Initial commit

vendor/github.com/hyperhq/hypercli/layer/ro_layer.go

@@ -0,0 +1,119 @@
+package layer
+
+import "io"
+
+type roLayer struct {
+	chainID    ChainID
+	diffID     DiffID
+	parent     *roLayer
+	cacheID    string
+	size       int64
+	layerStore *layerStore
+
+	referenceCount int
+	references     map[Layer]struct{}
+}
+
+func (rl *roLayer) TarStream() (io.ReadCloser, error) {
+	r, err := rl.layerStore.store.TarSplitReader(rl.chainID)
+	if err != nil {
+		return nil, err
+	}
+
+	pr, pw := io.Pipe()
+	go func() {
+		err := rl.layerStore.assembleTarTo(rl.cacheID, r, nil, pw)
+		if err != nil {
+			pw.CloseWithError(err)
+		} else {
+			pw.Close()
+		}
+	}()
+	return pr, nil
+}
+
+func (rl *roLayer) ChainID() ChainID {
+	return rl.chainID
+}
+
+func (rl *roLayer) DiffID() DiffID {
+	return rl.diffID
+}
+
+func (rl *roLayer) Parent() Layer {
+	if rl.parent == nil {
+		return nil
+	}
+	return rl.parent
+}
+
+func (rl *roLayer) Size() (size int64, err error) {
+	if rl.parent != nil {
+		size, err = rl.parent.Size()
+		if err != nil {
+			return
+		}
+	}
+
+	return size + rl.size, nil
+}
+
+func (rl *roLayer) DiffSize() (size int64, err error) {
+	return rl.size, nil
+}
+
+func (rl *roLayer) Metadata() (map[string]string, error) {
+	return rl.layerStore.driver.GetMetadata(rl.cacheID)
+}
+
+type referencedCacheLayer struct {
+	*roLayer
+}
+
+func (rl *roLayer) getReference() Layer {
+	ref := &referencedCacheLayer{
+		roLayer: rl,
+	}
+	rl.references[ref] = struct{}{}
+
+	return ref
+}
+
+func (rl *roLayer) hasReference(ref Layer) bool {
+	_, ok := rl.references[ref]
+	return ok
+}
+
+func (rl *roLayer) hasReferences() bool {
+	return len(rl.references) > 0
+}
+
+func (rl *roLayer) deleteReference(ref Layer) {
+	delete(rl.references, ref)
+}
+
+func (rl *roLayer) depth() int {
+	if rl.parent == nil {
+		return 1
+	}
+	return rl.parent.depth() + 1
+}
+
+func storeLayer(tx MetadataTransaction, layer *roLayer) error {
+	if err := tx.SetDiffID(layer.diffID); err != nil {
+		return err
+	}
+	if err := tx.SetSize(layer.size); err != nil {
+		return err
+	}
+	if err := tx.SetCacheID(layer.cacheID); err != nil {
+		return err
+	}
+	if layer.parent != nil {
+		if err := tx.SetParent(layer.parent.chainID); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}