From aaaf3f072601923594754e46c1f0152847d9c2d9 Mon Sep 17 00:00:00 2001
From: "Guillaume J. Charmes" <guillaume.charmes@dotcloud.com>
Date: Wed, 8 May 2013 19:08:11 -0700
Subject: [PATCH] Store the actual archive when commit

---
 graph.go    |  6 +++---
 image.go    | 45 +++++++++++++++++++++++++++++++++++++++++----
 registry.go |  2 +-
 3 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/graph.go b/graph.go
index 84b8c9a1e9..24b8975dbd 100644
--- a/graph.go
+++ b/graph.go
@@ -112,7 +112,7 @@ func (graph *Graph) Create(layerData Archive, container *Container, comment, aut
 		img.Container = container.Id
 		img.ContainerConfig = *container.Config
 	}
-	if err := graph.Register(layerData, img); err != nil {
+	if err := graph.Register(layerData, true, img); err != nil {
 		return nil, err
 	}
 	go img.Checksum()
@@ -121,7 +121,7 @@ func (graph *Graph) Create(layerData Archive, container *Container, comment, aut
 
 // Register imports a pre-existing image into the graph.
 // FIXME: pass img as first argument
-func (graph *Graph) Register(layerData Archive, img *Image) error {
+func (graph *Graph) Register(layerData Archive, store bool, img *Image) error {
 	if err := ValidateId(img.Id); err != nil {
 		return err
 	}
@@ -134,7 +134,7 @@ func (graph *Graph) Register(layerData Archive, img *Image) error {
 	if err != nil {
 		return fmt.Errorf("Mktemp failed: %s", err)
 	}
-	if err := StoreImage(img, layerData, tmp); err != nil {
+	if err := StoreImage(img, layerData, tmp, store); err != nil {
 		return err
 	}
 	// Commit
diff --git a/image.go b/image.go
index d208ed6ce8..55be632880 100644
--- a/image.go
+++ b/image.go
@@ -56,7 +56,7 @@ func LoadImage(root string) (*Image, error) {
 	return img, nil
 }
 
-func StoreImage(img *Image, layerData Archive, root string) error {
+func StoreImage(img *Image, layerData Archive, root string, store bool) error {
 	// Check that root doesn't already exist
 	if _, err := os.Stat(root); err == nil {
 		return fmt.Errorf("Image %s already exists", img.Id)
@@ -68,6 +68,28 @@ func StoreImage(img *Image, layerData Archive, root string) error {
 	if err := os.MkdirAll(layer, 0700); err != nil {
 		return err
 	}
+
+	if store {
+		layerArchive := layerArchivePath(root)
+		file, err := os.OpenFile(layerArchive, os.O_WRONLY|os.O_CREATE, 0600)
+		if err != nil {
+			return err
+		}
+		// FIXME: Retrieve the image layer size from here?
+		if _, err := io.Copy(file, layerData); err != nil {
+			return err
+		}
+		// FIXME: Don't close/open, read/write instead of Copy
+		file.Close()
+
+		file, err = os.Open(layerArchive)
+		if err != nil {
+			return err
+		}
+		defer file.Close()
+		layerData = file
+	}
+
 	if err := Untar(layerData, layer); err != nil {
 		return err
 	}
@@ -86,6 +108,10 @@ func layerPath(root string) string {
 	return path.Join(root, "layer")
 }
 
+func layerArchivePath(root string) string {
+	return path.Join(root, "layer.tar.xz")
+}
+
 func jsonPath(root string) string {
 	return path.Join(root, "json")
 }
@@ -290,9 +316,20 @@ func (img *Image) Checksum() (string, error) {
 		return "", err
 	}
 
-	layerData, err := Tar(layer, Xz)
-	if err != nil {
-		return "", err
+	var layerData io.Reader
+
+	if file, err := os.Open(layerArchivePath(root)); err != nil {
+		if os.IsNotExist(err) {
+			layerData, err = Tar(layer, Xz)
+			if err != nil {
+				return "", err
+			}
+		} else {
+			return "", err
+		}
+	} else {
+		defer file.Close()
+		layerData = file
 	}
 
 	h := sha256.New()
diff --git a/registry.go b/registry.go
index bf6556f6d5..f674b61ebb 100644
--- a/registry.go
+++ b/registry.go
@@ -259,7 +259,7 @@ func (graph *Graph) PullImage(stdout io.Writer, imgId, registry string, token []
 				// FIXME: Keep goging in case of error?
 				return err
 			}
-			if err = graph.Register(layer, img); err != nil {
+			if err = graph.Register(layer, false, img); err != nil {
 				return err
 			}
 		}