working commit

pkg/repocli/imager.go

@@ -85,6 +85,10 @@ func NewImagerFromPlace(place string) (*Imager, error) {
 	return imager, err
 }
 
+func (ima *Imager) Index() *ocispec.Index {
+	return &ima.index
+}
+
 func (ima *Imager) ReadManifest(ctx context.Context, digstr string) (bool, string, []byte, error) {
 	var exist bool
 	var mime string
@@ -181,6 +185,28 @@ func (ima *Imager) writeManifest(ctx context.Context, digest, mime string, paylo
 	return err
 }
 
+func (ima *Imager) readIndex(ctx context.Context) (*ocispec.Index, error) {
+	// Read index
+	var err error
+	res := &ocispec.Index{}
+	ipath := filepath.Join(ima.place, ocispec.ImageIndexFile)
+	ifile, err := os.OpenFile(ipath, os.O_RDONLY, 0)
+	if err != nil {
+		return res, err
+	}
+	defer ifile.Close()
+	buffer := bytes.NewBuffer(nil)
+	_, err = io.Copy(buffer, buffer)
+	if err != nil {
+		return res, err
+	}
+	err = json.Unmarshal(buffer.Bytes(), res)
+	if err != nil {
+		return res, err
+	}
+	return res, err
+}
+
 func (ima *Imager) writeIndex(ctx context.Context) error {
 	indexdat, err := json.Marshal(ima.index)
 	if err != nil {
@@ -293,3 +319,26 @@ func (ima *Imager) ReadLayer(ctx context.Context, digstr string, writer io.Write
 	exist = true
 	return exist, err
 }
+
+func (ima *Imager) LayerReader(ctx context.Context, digstr string) (int64, io.ReadCloser, error) {
+	var reader io.ReadCloser
+	var err error
+	var size int64
+	digobj, err := ocidigest.Parse(digstr)
+	if err != nil {
+		return size, reader, err
+	}
+	subdir := string(digobj.Algorithm())
+	mpath := filepath.Join(ima.place, ocispec.ImageBlobsDir, subdir, digobj.Encoded())
+	stat, err := os.Stat(mpath)
+	if err != nil {
+		return size, reader, err
+	}
+	size = stat.Size()
+	mfile, err := os.OpenFile(mpath, os.O_RDONLY, 0)
+	if err != nil {
+		return size, reader, err
+	}
+	reader = mfile
+	return size, reader, err
+}