The normalisation of filenames turns out to be the tricky part here,
because the associated files coming out of the keys db may look like
"./foo/bar" or "../bar". For the former to match a glob like "foo/*",
it needs to be normalised.
Note that, on windows, normalise "./foo/bar" = "foo\\bar"
which a glob like "foo/*" won't match. So the glob is matched a second
time, on the toInternalGitPath, so allowing the user to provide a glob
with the slashes in either direction. However, this still won't support
some wacky edge cases like the user providing a glob of "foo/bar\\*"
Sponsored-by: Dartmouth College's Datalad project
When two files have the same content, and a required content expression
matches one but not the other, dropping the latter file will fail as it
would also remove the content of the required file.
This will slow down drop (w/o --auto), dropunused, mirror, and move, by one
keys db lookup per file. But I did include an optimisation to avoid a
double db lookup in the drop --auto / sync --content case. I suspect that
dropunused could also use PreferredContentChecked True, but haven't
entirely thought it through and it's rarely used with enough files for the
optimisation to matter.
Sponsored-by: Dartmouth College's Datalad project
git-annex test hung, at varying points depending
on when git decided to run the smudge clean filter.
Recent changes to reconcileStaged caused a deadlock, when git write-tree
for some reason decides to run the smudge clean filter. Which tries
to open the keys db, and blocks waiting for the lock file that its
grandparent has locked.
I don't know why git write-tree does that. It's supposed to only write a
tree from the index which needs no smudge/clean filtering.
I've verified that, in a situation where git write-tree runs the clean
filter, disabling the filter results in a tree being written that
contains the annex link, not eg, the worktree file content. So it seems
safe to disable the clean filter, but also this seems likely to be
working around a bug in git because it seems it is running the clean
filter in a situation where the object has already been cleaned.
Sponsored-by: Dartmouth College's Datalad project
When the keys db is opened for read, and did not exist yet, it used to
skip creating it, and return mempty values. But that prevents
reconcileStaged from populating associated files information in time for
the read. This fixes the one remaining case I know of where
the fix in a56b151f90 didn't work.
Note that, when there is a permissions error, it still avoids creating
the db and returns mempty for all queries. This does mean that
reconcileStaged does not run and so it may want to drop files that it
should not. However, presumably a permissions error on the keys database
also means that the user does not have permission to delete annex
objects, so they won't be able to drop the files anyway.
Sponsored-by: Dartmouth College's Datalad project
* drop: When two files have the same content, and a preferred content
expression matches one but not the other, do not drop the file.
* sync --content, assistant: Fix an edge case where a file that is not
preferred content did not get dropped.
The sync --content edge case is that handleDropsFrom loaded associated files
and used them without verifying that the information from the database was
not stale.
It seemed best to avoid changing --want-drop's behavior, this way when
debugging a preferred content expression with it, the files matched will
still reflect the expression. So added a note to the --want-drop documentation,
to make clear it may not behave identically to git-annex drop --auto.
While it would be possible to introspect the preferred content
expression to see if it matches on filenames, and only look up the
associated files when it does, it's generally fairly rare for 2 files to
have the same content, and the database lookup is already avoided when
there's only 1 file, so I did not implement that further optimisation.
Note that there are still some situations where the associated files
database does not get locked files recorded in it, which will prevent
this fix from working.
Sponsored-by: Dartmouth College's Datalad project
All code that uses associated files already deals with this problem,
which used to be worse. Unfortunately I was not able to entirely
eliminate it, although it happens in fewer cases now.
Eg, when git commit runs the smudge filter.
Commit 428c91606b introduced the crash,
as write-tree fails in those situations. Now it will work, and git-annex
always gets up-to-date information even in those situations. It does
need to do a bit more work, each time git-annex is run with the index
locked. Although if the index is unmodified from the last time
write-tree succeeded, that work is avoided.
