refactor: apply metadata render interface to oras pull command (#1587)

Signed-off-by: Xiaoxuan Wang <[email protected]>

Author: wangxiaoxuan273

cmd/oras/internal/display/metadata/interface.go

@@ -59,12 +59,14 @@ type ManifestFetchHandler interface {
 
 // PullHandler handles metadata output for pull events.
 type PullHandler interface {
+	Renderer
+
 	// OnLayerSkipped is called when a layer is skipped.
 	OnLayerSkipped(ocispec.Descriptor) error
 	// OnFilePulled is called after a file is pulled.
 	OnFilePulled(name string, outputDir string, desc ocispec.Descriptor, descPath string) error
-	// OnCompleted is called when the pull cmd execution is completed.
-	OnCompleted(opts *option.Target, desc ocispec.Descriptor) error
+	// OnPulled is called when a pull operation completes.
+	OnPulled(target *option.Target, desc ocispec.Descriptor)
 }
 
 // TaggedHandler handles status output for tag command.

cmd/oras/internal/display/metadata/json/pull.go

@@ -30,11 +30,7 @@ type PullHandler struct {
 	path   string
 	pulled model.Pulled
 	out    io.Writer
-}
-
-// OnLayerSkipped implements metadata.PullHandler.
-func (ph *PullHandler) OnLayerSkipped(ocispec.Descriptor) error {
-	return nil
+	root   ocispec.Descriptor
 }
 
 // NewPullHandler returns a new handler for Pull events.
@@ -45,12 +41,22 @@ func NewPullHandler(out io.Writer, path string) metadata.PullHandler {
 	}
 }
 
+// OnLayerSkipped implements metadata.PullHandler.
+func (ph *PullHandler) OnLayerSkipped(ocispec.Descriptor) error {
+	return nil
+}
+
 // OnFilePulled implements metadata.PullHandler.
 func (ph *PullHandler) OnFilePulled(name string, outputDir string, desc ocispec.Descriptor, descPath string) error {
 	return ph.pulled.Add(name, outputDir, desc, descPath)
 }
 
-// OnCompleted implements metadata.PullHandler.
-func (ph *PullHandler) OnCompleted(opts *option.Target, desc ocispec.Descriptor) error {
-	return output.PrintPrettyJSON(ph.out, model.NewPull(ph.path+"@"+desc.Digest.String(), ph.pulled.Files()))
+// OnPulled implements metadata.PullHandler.
+func (ph *PullHandler) OnPulled(_ *option.Target, desc ocispec.Descriptor) {
+	ph.root = desc
+}
+
+// Render implements metadata.PullHandler.
+func (ph *PullHandler) Render() error {
+	return output.PrintPrettyJSON(ph.out, model.NewPull(ph.path+"@"+ph.root.Digest.String(), ph.pulled.Files()))
 }

cmd/oras/internal/display/metadata/template/pull.go

@@ -31,11 +31,26 @@ type PullHandler struct {
 	path     string
 	out      io.Writer
 	pulled   model.Pulled
+	root     ocispec.Descriptor
 }
 
-// OnCompleted implements metadata.PullHandler.
-func (ph *PullHandler) OnCompleted(opts *option.Target, desc ocispec.Descriptor) error {
-	return output.ParseAndWrite(ph.out, model.NewPull(ph.path+"@"+desc.Digest.String(), ph.pulled.Files()), ph.template)
+// NewPullHandler returns a new handler for pull events.
+func NewPullHandler(out io.Writer, path string, template string) metadata.PullHandler {
+	return &PullHandler{
+		path:     path,
+		template: template,
+		out:      out,
+	}
+}
+
+// OnPulled implements metadata.PullHandler.
+func (ph *PullHandler) OnPulled(_ *option.Target, desc ocispec.Descriptor) {
+	ph.root = desc
+}
+
+// Render implements metadata.PullHandler.
+func (ph *PullHandler) Render() error {
+	return output.ParseAndWrite(ph.out, model.NewPull(ph.path+"@"+ph.root.Digest.String(), ph.pulled.Files()), ph.template)
 }
 
 // OnFilePulled implements metadata.PullHandler.
@@ -47,12 +62,3 @@ func (ph *PullHandler) OnFilePulled(name string, outputDir string, desc ocispec.
 func (ph *PullHandler) OnLayerSkipped(ocispec.Descriptor) error {
 	return nil
 }
-
-// NewPullHandler returns a new handler for pull events.
-func NewPullHandler(out io.Writer, path string, template string) metadata.PullHandler {
-	return &PullHandler{
-		path:     path,
-		template: template,
-		out:      out,
-	}
-}

cmd/oras/internal/display/metadata/text/pull.go

@@ -28,18 +28,15 @@ import (
 type PullHandler struct {
 	printer      *output.Printer
 	layerSkipped atomic.Bool
+	target       *option.Target
+	root         ocispec.Descriptor
 }
 
-// OnCompleted implements metadata.PullHandler.
-func (ph *PullHandler) OnCompleted(opts *option.Target, desc ocispec.Descriptor) error {
-	if ph.layerSkipped.Load() {
-		_ = ph.printer.Printf("Skipped pulling layers without file name in %q\n", ocispec.AnnotationTitle)
-		_ = ph.printer.Printf("Use 'oras copy %s --to-oci-layout <layout-dir>' to pull all layers.\n", opts.RawReference)
-	} else {
-		_ = ph.printer.Println("Pulled", opts.AnnotatedReference())
-		_ = ph.printer.Println("Digest:", desc.Digest)
+// NewPullHandler returns a new handler for Pull events.
+func NewPullHandler(printer *output.Printer) metadata.PullHandler {
+	return &PullHandler{
+		printer: printer,
 	}
-	return nil
 }
 
 func (ph *PullHandler) OnFilePulled(_ string, _ string, _ ocispec.Descriptor, _ string) error {
@@ -52,9 +49,20 @@ func (ph *PullHandler) OnLayerSkipped(ocispec.Descriptor) error {
 	return nil
 }
 
-// NewPullHandler returns a new handler for Pull events.
-func NewPullHandler(printer *output.Printer) metadata.PullHandler {
-	return &PullHandler{
-		printer: printer,
+// OnPulled implements metadata.PullHandler.
+func (ph *PullHandler) OnPulled(target *option.Target, desc ocispec.Descriptor) {
+	ph.target = target
+	ph.root = desc
+}
+
+// Render implements metadata.PullHandler.
+func (ph *PullHandler) Render() error {
+	if ph.layerSkipped.Load() {
+		_ = ph.printer.Printf("Skipped pulling layers without file name in %q\n", ocispec.AnnotationTitle)
+		_ = ph.printer.Printf("Use 'oras copy %s --to-oci-layout <layout-dir>' to pull all layers.\n", ph.target.RawReference)
+	} else {
+		_ = ph.printer.Println("Pulled", ph.target.AnnotatedReference())
+		_ = ph.printer.Println("Digest:", ph.root.Digest)
 	}
+	return nil
 }

cmd/oras/root/pull.go

@@ -163,8 +163,8 @@ func runPull(cmd *cobra.Command, opts *pullOptions) (pullError error) {
 		}
 		return err
 	}
-
-	return metadataHandler.OnCompleted(&opts.Target, desc)
+	metadataHandler.OnPulled(&opts.Target, desc)
+	return metadataHandler.Render()
 }
 
 func doPull(ctx context.Context, src oras.ReadOnlyTarget, dst oras.GraphTarget, opts oras.CopyOptions, metadataHandler metadata.PullHandler, statusHandler status.PullHandler, po *pullOptions) (ocispec.Descriptor, error) {