Add support for label storage in local content store

Allows running tests which require labels on the content store

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

content/local/store.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -27,6 +28,19 @@ var (
 	}
 )
 
+// LabelStore is used to store mutable labels for digests
+type LabelStore interface {
+	// Get returns all the labels for the given digest
+	Get(digest.Digest) (map[string]string, error)
+
+	// Set sets all the labels for a given digest
+	Set(digest.Digest, map[string]string) error
+
+	// Update replaces the given labels for a digest,
+	// a key with an empty value removes a label.
+	Update(digest.Digest, map[string]string) (map[string]string, error)
+}
+
 // Store is digest-keyed store for content. All data written into the store is
 // stored under a verifiable digest.
 //
@@ -34,16 +48,27 @@ var (
 // including resumable ingest.
 type store struct {
 	root string
+	ls   LabelStore
 }
 
 // NewStore returns a local content store
 func NewStore(root string) (content.Store, error) {
+	return NewLabeledStore(root, nil)
+}
+
+// NewLabeledStore returns a new content store using the provided label store
+//
+// Note: content stores which are used underneath a metadata store may not
+// require labels and should use `NewStore`. `NewLabeledStore` is primarily
+// useful for tests or standalone implementations.
+func NewLabeledStore(root string, ls LabelStore) (content.Store, error) {
 	if err := os.MkdirAll(filepath.Join(root, "ingest"), 0777); err != nil && !os.IsExist(err) {
 		return nil, err
 	}
 
 	return &store{
 		root: root,
+		ls:   ls,
 	}, nil
 }
 
@@ -57,16 +82,23 @@ func (s *store) Info(ctx context.Context, dgst digest.Digest) (content.Info, err
 
 		return content.Info{}, err
 	}
-
-	return s.info(dgst, fi), nil
+	var labels map[string]string
+	if s.ls != nil {
+		labels, err = s.ls.Get(dgst)
+		if err != nil {
+			return content.Info{}, err
+		}
+	}
+	return s.info(dgst, fi, labels), nil
 }
 
-func (s *store) info(dgst digest.Digest, fi os.FileInfo) content.Info {
+func (s *store) info(dgst digest.Digest, fi os.FileInfo, labels map[string]string) content.Info {
 	return content.Info{
 		Digest:    dgst,
 		Size:      fi.Size(),
 		CreatedAt: fi.ModTime(),
-		UpdatedAt: fi.ModTime(),
+		UpdatedAt: getATime(fi),
+		Labels:    labels,
 	}
 }
 
@@ -111,8 +143,66 @@ func (s *store) Delete(ctx context.Context, dgst digest.Digest) error {
 }
 
 func (s *store) Update(ctx context.Context, info content.Info, fieldpaths ...string) (content.Info, error) {
-	// TODO: Support persisting and updating mutable content data
-	return content.Info{}, errors.Wrapf(errdefs.ErrFailedPrecondition, "update not supported on immutable content store")
+	if s.ls == nil {
+		return content.Info{}, errors.Wrapf(errdefs.ErrFailedPrecondition, "update not supported on immutable content store")
+	}
+
+	p := s.blobPath(info.Digest)
+	fi, err := os.Stat(p)
+	if err != nil {
+		if os.IsNotExist(err) {
+			err = errors.Wrapf(errdefs.ErrNotFound, "content %v", info.Digest)
+		}
+
+		return content.Info{}, err
+	}
+
+	var (
+		all    bool
+		labels map[string]string
+	)
+	if len(fieldpaths) > 0 {
+		for _, path := range fieldpaths {
+			if strings.HasPrefix(path, "labels.") {
+				if labels == nil {
+					labels = map[string]string{}
+				}
+
+				key := strings.TrimPrefix(path, "labels.")
+				labels[key] = info.Labels[key]
+				continue
+			}
+
+			switch path {
+			case "labels":
+				all = true
+				labels = info.Labels
+			default:
+				return content.Info{}, errors.Wrapf(errdefs.ErrInvalidArgument, "cannot update %q field on content info %q", path, info.Digest)
+			}
+		}
+	} else {
+		all = true
+		labels = info.Labels
+	}
+
+	if all {
+		err = s.ls.Set(info.Digest, labels)
+	} else {
+		labels, err = s.ls.Update(info.Digest, labels)
+	}
+	if err != nil {
+		return content.Info{}, err
+	}
+
+	info = s.info(info.Digest, fi, labels)
+	info.UpdatedAt = time.Now()
+
+	if err := os.Chtimes(p, info.UpdatedAt, info.CreatedAt); err != nil {
+		log.G(ctx).WithError(err).Warnf("could not change access time for %s", info.Digest)
+	}
+
+	return info, nil
 }
 
 func (s *store) Walk(ctx context.Context, fn content.WalkFunc, filters ...string) error {
@@ -154,7 +244,14 @@ func (s *store) Walk(ctx context.Context, fn content.WalkFunc, filters ...string
 			// store or extra paths not expected previously.
 		}
 
-		return fn(s.info(dgst, fi))
+		var labels map[string]string
+		if s.ls != nil {
+			labels, err = s.ls.Get(dgst)
+			if err != nil {
+				return err
+			}
+		}
+		return fn(s.info(dgst, fi, labels))
 	})
 }
 

content/local/store_test.go

@@ -14,6 +14,7 @@ import (
 	"path/filepath"
 	"reflect"
 	"runtime"
+	"sync"
 	"testing"
 	"time"
 
@@ -23,9 +24,55 @@ import (
 	"github.com/opencontainers/go-digest"
 )
 
+type memoryLabelStore struct {
+	l      sync.Mutex
+	labels map[digest.Digest]map[string]string
+}
+
+func newMemoryLabelStore() LabelStore {
+	return &memoryLabelStore{
+		labels: map[digest.Digest]map[string]string{},
+	}
+}
+
+func (mls *memoryLabelStore) Get(d digest.Digest) (map[string]string, error) {
+	mls.l.Lock()
+	labels := mls.labels[d]
+	mls.l.Unlock()
+
+	return labels, nil
+}
+
+func (mls *memoryLabelStore) Set(d digest.Digest, labels map[string]string) error {
+	mls.l.Lock()
+	mls.labels[d] = labels
+	mls.l.Unlock()
+
+	return nil
+}
+
+func (mls *memoryLabelStore) Update(d digest.Digest, update map[string]string) (map[string]string, error) {
+	mls.l.Lock()
+	labels, ok := mls.labels[d]
+	if !ok {
+		labels = map[string]string{}
+	}
+	for k, v := range update {
+		if v == "" {
+			delete(labels, k)
+		} else {
+			labels[k] = v
+		}
+	}
+	mls.labels[d] = labels
+	mls.l.Unlock()
+
+	return labels, nil
+}
+
 func TestContent(t *testing.T) {
 	testsuite.ContentSuite(t, "fs", func(ctx context.Context, root string) (content.Store, func() error, error) {
-		cs, err := NewStore(root)
+		cs, err := NewLabeledStore(root, newMemoryLabelStore())
 		if err != nil {
 			return nil, nil, err
 		}

content/local/store_unix.go

@@ -18,3 +18,12 @@ func getStartTime(fi os.FileInfo) time.Time {
 
 	return fi.ModTime()
 }
+
+func getATime(fi os.FileInfo) time.Time {
+	if st, ok := fi.Sys().(*syscall.Stat_t); ok {
+		return time.Unix(int64(sys.StatAtime(st).Sec),
+			int64(sys.StatAtime(st).Nsec))
+	}
+
+	return fi.ModTime()
+}

content/local/store_windows.go

@@ -8,3 +8,7 @@ import (
 func getStartTime(fi os.FileInfo) time.Time {
 	return fi.ModTime()
 }
+
+func getATime(fi os.FileInfo) time.Time {
+	return fi.ModTime()
+}

content/local/writer.go

@@ -56,6 +56,13 @@ func (w *writer) Write(p []byte) (n int, err error) {
 }
 
 func (w *writer) Commit(ctx context.Context, size int64, expected digest.Digest, opts ...content.Opt) error {
+	var base content.Info
+	for _, opt := range opts {
+		if err := opt(&base); err != nil {
+			return err
+		}
+	}
+
 	if w.fp == nil {
 		return errors.Wrap(errdefs.ErrFailedPrecondition, "cannot commit on closed writer")
 	}
@@ -123,6 +130,12 @@ func (w *writer) Commit(ctx context.Context, size int64, expected digest.Digest,
 	w.fp = nil
 	unlock(w.ref)
 
+	if w.s.ls != nil && base.Labels != nil {
+		if err := w.s.ls.Set(dgst, base.Labels); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 

content/testsuite/testsuite.go

@@ -21,12 +21,6 @@ import (
 func ContentSuite(t *testing.T, name string, storeFn func(ctx context.Context, root string) (content.Store, func() error, error)) {
 	t.Run("Writer", makeTest(t, name, storeFn, checkContentStoreWriter))
 	t.Run("UploadStatus", makeTest(t, name, storeFn, checkUploadStatus))
-}
-
-// ContentLabelSuite runs a test suite for the content store supporting
-// labels.
-// TODO: Merge this with ContentSuite once all content stores support labels
-func ContentLabelSuite(t *testing.T, name string, storeFn func(ctx context.Context, root string) (content.Store, func() error, error)) {
 	t.Run("Labels", makeTest(t, name, storeFn, checkLabels))
 }
 

content_test.go

@@ -39,5 +39,4 @@ func TestContentClient(t *testing.T) {
 		t.Skip()
 	}
 	testsuite.ContentSuite(t, "ContentClient", newContentStore)
-	testsuite.ContentLabelSuite(t, "ContentClient", newContentStore)
 }

metadata/content_test.go

@@ -30,5 +30,4 @@ func createContentStore(ctx context.Context, root string) (content.Store, func()
 
 func TestContent(t *testing.T) {
 	testsuite.ContentSuite(t, "metadata", createContentStore)
-	testsuite.ContentLabelSuite(t, "metadata", createContentStore)
 }