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)
}
// Diff produces an archive of the changes between the specified
// layer and its parent layer which may be "".
func (gdw *naiveDiffDriver) Diff(id, parent string) (arch archive.Archive, err error) {
driver := gdw.ProtoDriver
layerFs, err := driver.Get(id, "")
if err != nil {
return nil, err
}
defer func() {
if err != nil {
driver.Put(id)
}
}()
if parent == "" {
archive, err := archive.Tar(layerFs, archive.Uncompressed)
if err != nil {
return nil, err
}
return ioutils.NewReadCloserWrapper(archive, func() error {
err := archive.Close()
driver.Put(id)
return err
}), nil
}
parentFs, err := driver.Get(parent, "")
if err != nil {
return nil, err
}
defer driver.Put(parent)
changes, err := archive.ChangesDirs(layerFs, parentFs)
if err != nil {
return nil, err
}
archive, err := archive.ExportChanges(layerFs, changes)
if err != nil {
return nil, err
}
return ioutils.NewReadCloserWrapper(archive, func() error {
err := archive.Close()
driver.Put(id)
return err
}), nil
}