Is there a way to create sparse files from Rust? Here, by Sparse file I mean files where if an entire Page is 0, the OS optimizes it away.
Googling, there are various ways to create such files via truncate or dd. However, I can't find anyway to create one from Rust (googling returns sparse linear algebra libraries).
[Context: for mmapped on-disk b-trees, if we drop an entire page, we don't want it to waste disk space.]