refactor(tvix/castore/import): restructure directory uploader a bit r/7927

Have a Option<Box<dyn DirectoryPutter>>, which is lazily initialized
whenever we first want to upload a directory.

Have the loop explicitly break when it encounters the root_node, and
deal with the flushing after the loop.

Deal with the FUTUREWORK (assertion for root directory digest matching
what the DirectoryPutter returns).

Change-Id: Iefc4904d8b8387e868fb752d40e3e4e4218c7407
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11417
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: Connor Brewster <cbrewster@hey.com>

0 files changed, 0 insertions, 0 deletions