Merge pull request #36504 from dmcgowan/layer-store-remove-metastore-interface

layer: remove metadata store interface

layer/filestore.go

@@ -37,10 +37,10 @@ type fileMetadataTransaction struct {
 	ws    *ioutils.AtomicWriteSet
 }
 
-// NewFSMetadataStore returns an instance of a metadata store
+// newFSMetadataStore returns an instance of a metadata store
 // which is backed by files on disk using the provided root
 // as the root of metadata files.
-func NewFSMetadataStore(root string) (MetadataStore, error) {
+func newFSMetadataStore(root string) (*fileMetadataStore, error) {
 	if err := os.MkdirAll(root, 0700); err != nil {
 		return nil, err
 	}
@@ -66,7 +66,7 @@ func (fms *fileMetadataStore) getMountFilename(mount, filename string) string {
 	return filepath.Join(fms.getMountDirectory(mount), filename)
 }
 
-func (fms *fileMetadataStore) StartTransaction() (MetadataTransaction, error) {
+func (fms *fileMetadataStore) StartTransaction() (*fileMetadataTransaction, error) {
 	tmpDir := filepath.Join(fms.root, "tmp")
 	if err := os.MkdirAll(tmpDir, 0755); err != nil {
 		return nil, err

layer/filestore_test.go

@@ -24,12 +24,12 @@ func newFileMetadataStore(t *testing.T) (*fileMetadataStore, string, func()) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	fms, err := NewFSMetadataStore(td)
+	fms, err := newFSMetadataStore(td)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	return fms.(*fileMetadataStore), td, func() {
+	return fms, td, func() {
 		if err := os.RemoveAll(td); err != nil {
 			t.Logf("Failed to cleanup %q: %s", td, err)
 		}

layer/layer.go

@@ -201,54 +201,6 @@ type DescribableStore interface {
 	RegisterWithDescriptor(io.Reader, ChainID, distribution.Descriptor) (Layer, error)
 }
 
-// MetadataTransaction represents functions for setting layer metadata
-// with a single transaction.
-type MetadataTransaction interface {
-	SetSize(int64) error
-	SetParent(parent ChainID) error
-	SetDiffID(DiffID) error
-	SetCacheID(string) error
-	SetDescriptor(distribution.Descriptor) error
-	setOS(string) error
-	TarSplitWriter(compressInput bool) (io.WriteCloser, error)
-
-	Commit(ChainID) error
-	Cancel() error
-	String() string
-}
-
-// MetadataStore represents a backend for persisting
-// metadata about layers and providing the metadata
-// for restoring a Store.
-type MetadataStore interface {
-	// StartTransaction starts an update for new metadata
-	// which will be used to represent an ID on commit.
-	StartTransaction() (MetadataTransaction, error)
-
-	GetSize(ChainID) (int64, error)
-	GetParent(ChainID) (ChainID, error)
-	GetDiffID(ChainID) (DiffID, error)
-	GetCacheID(ChainID) (string, error)
-	GetDescriptor(ChainID) (distribution.Descriptor, error)
-	getOS(ChainID) (string, error)
-	TarSplitReader(ChainID) (io.ReadCloser, error)
-
-	SetMountID(string, string) error
-	SetInitID(string, string) error
-	SetMountParent(string, ChainID) error
-
-	GetMountID(string) (string, error)
-	GetInitID(string) (string, error)
-	GetMountParent(string) (ChainID, error)
-
-	// List returns the full list of referenced
-	// read-only and read-write layers
-	List() ([]ChainID, []string, error)
-
-	Remove(ChainID) error
-	RemoveMount(string) error
-}
-
 // CreateChainID returns ID for a layerDigest slice
 func CreateChainID(dgsts []DiffID) ChainID {
 	return createChainIDFromParent("", dgsts...)

layer/layer_store.go

@@ -27,7 +27,7 @@ import (
 const maxLayerDepth = 125
 
 type layerStore struct {
-	store       MetadataStore
+	store       *fileMetadataStore
 	driver      graphdriver.Driver
 	useTarSplit bool
 
@@ -65,18 +65,15 @@ func NewStoreFromOptions(options StoreOptions) (Store, error) {
 	}
 	logrus.Debugf("Initialized graph driver %s", driver)
 
-	fms, err := NewFSMetadataStore(fmt.Sprintf(options.MetadataStorePathTemplate, driver))
-	if err != nil {
-		return nil, err
-	}
+	root := fmt.Sprintf(options.MetadataStorePathTemplate, driver)
 
-	return NewStoreFromGraphDriver(fms, driver, options.OS)
+	return newStoreFromGraphDriver(root, driver, options.OS)
 }
 
-// NewStoreFromGraphDriver creates a new Store instance using the provided
+// newStoreFromGraphDriver creates a new Store instance using the provided
 // metadata store and graph driver. The metadata store will be used to restore
 // the Store.
-func NewStoreFromGraphDriver(store MetadataStore, driver graphdriver.Driver, os string) (Store, error) {
+func newStoreFromGraphDriver(root string, driver graphdriver.Driver, os string) (Store, error) {
 	if !system.IsOSSupported(os) {
 		return nil, fmt.Errorf("failed to initialize layer store as operating system '%s' is not supported", os)
 	}
@@ -85,8 +82,13 @@ func NewStoreFromGraphDriver(store MetadataStore, driver graphdriver.Driver, os
 		caps = capDriver.Capabilities()
 	}
 
+	ms, err := newFSMetadataStore(root)
+	if err != nil {
+		return nil, err
+	}
+
 	ls := &layerStore{
-		store:       store,
+		store:       ms,
 		driver:      driver,
 		layerMap:    map[ChainID]*roLayer{},
 		mounts:      map[string]*mountedLayer{},
@@ -94,7 +96,7 @@ func NewStoreFromGraphDriver(store MetadataStore, driver graphdriver.Driver, os
 		os:          os,
 	}
 
-	ids, mounts, err := store.List()
+	ids, mounts, err := ms.List()
 	if err != nil {
 		return nil, err
 	}
@@ -225,7 +227,7 @@ func (ls *layerStore) loadMount(mount string) error {
 	return nil
 }
 
-func (ls *layerStore) applyTar(tx MetadataTransaction, ts io.Reader, parent string, layer *roLayer) error {
+func (ls *layerStore) applyTar(tx *fileMetadataTransaction, ts io.Reader, parent string, layer *roLayer) error {
 	digester := digest.Canonical.Digester()
 	tr := io.TeeReader(ts, digester.Hash())
 

layer/layer_test.go

@@ -69,11 +69,8 @@ func newTestStore(t *testing.T) (Store, string, func()) {
 	}
 
 	graph, graphcleanup := newTestGraphDriver(t)
-	fms, err := NewFSMetadataStore(td)
-	if err != nil {
-		t.Fatal(err)
-	}
-	ls, err := NewStoreFromGraphDriver(fms, graph, runtime.GOOS)
+
+	ls, err := newStoreFromGraphDriver(td, graph, runtime.GOOS)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -403,7 +400,7 @@ func TestStoreRestore(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	ls2, err := NewStoreFromGraphDriver(ls.(*layerStore).store, ls.(*layerStore).driver, runtime.GOOS)
+	ls2, err := newStoreFromGraphDriver(ls.(*layerStore).store.root, ls.(*layerStore).driver, runtime.GOOS)
 	if err != nil {
 		t.Fatal(err)
 	}

layer/migration_test.go

@@ -90,11 +90,8 @@ func TestLayerMigration(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	fms, err := NewFSMetadataStore(filepath.Join(td, "layers"))
-	if err != nil {
-		t.Fatal(err)
-	}
-	ls, err := NewStoreFromGraphDriver(fms, graph, runtime.GOOS)
+	root := filepath.Join(td, "layers")
+	ls, err := newStoreFromGraphDriver(root, graph, runtime.GOOS)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -218,11 +215,8 @@ func TestLayerMigrationNoTarsplit(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	fms, err := NewFSMetadataStore(filepath.Join(td, "layers"))
-	if err != nil {
-		t.Fatal(err)
-	}
-	ls, err := NewStoreFromGraphDriver(fms, graph, runtime.GOOS)
+	root := filepath.Join(td, "layers")
+	ls, err := newStoreFromGraphDriver(root, graph, runtime.GOOS)
 	if err != nil {
 		t.Fatal(err)
 	}

layer/ro_layer.go

@@ -121,7 +121,7 @@ func (rl *roLayer) depth() int {
 	return rl.parent.depth() + 1
 }
 
-func storeLayer(tx MetadataTransaction, layer *roLayer) error {
+func storeLayer(tx *fileMetadataTransaction, layer *roLayer) error {
 	if err := tx.SetDiffID(layer.diffID); err != nil {
 		return err
 	}