, oldRoute *route.Route, newRoute *route.Route) {
+func (handler *EventHandler) Update(parent *task.Task, oldRoute *route.Route, newRoute *route.Route) {
 	oldRoute.Finish("route update")
 	err := handler.provider.startRoute(parent, newRoute)
 	if err != nil {

internal/route/provider/provider.go

@@ -100,7 +100,7 @@ func (p *Provider) MarshalText() ([]byte, error) {
 	return []byte(p.String()), nil
 }
 
-func (p *Provider) startRoute(parent task.Task, r *R.Route) E.Error {
+func (p *Provider) startRoute(parent *task.Task, r *R.Route) E.Error {
 	subtask := parent.Subtask(p.String() + "/" + r.Entry.Alias)
 	err := r.Start(subtask)
 	if err != nil {
@@ -115,8 +115,8 @@ func (p *Provider) startRoute(parent task.Task, r *R.Route) E.Error {
 	return nil
 }
 
-// Start implements task.TaskStarter.
+// Start implements*task.TaskStarter.
-func (p *Provider) Start(configSubtask task.Task) E.Error {
+func (p *Provider) Start(configSubtask *task.Task) E.Error {
 	// routes and event queue will stop on parent cancel
 	providerTask := configSubtask
 
@@ -128,7 +128,7 @@ func (p *Provider) Start(configSubtask task.Task) E.Error {
 	eventQueue := events.NewEventQueue(
 		providerTask,
 		providerEventFlushInterval,
-		func(flushTask task.Task, events []events.Event) {
+		func(flushTask *task.Task, events []events.Event) {
 			handler := p.newEventHandler()
 			// routes' lifetime should follow the provider's lifetime
 			handler.Handle(providerTask, events)

internal/route/stream.go

@@ -24,7 +24,7 @@ type StreamRoute struct {
 
 	HealthMon health.HealthMonitor `json:"health"`
 
-	task task.Task
+	task *task.Task
 
 	l zerolog.Logger
 }
@@ -47,8 +47,8 @@ func (r *StreamRoute) String() string {
 	return fmt.Sprintf("stream %s", r.Alias)
 }
 
-// Start implements task.TaskStarter.
+// Start implements*task.TaskStarter.
-func (r *StreamRoute) Start(providerSubtask task.Task) E.Error {
+func (r *StreamRoute) Start(providerSubtask *task.Task) E.Error {
 	if entry.ShouldNotServe(r) {
 		providerSubtask.Finish("should not serve")
 		return nil

internal/task/task.go

@@ -16,11 +16,11 @@ import (
 
 var globalTask = createGlobalTask()
 
-func createGlobalTask() (t *task) {
+func createGlobalTask() (t *Task) {
-	t = new(task)
+	t = new(Task)
 	t.name = "root"
 	t.ctx, t.cancel = context.WithCancelCause(context.Background())
-	t.subtasks = F.NewSet[*task]()
+	t.subtasks = F.NewSet[*Task]()
 	return
 }
 
@@ -29,52 +29,6 @@ func testResetGlobalTask() {
 }
 
 type (
-	// Task controls objects' lifetime.
-	//
-	// Objects that uses a task should implement the TaskStarter and the TaskFinisher interface.
-	//
-	// When passing a Task object to another function,
-	// it must be a sub-task of the current task,
-	// in name of "`currentTaskName`Subtask"
-	//
-	// Use Task.Finish to stop all subtasks of the task.
-	Task interface {
-		TaskFinisher
-		fmt.Stringer
-		// Name returns the name of the task.
-		Name() string
-		// Context returns the context associated with the task. This context is
-		// canceled when Finish of the task is called, or parent task is canceled.
-		Context() context.Context
-		// FinishCause returns the reason / error that caused the task to be finished.
-		FinishCause() error
-		// Parent returns the parent task of the current task.
-		Parent() Task
-		// Subtask returns a new subtask with the given name, derived from the parent's context.
-		//
-		// If the parent's context is already canceled, the returned subtask will be canceled immediately.
-		//
-		// This should not be called after Finish, Wait, or WaitSubTasks is called.
-		Subtask(name string) Task
-		// OnFinished calls fn when all subtasks are finished.
-		//
-		// It cannot be called after Finish or Wait is called.
-		OnFinished(about string, fn func())
-		// OnCancel calls fn when the task is canceled.
-		//
-		// It cannot be called after Finish or Wait is called.
-		OnCancel(about string, fn func())
-		// Wait waits for all subtasks, itself, OnFinished and OnSubtasksFinished to finish.
-		//
-		// It must be called only after Finish is called.
-		Wait()
-		// WaitSubTasks waits for all subtasks of the task to finish.
-		//
-		// No more subtasks can be added after this call.
-		//
-		// It can be called before Finish is called.
-		WaitSubTasks()
-	}
 	TaskStarter interface {
 		// Start starts the object that implements TaskStarter,
 		// and returns an error if it fails to start.
@@ -82,7 +36,7 @@ type (
 		// The task passed must be a subtask of the caller task.
 		//
 		// callerSubtask.Finish must be called when start fails or the object is finished.
-		Start(callerSubtask Task) E.Error
+		Start(callerSubtask *Task) E.Error
 	}
 	TaskFinisher interface {
 		// Finish marks the task as finished and cancel its context.
@@ -93,12 +47,21 @@ type (
 		// Note that it will also cancel all subtasks.
 		Finish(reason any)
 	}
-	task struct {
+	// Task controls objects' lifetime.
+	//
+	// Objects that uses a Task should implement the TaskStarter and the TaskFinisher interface.
+	//
+	// When passing a Task object to another function,
+	// it must be a sub-Task of the current Task,
+	// in name of "`currentTaskName`Subtask"
+	//
+	// Use Task.Finish to stop all subtasks of the Task.
+	Task struct {
 		ctx    context.Context
 		cancel context.CancelCauseFunc
 
-		parent     *task
+		parent     *Task
-		subtasks   F.Set[*task]
+		subtasks   F.Set[*Task]
 		subTasksWg sync.WaitGroup
 
 		name string
@@ -119,7 +82,7 @@ var (
 )
 
 // GlobalTask returns a new Task with the given name, derived from the global context.
-func GlobalTask(format string, args ...any) Task {
+func GlobalTask(format string, args ...any) *Task {
 	if len(args) > 0 {
 		format = fmt.Sprintf(format, args...)
 	}
@@ -168,11 +131,12 @@ func GlobalContextWait(timeout time.Duration) (err error) {
 	}
 }
 
-func (t *task) trace(msg string) {
+func (t *Task) trace(msg string) {
 	logger.Trace().Str("name", t.name).Msg(msg)
 }
 
-func (t *task) Name() string {
+// Name returns the name of the task.
+func (t *Task) Name() string {
 	if !common.IsTrace {
 		return t.name
 	}
@@ -180,15 +144,19 @@ func (t *task) Name() string {
 	return parts[len(parts)-1]
 }
 
-func (t *task) String() string {
+// String returns the name of the task.
+func (t *Task) String() string {
 	return t.name
 }
 
-func (t *task) Context() context.Context {
+// Context returns the context associated with the task. This context is
+// canceled when Finish of the task is called, or parent task is canceled.
+func (t *Task) Context() context.Context {
 	return t.ctx
 }
 
-func (t *task) FinishCause() error {
+// FinishCause returns the reason / error that caused the task to be finished.
+func (t *Task) FinishCause() error {
 	cause := context.Cause(t.ctx)
 	if cause == nil {
 		return t.ctx.Err()
@@ -196,11 +164,12 @@ func (t *task) FinishCause() error {
 	return cause
 }
 
-func (t *task) Parent() Task {
+// Parent returns the parent task of the current task.
+func (t *Task) Parent() *Task {
 	return t.parent
 }
 
-func (t *task) runAllOnFinished(onCompTask Task) {
+func (t *Task) runAllOnFinished(onCompTask *Task) {
 	<-t.ctx.Done()
 	t.WaitSubTasks()
 	for _, OnFinishedFunc := range t.OnFinishedFuncs {
@@ -210,7 +179,10 @@ func (t *task) runAllOnFinished(onCompTask Task) {
 	onCompTask.Finish(fmt.Errorf("%w: %s, reason: %s", ErrTaskCanceled, t.name, "done"))
 }
 
-func (t *task) OnFinished(about string, fn func()) {
+// OnFinished calls fn when all subtasks are finished.
+//
+// It cannot be called after Finish or Wait is called.
+func (t *Task) OnFinished(about string, fn func()) {
 	if t.parent == globalTask {
 		t.OnCancel(about, fn)
 		return
@@ -239,7 +211,10 @@ func (t *task) OnFinished(about string, fn func()) {
 	t.OnFinishedFuncs = append(t.OnFinishedFuncs, wrapped)
 }
 
-func (t *task) OnCancel(about string, fn func()) {
+// OnCancel calls fn when the task is canceled.
+//
+// It cannot be called after Finish or Wait is called.
+func (t *Task) OnCancel(about string, fn func()) {
 	onCompTask := GlobalTask(t.name + " > OnFinished")
 	go func() {
 		<-t.ctx.Done()
@@ -249,7 +224,13 @@ func (t *task) OnCancel(about string, fn func()) {
 	}()
 }
 
-func (t *task) Finish(reason any) {
+// Finish marks the task as finished and cancel its context.
+//
+// Then call Wait to wait for all subtasks, OnFinished and OnSubtasksFinished
+// of the task to finish.
+//
+// Note that it will also cancel all subtasks.
+func (t *Task) Finish(reason any) {
 	var format string
 	switch reason.(type) {
 	case error:
@@ -265,22 +246,27 @@ func (t *task) Finish(reason any) {
 	t.Wait()
 }
 
-func (t *task) Subtask(name string) Task {
+// Subtask returns a new subtask with the given name, derived from the parent's context.
+//
+// If the parent's context is already canceled, the returned subtask will be canceled immediately.
+//
+// This should not be called after Finish, Wait, or WaitSubTasks is called.
+func (t *Task) Subtask(name string) *Task {
 	ctx, cancel := context.WithCancelCause(t.ctx)
 	return t.newSubTask(ctx, cancel, name)
 }
 
-func (t *task) newSubTask(ctx context.Context, cancel context.CancelCauseFunc, name string) *task {
+func (t *Task) newSubTask(ctx context.Context, cancel context.CancelCauseFunc, name string) *Task {
 	parent := t
 	if common.IsTrace {
 		name = parent.name + " > " + name
 	}
-	subtask := &task{
+	subtask := &Task{
 		ctx:      ctx,
 		cancel:   cancel,
 		name:     name,
 		parent:   parent,
-		subtasks: F.NewSet[*task](),
+		subtasks: F.NewSet[*Task](),
 	}
 	parent.subTasksWg.Add(1)
 	parent.subtasks.Add(subtask)
@@ -299,13 +285,21 @@ func (t *task) newSubTask(ctx context.Context, cancel context.CancelCauseFunc, n
 	return subtask
 }
 
-func (t *task) Wait() {
+// Wait waits for all subtasks, itself, OnFinished and OnSubtasksFinished to finish.
+//
+// It must be called only after Finish is called.
+func (t *Task) Wait() {
 	<-t.ctx.Done()
 	t.WaitSubTasks()
 	t.onFinishedWg.Wait()
 }
 
-func (t *task) WaitSubTasks() {
+// WaitSubTasks waits for all subtasks of the task to finish.
+//
+// No more subtasks can be added after this call.
+//
+// It can be called before Finish is called.
+func (t *Task) WaitSubTasks() {
 	t.subTasksWg.Wait()
 }
 
@@ -322,7 +316,7 @@ func (t *task) WaitSubTasks() {
 //
 // The returned string is not guaranteed to be stable, and may change between
 // runs of the program. It is intended for debugging purposes only.
-func (t *task) tree(prefix ...string) string {
+func (t *Task) tree(prefix ...string) string {
 	var sb strings.Builder
 	var pre string
 	if len(prefix) > 0 {
@@ -330,7 +324,7 @@ func (t *task) tree(prefix ...string) string {
 		sb.WriteString(pre + "- ")
 	}
 	sb.WriteString(t.Name() + "\n")
-	t.subtasks.RangeAll(func(subtask *task) {
+	t.subtasks.RangeAll(func(subtask *Task) {
 		sb.WriteString(subtask.tree(pre + "  "))
 	})
 	return sb.String()
@@ -350,13 +344,13 @@ func (t *task) tree(prefix ...string) string {
 // The returned map is not guaranteed to be stable, and may change
 // between runs of the program. It is intended for debugging purposes
 // only.
-func (t *task) serialize() map[string]any {
+func (t *Task) serialize() map[string]any {
 	m := make(map[string]any)
 	parts := strings.Split(t.name, " > ")
 	m["name"] = parts[len(parts)-1]
 	if t.subtasks.Size() > 0 {
 		m["subtasks"] = make([]map[string]any, 0, t.subtasks.Size())
-		t.subtasks.RangeAll(func(subtask *task) {
+		t.subtasks.RangeAll(func(subtask *Task) {
 			m["subtasks"] = append(m["subtasks"].([]map[string]any), subtask.serialize())
 		})
 	}

internal/watcher/directory_watcher.go

@@ -26,7 +26,7 @@ type DirWatcher struct {
 	eventCh chan Event
 	errCh   chan E.Error
 
-	task task.Task
+	task *task.Task
 }
 
 // NewDirectoryWatcher returns a DirWatcher instance.
@@ -37,7 +37,7 @@ type DirWatcher struct {
 //
 // Note that the returned DirWatcher is not ready to use until the goroutine
 // started by NewDirectoryWatcher has finished.
-func NewDirectoryWatcher(callerSubtask task.Task, dirPath string) *DirWatcher {
+func NewDirectoryWatcher(callerSubtask *task.Task, dirPath string) *DirWatcher {
 	//! subdirectories are not watched
 	w, err := fsnotify.NewWatcher()
 	if err != nil {

internal/watcher/events/event_queue.go

@@ -10,14 +10,14 @@ import (
 
 type (
 	EventQueue struct {
-		task          task.Task
+		task          *task.Task
 		queue         []Event
 		ticker        *time.Ticker
 		flushInterval time.Duration
 		onFlush       OnFlushFunc
 		onError       OnErrorFunc
 	}
-	OnFlushFunc = func(flushTask task.Task, events []Event)
+	OnFlushFunc = func(flushTask *task.Task, events []Event)
 	OnErrorFunc = func(err E.Error)
 )
 
@@ -38,7 +38,7 @@ const eventQueueCapacity = 10
 // but the onFlush function can return earlier (e.g. run in another goroutine).
 //
 // If task is canceled before the flushInterval is reached, the events in queue will be discarded.
-func NewEventQueue(parent task.Task, flushInterval time.Duration, onFlush OnFlushFunc, onError OnErrorFunc) *EventQueue {
+func NewEventQueue(parent *task.Task, flushInterval time.Duration, onFlush OnFlushFunc, onError OnErrorFunc) *EventQueue {
 	return &EventQueue{
 		task:          parent.Subtask("event queue"),
 		queue:         make([]Event, 0, eventQueueCapacity),
@@ -53,7 +53,7 @@ func (e *EventQueue) Start(eventCh <-chan Event, errCh <-chan E.Error) {
 	if common.IsProduction {
 		origOnFlush := e.onFlush
 		// recover panic in onFlush when in production mode
-		e.onFlush = func(flushTask task.Task, events []Event) {
+		e.onFlush = func(flushTask *task.Task, events []Event) {
 			defer func() {
 				if err := recover(); err != nil {
 					e.onError(E.New("recovered panic in onFlush").

internal/watcher/health/monitor/monitor.go

@@ -36,7 +36,7 @@ type (
 
 		metric *metrics.Gauge
 
-		task task.Task
+		task *task.Task
 	}
 )
 
@@ -61,7 +61,7 @@ func (mon *monitor) ContextWithTimeout(cause string) (ctx context.Context, cance
 }
 
 // Start implements task.TaskStarter.
-func (mon *monitor) Start(routeSubtask task.Task) E.Error {
+func (mon *monitor) Start(routeSubtask *task.Task) E.Error {
 	mon.service = routeSubtask.Parent().Name()
 	mon.task = routeSubtask