// ApplyDiff applies the new layer on top of the root, if parent does not exist with will return a ErrApplyDiffFallback error.
func (d *Driver) ApplyDiff(id string, parent string, diff archive.Reader) (size int64, err error) {
dir := d.dir(id)
if parent == "" {
return 0, ErrApplyDiffFallback
}
parentRootDir := path.Join(d.dir(parent), "root")
if _, err := os.Stat(parentRootDir); err != nil {
return 0, ErrApplyDiffFallback
}
// We now know there is a parent, and it has a "root" directory containing
// the full root filesystem. We can just hardlink it and apply the
// layer. This relies on two things:
// 1) ApplyDiff is only run once on a clean (no writes to upper layer) container
// 2) ApplyDiff doesn't do any in-place writes to files (would break hardlinks)
// These are all currently true and are not expected to break
tmpRootDir, err := ioutil.TempDir(dir, "tmproot")
if err != nil {
return 0, err
}
defer func() {
if err != nil {
os.RemoveAll(tmpRootDir)
} else {
os.RemoveAll(path.Join(dir, "upper"))
os.RemoveAll(path.Join(dir, "work"))
os.RemoveAll(path.Join(dir, "merged"))
os.RemoveAll(path.Join(dir, "lower-id"))
}
}()
if err = copyDir(parentRootDir, tmpRootDir, copyHardlink); err != nil {
return 0, err
}
options := &archive.TarOptions{UIDMaps: d.uidMaps, GIDMaps: d.gidMaps}
if size, err = chrootarchive.ApplyUncompressedLayer(tmpRootDir, diff, options); err != nil {
return 0, err
}
rootDir := path.Join(dir, "root")
if err := os.Rename(tmpRootDir, rootDir); err != nil {
return 0, err
}
return
}
// 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.
// The layer should not be mounted when calling this function
func (d *Driver) ApplyDiff(id, parent string, diff archive.Reader) (int64, error) {
if d.info.Flavour == diffDriver {
start := time.Now().UTC()
logrus.Debugf("WindowsGraphDriver ApplyDiff: Start untar layer")
destination := d.dir(id)
destination = filepath.Dir(destination)
size, err := chrootarchive.ApplyUncompressedLayer(destination, diff, nil)
if err != nil {
return 0, err
}
logrus.Debugf("WindowsGraphDriver ApplyDiff: Untar time: %vs", time.Now().UTC().Sub(start).Seconds())
return size, nil
}
var layerChain []string
if parent != "" {
rPId, err := d.resolveID(parent)
if err != nil {
return 0, err
}
parentChain, err := d.getLayerChain(rPId)
if err != nil {
return 0, err
}
parentPath, err := hcsshim.GetLayerMountPath(d.info, rPId)
if err != nil {
return 0, err
}
layerChain = append(layerChain, parentPath)
layerChain = append(layerChain, parentChain...)
}
size, err := d.importLayer(id, diff, layerChain)
if err != nil {
return 0, err
}
if err = d.setLayerChain(id, layerChain); err != nil {
return 0, err
}
return size, nil
}
// 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.Reader) (size int64, err error) {
driver := gdw.ProtoDriver
// Mount the root filesystem so we can apply the diff/layer.
layerFs, err := driver.Get(id, "")
if err != nil {
return
}
defer driver.Put(id)
start := time.Now().UTC()
logrus.Debugf("Start untar layer")
if size, err = chrootarchive.ApplyUncompressedLayer(layerFs, diff); err != nil {
return
}
logrus.Debugf("Untar time: %vs", time.Now().UTC().Sub(start).Seconds())
return
}