Fix: use the fastest whether the result is successful

common/picker/picker.go

@@ -17,15 +17,12 @@ type Picker struct {
 
 	once   sync.Once
 	result interface{}
-
-	firstDone chan struct{}
 }
 
 func newPicker(ctx context.Context, cancel func()) *Picker {
 	return &Picker{
-		ctx:       ctx,
-		cancel:    cancel,
-		firstDone: make(chan struct{}, 1),
+		ctx:    ctx,
+		cancel: cancel,
 	}
 }
 
@@ -42,12 +39,6 @@ func WithTimeout(ctx context.Context, timeout time.Duration) (*Picker, context.C
 	return newPicker(ctx, cancel), ctx
 }
 
-// WithoutAutoCancel returns a new Picker and an associated Context derived from ctx,
-// but it wouldn't cancel context when the first element return.
-func WithoutAutoCancel(ctx context.Context) *Picker {
-	return newPicker(ctx, nil)
-}
-
 // Wait blocks until all function calls from the Go method have returned,
 // then returns the first nil error result (if any) from them.
 func (p *Picker) Wait() interface{} {
@@ -58,17 +49,6 @@ func (p *Picker) Wait() interface{} {
 	return p.result
 }
 
-// WaitWithoutCancel blocks until the first result return, if timeout will return nil.
-// The return of this function will not wait for the cancel of context.
-func (p *Picker) WaitWithoutCancel() interface{} {
-	select {
-	case <-p.firstDone:
-		return p.result
-	case <-p.ctx.Done():
-		return p.result
-	}
-}
-
 // Go calls the given function in a new goroutine.
 // The first call to return a nil error cancels the group; its result will be returned by Wait.
 func (p *Picker) Go(f func() (interface{}, error)) {
@@ -80,7 +60,6 @@ func (p *Picker) Go(f func() (interface{}, error)) {
 		if ret, err := f(); err == nil {
 			p.once.Do(func() {
 				p.result = ret
-				p.firstDone <- struct{}{}
 				if p.cancel != nil {
 					p.cancel()
 				}

common/picker/picker_test.go

@@ -37,30 +37,3 @@ func TestPicker_Timeout(t *testing.T) {
 	number := picker.Wait()
 	assert.Nil(t, number)
 }
-
-func TestPicker_WaitWithoutAutoCancel(t *testing.T) {
-	ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*60)
-	defer cancel()
-	picker := WithoutAutoCancel(ctx)
-
-	trigger := false
-	picker.Go(sleepAndSend(ctx, 10, 1))
-	picker.Go(func() (interface{}, error) {
-		timer := time.NewTimer(time.Millisecond * time.Duration(30))
-		select {
-		case <-timer.C:
-			trigger = true
-			return 2, nil
-		case <-ctx.Done():
-			return nil, ctx.Err()
-		}
-	})
-	elm := picker.WaitWithoutCancel()
-
-	assert.NotNil(t, elm)
-	assert.Equal(t, elm.(int), 1)
-
-	elm = picker.Wait()
-	assert.True(t, trigger)
-	assert.Equal(t, elm.(int), 1)
-}