util: simplify progress syncronization

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

util/progress/fromreader.go

@@ -11,7 +11,6 @@ import (
 )
 
 func FromReader(w Writer, name string, rc io.ReadCloser) {
-	status := w.Status()
 	dgst := digest.FromBytes([]byte(identity.NewID()))
 	tm := time.Now()
 
@@ -21,9 +20,9 @@ func FromReader(w Writer, name string, rc io.ReadCloser) {
 		Started: &tm,
 	}
 
-	status <- &client.SolveStatus{
+	w.Write(&client.SolveStatus{
 		Vertexes: []*client.Vertex{&vtx},
-	}
+	})
 
 	_, err := io.Copy(ioutil.Discard, rc)
 
@@ -33,8 +32,7 @@ func FromReader(w Writer, name string, rc io.ReadCloser) {
 	if err != nil {
 		vtx2.Error = err.Error()
 	}
-	status <- &client.SolveStatus{
+	w.Write(&client.SolveStatus{
 		Vertexes: []*client.Vertex{&vtx2},
-	}
-	close(status)
+	})
 }

util/progress/multiwriter.go

@@ -1,101 +1,32 @@
 package progress
 
 import (
-	"context"
 	"strings"
-	"sync"
 
 	"github.com/moby/buildkit/client"
-	"golang.org/x/sync/errgroup"
 )
 
-type MultiWriter struct {
-	w     Writer
-	eg    *errgroup.Group
-	once  sync.Once
-	ready chan struct{}
-}
-
-func (mw *MultiWriter) WithPrefix(pfx string, force bool) Writer {
-	in := make(chan *client.SolveStatus)
-	out := mw.w.Status()
-	p := &prefixed{
-		main: mw.w,
-		in:   in,
+func WithPrefix(w Writer, pfx string, force bool) Writer {
+	return &prefixed{
+		main:  w,
+		pfx:   pfx,
+		force: force,
 	}
-	mw.eg.Go(func() error {
-		mw.once.Do(func() {
-			close(mw.ready)
-		})
-		for {
-			select {
-			case v, ok := <-in:
-				if ok {
-					if force {
-						for _, v := range v.Vertexes {
-							v.Name = addPrefix(pfx, v.Name)
-						}
-					}
-					out <- v
-				} else {
-					return nil
-				}
-			case <-mw.Done():
-				return mw.Err()
-			}
-		}
-	})
-	return p
-}
-
-func (mw *MultiWriter) Done() <-chan struct{} {
-	return mw.w.Done()
-}
-
-func (mw *MultiWriter) Err() error {
-	return mw.w.Err()
-}
-
-func (mw *MultiWriter) Status() chan *client.SolveStatus {
-	return nil
 }
 
 type prefixed struct {
-	main Writer
-	in   chan *client.SolveStatus
+	main  Writer
+	pfx   string
+	force bool
 }
 
-func (p *prefixed) Done() <-chan struct{} {
-	return p.main.Done()
-}
-
-func (p *prefixed) Err() error {
-	return p.main.Err()
-}
-
-func (p *prefixed) Status() chan *client.SolveStatus {
-	return p.in
-}
-
-func NewMultiWriter(pw Writer) *MultiWriter {
-	if pw == nil {
-		return nil
-	}
-	eg, _ := errgroup.WithContext(context.TODO())
-
-	ready := make(chan struct{})
-
-	go func() {
-		<-ready
-		eg.Wait()
-		close(pw.Status())
-	}()
-
-	return &MultiWriter{
-		w:     pw,
-		eg:    eg,
-		ready: ready,
+func (p *prefixed) Write(v *client.SolveStatus) {
+	if p.force {
+		for _, v := range v.Vertexes {
+			v.Name = addPrefix(p.pfx, v.Name)
+		}
 	}
+	p.main.Write(v)
 }
 
 func addPrefix(pfx, name string) string {

util/progress/printer.go

@@ -9,32 +9,27 @@ import (
 	"github.com/moby/buildkit/util/progress/progressui"
 )
 
-type printer struct {
+type Printer struct {
 	status chan *client.SolveStatus
 	done   <-chan struct{}
 	err    error
 }
 
-func (p *printer) Done() <-chan struct{} {
-	return p.done
-}
-
-func (p *printer) Err() error {
+func (p *Printer) Wait() error {
+	close(p.status)
+	<-p.done
 	return p.err
 }
 
-func (p *printer) Status() chan *client.SolveStatus {
-	if p == nil {
-		return nil
-	}
-	return p.status
+func (p *Printer) Write(s *client.SolveStatus) {
+	p.status <- s
 }
 
-func NewPrinter(ctx context.Context, out console.File, mode string) Writer {
+func NewPrinter(ctx context.Context, out console.File, mode string) *Printer {
 	statusCh := make(chan *client.SolveStatus)
 	doneCh := make(chan struct{})
 
-	pw := &printer{
+	pw := &Printer{
 		status: statusCh,
 		done:   doneCh,
 	}

util/progress/reset.go

@@ -7,56 +7,45 @@ import (
 )
 
 func ResetTime(in Writer) Writer {
-	w := &pw{Writer: in, status: make(chan *client.SolveStatus), tm: time.Now()}
-	go func() {
-		for {
-			select {
-			case <-in.Done():
-				return
-			case st, ok := <-w.status:
-				if !ok {
-					close(in.Status())
-					return
-				}
-				if w.diff == nil {
-					for _, v := range st.Vertexes {
-						if v.Started != nil {
-							d := v.Started.Sub(w.tm)
-							w.diff = &d
-						}
-					}
-				}
-				if w.diff != nil {
-					for _, v := range st.Vertexes {
-						if v.Started != nil {
-							d := v.Started.Add(-*w.diff)
-							v.Started = &d
-						}
-						if v.Completed != nil {
-							d := v.Completed.Add(-*w.diff)
-							v.Completed = &d
-						}
-					}
-					for _, v := range st.Statuses {
-						if v.Started != nil {
-							d := v.Started.Add(-*w.diff)
-							v.Started = &d
-						}
-						if v.Completed != nil {
-							d := v.Completed.Add(-*w.diff)
-							v.Completed = &d
-						}
-						v.Timestamp = v.Timestamp.Add(-*w.diff)
-					}
-					for _, v := range st.Logs {
-						v.Timestamp = v.Timestamp.Add(-*w.diff)
-					}
-				}
-				in.Status() <- st
+	return &pw{Writer: in, status: make(chan *client.SolveStatus), tm: time.Now()}
+}
+
+func (w *pw) Write(st *client.SolveStatus) {
+	if w.diff == nil {
+		for _, v := range st.Vertexes {
+			if v.Started != nil {
+				d := v.Started.Sub(w.tm)
+				w.diff = &d
 			}
 		}
-	}()
-	return w
+	}
+	if w.diff != nil {
+		for _, v := range st.Vertexes {
+			if v.Started != nil {
+				d := v.Started.Add(-*w.diff)
+				v.Started = &d
+			}
+			if v.Completed != nil {
+				d := v.Completed.Add(-*w.diff)
+				v.Completed = &d
+			}
+		}
+		for _, v := range st.Statuses {
+			if v.Started != nil {
+				d := v.Started.Add(-*w.diff)
+				v.Started = &d
+			}
+			if v.Completed != nil {
+				d := v.Completed.Add(-*w.diff)
+				v.Completed = &d
+			}
+			v.Timestamp = v.Timestamp.Add(-*w.diff)
+		}
+		for _, v := range st.Logs {
+			v.Timestamp = v.Timestamp.Add(-*w.diff)
+		}
+	}
+	w.Writer.Write(st)
 }
 
 type pw struct {

util/progress/writer.go

@@ -9,13 +9,10 @@ import (
 )
 
 type Writer interface {
-	Done() <-chan struct{}
-	Err() error
-	Status() chan *client.SolveStatus
+	Write(*client.SolveStatus)
 }
 
 func Write(w Writer, name string, f func() error) {
-	status := w.Status()
 	dgst := digest.FromBytes([]byte(identity.NewID()))
 	tm := time.Now()
 
@@ -25,9 +22,9 @@ func Write(w Writer, name string, f func() error) {
 		Started: &tm,
 	}
 
-	status <- &client.SolveStatus{
+	w.Write(&client.SolveStatus{
 		Vertexes: []*client.Vertex{&vtx},
-	}
+	})
 
 	err := f()
 
@@ -37,7 +34,21 @@ func Write(w Writer, name string, f func() error) {
 	if err != nil {
 		vtx2.Error = err.Error()
 	}
-	status <- &client.SolveStatus{
+	w.Write(&client.SolveStatus{
 		Vertexes: []*client.Vertex{&vtx2},
-	}
+	})
+}
+
+func NewChannel(w Writer) chan *client.SolveStatus {
+	ch := make(chan *client.SolveStatus)
+	go func() {
+		for {
+			v, ok := <-ch
+			if !ok {
+				return
+			}
+			w.Write(v)
+		}
+	}()
+	return ch
 }