Optimise database to further speed up importing large trees from special
remotes.
See comment for details of why the other index didn't help cid queries.
It would probably be better to manually create an index on only cid, rather
than adding a second uniqueness constraint that is a larger index. But
persitent does not support creating indexes, and an attempt to manually add
it to the migration failed.
Sponsored-by: Nicholas Golder-Manning on Patreon
This avoids bottlenecking on git check-ignore in a particular situation.
Also, there may have been a correctness issue with it not having updated it.
When the exportdb is already up-to-date, this is not expensive. And the
exportdb is updated elsewhere, so usually it is up-to-date.
Sponsored-by: Joshua Antonishen on Patreon
Speeds up sync in an adjusted branch by avoiding re-adjusting the branch
unncessarily, particularly when it is adjusted with --hide-missing or
--unlock-present.
When there are a lot of files, that was the majority of the time of a
--no-content sync.
Uses a log file, which is updated when content presence changes. This
adds a little bit of overhead to every file get/drop when on such an
adjusted branch. The overhead is minimal for get of any size of file,
but might be noticable for drop in some cases. It seems like a reasonable
trade-off. It would be possible to update the log file only at the end, but
then it would not happen if the command is interrupted.
When not in an adjusted branch, there should be no additional overhead.
(getCurrentBranch is an MVar read, and it avoids the MVar read of
getGitConfig.)
Note that this does not deal with situations such as:
git checkout master, git-annex get, git checkout adjusted branch,
git-annex sync. The sync won't know that the adjusted branch needs to be
updated. Dealing with that would add overhead to operation in non-adjusted
branches, which I don't like. Also, there are other situations like having
two adjusted branches that both need to be updated like this, and switching
between them and sync not updating.
This does mean a behavior change to sync, since it did previously deal
with those situations. But, the documentation did not say that it did.
The man pages only talk about sync updating the adjusted branch after
it transfers content.
I did consider making sync keep track of content it transferred (and
dropped) and only update the adjusted branch then, not to catch up to other
changes made previously. That would perform better. But it seemed rather
hard to implement, and also it would have problems with races with a
concurrent get/drop, which this implementation avoids.
And it seemed pretty likely someone had gotten used to get/drop followed by
sync updating the branch. It seems much less likely someone is switching
branches, doing get/drop, and then switching back and expecting sync to update
the branch.
Re-running git-annex adjust still does a full re-adjusting of the branch,
for anyone who needs that.
Sponsored-by: Leon Schuermann on Patreon
Introduced recently in commit 64fc34b3da.
adjustBranch changes the sha that is recorded for the current branch
(eg the adjusted branch). So, have to get the original sha before
calling it.
Sponsored-by: Jack Hill on Patreon
Updating an adjusted branch can take a while when there are a lot of
files. HEAD was detached at the start, so if eg git-annex sync was
interrupted at the wrong point, there was a possibly wide window where
it would leave the repo with HEAD detached.
There's still a window, just much narrower. I don't know if it's
possible to close the window entirely. While git can clearly update
the currently checked out branch in eg git merge, it doesn't seem to
provide another way to do it.
Sponsored-by: Graham Spencer on Patreon
Speeds up eg git-annex sync --content by up to 50%. When it does not need
to transfer or drop anything, it now noops a lot more quickly.
I didn't see anything else in sync --content noop loop that could really
be sped up. It has to cat git objects to keys, stat object files, etc.
Sponsored-by: unqueued on Patreon
Reading from the cidsdb is responsible for about 25% of the runtime of
an import. Since the cidmap is used to store the same information in
ram, the cidsdb is not written to during an import any longer. And so,
if it started off empty (and updateFromLog wasn't needed), those reads
can just be skipped.
This is kind of a cheesy optimisation, since after any import from any
special remote, the database will no longer be empty, so it's a single
use optimisation. But it's probably not uncommon to start by importing a
lot of files, and it can save a lot of time then.
Sponsored-by: Brock Spratlen on Patreon
This didn't used to be needed because importKeys would import all
content and so doing another pass was redundant.
But since 40017089f2 it uses
importChanges, so only new files are imported. If a file that was
already imported before was dropped, that would prevent sync --content
from gettng its content again.
Sponsored-by: Jack Hill on Patreon
