feat: support progress output for attach, push and copy commands

cmd/oras/internal/display/print.go

@@ -29,9 +29,10 @@ import (
 
 var printLock sync.Mutex
 
-type printFunc func(ocispec.Descriptor) error
+// PrintFunc is the function type returned by StatusPrinter.
+type PrintFunc func(ocispec.Descriptor) error
 
-// Print objects to display concurrent-safely
+// Print objects to display concurrent-safely.
 func Print(a ...any) error {
 	printLock.Lock()
 	defer printLock.Unlock()
@@ -40,7 +41,7 @@ func Print(a ...any) error {
 }
 
 // StatusPrinter returns a tracking function for transfer status.
-func StatusPrinter(status string, verbose bool) printFunc {
+func StatusPrinter(status string, verbose bool) PrintFunc {
 	return func(desc ocispec.Descriptor) error {
 		return PrintStatus(desc, status, verbose)
 	}
@@ -60,7 +61,7 @@ func PrintStatus(desc ocispec.Descriptor, status string, verbose bool) error {
 }
 
 // PrintSuccessorStatus prints transfer status of successors.
-func PrintSuccessorStatus(ctx context.Context, desc ocispec.Descriptor, fetcher content.Fetcher, committed *sync.Map, print printFunc) error {
+func PrintSuccessorStatus(ctx context.Context, desc ocispec.Descriptor, fetcher content.Fetcher, committed *sync.Map, print PrintFunc) error {
 	successors, err := content.Successors(ctx, fetcher, desc)
 	if err != nil {
 		return err

cmd/oras/internal/display/track/target.go

@@ -17,7 +17,6 @@ package track
 
 import (
 	"context"
-	"errors"
 	"io"
 	"os"
 
@@ -104,10 +103,6 @@ func (t *graphTarget) Close() error {
 
 // Prompt prompts the user with the provided prompt and descriptor.
 func (t *graphTarget) Prompt(desc ocispec.Descriptor, prompt string, verbose bool) error {
-	if t == nil {
-		// this should not happen
-		return errors.New("cannot output progress with nil tracked target")
-	}
 	status, err := t.manager.Add()
 	if err != nil {
 		return err

cmd/oras/root/cp.go

@@ -146,8 +146,6 @@ func runCopy(ctx context.Context, opts copyOptions) error {
 }
 
 func doCopy(ctx context.Context, src oras.ReadOnlyGraphTarget, dst oras.GraphTarget, opts copyOptions) (ocispec.Descriptor, error) {
-	var tracked track.GraphTarget
-	var err error
 	// Prepare copy options
 	committed := &sync.Map{}
 	extendedCopyOptions := oras.DefaultExtendedCopyOptions
@@ -162,15 +160,13 @@ func doCopy(ctx context.Context, src oras.ReadOnlyGraphTarget, dst oras.GraphTar
 			return successorPrinter(d)
 		})
 	}
-	extendedCopyOptions.OnCopySkipped = func(ctx context.Context, desc ocispec.Descriptor) error {
-		committed.Store(desc.Digest.String(), desc.Annotations[ocispec.AnnotationTitle])
-		if tracked == nil {
-			return display.PrintStatus(desc, "Skipped", opts.Verbose)
-		}
-		return tracked.Prompt(desc, "Exists ", opts.Verbose)
-	}
+
 	if opts.TTY == nil {
 		// none TTY output
+		extendedCopyOptions.OnCopySkipped = func(ctx context.Context, desc ocispec.Descriptor) error {
+			committed.Store(desc.Digest.String(), desc.Annotations[ocispec.AnnotationTitle])
+			return display.PrintStatus(desc, "Exists ", opts.Verbose)
+		}
 		extendedCopyOptions.PreCopy = func(ctx context.Context, desc ocispec.Descriptor) error {
 			return display.PrintStatus(desc, "Copying", opts.Verbose)
 		}
@@ -183,18 +179,24 @@ func doCopy(ctx context.Context, src oras.ReadOnlyGraphTarget, dst oras.GraphTar
 		}
 	} else {
 		// TTY output
-		successorPrinter = func(desc ocispec.Descriptor) error {
-			return tracked.Prompt(desc, "Skipped", opts.Verbose)
-		}
-		tracked, err = track.NewTarget(dst, "Copying ", "Copied ", opts.TTY)
+
+		tracked, err := track.NewTarget(dst, "Copying ", "Copied ", opts.TTY)
 		if err != nil {
 			return ocispec.Descriptor{}, err
 		}
 		defer tracked.Close()
 		dst = tracked
+		successorPrinter = func(desc ocispec.Descriptor) error {
+			return tracked.Prompt(desc, "Skipped", opts.Verbose)
+		}
+		extendedCopyOptions.OnCopySkipped = func(ctx context.Context, desc ocispec.Descriptor) error {
+			committed.Store(desc.Digest.String(), desc.Annotations[ocispec.AnnotationTitle])
+			return tracked.Prompt(desc, "Exists ", opts.Verbose)
+		}
 	}
 
 	var desc ocispec.Descriptor
+	var err error
 	rOpts := oras.DefaultResolveOptions
 	rOpts.TargetPlatform = opts.Platform.Platform
 	if opts.recursive {

cmd/oras/root/push.go

@@ -241,15 +241,16 @@ func doPush(dst oras.Target, pack packFunc, copy copyFunc) (ocispec.Descriptor,
 
 func updateDisplayOption(opts *oras.CopyGraphOptions, fetcher content.Fetcher, verbose bool, tracked track.GraphTarget) {
 	committed := &sync.Map{}
-	opts.OnCopySkipped = func(ctx context.Context, desc ocispec.Descriptor) error {
-		committed.Store(desc.Digest.String(), desc.Annotations[ocispec.AnnotationTitle])
-		if tracked == nil {
-			return display.PrintStatus(desc, "Exists  ", verbose)
-		}
-		return tracked.Prompt(desc, "Exists   ", verbose)
-	}
+
 	if tracked == nil {
 		// non TTY
+		opts.OnCopySkipped = func(ctx context.Context, desc ocispec.Descriptor) error {
+			committed.Store(desc.Digest.String(), desc.Annotations[ocispec.AnnotationTitle])
+			if tracked == nil {
+				return display.PrintStatus(desc, "Exists  ", verbose)
+			}
+			return tracked.Prompt(desc, "Exists   ", verbose)
+		}
 		opts.PreCopy = func(ctx context.Context, desc ocispec.Descriptor) error {
 			return display.PrintStatus(desc, "Uploading", verbose)
 		}
@@ -263,6 +264,10 @@ func updateDisplayOption(opts *oras.CopyGraphOptions, fetcher content.Fetcher, v
 		return
 	}
 	// TTY
+	opts.OnCopySkipped = func(ctx context.Context, desc ocispec.Descriptor) error {
+		committed.Store(desc.Digest.String(), desc.Annotations[ocispec.AnnotationTitle])
+		return tracked.Prompt(desc, "Exists   ", verbose)
+	}
 	opts.PostCopy = func(ctx context.Context, desc ocispec.Descriptor) error {
 		committed.Store(desc.Digest.String(), desc.Annotations[ocispec.AnnotationTitle])
 		return display.PrintSuccessorStatus(ctx, desc, fetcher, committed, func(d ocispec.Descriptor) error {
@@ -275,16 +280,14 @@ type packFunc func() (ocispec.Descriptor, error)
 type copyFunc func(desc ocispec.Descriptor) error
 
 func getTrackedTarget(gt oras.GraphTarget, tty *os.File) (oras.GraphTarget, track.GraphTarget, error) {
-	var tracked track.GraphTarget
-	var err error
-	if tty != nil {
-		tracked, err = track.NewTarget(gt, "Uploading", "Uploaded ", tty)
-		if err != nil {
-			return nil, nil, err
-		}
-		gt = tracked
+	if tty == nil {
+		return gt, nil, nil
+	}
+	tracked, err := track.NewTarget(gt, "Uploading", "Uploaded ", tty)
+	if err != nil {
+		return nil, nil, err
 	}
-	return gt, tracked, nil
+	return tracked, tracked, nil
 }
 
 func pushArtifact(dst oras.Target, pack packFunc, copy copyFunc) (ocispec.Descriptor, error) {