@@ -71,6 +71,16 @@ func createChainIDFromParent(parent layer.ChainID, dgsts ...layer.DiffID) layer.

 	return createChainIDFromParent(layer.ChainID(dgst), dgsts[1:]...)

 }

+func (ls *mockLayerStore) Map() map[layer.ChainID]layer.Layer {

+	layers := map[layer.ChainID]layer.Layer{}

+

+	for k, v := range ls.layers {

+		layers[k] = v

+	}

+

+	return layers

+}

+

 func (ls *mockLayerStore) Register(reader io.Reader, parentID layer.ChainID) (layer.Layer, error) {

 	return ls.RegisterWithDescriptor(reader, parentID, distribution.Descriptor{})

 }

@@ -170,6 +170,7 @@ type MountInit func(root string) error

 type Store interface {

 	Register(io.Reader, ChainID) (Layer, error)

 	Get(ChainID) (Layer, error)

+	Map() map[ChainID]Layer

 	Release(Layer) ([]Metadata, error)

 	CreateRWLayer(id string, parent ChainID, mountLabel string, initFunc MountInit, storageOpt map[string]string) (RWLayer, error)

@@ -360,6 +360,19 @@ func (ls *layerStore) Get(l ChainID) (Layer, error) {

 	return layer.getReference(), nil

 }

+func (ls *layerStore) Map() map[ChainID]Layer {

+	ls.layerL.Lock()

+	defer ls.layerL.Unlock()

+

+	layers := map[ChainID]Layer{}

+

+	for k, v := range ls.layerMap {

+		layers[k] = v

+	}

+

+	return layers

+}

+

 func (ls *layerStore) deleteLayer(layer *roLayer, metadata *Metadata) error {

 	err := ls.driver.Remove(layer.cacheID)

 	if err != nil {