new file mode 100644

@@ -0,0 +1,97 @@

+// +build ignore

+

+// Simple tool to create an archive stream from an old and new directory

+//

+// By default it will stream the comparison of two temporary directories with junk files

+package main

+

+import (

+	"flag"

+	"fmt"

+	"io"

+	"io/ioutil"

+	"os"

+	"path"

+

+	"github.com/Sirupsen/logrus"

+	"github.com/docker/docker/pkg/archive"

+)

+

+var (

+	flDebug  = flag.Bool("D", false, "debugging output")

+	flNewDir = flag.String("newdir", "", "")

+	flOldDir = flag.String("olddir", "", "")

+	log      = logrus.New()

+)

+

+func main() {

+	flag.Usage = func() {

+		fmt.Println("Produce a tar from comparing two directory paths. By default a demo tar is created of around 200 files (including hardlinks)")

+		fmt.Printf("%s [OPTIONS]\n", os.Args[0])

+		flag.PrintDefaults()

+	}

+	flag.Parse()

+	log.Out = os.Stderr

+	if (len(os.Getenv("DEBUG")) > 0) || *flDebug {

+		logrus.SetLevel(logrus.DebugLevel)

+	}

+	var newDir, oldDir string

+

+	if len(*flNewDir) == 0 {

+		var err error

+		newDir, err = ioutil.TempDir("", "docker-test-newDir")

+		if err != nil {

+			log.Fatal(err)

+		}

+		defer os.RemoveAll(newDir)

+		if _, err := prepareUntarSourceDirectory(100, newDir, true); err != nil {

+			log.Fatal(err)

+		}

+	} else {

+		newDir = *flNewDir

+	}

+

+	if len(*flOldDir) == 0 {

+		oldDir, err := ioutil.TempDir("", "docker-test-oldDir")

+		if err != nil {

+			log.Fatal(err)

+		}

+		defer os.RemoveAll(oldDir)

+	} else {

+		oldDir = *flOldDir

+	}

+

+	changes, err := archive.ChangesDirs(newDir, oldDir)

+	if err != nil {

+		log.Fatal(err)

+	}

+

+	a, err := archive.ExportChanges(newDir, changes)

+	if err != nil {

+		log.Fatal(err)

+	}

+	defer a.Close()

+

+	i, err := io.Copy(os.Stdout, a)

+	if err != nil && err != io.EOF {

+		log.Fatal(err)

+	}

+	fmt.Fprintf(os.Stderr, "wrote archive of %d bytes", i)

+}

+

+func prepareUntarSourceDirectory(numberOfFiles int, targetPath string, makeLinks bool) (int, error) {

+	fileData := []byte("fooo")

+	for n := 0; n < numberOfFiles; n++ {

+		fileName := fmt.Sprintf("file-%d", n)

+		if err := ioutil.WriteFile(path.Join(targetPath, fileName), fileData, 0700); err != nil {

+			return 0, err

+		}

+		if makeLinks {

+			if err := os.Link(path.Join(targetPath, fileName), path.Join(targetPath, fileName+"-link")); err != nil {

+				return 0, err

+			}

+		}

+	}

+	totalSize := numberOfFiles * len(fileData)

+	return totalSize, nil

+}