[#1445] engine/test: Add test for GC handling of expired tombstones

Since the GC behavior is changing drastically. This test is needed
to ensure that the GC correctly deletes expired tombstones and graves.
The test uses graves of both old and new formats.

Signed-off-by: Aleksey Savchuk <a.savchuk@yadro.com>

pkg/local_object_storage/engine/gc_test.go

@@ -0,0 +1,111 @@
+package engine
+
+import (
+	"context"
+	"strconv"
+	"testing"
+	"time"
+
+	objectCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/testutil"
+	meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util"
+	objectV2 "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/api/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client"
+	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
+	cidtest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id/test"
+	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"github.com/panjf2000/ants/v2"
+	"github.com/stretchr/testify/require"
+)
+
+func testPopulateWithObjects(t testing.TB, engine *StorageEngine, cnt cid.ID, objectCount int) (objects []*objectSDK.Object) {
+	require.Positive(t, objectCount)
+
+	var putPrm PutPrm
+	for range objectCount {
+		putPrm.Object = testutil.GenerateObjectWithCID(cnt)
+		require.NoError(t, engine.Put(context.Background(), putPrm))
+		objects = append(objects, putPrm.Object)
+	}
+	return objects
+}
+
+func testInhumeObjects(t testing.TB, engine *StorageEngine, objects []*objectSDK.Object, expEpoch uint64) (tombstone *objectSDK.Object) {
+	require.NotEmpty(t, objects)
+	cnt := objectCore.AddressOf(objects[0]).Container()
+
+	tombstone = testutil.GenerateObjectWithCID(cnt)
+	tombstone.SetType(objectSDK.TypeTombstone)
+	testutil.AddAttribute(tombstone, objectV2.SysAttributeExpEpoch, strconv.FormatUint(expEpoch, 10))
+
+	var putPrm PutPrm
+	putPrm.Object = tombstone
+	require.NoError(t, engine.Put(context.Background(), putPrm))
+
+	var addrs []oid.Address
+	for _, object := range objects {
+		addrs = append(addrs, objectCore.AddressOf(object))
+	}
+	tombstoneAddr := objectCore.AddressOf(tombstone)
+
+	pivot := len(objects) / 2
+
+	var inhumePrm InhumePrm
+	inhumePrm.WithTarget(tombstoneAddr, expEpoch, addrs[:pivot]...)
+	err := engine.Inhume(context.Background(), inhumePrm)
+	require.NoError(t, err)
+
+	inhumePrm.WithTarget(tombstoneAddr, meta.NoExpirationEpoch, addrs[pivot:]...)
+	err = engine.Inhume(context.Background(), inhumePrm)
+	require.NoError(t, err)
+
+	return
+}
+
+func TestGCHandleExpiredTombstones(t *testing.T) {
+	t.Parallel()
+
+	const (
+		numShards   = 2
+		objectCount = 10 * numShards
+		expEpoch    = 1
+	)
+
+	container := cidtest.ID()
+
+	engine := testNewEngine(t).
+		setShardsNumAdditionalOpts(t, numShards, func(_ int) []shard.Option {
+			return []shard.Option{
+				shard.WithGCWorkerPoolInitializer(func(sz int) util.WorkerPool {
+					pool, err := ants.NewPool(sz)
+					require.NoError(t, err)
+					return pool
+				}),
+				shard.WithTombstoneSource(tss{expEpoch}),
+			}
+		}).prepare(t).engine
+	defer func() { require.NoError(t, engine.Close(context.Background())) }()
+
+	objects := testPopulateWithObjects(t, engine, container, objectCount)
+	tombstone := testInhumeObjects(t, engine, objects, expEpoch)
+
+	engine.HandleNewEpoch(context.Background(), expEpoch+1)
+
+	var headPrm HeadPrm
+	require.Eventually(t, func() bool {
+		for _, object := range objects {
+			headPrm.WithAddress(objectCore.AddressOf(object))
+			_, err := engine.Head(context.Background(), headPrm)
+			if !client.IsErrObjectNotFound(err) {
+				return false
+			}
+		}
+
+		headPrm.WithAddress(objectCore.AddressOf(tombstone))
+		_, err := engine.Head(context.Background(), headPrm)
+		return client.IsErrObjectNotFound(err)
+	}, 10*time.Second, 1*time.Second)
+}