[#947] tree: Add method to list all trees

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

pkg/local_object_storage/pilorama/interface.go

@@ -63,6 +63,9 @@ type ForestStorage interface {
 	SetMode(m mode.Mode) error
 	SetParentID(id string)
 	Forest
+
+	// TreeListTrees returns all pairs "containerID:treeID".
+	TreeListTrees(ctx context.Context, prm TreeListTreesPrm) (*TreeListTreesResult, error)
 }
 
 const (
@@ -85,3 +88,44 @@ var ErrInvalidCIDDescriptor = logicerr.New("cid descriptor is invalid")
 func (d CIDDescriptor) checkValid() bool {
 	return 0 <= d.Position && d.Position < d.Size
 }
+
+var treeListTreesBatchSizeDefault = 1000
+
+type ContainerIDTreeID struct {
+	CID    cidSDK.ID
+	TreeID string
+}
+
+type TreeListTreesPrm struct {
+	NextPageToken []byte
+	// BatchSize is batch size to list trees. If not lower or equals zero, than treeListTreesBatchSizeDefault is used.
+	BatchSize int
+}
+
+type TreeListTreesResult struct {
+	NextPageToken []byte
+	Items         []ContainerIDTreeID
+}
+
+func TreeListAll(ctx context.Context, f ForestStorage) ([]ContainerIDTreeID, error) {
+	return treeListAll(ctx, f, treeListTreesBatchSizeDefault)
+}
+
+func treeListAll(ctx context.Context, f ForestStorage, batchSize int) ([]ContainerIDTreeID, error) {
+	var prm TreeListTreesPrm
+	var result []ContainerIDTreeID
+	first := true
+
+	for len(prm.NextPageToken) > 0 || first {
+		first = false
+
+		res, err := f.TreeListTrees(ctx, prm)
+		if err != nil {
+			return nil, err
+		}
+		prm.NextPageToken = res.NextPageToken
+		result = append(result, res.Items...)
+	}
+
+	return result, nil
+}