Module spool 

Where write buffers and read caches are spooled.

Both the write path and the read path back their temp files with real disk, never $TMPDIR: on most current Linux distros /tmp is a tmpfs, so spooling a multi-gigabyte upload there fills RAM and gets the process stopped by the OOM killer. The spool lives under the user’s cache directory instead.

The files stay unlinked (tempfile::tempfile_in), so a crash reclaims their space with no cleanup pass and no leftovers.

Enums

CacheConvention

Cache-directory convention to follow when no explicit spool dir is given.

Functions

prepare_spool_dir

Create the spool directory if needed and prove it’s writable.

resolve_spool_dir

Resolve the spool directory from an optional override and the environment.

spool_dir_from_env

Resolve the spool directory from the live environment.