tree 1f209a386d1d1c26f71eed5618974cadba180eb9
parent 3d2bb2a400c48bc51e43db11ac154d999a97881b
author Googler <chiwang@google.com> 1666614619 -0700
committer Copybara-Service <copybara-worker@google.com> 1666614701 -0700

Check digest of local file to decide whether to re-download it.

Normally, for a non-clean build (outputBase is not clean), skyframe is able to detect modifications, invalid the action, and rerun. Before rerun, it will delete the stales outputs. So we only use `path.exists()` to decide whether we should download an input.

However, there are some files  under the outputBase are not tracked by skyframe. In that case, we could wrongly use a staled output.

PiperOrigin-RevId: 483352318
Change-Id: I7e100100e6c3218630c5dc9bf3f900b2de232e0e