[#1686] local_object_storage: Add generic tests

Use them for writecache as a simple example.

Signed-off-by: Evgenii Stratonikov <evgeniy@morphbits.ru>

pkg/local_object_storage/internal/storagetest/storage.go

@@ -0,0 +1,120 @@
+package storagetest
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/shard/mode"
+	"github.com/stretchr/testify/require"
+)
+
+// Component represents single storage component.
+type Component interface {
+	Open(bool) error
+	SetMode(mode.Mode) error
+	Init() error
+	Close() error
+}
+
+// Constructor constructs storage component.
+// Each call must create a component using different file-system path.
+type Constructor = func(t *testing.T) Component
+
+// TestAll checks that storage component doesn't panic under
+// any circumstances during shard operation.
+func TestAll(t *testing.T, cons Constructor) {
+	modes := []mode.Mode{
+		mode.ReadWrite,
+		mode.ReadOnly,
+		mode.Degraded,
+		mode.DegradedReadOnly,
+	}
+
+	t.Run("close after open", func(t *testing.T) {
+		TestCloseAfterOpen(t, cons)
+	})
+	t.Run("close twice", func(t *testing.T) {
+		TestCloseTwice(t, cons)
+	})
+	t.Run("set mode", func(t *testing.T) {
+		for _, m := range modes {
+			t.Run(m.String(), func(t *testing.T) {
+				TestSetMode(t, cons, m)
+			})
+		}
+	})
+	t.Run("mode transition", func(t *testing.T) {
+		for _, from := range modes {
+			for _, to := range modes {
+				TestModeTransition(t, cons, from, to)
+			}
+		}
+	})
+}
+
+// TestCloseAfterOpen checks that `Close` can be done right after `Open`.
+// Use-case: open shard, encounter error, close before the initialization.
+func TestCloseAfterOpen(t *testing.T, cons Constructor) {
+	t.Run("RW", func(t *testing.T) {
+		// Use-case: irrecoverable error on some components, close everything.
+		s := cons(t)
+		require.NoError(t, s.Open(false))
+		require.NoError(t, s.Close())
+	})
+	t.Run("RO", func(t *testing.T) {
+		// Use-case: irrecoverable error on some components, close everything.
+		// Open in read-only must be done after the db is here.
+		s := cons(t)
+		require.NoError(t, s.Open(false))
+		require.NoError(t, s.Init())
+		require.NoError(t, s.Close())
+
+		require.NoError(t, s.Open(true))
+		require.NoError(t, s.Close())
+	})
+}
+
+// TestCloseTwice checks that `Close` can be done twice.
+func TestCloseTwice(t *testing.T, cons Constructor) {
+	// Use-case: move to maintenance mode twice, first time failed.
+	s := cons(t)
+	require.NoError(t, s.Open(false))
+	require.NoError(t, s.Init())
+	require.NoError(t, s.Close())
+	require.NoError(t, s.Close()) // already closed, no-op
+}
+
+// TestSetMode checks that any mode transition can be done safely.
+func TestSetMode(t *testing.T, cons Constructor, m mode.Mode) {
+	t.Run("before init", func(t *testing.T) {
+		// Use-case: metabase `Init` failed,
+		// call `SetMode` on all not-yet-initialized components.
+		s := cons(t)
+		require.NoError(t, s.Open(false))
+		require.NoError(t, s.SetMode(m))
+
+		t.Run("after open in RO", func(t *testing.T) {
+			require.NoError(t, s.Close())
+			require.NoError(t, s.Open(true))
+			require.NoError(t, s.SetMode(m))
+		})
+
+		require.NoError(t, s.Close())
+	})
+	t.Run("after init", func(t *testing.T) {
+		s := cons(t)
+		// Use-case: notmal node operation.
+		require.NoError(t, s.Open(false))
+		require.NoError(t, s.Init())
+		require.NoError(t, s.SetMode(m))
+	})
+}
+
+func TestModeTransition(t *testing.T, cons Constructor, from, to mode.Mode) {
+	// Use-case: normal node operation.
+	s := cons(t)
+	require.NoError(t, s.Open(false))
+	require.NoError(t, s.Init())
+	require.NoError(t, s.SetMode(from))
+	require.NoError(t, s.SetMode(to))
+	require.NoError(t, s.Close())
+}

pkg/local_object_storage/writecache/generic_test.go

@@ -0,0 +1,29 @@
+package writecache
+
+import (
+	"os"
+	"path/filepath"
+	"strconv"
+	"testing"
+
+	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/internal/storagetest"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zaptest"
+)
+
+func TestGeneric(t *testing.T) {
+	defer func() { _ = os.RemoveAll(t.Name()) }()
+
+	var n int
+	newCache := func(t *testing.T) storagetest.Component {
+		n++
+		dir := filepath.Join(t.Name(), strconv.Itoa(n))
+		require.NoError(t, os.MkdirAll(dir, os.ModePerm))
+		return New(
+			WithLogger(zaptest.NewLogger(t)),
+			WithFlushWorkersCount(2),
+			WithPath(dir))
+	}
+
+	storagetest.TestAll(t, newCache)
+}

pkg/local_object_storage/writecache/writecache.go

@@ -80,7 +80,6 @@ var (
 func New(opts ...Option) Cache {
 	c := &cache{
 		flushCh: make(chan *object.Object),
-		closeCh: make(chan struct{}),
 		mode:    mode.ReadWrite,
 
 		compressFlags: make(map[string]struct{}),
@@ -121,11 +120,13 @@ func (c *cache) Open(readOnly bool) error {
 		return err
 	}
 
-	if c.objCounters == nil {
-		c.objCounters = &counters{
-			db: c.db,
-			fs: c.fsTree,
-		}
+	// Opening after Close is done during maintenance mode,
+	// thus we need to create a channel here.
+	c.closeCh = make(chan struct{})
+
+	c.objCounters = &counters{
+		db: c.db,
+		fs: c.fsTree,
 	}
 
 	return c.objCounters.Read()
@@ -145,14 +146,25 @@ func (c *cache) Close() error {
 		return err
 	}
 
-	close(c.closeCh)
+	if c.closeCh != nil {
+		close(c.closeCh)
+	}
 	c.wg.Wait()
+	if c.closeCh != nil {
+		c.closeCh = nil
+	}
 
 	if c.objCounters != nil {
 		c.objCounters.FlushAndClose()
+		c.objCounters = nil
 	}
+
+	var err error
 	if c.db != nil {
-		return c.db.Close()
+		err = c.db.Close()
+		if err != nil {
+			c.db = nil
+		}
 	}
 	return nil
 }