Windows: Remove dead code RegisterDiffIDs

Signed-off-by: John Howard <jhoward@microsoft.com>

layer/layer_windows.go

@@ -2,11 +2,8 @@ package layer
 
 import (
 	"errors"
-	"fmt"
 
-	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/daemon/graphdriver"
-	"github.com/opencontainers/go-digest"
 )
 
 // GetLayerPath returns the path to a layer
@@ -35,59 +32,6 @@ func GetLayerPath(s Store, layer ChainID) (string, error) {
 	return path, nil
 }
 
-func (ls *layerStore) RegisterDiffID(graphID string, size int64) (Layer, error) {
-	var err error // this is used for cleanup in existingLayer case
-	diffID := digest.FromBytes([]byte(graphID))
-
-	// Create new roLayer
-	layer := &roLayer{
-		cacheID:        graphID,
-		diffID:         DiffID(diffID),
-		referenceCount: 1,
-		layerStore:     ls,
-		references:     map[Layer]struct{}{},
-		size:           size,
-	}
-
-	tx, err := ls.store.StartTransaction()
-	if err != nil {
-		return nil, err
-	}
-	defer func() {
-		if err != nil {
-			if err := tx.Cancel(); err != nil {
-				logrus.Errorf("Error canceling metadata transaction %q: %s", tx.String(), err)
-			}
-		}
-	}()
-
-	layer.chainID = createChainIDFromParent("", layer.diffID)
-
-	if !ls.driver.Exists(layer.cacheID) {
-		return nil, fmt.Errorf("layer %q is unknown to driver", layer.cacheID)
-	}
-	if err = storeLayer(tx, layer); err != nil {
-		return nil, err
-	}
-
-	ls.layerL.Lock()
-	defer ls.layerL.Unlock()
-
-	if existingLayer := ls.getWithoutLock(layer.chainID); existingLayer != nil {
-		// Set error for cleanup, but do not return
-		err = errors.New("layer already exists")
-		return existingLayer.getReference(), nil
-	}
-
-	if err = tx.Commit(layer.chainID); err != nil {
-		return nil, err
-	}
-
-	ls.layerMap[layer.chainID] = layer
-
-	return layer.getReference(), nil
-}
-
 func (ls *layerStore) mountID(name string) string {
 	// windows has issues if container ID doesn't match mount ID
 	return name