Use enumerated kind in boltdb proto message

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)

snapshot/storage/boltdb/bolt.go

@@ -96,13 +96,24 @@ func (ms *boltMetastore) createBucketIfNotExists(ctx context.Context, fn func(ct
 	return fn(ctx, bkt)
 }
 
-func fromProtoActive(active bool) snapshot.Kind {
+func fromProtoKind(k Kind) snapshot.Kind {
-	if active {
+	if k == KindActive {
 		return snapshot.KindActive
 	}
 	return snapshot.KindCommitted
 }
 
+func toProtoKind(k snapshot.Kind) Kind {
+	switch k {
+	case snapshot.KindActive:
+		return KindActive
+	case snapshot.KindCommitted:
+		return KindCommitted
+	default:
+		panic("unknown kind")
+	}
+}
+
 func parentKey(parent, child uint64) []byte {
 	b := make([]byte, binary.Size([]uint64{parent, child}))
 	i := binary.PutUvarint(b, parent)
@@ -127,7 +138,7 @@ func (ms *boltMetastore) Stat(ctx context.Context, key string) (snapshot.Info, e
 	return snapshot.Info{
 		Name:     key,
 		Parent:   ss.Parent,
-		Kind:     fromProtoActive(ss.Active),
+		Kind:     fromProtoKind(ss.Kind),
 		Readonly: ss.Readonly,
 	}, nil
 }
@@ -147,7 +158,7 @@ func (ms *boltMetastore) Walk(ctx context.Context, fn func(context.Context, snap
 			info := snapshot.Info{
 				Name:     string(k),
 				Parent:   ss.Parent,
-				Kind:     fromProtoActive(ss.Active),
+				Kind:     fromProtoKind(ss.Kind),
 				Readonly: ss.Readonly,
 			}
 			return fn(ctx, info)
@@ -166,7 +177,7 @@ func (ms *boltMetastore) CreateActive(ctx context.Context, key, parent string, r
 				return errors.Wrap(err, "failed to get parent snapshot")
 			}
 
-			if parentS.Active {
+			if parentS.Kind == KindActive {
 				return errors.Errorf("cannot create active from active")
 			}
 		}
@@ -183,7 +194,7 @@ func (ms *boltMetastore) CreateActive(ctx context.Context, key, parent string, r
 		ss := Snapshot{
 			ID:       id,
 			Parent:   parent,
-			Active:   true,
+			Kind:     KindActive,
 			Readonly: readonly,
 		}
 		if err := putSnapshot(bkt, key, &ss); err != nil {
@@ -228,7 +239,7 @@ func (ms *boltMetastore) GetActive(ctx context.Context, key string) (a storage.A
 		if err := proto.Unmarshal(b, &ss); err != nil {
 			return errors.Wrap(err, "failed to unmarshal snapshot")
 		}
-		if !ss.Active {
+		if ss.Kind != KindActive {
 			return errors.Errorf("active not found")
 		}
 
@@ -309,7 +320,7 @@ func (ms *boltMetastore) Remove(ctx context.Context, key string) (id string, k s
 		}
 
 		id = fmt.Sprintf("%d", ss.ID)
-		k = fromProtoActive(ss.Active)
+		k = fromProtoKind(ss.Kind)
 
 		return nil
 	})
@@ -328,14 +339,14 @@ func (ms *boltMetastore) Commit(ctx context.Context, key, name string) (id strin
 		if err := getSnapshot(bkt, key, &ss); err != nil {
 			return errors.Wrap(err, "failed to get active snapshot")
 		}
-		if !ss.Active {
+		if ss.Kind != KindActive {
 			return errors.Errorf("key is not active snapshot")
 		}
 		if ss.Readonly {
 			return errors.Errorf("active snapshot is readonly")
 		}
 
-		ss.Active = false
+		ss.Kind = KindCommitted
 		ss.Readonly = true
 
 		if err := putSnapshot(bkt, name, &ss); err != nil {

snapshot/storage/boltdb/record.pb.go

@@ -34,10 +34,34 @@ var _ = math.Inf
 // proto package needs to be updated.
 const _ = proto.GoGoProtoPackageIsVersion2 // please upgrade the proto package
 
+// Kind defines the kind of snapshot.
+type Kind int32
+
+const (
+	// KindActive represents an active snapshot
+	KindActive Kind = 0
+	// KindCommitted represents a committed immutable snapshot
+	KindCommitted Kind = 1
+)
+
+var Kind_name = map[int32]string{
+	0: "ACTIVE",
+	1: "COMMITTED",
+}
+var Kind_value = map[string]int32{
+	"ACTIVE":    0,
+	"COMMITTED": 1,
+}
+
+func (x Kind) String() string {
+	return proto.EnumName(Kind_name, int32(x))
+}
+func (Kind) EnumDescriptor() ([]byte, []int) { return fileDescriptorRecord, []int{0} }
+
 type Snapshot struct {
 	ID       uint64 `protobuf:"varint,1,opt,name=id,proto3" json:"id,omitempty"`
 	Parent   string `protobuf:"bytes,2,opt,name=parent,proto3" json:"parent,omitempty"`
-	Active   bool   `protobuf:"varint,4,opt,name=active,proto3" json:"active,omitempty"`
+	Kind     Kind   `protobuf:"varint,4,opt,name=kind,proto3,enum=containerd.v1.Kind" json:"kind,omitempty"`
 	Readonly bool   `protobuf:"varint,5,opt,name=readonly,proto3" json:"readonly,omitempty"`
 }
 
@@ -47,6 +71,7 @@ func (*Snapshot) Descriptor() ([]byte, []int) { return fileDescriptorRecord, []i
 
 func init() {
 	proto.RegisterType((*Snapshot)(nil), "containerd.v1.Snapshot")
+	proto.RegisterEnum("containerd.v1.Kind", Kind_name, Kind_value)
 }
 func (m *Snapshot) Marshal() (dAtA []byte, err error) {
 	size := m.Size()
@@ -74,15 +99,10 @@ func (m *Snapshot) MarshalTo(dAtA []byte) (int, error) {
 		i = encodeVarintRecord(dAtA, i, uint64(len(m.Parent)))
 		i += copy(dAtA[i:], m.Parent)
 	}
-	if m.Active {
+	if m.Kind != 0 {
 		dAtA[i] = 0x20
 		i++
-		if m.Active {
+		i = encodeVarintRecord(dAtA, i, uint64(m.Kind))
-			dAtA[i] = 1
-		} else {
-			dAtA[i] = 0
-		}
-		i++
 	}
 	if m.Readonly {
 		dAtA[i] = 0x28
@@ -134,8 +154,8 @@ func (m *Snapshot) Size() (n int) {
 	if l > 0 {
 		n += 1 + l + sovRecord(uint64(l))
 	}
-	if m.Active {
+	if m.Kind != 0 {
-		n += 2
+		n += 1 + sovRecord(uint64(m.Kind))
 	}
 	if m.Readonly {
 		n += 2
@@ -163,7 +183,7 @@ func (this *Snapshot) String() string {
 	s := strings.Join([]string{`&Snapshot{`,
 		`ID:` + fmt.Sprintf("%v", this.ID) + `,`,
 		`Parent:` + fmt.Sprintf("%v", this.Parent) + `,`,
-		`Active:` + fmt.Sprintf("%v", this.Active) + `,`,
+		`Kind:` + fmt.Sprintf("%v", this.Kind) + `,`,
 		`Readonly:` + fmt.Sprintf("%v", this.Readonly) + `,`,
 		`}`,
 	}, "")
@@ -256,9 +276,9 @@ func (m *Snapshot) Unmarshal(dAtA []byte) error {
 			iNdEx = postIndex
 		case 4:
 			if wireType != 0 {
-				return fmt.Errorf("proto: wrong wireType = %d for field Active", wireType)
+				return fmt.Errorf("proto: wrong wireType = %d for field Kind", wireType)
 			}
-			var v int
+			m.Kind = 0
 			for shift := uint(0); ; shift += 7 {
 				if shift >= 64 {
 					return ErrIntOverflowRecord
@@ -268,12 +288,11 @@ func (m *Snapshot) Unmarshal(dAtA []byte) error {
 				}
 				b := dAtA[iNdEx]
 				iNdEx++
-				v |= (int(b) & 0x7F) << shift
+				m.Kind |= (Kind(b) & 0x7F) << shift
 				if b < 0x80 {
 					break
 				}
 			}
-			m.Active = bool(v != 0)
 		case 5:
 			if wireType != 0 {
 				return fmt.Errorf("proto: wrong wireType = %d for field Readonly", wireType)
@@ -425,20 +444,25 @@ func init() {
 }
 
 var fileDescriptorRecord = []byte{
-	// 225 bytes of a gzipped FileDescriptorProto
+	// 314 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x44, 0x8e, 0xb1, 0x4e, 0xc3, 0x30,
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x54, 0x8f, 0xcf, 0x4a, 0xf3, 0x40,
-	0x10, 0x86, 0x7b, 0x51, 0x89, 0x82, 0x25, 0x96, 0x08, 0x55, 0x56, 0x07, 0x13, 0x31, 0x65, 0x8a,
+	0x14, 0xc5, 0x33, 0x21, 0x5f, 0x68, 0x87, 0xaf, 0xa5, 0x46, 0x29, 0x21, 0x8b, 0x71, 0x70, 0x63,
-	0x85, 0x78, 0x02, 0x2a, 0x16, 0xd6, 0xf0, 0x04, 0x8e, 0x6d, 0xa5, 0x16, 0xc5, 0x17, 0x5d, 0x8e,
+	0x70, 0x91, 0x41, 0x7d, 0x82, 0xfe, 0x5b, 0x94, 0x52, 0x84, 0x58, 0xdc, 0x27, 0x99, 0x21, 0x1d,
-	0x4a, 0x6c, 0x3c, 0x5e, 0x47, 0x46, 0x26, 0x44, 0xfd, 0x24, 0xa8, 0x21, 0xa2, 0xdb, 0x7d, 0xf7,
+	0xda, 0xce, 0x2d, 0xd3, 0xb1, 0xe0, 0x4a, 0x97, 0xd2, 0x77, 0xe8, 0x4a, 0x9f, 0xc2, 0x27, 0xe8,
-	0xdd, 0xfd, 0xfa, 0xc5, 0x43, 0x1f, 0x78, 0xfb, 0xd6, 0x35, 0x16, 0x5f, 0xb5, 0x43, 0xfb, 0xe2,
+	0xd2, 0xa5, 0x2b, 0xb1, 0x79, 0x12, 0x69, 0x5a, 0x14, 0x77, 0xf7, 0xdc, 0xf3, 0xbb, 0xe7, 0x72,
-	0x49, 0x5b, 0x8c, 0x6c, 0x42, 0xf4, 0xe4, 0xf4, 0x18, 0xcd, 0x30, 0x6e, 0x91, 0xf5, 0xc8, 0x48,
+	0x70, 0x2b, 0x97, 0x66, 0x7c, 0x9f, 0x46, 0x19, 0xcc, 0x18, 0x87, 0x6c, 0x22, 0x34, 0xcb, 0x40,
-	0xa6, 0xf7, 0xba, 0xc3, 0x1d, 0xbb, 0x4e, 0x93, 0xb7, 0x48, 0xae, 0x19, 0x08, 0x19, 0xcb, 0xab,
+	0x99, 0x44, 0x2a, 0xa1, 0x39, 0x5b, 0xa8, 0x64, 0xbe, 0x18, 0x83, 0x61, 0x0b, 0x03, 0x3a, 0xc9,
-	0xf3, 0x43, 0xb3, 0xbf, 0x5b, 0x5f, 0xf7, 0xd8, 0xe3, 0x64, 0xf4, 0x69, 0xfa, 0x3b, 0xba, 0x8d,
+	0x05, 0x4b, 0x61, 0x6a, 0x78, 0xca, 0xb4, 0xc8, 0x40, 0xf3, 0x68, 0xae, 0xc1, 0x80, 0x57, 0xfb,
-	0xa2, 0x78, 0x9e, 0xc3, 0xca, 0x95, 0xc8, 0x82, 0x93, 0x50, 0x41, 0xbd, 0xdc, 0xe4, 0xe9, 0xfb,
+	0x3d, 0x88, 0x96, 0x97, 0xc1, 0x49, 0x0e, 0x39, 0x94, 0x0e, 0xdb, 0x4d, 0x7b, 0xe8, 0xec, 0x11,
-	0x26, 0x7b, 0x7a, 0x6c, 0xb3, 0xe0, 0xca, 0x95, 0xc8, 0x07, 0x43, 0x3e, 0xb2, 0xcc, 0x2a, 0xa8,
+	0x57, 0x6e, 0x0f, 0x61, 0x5e, 0x13, 0xdb, 0x92, 0xfb, 0x88, 0xa2, 0xd0, 0x69, 0xbb, 0xc5, 0xe7,
-	0x2f, 0xdb, 0x99, 0x4e, 0x7b, 0x63, 0x39, 0xec, 0xbd, 0x5c, 0x56, 0x50, 0x17, 0xed, 0x4c, 0xe5,
+	0xa9, 0xdd, 0xef, 0xc6, 0xb6, 0xe4, 0x5e, 0x13, 0xbb, 0xf3, 0x44, 0x0b, 0x65, 0x7c, 0x9b, 0xa2,
-	0x5a, 0x14, 0xe4, 0x8d, 0xc3, 0xb8, 0x7b, 0x97, 0x17, 0x93, 0xf9, 0xe7, 0x8d, 0x3c, 0x1c, 0xd5,
+	0xb0, 0x1a, 0x1f, 0x94, 0x77, 0x8e, 0x9d, 0x89, 0x54, 0xdc, 0x77, 0x28, 0x0a, 0xeb, 0x57, 0xc7,
-	0xe2, 0xeb, 0xa8, 0x16, 0x1f, 0x49, 0xc1, 0x21, 0x29, 0xf8, 0x4c, 0x0a, 0x7e, 0x92, 0x82, 0x2e,
+	0xd1, 0x9f, 0x7f, 0xd1, 0x40, 0x2a, 0x1e, 0x97, 0x80, 0x17, 0xe0, 0x8a, 0x16, 0x09, 0x07, 0x35,
-	0x9f, 0x0a, 0xdd, 0xff, 0x06, 0x00, 0x00, 0xff, 0xff, 0xd3, 0xbe, 0x14, 0x8b, 0xfa, 0x00, 0x00,
+	0x7d, 0xf0, 0xff, 0x51, 0x14, 0x56, 0xe2, 0x1f, 0x7d, 0x11, 0x63, 0x67, 0xb0, 0x67, 0xdc, 0x56,
-	0x00,
+	0x67, 0xd4, 0xbf, 0xeb, 0x35, 0xac, 0xa0, 0xbe, 0x5a, 0x53, 0xbc, 0xdb, 0xb6, 0x32, 0x23, 0x97,
+	0xc2, 0xa3, 0xb8, 0xda, 0xb9, 0x19, 0x0e, 0xfb, 0xa3, 0x51, 0xaf, 0xdb, 0x40, 0xc1, 0xd1, 0x6a,
+	0x4d, 0x6b, 0x3b, 0xbb, 0x03, 0xb3, 0x99, 0x34, 0x46, 0xf0, 0xe0, 0xff, 0xf3, 0x0b, 0xb1, 0xde,
+	0x5e, 0x49, 0x99, 0xd5, 0xf6, 0x37, 0x5b, 0x62, 0x7d, 0x6c, 0x89, 0xf5, 0x54, 0x10, 0xb4, 0x29,
+	0x08, 0x7a, 0x2f, 0x08, 0xfa, 0x2a, 0x08, 0x4a, 0xdd, 0xb2, 0xf5, 0xf5, 0x77, 0x00, 0x00, 0x00,
+	0xff, 0xff, 0x9c, 0xce, 0xfc, 0xc2, 0x5f, 0x01, 0x00, 0x00,
 }

snapshot/storage/boltdb/record.proto

@@ -4,9 +4,21 @@ package containerd.v1;
 
 import "gogoproto/gogo.proto";
 
+// Kind defines the kind of snapshot.
+enum Kind {
+	option (gogoproto.goproto_enum_prefix) = false;
+	option (gogoproto.enum_customname) = "Kind";
+
+	// KindActive represents an active snapshot
+	ACTIVE = 0 [(gogoproto.enumvalue_customname) = "KindActive"];
+
+	// KindCommitted represents a committed immutable snapshot
+	COMMITTED = 1 [(gogoproto.enumvalue_customname) = "KindCommitted"];
+}
+
 message Snapshot {
 	uint64 id = 1 [(gogoproto.customname) = "ID"];
 	string parent = 2;
-	bool active = 4;
+	Kind kind = 4;
 	bool readonly = 5;
 }