@@ -2,7 +2,6 @@ package docker

 import (

 	"archive/tar"

-	"bufio"

 	"bytes"

 	"fmt"

 	"github.com/dotcloud/docker/utils"

@@ -26,10 +25,6 @@ const (

 )

 func DetectCompression(source []byte) Compression {

-	for _, c := range source[:10] {

-		utils.Debugf("%x", c)

-	}

-

 	sourceLen := len(source)

 	for compression, m := range map[Compression][]byte{

 		Bzip2: {0x42, 0x5A, 0x68},

@@ -110,17 +105,26 @@ func Untar(archive io.Reader, path string) error {

 	if archive == nil {

 		return fmt.Errorf("Empty archive")

 	}

-	bufferedArchive := bufio.NewReaderSize(archive, 10)

-	buf, err := bufferedArchive.Peek(10)

-	if err != nil {

-		return err

+

+	buf := make([]byte, 10)

+	totalN := 0

+	for totalN < 10 {

+		if n, err := archive.Read(buf[totalN:]); err != nil {

+			if err == io.EOF {

+				return fmt.Errorf("Tarball too short")

+			}

+			return err

+		} else {

+			totalN += n

+			utils.Debugf("[tar autodetect] n: %d", n)

+		}

 	}

 	compression := DetectCompression(buf)

 	utils.Debugf("Archive compression detected: %s", compression.Extension())

 	cmd := exec.Command("tar", "--numeric-owner", "-f", "-", "-C", path, "-x"+compression.Flag())

-	cmd.Stdin = bufferedArchive

+	cmd.Stdin = io.MultiReader(bytes.NewReader(buf), archive)

 	// Hardcode locale environment for predictable outcome regardless of host configuration.

 	//   (see https://github.com/dotcloud/docker/issues/355)

 	cmd.Env = []string{"LANG=en_US.utf-8", "LC_ALL=en_US.utf-8"}

@@ -94,9 +94,12 @@ func StoreImage(img *Image, layerData Archive, root string, store bool) error {

 	}

 	// If layerData is not nil, unpack it into the new layer

 	if layerData != nil {

+		start := time.Now()

+		utils.Debugf("Start untar layer")

 		if err := Untar(layerData, layer); err != nil {

 			return err

 		}

+		utils.Debugf("Untar time: %vs\n", time.Now().Sub(start).Seconds())

 	}

 	return StoreSize(img, root)