[#83] Don't create extra delete marker

We shouldn't create delete marker if:
1. object doesn't exist at all
2. last version is already a delete marker

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

CHANGELOG.md

@@ -8,6 +8,7 @@ This document outlines major changes between releases.
 - Clean up List and Name caches when object is missing in Tree service (#57)
 - Get empty bucket CORS from frostfs (TrueCloudLab#36)
 - Don't count pool error on client abort (#35)
+- Don't create unnecessary delete-markers (#83)
 
 ### Added
 - Return `X-Owner-Id` in `head-bucket` response (#79)
@@ -29,6 +30,7 @@ This document outlines major changes between releases.
 - Limit number of objects to delete at one time (TrueCloudLab#37)
 - CompleteMultipartUpload handler now sends whitespace characters to keep alive client's connection (#60)
 - Support new system attributes (#64)
+- Changed values for `frostfs_s3_gw_state_health` metric (#91)
 
 ## [0.26.0] - 2022-12-28
 

api/handler/delete_test.go

@@ -147,6 +147,81 @@ func TestRemoveDeleteMarker(t *testing.T) {
 	require.True(t, existInMockedFrostFS(tc, bktInfo, objInfo), "object doesn't exist but should")
 }
 
+func TestDeleteMarkerVersioned(t *testing.T) {
+	tc := prepareHandlerContext(t)
+
+	bktName, objName := "bucket-for-removal", "object-to-delete"
+	createVersionedBucketAndObject(t, tc, bktName, objName)
+
+	t.Run("not create new delete marker if last version is delete marker", func(t *testing.T) {
+		deleteMarkerVersion, isDeleteMarker := deleteObject(t, tc, bktName, objName, emptyVersion)
+		require.True(t, isDeleteMarker)
+		versions := listVersions(t, tc, bktName)
+		require.Equal(t, deleteMarkerVersion, versions.DeleteMarker[0].VersionID)
+
+		_, isDeleteMarker = deleteObject(t, tc, bktName, objName, emptyVersion)
+		require.True(t, isDeleteMarker)
+		versions = listVersions(t, tc, bktName)
+		require.Len(t, versions.DeleteMarker, 1)
+		require.Equal(t, deleteMarkerVersion, versions.DeleteMarker[0].VersionID)
+	})
+
+	t.Run("do not create delete marker if object does not exist", func(t *testing.T) {
+		versionsBefore := listVersions(t, tc, bktName)
+		_, isDeleteMarker := deleteObject(t, tc, bktName, "dummy", emptyVersion)
+		require.False(t, isDeleteMarker)
+		versionsAfter := listVersions(t, tc, bktName)
+		require.Equal(t, versionsBefore, versionsAfter)
+	})
+}
+
+func TestDeleteMarkerSuspended(t *testing.T) {
+	tc := prepareHandlerContext(t)
+
+	bktName, objName := "bucket-for-removal", "object-to-delete"
+	bktInfo, _ := createVersionedBucketAndObject(t, tc, bktName, objName)
+	putBucketVersioning(t, tc, bktName, false)
+
+	t.Run("not create new delete marker if last version is delete marker", func(t *testing.T) {
+		deleteMarkerVersion, isDeleteMarker := deleteObject(t, tc, bktName, objName, emptyVersion)
+		require.True(t, isDeleteMarker)
+		require.Equal(t, data.UnversionedObjectVersionID, deleteMarkerVersion)
+
+		deleteMarkerVersion, isDeleteMarker = deleteObject(t, tc, bktName, objName, emptyVersion)
+		require.True(t, isDeleteMarker)
+		require.Equal(t, data.UnversionedObjectVersionID, deleteMarkerVersion)
+
+		versions := listVersions(t, tc, bktName)
+		require.Len(t, versions.DeleteMarker, 1)
+		require.Equal(t, deleteMarkerVersion, versions.DeleteMarker[0].VersionID)
+	})
+
+	t.Run("do not create delete marker if object does not exist", func(t *testing.T) {
+		versionsBefore := listVersions(t, tc, bktName)
+		_, isDeleteMarker := deleteObject(t, tc, bktName, "dummy", emptyVersion)
+		require.False(t, isDeleteMarker)
+		versionsAfter := listVersions(t, tc, bktName)
+		require.Equal(t, versionsBefore, versionsAfter)
+	})
+
+	t.Run("remove last unversioned non delete marker", func(t *testing.T) {
+		objName := "obj3"
+		putObject(t, tc, bktName, objName)
+
+		nodeVersion, err := tc.tree.GetUnversioned(tc.Context(), bktInfo, objName)
+		require.NoError(t, err)
+
+		deleteMarkerVersion, isDeleteMarker := deleteObject(t, tc, bktName, objName, emptyVersion)
+		require.True(t, isDeleteMarker)
+		require.Equal(t, data.UnversionedObjectVersionID, deleteMarkerVersion)
+
+		objVersions := getVersion(listVersions(t, tc, bktName), objName)
+		require.Len(t, objVersions, 0)
+
+		require.False(t, tc.MockedPool().ObjectExists(nodeVersion.OID))
+	})
+}
+
 func TestDeleteObjectCombined(t *testing.T) {
 	tc := prepareHandlerContext(t)
 
@@ -197,7 +272,7 @@ func TestDeleteMarkers(t *testing.T) {
 	deleteObject(t, tc, bktName, objName, emptyVersion)
 
 	versions := listVersions(t, tc, bktName)
-	require.Len(t, versions.DeleteMarker, 3, "invalid delete markers length")
+	require.Len(t, versions.DeleteMarker, 0, "invalid delete markers length")
 	require.Len(t, versions.Version, 0, "versions must be empty")
 
 	require.Len(t, listOIDsFromMockedFrostFS(t, tc, bktName), 0, "shouldn't be any object in frostfs")
@@ -316,6 +391,16 @@ func listVersions(t *testing.T, tc *handlerContext, bktName string) *ListObjects
 	return res
 }
 
+func getVersion(resp *ListObjectsVersionsResponse, objName string) []*ObjectVersionResponse {
+	var res []*ObjectVersionResponse
+	for i, version := range resp.Version {
+		if version.Key == objName {
+			res = append(res, &resp.Version[i])
+		}
+	}
+	return res
+}
+
 func putObject(t *testing.T, tc *handlerContext, bktName, objName string) {
 	body := bytes.NewReader([]byte("content"))
 	w, r := prepareTestPayloadRequest(tc, bktName, objName, body)

api/handler/handlers_test.go

@@ -33,6 +33,7 @@ type handlerContext struct {
 	t       *testing.T
 	h       *handler
 	tp      *layer.TestFrostFS
+	tree    *tree.Tree
 	context context.Context
 }
 
@@ -85,11 +86,13 @@ func prepareHandlerContext(t *testing.T) *handlerContext {
 	var owner user.ID
 	user.IDFromKey(&owner, key.PrivateKey.PublicKey)
 
+	treeMock := NewTreeServiceMock(t)
+
 	layerCfg := &layer.Config{
 		Caches:      layer.DefaultCachesConfigs(zap.NewExample()),
 		AnonKey:     layer.AnonymousKey{Key: key},
 		Resolver:    testResolver,
-		TreeService: NewTreeServiceMock(t),
+		TreeService: treeMock,
 	}
 
 	var pp netmap.PlacementPolicy
@@ -110,6 +113,7 @@ func prepareHandlerContext(t *testing.T) *handlerContext {
 		t:       t,
 		h:       h,
 		tp:      tp,
+		tree:    treeMock,
 		context: context.WithValue(context.Background(), api.BoxData, newTestAccessBox(t, key)),
 	}
 }

api/layer/layer.go

@@ -561,21 +561,38 @@ func (n *layer) deleteObject(ctx context.Context, bkt *data.BucketInfo, settings
 		return obj
 	}
 
-	var newVersion *data.NodeVersion
+	lastVersion, err := n.getLastNodeVersion(ctx, bkt, obj)
+	if err != nil {
+		obj.Error = err
+		return n.handleNotFoundError(bkt, obj)
+	}
 
 	if settings.VersioningSuspended() {
 		obj.VersionID = data.UnversionedObjectVersionID
 
-		var nodeVersion *data.NodeVersion
-		if nodeVersion, obj.Error = n.getNodeVersionToDelete(ctx, bkt, obj); obj.Error != nil {
-			return n.handleNotFoundError(bkt, obj)
+		var nullVersionToDelete *data.NodeVersion
+		if lastVersion.IsUnversioned {
+			if !lastVersion.IsDeleteMarker() {
+				nullVersionToDelete = lastVersion
+			}
+		} else if nullVersionToDelete, obj.Error = n.getNodeVersionToDelete(ctx, bkt, obj); obj.Error != nil {
+			if !isNotFoundError(obj.Error) {
+				return obj
+			}
 		}
 
-		if obj.DeleteMarkVersion, obj.Error = n.removeOldVersion(ctx, bkt, nodeVersion, obj); obj.Error != nil {
-			return obj
+		if nullVersionToDelete != nil {
+			if obj.DeleteMarkVersion, obj.Error = n.removeOldVersion(ctx, bkt, nullVersionToDelete, obj); obj.Error != nil {
+				return obj
+			}
 		}
 	}
 
+	if lastVersion.IsDeleteMarker() {
+		obj.DeleteMarkVersion = lastVersion.OID.EncodeToString()
+		return obj
+	}
+
 	randOID, err := getRandomOID()
 	if err != nil {
 		obj.Error = fmt.Errorf("couldn't get random oid: %w", err)
@@ -584,7 +601,7 @@ func (n *layer) deleteObject(ctx context.Context, bkt *data.BucketInfo, settings
 
 	obj.DeleteMarkVersion = randOID.EncodeToString()
 
-	newVersion = &data.NodeVersion{
+	newVersion := &data.NodeVersion{
 		BaseNodeVersion: data.BaseNodeVersion{
 			OID:      randOID,
 			FilePath: obj.Name,
@@ -606,8 +623,7 @@ func (n *layer) deleteObject(ctx context.Context, bkt *data.BucketInfo, settings
 }
 
 func (n *layer) handleNotFoundError(bkt *data.BucketInfo, obj *VersionedObject) *VersionedObject {
-	if errors.IsS3Error(obj.Error, errors.ErrNoSuchKey) ||
-		errors.IsS3Error(obj.Error, errors.ErrNoSuchVersion) {
+	if isNotFoundError(obj.Error) {
 		obj.Error = nil
 		n.cache.CleanListCacheEntriesContainingObject(obj.Name, bkt.CID)
 		n.cache.DeleteObjectName(bkt.CID, bkt.Name, obj.Name)
@@ -616,6 +632,11 @@ func (n *layer) handleNotFoundError(bkt *data.BucketInfo, obj *VersionedObject)
 	return obj
 }
 
+func isNotFoundError(err error) bool {
+	return errors.IsS3Error(err, errors.ErrNoSuchKey) ||
+		errors.IsS3Error(err, errors.ErrNoSuchVersion)
+}
+
 func (n *layer) getNodeVersionToDelete(ctx context.Context, bkt *data.BucketInfo, obj *VersionedObject) (*data.NodeVersion, error) {
 	objVersion := &ObjectVersion{
 		BktInfo:               bkt,
@@ -627,6 +648,17 @@ func (n *layer) getNodeVersionToDelete(ctx context.Context, bkt *data.BucketInfo
 	return n.getNodeVersion(ctx, objVersion)
 }
 
+func (n *layer) getLastNodeVersion(ctx context.Context, bkt *data.BucketInfo, obj *VersionedObject) (*data.NodeVersion, error) {
+	objVersion := &ObjectVersion{
+		BktInfo:               bkt,
+		ObjectName:            obj.Name,
+		VersionID:             "",
+		NoErrorOnDeleteMarker: true,
+	}
+
+	return n.getNodeVersion(ctx, objVersion)
+}
+
 func (n *layer) removeOldVersion(ctx context.Context, bkt *data.BucketInfo, nodeVersion *data.NodeVersion, obj *VersionedObject) (string, error) {
 	if nodeVersion.IsDeleteMarker() {
 		return obj.VersionID, nil

api/layer/neofs_mock.go

@@ -15,6 +15,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/accessbox"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/checksum"
+	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/eacl"
@@ -55,6 +56,16 @@ func (t *TestFrostFS) Objects() []*object.Object {
 	return res
 }
 
+func (t *TestFrostFS) ObjectExists(objID oid.ID) bool {
+	for _, obj := range t.objects {
+		if id, _ := obj.ID(); id.Equals(objID) {
+			return true
+		}
+	}
+
+	return false
+}
+
 func (t *TestFrostFS) AddObject(key string, obj *object.Object) {
 	t.objects[key] = obj
 }
@@ -161,7 +172,7 @@ func (t *TestFrostFS) ReadObject(ctx context.Context, prm PrmObjectRead) (*Objec
 		}, nil
 	}
 
-	return nil, fmt.Errorf("object not found %s", addr)
+	return nil, fmt.Errorf("%w: %s", apistatus.ObjectNotFound{}, addr)
 }
 
 func (t *TestFrostFS) CreateObject(ctx context.Context, prm PrmObjectCreate) (oid.ID, error) {

cmd/s3-gw/app.go

@@ -182,6 +182,7 @@ func (a *App) initAPI(ctx context.Context) {
 
 func (a *App) initMetrics() {
 	a.metrics = metrics.NewAppMetrics(a.log, frostfs.NewPoolStatistic(a.pool), a.cfg.GetBool(cfgPrometheusEnabled))
+	a.metrics.SetHealth(metrics.HealthStatusStarting)
 }
 
 func (a *App) initResolver() {
@@ -369,7 +370,7 @@ func (a *App) Wait() {
 }
 
 func (a *App) setHealthStatus() {
-	a.metrics.SetHealth(1)
+	a.metrics.SetHealth(metrics.HealthStatusReady)
 }
 
 // Serve runs HTTP server to handle S3 API requests.

metrics/app.go

@@ -37,7 +37,7 @@ func (m *AppMetrics) SetEnabled(enabled bool) {
 	m.mu.Unlock()
 }
 
-func (m *AppMetrics) SetHealth(status int32) {
+func (m *AppMetrics) SetHealth(status HealthStatus) {
 	if !m.isEnabled() {
 		return
 	}
@@ -48,7 +48,7 @@ func (m *AppMetrics) SetHealth(status int32) {
 func (m *AppMetrics) Shutdown() {
 	m.mu.Lock()
 	if m.enabled {
-		m.gate.State.SetHealth(0)
+		m.gate.State.SetHealth(HealthStatusShuttingDown)
 		m.enabled = false
 	}
 	m.gate.Unregister()

metrics/state.go

@@ -4,6 +4,16 @@ import "github.com/prometheus/client_golang/prometheus"
 
 const stateSubsystem = "state"
 
+// HealthStatus of the gate application.
+type HealthStatus int32
+
+const (
+	HealthStatusUndefined    HealthStatus = 0
+	HealthStatusStarting     HealthStatus = 1
+	HealthStatusReady        HealthStatus = 2
+	HealthStatusShuttingDown HealthStatus = 3
+)
+
 type stateMetrics struct {
 	healthCheck prometheus.Gauge
 }
@@ -27,6 +37,6 @@ func (m stateMetrics) unregister() {
 	prometheus.Unregister(m.healthCheck)
 }
 
-func (m stateMetrics) SetHealth(s int32) {
+func (m stateMetrics) SetHealth(s HealthStatus) {
 	m.healthCheck.Set(float64(s))
 }