Merge pull request #9720 from jlhawn/apply_diff_optimize

Refactor to optimize storage driver ApplyDiff()

daemon/graphdriver/aufs/aufs.go

@@ -312,7 +312,7 @@ func (a *Driver) applyDiff(id string, diff archive.ArchiveReader) error {
 // DiffSize calculates the changes between the specified id
 // and its parent and returns the size in bytes of the changes
 // relative to its base filesystem directory.
-func (a *Driver) DiffSize(id, parent string) (bytes int64, err error) {
+func (a *Driver) DiffSize(id, parent string) (size int64, err error) {
 	// AUFS doesn't need the parent layer to calculate the diff size.
 	return utils.TreeSize(path.Join(a.rootPath(), "diff", id))
 }
@@ -320,7 +320,7 @@ func (a *Driver) DiffSize(id, parent string) (bytes int64, err error) {
 // ApplyDiff extracts the changeset from the given diff into the
 // layer with the specified id and parent, returning the size of the
 // new layer in bytes.
-func (a *Driver) ApplyDiff(id, parent string, diff archive.ArchiveReader) (bytes int64, err error) {
+func (a *Driver) ApplyDiff(id, parent string, diff archive.ArchiveReader) (size int64, err error) {
 	// AUFS doesn't need the parent id to apply the diff.
 	if err = a.applyDiff(id, diff); err != nil {
 		return

daemon/graphdriver/driver.go

@@ -63,11 +63,11 @@ type Driver interface {
 	// ApplyDiff extracts the changeset from the given diff into the
 	// layer with the specified id and parent, returning the size of the
 	// new layer in bytes.
-	ApplyDiff(id, parent string, diff archive.ArchiveReader) (bytes int64, err error)
+	ApplyDiff(id, parent string, diff archive.ArchiveReader) (size int64, err error)
 	// DiffSize calculates the changes between the specified id
 	// and its parent and returns the size in bytes of the changes
 	// relative to its base filesystem directory.
-	DiffSize(id, parent string) (bytes int64, err error)
+	DiffSize(id, parent string) (size int64, err error)
 }
 
 var (

daemon/graphdriver/fsdiff.go

@@ -3,14 +3,12 @@
 package graphdriver
 
 import (
-	"fmt"
 	"time"
 
 	log "github.com/Sirupsen/logrus"
 	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/docker/pkg/chrootarchive"
 	"github.com/docker/docker/pkg/ioutils"
-	"github.com/docker/docker/utils"
 )
 
 // naiveDiffDriver takes a ProtoDriver and adds the
@@ -27,8 +25,8 @@ type naiveDiffDriver struct {
 // it may or may not support on its own:
 //     Diff(id, parent string) (archive.Archive, error)
 //     Changes(id, parent string) ([]archive.Change, error)
-//     ApplyDiff(id, parent string, diff archive.ArchiveReader) (bytes int64, err error)
-//     DiffSize(id, parent string) (bytes int64, err error)
+//     ApplyDiff(id, parent string, diff archive.ArchiveReader) (size int64, err error)
+//     DiffSize(id, parent string) (size int64, err error)
 func NaiveDiffDriver(driver ProtoDriver) Driver {
 	return &naiveDiffDriver{ProtoDriver: driver}
 }
@@ -111,7 +109,7 @@ func (gdw *naiveDiffDriver) Changes(id, parent string) ([]archive.Change, error)
 // ApplyDiff extracts the changeset from the given diff into the
 // layer with the specified id and parent, returning the size of the
 // new layer in bytes.
-func (gdw *naiveDiffDriver) ApplyDiff(id, parent string, diff archive.ArchiveReader) (bytes int64, err error) {
+func (gdw *naiveDiffDriver) ApplyDiff(id, parent string, diff archive.ArchiveReader) (size int64, err error) {
 	driver := gdw.ProtoDriver
 
 	// Mount the root filesystem so we can apply the diff/layer.
@@ -123,34 +121,18 @@ func (gdw *naiveDiffDriver) ApplyDiff(id, parent string, diff archive.ArchiveRea
 
 	start := time.Now().UTC()
 	log.Debugf("Start untar layer")
-	if err = chrootarchive.ApplyLayer(layerFs, diff); err != nil {
+	if size, err = chrootarchive.ApplyLayer(layerFs, diff); err != nil {
 		return
 	}
 	log.Debugf("Untar time: %vs", time.Now().UTC().Sub(start).Seconds())
 
-	if parent == "" {
-		return utils.TreeSize(layerFs)
-	}
-
-	parentFs, err := driver.Get(parent, "")
-	if err != nil {
-		err = fmt.Errorf("Driver %s failed to get image parent %s: %s", driver, parent, err)
-		return
-	}
-	defer driver.Put(parent)
-
-	changes, err := archive.ChangesDirs(layerFs, parentFs)
-	if err != nil {
-		return
-	}
-
-	return archive.ChangesSize(layerFs, changes), nil
+	return
 }
 
 // DiffSize calculates the changes between the specified layer
 // and its parent and returns the size in bytes of the changes
 // relative to its base filesystem directory.
-func (gdw *naiveDiffDriver) DiffSize(id, parent string) (bytes int64, err error) {
+func (gdw *naiveDiffDriver) DiffSize(id, parent string) (size int64, err error) {
 	driver := gdw.ProtoDriver
 
 	changes, err := gdw.Changes(id, parent)

daemon/graphdriver/overlay/overlay.go

@@ -28,7 +28,7 @@ var (
 
 type ApplyDiffProtoDriver interface {
 	graphdriver.ProtoDriver
-	ApplyDiff(id, parent string, diff archive.ArchiveReader) (bytes int64, err error)
+	ApplyDiff(id, parent string, diff archive.ArchiveReader) (size int64, err error)
 }
 
 type naiveDiffDriverWithApply struct {
@@ -309,7 +309,7 @@ func (d *Driver) Put(id string) {
 	delete(d.active, id)
 }
 
-func (d *Driver) ApplyDiff(id string, parent string, diff archive.ArchiveReader) (bytes int64, err error) {
+func (d *Driver) ApplyDiff(id string, parent string, diff archive.ArchiveReader) (size int64, err error) {
 	dir := d.dir(id)
 
 	if parent == "" {
@@ -347,7 +347,7 @@ func (d *Driver) ApplyDiff(id string, parent string, diff archive.ArchiveReader)
 		return 0, err
 	}
 
-	if err := chrootarchive.ApplyLayer(tmpRootDir, diff); err != nil {
+	if size, err = chrootarchive.ApplyLayer(tmpRootDir, diff); err != nil {
 		return 0, err
 	}
 
@@ -356,12 +356,7 @@ func (d *Driver) ApplyDiff(id string, parent string, diff archive.ArchiveReader)
 		return 0, err
 	}
 
-	changes, err := archive.ChangesDirs(rootDir, parentRootDir)
-	if err != nil {
-		return 0, err
-	}
-
-	return archive.ChangesSize(rootDir, changes), nil
+	return
 }
 
 func (d *Driver) Exists(id string) bool {

pkg/archive/changes_test.go

@@ -286,7 +286,7 @@ func TestApplyLayer(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if err := ApplyLayer(src, layerCopy); err != nil {
+	if _, err := ApplyLayer(src, layerCopy); err != nil {
 		t.Fatal(err)
 	}
 

pkg/archive/diff.go

@@ -15,7 +15,7 @@ import (
 	"github.com/docker/docker/pkg/system"
 )
 
-func UnpackLayer(dest string, layer ArchiveReader) error {
+func UnpackLayer(dest string, layer ArchiveReader) (size int64, err error) {
 	tr := tar.NewReader(layer)
 	trBuf := pools.BufioReader32KPool.Get(tr)
 	defer pools.BufioReader32KPool.Put(trBuf)
@@ -33,9 +33,11 @@ func UnpackLayer(dest string, layer ArchiveReader) error {
 			break
 		}
 		if err != nil {
-			return err
+			return 0, err
 		}
 
+		size += hdr.Size
+
 		// Normalize name, for safety and for a simple is-root check
 		hdr.Name = filepath.Clean(hdr.Name)
 
@@ -48,7 +50,7 @@ func UnpackLayer(dest string, layer ArchiveReader) error {
 			if _, err := os.Lstat(parentPath); err != nil && os.IsNotExist(err) {
 				err = os.MkdirAll(parentPath, 0600)
 				if err != nil {
-					return err
+					return 0, err
 				}
 			}
 		}
@@ -63,12 +65,12 @@ func UnpackLayer(dest string, layer ArchiveReader) error {
 				aufsHardlinks[basename] = hdr
 				if aufsTempdir == "" {
 					if aufsTempdir, err = ioutil.TempDir("", "dockerplnk"); err != nil {
-						return err
+						return 0, err
 					}
 					defer os.RemoveAll(aufsTempdir)
 				}
 				if err := createTarFile(filepath.Join(aufsTempdir, basename), dest, hdr, tr, true); err != nil {
-					return err
+					return 0, err
 				}
 			}
 			continue
@@ -77,10 +79,10 @@ func UnpackLayer(dest string, layer ArchiveReader) error {
 		path := filepath.Join(dest, hdr.Name)
 		rel, err := filepath.Rel(dest, path)
 		if err != nil {
-			return err
+			return 0, err
 		}
 		if strings.HasPrefix(rel, "..") {
-			return breakoutError(fmt.Errorf("%q is outside of %q", hdr.Name, dest))
+			return 0, breakoutError(fmt.Errorf("%q is outside of %q", hdr.Name, dest))
 		}
 		base := filepath.Base(path)
 
@@ -88,7 +90,7 @@ func UnpackLayer(dest string, layer ArchiveReader) error {
 			originalBase := base[len(".wh."):]
 			originalPath := filepath.Join(filepath.Dir(path), originalBase)
 			if err := os.RemoveAll(originalPath); err != nil {
-				return err
+				return 0, err
 			}
 		} else {
 			// If path exits we almost always just want to remove and replace it.
@@ -98,7 +100,7 @@ func UnpackLayer(dest string, layer ArchiveReader) error {
 			if fi, err := os.Lstat(path); err == nil {
 				if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) {
 					if err := os.RemoveAll(path); err != nil {
-						return err
+						return 0, err
 					}
 				}
 			}
@@ -113,18 +115,18 @@ func UnpackLayer(dest string, layer ArchiveReader) error {
 				linkBasename := filepath.Base(hdr.Linkname)
 				srcHdr = aufsHardlinks[linkBasename]
 				if srcHdr == nil {
-					return fmt.Errorf("Invalid aufs hardlink")
+					return 0, fmt.Errorf("Invalid aufs hardlink")
 				}
 				tmpFile, err := os.Open(filepath.Join(aufsTempdir, linkBasename))
 				if err != nil {
-					return err
+					return 0, err
 				}
 				defer tmpFile.Close()
 				srcData = tmpFile
 			}
 
 			if err := createTarFile(path, dest, srcHdr, srcData, true); err != nil {
-				return err
+				return 0, err
 			}
 
 			// Directory mtimes must be handled at the end to avoid further
@@ -139,27 +141,29 @@ func UnpackLayer(dest string, layer ArchiveReader) error {
 		path := filepath.Join(dest, hdr.Name)
 		ts := []syscall.Timespec{timeToTimespec(hdr.AccessTime), timeToTimespec(hdr.ModTime)}
 		if err := syscall.UtimesNano(path, ts); err != nil {
-			return err
+			return 0, err
 		}
 	}
-	return nil
+
+	return size, nil
 }
 
 // ApplyLayer parses a diff in the standard layer format from `layer`, and
-// applies it to the directory `dest`.
-func ApplyLayer(dest string, layer ArchiveReader) error {
+// applies it to the directory `dest`. Returns the size in bytes of the
+// contents of the layer.
+func ApplyLayer(dest string, layer ArchiveReader) (int64, error) {
 	dest = filepath.Clean(dest)
 
 	// We need to be able to set any perms
 	oldmask, err := system.Umask(0)
 	if err != nil {
-		return err
+		return 0, err
 	}
 	defer system.Umask(oldmask) // ignore err, ErrNotSupportedPlatform
 
 	layer, err = DecompressStream(layer)
 	if err != nil {
-		return err
+		return 0, err
 	}
 	return UnpackLayer(dest, layer)
 }

pkg/archive/utils_test.go

@@ -17,7 +17,8 @@ var testUntarFns = map[string]func(string, io.Reader) error{
 		return Untar(r, dest, nil)
 	},
 	"applylayer": func(dest string, r io.Reader) error {
-		return ApplyLayer(dest, ArchiveReader(r))
+		_, err := ApplyLayer(dest, ArchiveReader(r))
+		return err
 	},
 }
 

pkg/chrootarchive/archive_test.go

@@ -95,7 +95,7 @@ func TestChrootApplyEmptyArchiveFromSlowReader(t *testing.T) {
 		t.Fatal(err)
 	}
 	stream := &slowEmptyTarReader{size: 10240, chunkSize: 1024}
-	if err := ApplyLayer(dest, stream); err != nil {
+	if _, err := ApplyLayer(dest, stream); err != nil {
 		t.Fatal(err)
 	}
 }

pkg/chrootarchive/diff.go

@@ -1,6 +1,8 @@
 package chrootarchive
 
 import (
+	"bytes"
+	"encoding/json"
 	"flag"
 	"fmt"
 	"io"
@@ -14,6 +16,10 @@ import (
 	"github.com/docker/docker/pkg/reexec"
 )
 
+type applyLayerResponse struct {
+	LayerSize int64 `json:"layerSize"`
+}
+
 func applyLayer() {
 	runtime.LockOSThread()
 	flag.Parse()
@@ -21,6 +27,7 @@ func applyLayer() {
 	if err := chroot(flag.Arg(0)); err != nil {
 		fatal(err)
 	}
+
 	// We need to be able to set any perms
 	oldmask := syscall.Umask(0)
 	defer syscall.Umask(oldmask)
@@ -28,33 +35,53 @@ func applyLayer() {
 	if err != nil {
 		fatal(err)
 	}
+
 	os.Setenv("TMPDIR", tmpDir)
-	err = archive.UnpackLayer("/", os.Stdin)
+	size, err := archive.UnpackLayer("/", os.Stdin)
 	os.RemoveAll(tmpDir)
 	if err != nil {
 		fatal(err)
 	}
-	os.RemoveAll(tmpDir)
+
+	encoder := json.NewEncoder(os.Stdout)
+	if err := encoder.Encode(applyLayerResponse{size}); err != nil {
+		fatal(fmt.Errorf("unable to encode layerSize JSON: %s", err))
+	}
+
+	flush(os.Stdout)
 	flush(os.Stdin)
 	os.Exit(0)
 }
 
-func ApplyLayer(dest string, layer archive.ArchiveReader) error {
+func ApplyLayer(dest string, layer archive.ArchiveReader) (size int64, err error) {
 	dest = filepath.Clean(dest)
 	decompressed, err := archive.DecompressStream(layer)
 	if err != nil {
-		return err
+		return 0, err
 	}
+
 	defer func() {
 		if c, ok := decompressed.(io.Closer); ok {
 			c.Close()
 		}
 	}()
+
 	cmd := reexec.Command("docker-applyLayer", dest)
 	cmd.Stdin = decompressed
-	out, err := cmd.CombinedOutput()
-	if err != nil {
-		return fmt.Errorf("ApplyLayer %s %s", err, out)
+
+	outBuf, errBuf := new(bytes.Buffer), new(bytes.Buffer)
+	cmd.Stdout, cmd.Stderr = outBuf, errBuf
+
+	if err = cmd.Run(); err != nil {
+		return 0, fmt.Errorf("ApplyLayer %s stdout: %s stderr: %s", err, outBuf, errBuf)
+	}
+
+	// Stdout should be a valid JSON struct representing an applyLayerResponse.
+	response := applyLayerResponse{}
+	decoder := json.NewDecoder(outBuf)
+	if err = decoder.Decode(&response); err != nil {
+		return 0, fmt.Errorf("unable to decode ApplyLayer JSON response: %s", err)
 	}
-	return nil
+
+	return response.LayerSize, nil
 }