Reduce IO operations during Loading
Reduce IO operations during Loading

Reviewed By: paulinus

Differential Revision: D29298151

fbshipit-source-id: 1f17130fb2d212c7e3f1b55d987229f8e43fe3bf

mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM