Refactor common boltdb fields to subpackage

Moves label and timestamp bolt functions to subpackage
for use outside the metadata package without importing
metadata package.

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

metadata/boltutil/helpers.go

@@ -1,4 +1,4 @@
-package metadata
+package boltutil
 
 import (
 	"time"
@@ -7,19 +7,36 @@ import (
 	"github.com/pkg/errors"
 )
 
-func readLabels(m map[string]string, bkt *bolt.Bucket) error {
+var (
-	return bkt.ForEach(func(k, v []byte) error {
+	bucketKeyLabels    = []byte("labels")
-		m[string(k)] = string(v)
+	bucketKeyCreatedAt = []byte("createdat")
+	bucketKeyUpdatedAt = []byte("updatedat")
+)
+
+// ReadLabels reads the labels key from the bucket
+// Uses the key "labels"
+func ReadLabels(bkt *bolt.Bucket) (map[string]string, error) {
+	lbkt := bkt.Bucket(bucketKeyLabels)
+	if lbkt == nil {
+		return nil, nil
+	}
+	labels := map[string]string{}
+	if err := lbkt.ForEach(func(k, v []byte) error {
+		labels[string(k)] = string(v)
 		return nil
-	})
+	}); err != nil {
+		return nil, err
+	}
+	return labels, nil
 }
 
-// writeLabels will write a new labels bucket to the provided bucket at key
+// WriteLabels will write a new labels bucket to the provided bucket at key
 // bucketKeyLabels, replacing the contents of the bucket with the provided map.
 //
 // The provide map labels will be modified to have the final contents of the
 // bucket. Typically, this removes zero-value entries.
-func writeLabels(bkt *bolt.Bucket, labels map[string]string) error {
+// Uses the key "labels"
+func WriteLabels(bkt *bolt.Bucket, labels map[string]string) error {
 	// Remove existing labels to keep from merging
 	if lbkt := bkt.Bucket(bucketKeyLabels); lbkt != nil {
 		if err := bkt.DeleteBucket(bucketKeyLabels); err != nil {
@@ -50,7 +67,9 @@ func writeLabels(bkt *bolt.Bucket, labels map[string]string) error {
 	return nil
 }
 
-func readTimestamps(created, updated *time.Time, bkt *bolt.Bucket) error {
+// ReadTimestamps reads created and updated timestamps from a bucket.
+// Uses keys "createdat" and "updatedat"
+func ReadTimestamps(bkt *bolt.Bucket, created, updated *time.Time) error {
 	for _, f := range []struct {
 		b []byte
 		t *time.Time
@@ -68,7 +87,9 @@ func readTimestamps(created, updated *time.Time, bkt *bolt.Bucket) error {
 	return nil
 }
 
-func writeTimestamps(bkt *bolt.Bucket, created, updated time.Time) error {
+// WriteTimestamps writes created and updated timestamps to a bucket.
+// Uses keys "createdat" and "updatedat"
+func WriteTimestamps(bkt *bolt.Bucket, created, updated time.Time) error {
 	createdAt, err := created.MarshalBinary()
 	if err != nil {
 		return err

metadata/buckets.go

@@ -41,7 +41,6 @@ var (
 	bucketKeyDigest    = []byte("digest")
 	bucketKeyMediaType = []byte("mediatype")
 	bucketKeySize      = []byte("size")
-	bucketKeyLabels    = []byte("labels")
 	bucketKeyImage     = []byte("image")
 	bucketKeyRuntime   = []byte("runtime")
 	bucketKeyName      = []byte("name")
@@ -49,8 +48,6 @@ var (
 	bucketKeySpec      = []byte("spec")
 	bucketKeyRootFS    = []byte("rootfs")
 	bucketKeyTarget    = []byte("target")
-	bucketKeyCreatedAt = []byte("createdat")
-	bucketKeyUpdatedAt = []byte("updatedat")
 )
 
 func getBucket(tx *bolt.Tx, keys ...[]byte) *bolt.Bucket {

metadata/containers.go

@@ -10,6 +10,7 @@ import (
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/filters"
 	"github.com/containerd/containerd/identifiers"
+	"github.com/containerd/containerd/metadata/boltutil"
 	"github.com/containerd/containerd/namespaces"
 	"github.com/gogo/protobuf/proto"
 	"github.com/gogo/protobuf/types"
@@ -206,6 +207,16 @@ func (s *containerStore) Delete(ctx context.Context, id string) error {
 }
 
 func readContainer(container *containers.Container, bkt *bolt.Bucket) error {
+	labels, err := boltutil.ReadLabels(bkt)
+	if err != nil {
+		return err
+	}
+	container.Labels = labels
+
+	if err := boltutil.ReadTimestamps(bkt, &container.CreatedAt, &container.UpdatedAt); err != nil {
+		return err
+	}
+
 	return bkt.ForEach(func(k, v []byte) error {
 		switch string(k) {
 		case string(bucketKeyImage):
@@ -239,24 +250,7 @@ func readContainer(container *containers.Container, bkt *bolt.Bucket) error {
 			container.Spec = &any
 		case string(bucketKeyRootFS):
 			container.RootFS = string(v)
-		case string(bucketKeyCreatedAt):
-			if err := container.CreatedAt.UnmarshalBinary(v); err != nil {
-				return err
-			}
-		case string(bucketKeyUpdatedAt):
-			if err := container.UpdatedAt.UnmarshalBinary(v); err != nil {
-				return err
-			}
-		case string(bucketKeyLabels):
-			lbkt := bkt.Bucket(bucketKeyLabels)
-			if lbkt == nil {
-				return nil
-			}
-			container.Labels = map[string]string{}
 
-			if err := readLabels(container.Labels, lbkt); err != nil {
-				return err
-			}
 		}
 
 		return nil
@@ -264,7 +258,7 @@ func readContainer(container *containers.Container, bkt *bolt.Bucket) error {
 }
 
 func writeContainer(bkt *bolt.Bucket, container *containers.Container) error {
-	if err := writeTimestamps(bkt, container.CreatedAt, container.UpdatedAt); err != nil {
+	if err := boltutil.WriteTimestamps(bkt, container.CreatedAt, container.UpdatedAt); err != nil {
 		return err
 	}
 
@@ -314,5 +308,5 @@ func writeContainer(bkt *bolt.Bucket, container *containers.Container) error {
 		}
 	}
 
-	return writeLabels(bkt, container.Labels)
+	return boltutil.WriteLabels(bkt, container.Labels)
 }

metadata/content.go

@@ -11,6 +11,7 @@ import (
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/filters"
+	"github.com/containerd/containerd/metadata/boltutil"
 	"github.com/containerd/containerd/namespaces"
 	digest "github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
@@ -390,24 +391,18 @@ func (nw *namespacedWriter) commit(tx *bolt.Tx, size int64, expected digest.Dige
 		return err
 	}
 
+	commitTime := time.Now().UTC()
+
 	sizeEncoded, err := encodeSize(size)
 	if err != nil {
 		return err
 	}
 
-	timeEncoded, err := time.Now().UTC().MarshalBinary()
+	if err := boltutil.WriteTimestamps(bkt, commitTime, commitTime); err != nil {
-	if err != nil {
 		return err
 	}
-
+	if err := bkt.Put(bucketKeySize, sizeEncoded); err != nil {
-	for _, v := range [][2][]byte{
+		return err
-		{bucketKeyCreatedAt, timeEncoded},
-		{bucketKeyUpdatedAt, timeEncoded},
-		{bucketKeySize, sizeEncoded},
-	} {
-		if err := bkt.Put(v[0], v[1]); err != nil {
-			return err
-		}
 	}
 
 	return nil
@@ -451,17 +446,15 @@ func (cs *contentStore) checkAccess(ctx context.Context, dgst digest.Digest) err
 }
 
 func readInfo(info *content.Info, bkt *bolt.Bucket) error {
-	if err := readTimestamps(&info.CreatedAt, &info.UpdatedAt, bkt); err != nil {
+	if err := boltutil.ReadTimestamps(bkt, &info.CreatedAt, &info.UpdatedAt); err != nil {
 		return err
 	}
 
-	lbkt := bkt.Bucket(bucketKeyLabels)
+	labels, err := boltutil.ReadLabels(bkt)
-	if lbkt != nil {
+	if err != nil {
-		info.Labels = map[string]string{}
+		return err
-		if err := readLabels(info.Labels, lbkt); err != nil {
-			return err
-		}
 	}
+	info.Labels = labels
 
 	if v := bkt.Get(bucketKeySize); len(v) > 0 {
 		info.Size, _ = binary.Varint(v)
@@ -471,11 +464,11 @@ func readInfo(info *content.Info, bkt *bolt.Bucket) error {
 }
 
 func writeInfo(info *content.Info, bkt *bolt.Bucket) error {
-	if err := writeTimestamps(bkt, info.CreatedAt, info.UpdatedAt); err != nil {
+	if err := boltutil.WriteTimestamps(bkt, info.CreatedAt, info.UpdatedAt); err != nil {
 		return err
 	}
 
-	if err := writeLabels(bkt, info.Labels); err != nil {
+	if err := boltutil.WriteLabels(bkt, info.Labels); err != nil {
 		return errors.Wrapf(err, "writing labels for info %v", info.Digest)
 	}
 

metadata/images.go

@@ -11,6 +11,7 @@ import (
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/filters"
 	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/metadata/boltutil"
 	"github.com/containerd/containerd/namespaces"
 	digest "github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
@@ -191,17 +192,15 @@ func (s *imageStore) Delete(ctx context.Context, name string) error {
 }
 
 func readImage(image *images.Image, bkt *bolt.Bucket) error {
-	if err := readTimestamps(&image.CreatedAt, &image.UpdatedAt, bkt); err != nil {
+	if err := boltutil.ReadTimestamps(bkt, &image.CreatedAt, &image.UpdatedAt); err != nil {
 		return err
 	}
 
-	lbkt := bkt.Bucket(bucketKeyLabels)
+	labels, err := boltutil.ReadLabels(bkt)
-	if lbkt != nil {
+	if err != nil {
-		image.Labels = map[string]string{}
+		return err
-		if err := readLabels(image.Labels, lbkt); err != nil {
-			return err
-		}
 	}
+	image.Labels = labels
 
 	tbkt := bkt.Bucket(bucketKeyTarget)
 	if tbkt == nil {
@@ -228,11 +227,11 @@ func readImage(image *images.Image, bkt *bolt.Bucket) error {
 }
 
 func writeImage(bkt *bolt.Bucket, image *images.Image) error {
-	if err := writeTimestamps(bkt, image.CreatedAt, image.UpdatedAt); err != nil {
+	if err := boltutil.WriteTimestamps(bkt, image.CreatedAt, image.UpdatedAt); err != nil {
 		return err
 	}
 
-	if err := writeLabels(bkt, image.Labels); err != nil {
+	if err := boltutil.WriteLabels(bkt, image.Labels); err != nil {
 		return errors.Wrapf(err, "writing labels for image %v", image.Name)
 	}