server/buildfile.go -> builder/builder.go; add maintainers file

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
Upstream-commit: 3a177ccd3afdfe481a7248fccb2efe0f2cbdfcca
Component: engine

components/engine/daemon/container.go

@@ -513,7 +513,7 @@ func (container *Container) monitor(callback execdriver.StartCallback) error {
 	if container.daemon != nil && container.daemon.srv != nil && container.daemon.srv.IsRunning() {
 		// FIXME: here is race condition between two RUN instructions in Dockerfile
 		// because they share same runconfig and change image. Must be fixed
-		// in server/buildfile.go
+		// in builder/builder.go
 		if err := container.toDisk(); err != nil {
 			utils.Errorf("Error dumping container %s state to disk: %s\n", container.ID, err)
 		}

components/engine/daemon/daemon.go

@@ -1099,3 +1099,35 @@ func (daemon *Daemon) checkLocaldns() error {
 	}
 	return nil
 }
+
+func (daemon *Daemon) ImageGetCached(imgID string, config *runconfig.Config) (*image.Image, error) {
+	// Retrieve all images
+	images, err := daemon.Graph().Map()
+	if err != nil {
+		return nil, err
+	}
+
+	// Store the tree in a map of map (map[parentId][childId])
+	imageMap := make(map[string]map[string]struct{})
+	for _, img := range images {
+		if _, exists := imageMap[img.Parent]; !exists {
+			imageMap[img.Parent] = make(map[string]struct{})
+		}
+		imageMap[img.Parent][img.ID] = struct{}{}
+	}
+
+	// Loop on the children of the given image and check the config
+	var match *image.Image
+	for elem := range imageMap[imgID] {
+		img, err := daemon.Graph().Get(elem)
+		if err != nil {
+			return nil, err
+		}
+		if runconfig.Compare(&img.ContainerConfig, config) {
+			if match == nil || match.Created.Before(img.Created) {
+				match = img
+			}
+		}
+	}
+	return match, nil
+}