slicer: Fixed object upload in some cases

The case when the reader returns io.EOF with the last data chunk. Slicer was closing the writer without payload writing.

Signed-off-by: Evgenii Baidakov <evgenii@nspcc.io>

object/slicer/slicer.go

@@ -173,24 +173,26 @@ func slice(ctx context.Context, ow ObjectWriter, header object.Object, data io.R
 
 	for {
 		n, err = data.Read(bChunk)
-		if err != nil {
-			if !errors.Is(err, io.EOF) {
-				return rootID, fmt.Errorf("read payload chunk: %w", err)
+		if n > 0 {
+			if _, err = writer.Write(bChunk[:n]); err != nil {
+				return oid.ID{}, err
 			}
+		}
 
-			// no more data to read
-
-			if err = writer.Close(); err != nil {
-				return rootID, fmt.Errorf("writer close: %w", err)
-			}
+		if err == nil {
+			continue
+		}
 
-			rootID = writer.ID()
-			break
+		if !errors.Is(err, io.EOF) {
+			return rootID, fmt.Errorf("read payload chunk: %w", err)
 		}
 
-		if _, err = writer.Write(bChunk[:n]); err != nil {
-			return oid.ID{}, err
+		if err = writer.Close(); err != nil {
+			return rootID, fmt.Errorf("writer close: %w", err)
 		}
+
+		rootID = writer.ID()
+		break
 	}
 
 	return rootID, nil

object/slicer/slicer_test.go

@@ -269,6 +269,30 @@ func testSlicer(t *testing.T, size, sizeLimit uint64) {
 	}
 }
 
+// eofOnLastChunkReader is a special reader for tests. It returns io.EOF with the last data portion.
+type eofOnLastChunkReader struct {
+	isZeroOnEOF bool
+	payload     []byte
+	i           int
+}
+
+func (l *eofOnLastChunkReader) Read(p []byte) (int, error) {
+	n := copy(p, l.payload[l.i:])
+	l.i += n
+
+	if l.i == len(l.payload) {
+		if n == 0 {
+			return 0, io.EOF
+		}
+
+		if !l.isZeroOnEOF {
+			return n, io.EOF
+		}
+	}
+
+	return n, nil
+}
+
 func testSlicerByHeaderType(t *testing.T, checker *slicedObjectChecker, in input, opts slicer.Options) {
 	ctx := context.Background()
 
@@ -296,6 +320,34 @@ func testSlicerByHeaderType(t *testing.T, checker *slicedObjectChecker, in input
 		checker.chainCollector.verify(checker.input, rootID)
 	})
 
+	t.Run("slicer.Put, io.EOF in last chunk", func(t *testing.T) {
+		checker.chainCollector = newChainCollector(t)
+
+		var hdr object.Object
+		hdr.SetSessionToken(opts.Session())
+		hdr.SetContainerID(in.container)
+		hdr.SetOwnerID(&in.owner)
+		hdr.SetAttributes(in.attributes...)
+
+		rootID, err := slicer.Put(ctx, checker, hdr, checker.input.signer, &eofOnLastChunkReader{payload: in.payload}, opts)
+		require.NoError(t, err)
+		checker.chainCollector.verify(checker.input, rootID)
+	})
+
+	t.Run("slicer.Put, io.EOF after last chunk", func(t *testing.T) {
+		checker.chainCollector = newChainCollector(t)
+
+		var hdr object.Object
+		hdr.SetSessionToken(opts.Session())
+		hdr.SetContainerID(in.container)
+		hdr.SetOwnerID(&in.owner)
+		hdr.SetAttributes(in.attributes...)
+
+		rootID, err := slicer.Put(ctx, checker, hdr, checker.input.signer, &eofOnLastChunkReader{payload: in.payload, isZeroOnEOF: true}, opts)
+		require.NoError(t, err)
+		checker.chainCollector.verify(checker.input, rootID)
+	})
+
 	t.Run("Slicer.InitPut", func(t *testing.T) {
 		checker.chainCollector = newChainCollector(t)