From 08a87d4b3b3f76ac9d73309b1042aa75d6634ed9 Mon Sep 17 00:00:00 2001
From: "Guillaume J. Charmes" <guillaume@dotcloud.com>
Date: Mon, 8 Jul 2013 13:30:03 -0700
Subject: [PATCH] Fix #1162 - Remove bufio from Untar

---
 archive.go | 24 ++++++++++++++----------
 image.go   |  3 +++
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/archive.go b/archive.go
index c9a650cb8d..01af86006f 100644
--- a/archive.go
+++ b/archive.go
@@ -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"}
diff --git a/image.go b/image.go
index bb6598b262..e1b1ac0418 100644
--- a/image.go
+++ b/image.go
@@ -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)