When an export conflict prevents accessing a special remote, be clearer
about what the problem is and how to resolve it.
This commit was sponsored by Trenton Cronholm on Patreon.
I suspect this may be due to SQLITE_IOERR_SHORT_READ, but have not
verified.
I was able to reproduce it on Linux after running the test suite in a loop
for 1-3 hours until it failed.
The WAL mode entry change in 3963c5fcf5
may have hidden the problem I was seeing; I have not seen an ErrorIO
since then.
I don't know the circumstances, but have a report of this:
git-annex: failed to commit changes to sqlite database: Just SQLite3 returned
ErrorConstraint while attempting to perform step.
All 3 tables in the export db have uniqueness constraints on them,
insertUnique is used for all the rest, but this use of insertMany
means it doesn't check the constraint. I guess that's what caused the
crash, but I have not been able to test it yet.
Use putMany when available, as it should be faster than mapM of insertMany.
This commit was sponsored by Brock Spratlen on Patreon.
I don't know why git diff --raw would run the clean filter, but it did
with this version of git. Perhaps it is cleaning the file to generate the
diff to search with -G? But then why would newer gits not run the clean
filter?
It caused git annex to deadlock because the keys database was locked
and ran a git command that ran git-annex, which tried to read from the
keys database.
This commit was sponsored by Brett Eisenberg on Patreon.
Update pointer file next time reconcileStaged is run to recover from the
race.
Note that restagePointerFile causes git to run the clean filter,
and that will run reconcileStaged. So, normally by the time the git
annex get/drop command finishes, the race has already been dealt with.
It may be that, in some case, that won't happen and the race will be
dealt with at a later point. git-annex could run reconcileStaged at
shutdown if that becomes a problem.
This does not handle the situation where the git mv is committed before
git-annex gets a chance to run again. git commit does run the clean
filter, and that happens to re-inject the content if it was supposed to
be dropped but is still populated. But, the case where the file was
supposed to be gotten but is not populated is not handled yet.
This commit was supported by the NSF-funded DataLad project.
The bug occurred when closeDb was not called, and garbage collection of
the DbHandle didn't give the workerThread time to shut down. Fixed by
exiting the runSqlite action when a commit is made.
(MultiWriter mode already forked off a runSqlite action, so avoided the
problem.)
This commit was sponsored by Brock Spratlen on Patreon.
Now when one repository has exported a tree, another repository can get
files from the export, after syncing.
There's a bug: While the database update works, somehow the database on
disk does not get updated, and so the database update is run the next
time, etc. Wasn't able to figure out why yet.
This commit was sponsored by Ole-Morten Duesund on Patreon.
New table needed to look up what filenames are used in the currently
exported tree, for reasons explained in export.mdwn.
Also, added smart constructors for ExportLocation and ExportDirectory to
make sure they contain filepaths with the right direction slashes.
And some code refactoring.
This commit was sponsored by Francois Marier on Patreon.
The subtle part of this is what happens when the remote fails to remove
an empty directory. The removal from the export needs to fail in that
case, so the removal will be tried again later. However, removeExportLocation
has already been run and changed the export db, so if the next run
checks getExportLocation, it might decide nothing remains to be done,
leaving the empty directory.
Dealt with that by making removeEmptyDirectories, handle a failure
by calling addExportLocation, reverting the database changes so the next
run will be guaranteed to try deleting the empty directory again.
This commit was sponsored by Thomas Hochstein on Patreon.
The export database has writes made to it and then expects to read back
the same data immediately. But, the way that Database.Handle does
writes, in order to support multiple writers, makes that not work, due
to caching issues. This resulted in export re-uploading files it had
already successfully renamed into place.
Fixed by allowing databases to be opened in MultiWriter or SingleWriter
mode. The export database only needs to support a single writer; it does
not make sense for multiple exports to run at the same time to the same
special remote.
All other databases still use MultiWriter mode. And by inspection,
nothing else in git-annex seems to be relying on being able to
immediately query for changes that were just written to the database.
This commit was supported by the NSF-funded DataLad project.
Removed uncorrect UniqueKey key in db schema; a key can appear multiple
times with different files.
The database has to be flushed after each removal. But when adding files
to the export, lots of changes are able to be queued up w/o flushing.
So it's still fairly efficient.
If large removals of files from exports are too slow, an alternative
would be to make two passes over the diff, one pass queueing deletions
from the database, then a flush and the a second pass updating the
location log. But that would use more memory, and need to look up
exportKey twice per removed file, so I've avoided such optimisation yet.
This commit was supported by the NSF-funded DataLad project.
Went with a separate db per export remote, rather than a single export
database. Mostly because there will probably not be a lot of separate
export remotes, and it might be convenient to be able to delete a given
remote's export database.
This commit was supported by the NSF-funded DataLad project.
Refactored some common code into initDb.
This only deals with the problem when creating new databases. If a repo
got bad permissions into it, it's up to the user to deal with it.
This commit was sponsored by Ole-Morten Duesund on Patreon.
hSetEncoding of a closed handle segfaults.
https://ghc.haskell.org/trac/ghc/ticket/71618484c0c197 introduced the crash.
In particular, stdin may get closed (by eg, getContents) and then trying
to set its encoding will crash. We didn't need to adjust stdin's
encoding anyway, but only stderr, to work around
https://github.com/yesodweb/persistent/issues/474
Thanks to Mesar Hameed for assistance related to reproducing this bug.
ghc 8 added backtraces on uncaught errors. This is great, but git-annex was
using error in many places for a error message targeted at the user, in
some known problem case. A backtrace only confuses such a message, so omit it.
Notably, commands like git annex drop that failed due to eg, numcopies,
used to use error, so had a backtrace.
This commit was sponsored by Ethan Aubin.
The keys database handle needs to be closed after merging, because the
smudge filter, in another process, updates the database. Old cached info
can be read for a while from the open database handle; closing it ensures
that the info written by the smudge filter is available.
This is pretty horribly ad-hoc, and it's especially nasty that the
transferrer closes the database every time.
This is a mostly backwards compatable change. I broke backwards
compatability in the case where a filename starts with double-quote.
That seems likely to be very rare, and v6 unlocked files are a new feature
anyway, and fsck needs to fix missing associated file mappings anyway. So,
I decided that is good enough.
The encoding used is to just show the String when it contains a problem
character. While that adds some overhead to addAssociatedFile and
removeAssociatedFile, those are not called very often. This approach has
minimal decode overhead, because most filenames won't be encoded that way,
and it only has to look for the leading double-quote to skip the expensive
read. So, getAssociatedFiles remains fast.
I did consider using ByteString instead, but getting a FilePath converted
with all chars intact, even surrigates, is difficult, and it looks like
instance PersistField ByteString uses Text, which I don't trust for problem
encoded data. It would probably be slower too, and it would make the
database less easy to inspect manually.
This lets readonly repos be used. If a repo is readonly, we can ignore the
keys database, because nothing that we can do will change the state of the
repo anyway.
