[#0] tree: Split GetOpLog stream

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/services/tree/sync.go

@@ -219,19 +219,26 @@ func (s *Service) startStream(ctx context.Context, cid cid.ID, treeID string,
 
 	rawCID := make([]byte, sha256.Size)
 	cid.Encode(rawCID)
+	from := height
+	const batchSize = 10_000
 
+	for {
+		count := 0
 		req := &GetOpLogRequest{
 			Body: &GetOpLogRequest_Body{
 				ContainerId: rawCID,
 				TreeId:      treeID,
-			Height:      height,
+				Height:      from,
 			},
 		}
 		if err := SignMessage(req, s.key); err != nil {
 			return err
 		}
 
-	c, err := treeClient.GetOpLog(ctx, req)
+		streamCtx, cancel := context.WithCancel(ctx)
+		defer cancel()
+
+		c, err := treeClient.GetOpLog(streamCtx, req)
 		if err != nil {
 			return fmt.Errorf("can't initialize client: %w", err)
 		}
@@ -245,12 +252,24 @@ func (s *Service) startStream(ctx context.Context, cid cid.ID, treeID string,
 			if err := m.Meta.FromBytes(lm.GetMeta()); err != nil {
 				return err
 			}
+			from = m.Time
 			opsCh <- m
+			count++
+			if count == batchSize {
+				break // c.Recv()
+			}
+		}
+		if err == nil {
+			// count == batchSize
+			// close current stream and start new one
+			cancel()
+			continue
+		}
+		if errors.Is(err, io.EOF) {
+			return nil
 		}
-	if !errors.Is(err, io.EOF) {
 		return err
 	}
-	return nil
 }
 
 // synchronizeTree synchronizes operations getting them from different nodes.