From 0ef3d5ab03f696f3e97b6e940947362a6d43b6d9 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Tue, 18 Jan 2022 17:27:07 +0300
Subject: [PATCH] [#1085] writecache: persist in-memory objects before shutdown

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
---
 .../shard/evacuate_test.go                    |  2 +-
 pkg/local_object_storage/shard/shard_test.go  |  5 +-
 .../shard/shutdown_test.go                    | 52 +++++++++++++++++++
 .../writecache/writecache.go                  |  3 ++
 4 files changed, 58 insertions(+), 4 deletions(-)
 create mode 100644 pkg/local_object_storage/shard/shutdown_test.go

diff --git a/pkg/local_object_storage/shard/evacuate_test.go b/pkg/local_object_storage/shard/evacuate_test.go
index 4cef3ceb8c..3f5f74a21e 100644
--- a/pkg/local_object_storage/shard/evacuate_test.go
+++ b/pkg/local_object_storage/shard/evacuate_test.go
@@ -39,7 +39,7 @@ func testEvacuate(t *testing.T, objCount int, hasWriteCache bool) {
 	if !hasWriteCache {
 		sh = newShard(t, false)
 	} else {
-		sh = newCustomShard(t, true,
+		sh = newCustomShard(t, t.TempDir(), true,
 			writecache.WithSmallObjectSize(wcSmallObjectSize),
 			writecache.WithMaxObjectSize(wcBigObjectSize))
 	}
diff --git a/pkg/local_object_storage/shard/shard_test.go b/pkg/local_object_storage/shard/shard_test.go
index e4e4ae3b31..08905fbd6b 100644
--- a/pkg/local_object_storage/shard/shard_test.go
+++ b/pkg/local_object_storage/shard/shard_test.go
@@ -27,11 +27,10 @@ import (
 )
 
 func newShard(t testing.TB, enableWriteCache bool) *shard.Shard {
-	return newCustomShard(t, enableWriteCache, writecache.WithMaxMemSize(0))
+	return newCustomShard(t, t.TempDir(), enableWriteCache, writecache.WithMaxMemSize(0))
 }
 
-func newCustomShard(t testing.TB, enableWriteCache bool, wcOpts ...writecache.Option) *shard.Shard {
-	rootPath := t.Name()
+func newCustomShard(t testing.TB, rootPath string, enableWriteCache bool, wcOpts ...writecache.Option) *shard.Shard {
 	if enableWriteCache {
 		rootPath = path.Join(rootPath, "wc")
 	} else {
diff --git a/pkg/local_object_storage/shard/shutdown_test.go b/pkg/local_object_storage/shard/shutdown_test.go
new file mode 100644
index 0000000000..36d13030a5
--- /dev/null
+++ b/pkg/local_object_storage/shard/shutdown_test.go
@@ -0,0 +1,52 @@
+package shard_test
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/nspcc-dev/neofs-node/pkg/core/object"
+	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/shard"
+	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/writecache"
+	cidtest "github.com/nspcc-dev/neofs-sdk-go/container/id/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWriteCacheObjectLoss(t *testing.T) {
+	const (
+		smallSize = 1024
+		objCount  = 100
+	)
+
+	objects := make([]*object.Object, objCount)
+	for i := range objects {
+		size := smallSize
+		//if i%2 == 0 {
+		size = smallSize / 2
+		//}
+		data := make([]byte, size)
+		rand.Read(data)
+
+		objects[i] = generateRawObjectWithPayload(cidtest.ID(), data).Object()
+	}
+
+	dir := t.TempDir()
+	wcOpts := []writecache.Option{
+		writecache.WithSmallObjectSize(smallSize),
+		writecache.WithMaxObjectSize(smallSize * 2)}
+
+	sh := newCustomShard(t, dir, true, wcOpts...)
+
+	for i := range objects {
+		_, err := sh.Put(new(shard.PutPrm).WithObject(objects[i]))
+		require.NoError(t, err)
+	}
+	require.NoError(t, sh.Close())
+
+	sh = newCustomShard(t, dir, true, wcOpts...)
+	defer releaseShard(sh, t)
+
+	for i := range objects {
+		_, err := sh.Get(new(shard.GetPrm).WithAddress(objects[i].Address()))
+		require.NoError(t, err, i)
+	}
+}
diff --git a/pkg/local_object_storage/writecache/writecache.go b/pkg/local_object_storage/writecache/writecache.go
index f3f5c08525..5bdad7e3bc 100644
--- a/pkg/local_object_storage/writecache/writecache.go
+++ b/pkg/local_object_storage/writecache/writecache.go
@@ -140,6 +140,9 @@ func (c *cache) Init() error {
 
 // Close closes db connection and stops services. Executes ObjectCounters.FlushAndClose op.
 func (c *cache) Close() error {
+	// Finish all in-progress operations.
+	c.SetMode(ModeReadOnly)
+
 	close(c.closeCh)
 	c.objCounters.FlushAndClose()
 	return c.db.Close()