Turns out that Data.List.Utils.split is slow and makes a lot of
allocations. Here's a much simpler single character splitter that behaves
the same (even in wacky corner cases) while running in half the time and
75% the allocations.
As well as being an optimisation, this helps move toward eliminating use of
missingh.
(Data.List.Split.splitOn is nearly as slow as Data.List.Utils.split and
allocates even more.)
I have not benchmarked the effect on git-annex, but would not be surprised
to see some parsing of eg, large streams from git commands run twice as
fast, and possibly in less memory.
This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
Having one module that knows about all the filenames used on the branch
allows working back from an arbitrary filename to enough information about
it to implement dropping dead remotes and doing other log file compacting
as part of a forget transition.
Monitors git-annex branch for changes, which are noticed by the Merger
thread whenever the branch ref is changed (either due to an incoming push,
or a local change), and refreshes cached config values for modified config
files.
Rate limited to run no more often than once per minute. This is important
because frequent git-annex branch changes happen when files are being
added, or transferred, etc.
A primary use case is that, when preferred content changes are made,
and get pushed to remotes, the remotes start honoring those settings.
Other use cases include propigating repository description and trust
changes to remotes, and learning when a remote has added a new special
remote, so the webapp can present the GUI to enable that special remote
locally.
Also added a uuid.log cache. All other config files already had caches.
semitrusted uuids rarely are listed in trust.log, so a special case
is needed to get a list of them. Take the difference of all known uuids
with non-semitrusted uuids.