Joey Hess [Tue, 28 Dec 2021 17:23:32 +0000 (13:23 -0400)]
handle transitions with read-only unmerged git-annex branches
Capstone to this feature. Any transitions that have been performed on an
unmerged remote ref but not on the local git-annex branch, or vice-versa
have to be applied on the fly when reading files.
Joey Hess [Mon, 27 Dec 2021 19:28:31 +0000 (15:28 -0400)]
handle Annex.Branch.files with read-only unmerged git-annex branches
It would be difficult to make Annex.Branch.files query the unmerged
git-annex branches. Might be possible, similar to what was discussed in 7f6b2ca49cd6f6b6dd6cc9e96d0232a213a82e63 but again I decided to make it
not do anything in that situation to start with before adding such a
complicated thing.
git-annex info uses it when getting info about a repostory. The choices
were to make that fail with an error, or display the info it can, and
change the output slightly for the bits of info it cannot access. While
that is a behavior change, and I want to avoid any behavior changes due
to unmerged git-annex branches in a read-only repo, displaying a message
that is not a number seems unlikely to break anything that was consuming
a number, any worse than throwing an exception would. Probably.
Also git-annex unused --from origin is made to throw an error, but
it would fail later anyway when trying to write to the unused log files.
Joey Hess [Mon, 27 Dec 2021 18:30:51 +0000 (14:30 -0400)]
handle overBranchFileContents with read-only unmerged git-annex branches
This makes --all error out in that situation. Which is better than
ignoring information from the branches.
To really handle the branches right, overBranchFileContents would need
to both query all the branches and union merge file contents
(or perhaps not provide any file content), as well as diffing between
branches to find files that are only present in the unmerged branches.
And also, it would need to handle transitions..
Joey Hess [Mon, 27 Dec 2021 18:08:50 +0000 (14:08 -0400)]
disable precaching git-annex branch when there are unmerged branches in a read-only repo
The way precaching works, it can't merge in information from those
branches efficiently, so just disable it and fall back to
Annex.Branch.get in order to get the correct information.
Joey Hess [Sun, 26 Dec 2021 18:28:42 +0000 (14:28 -0400)]
merge git-annex branch in memory in read-only repository
Improved support for using git-annex in a read-only repository, git-annex
branch information from remotes that cannot be merged into the git-annex
branch will now not crash it, but will be merged in memory.
To avoid this making git-annex behave one way in a read-only repository,
and another way when it can write, it's important that Annex.Branch.get
return the same thing (modulo log file compaction) in both cases.
This manages that mostly. There are some exceptions:
- When there is a transition in one of the remote git-annex branches
that has not yet been applied to the local or other git-annex branches.
Transitions are not handled.
- `git-annex log` runs git log on the git-annex branch, and so
it will not be able to show information coming from the other, not yet
merged branches.
- Annex.Branch.files only looks at files in the git-annex branch and not
unmerged branches. This affects git-annex info output.
- Annex.Branch.hs.overBranchFileContents ditto. Affects --all and
also importfeed (but importfeed cannot work in a read-only repo
anyway).
- CmdLine.Seek.seekFilteredKeys when precaching location logs.
Note use of Annex.Branch.fullname
- Database.ContentIdentifier.needsUpdateFromLog and updateFromLog
These warts make this not suitable to be merged yet.
This readonly code path is more expensive, since it has to query several
branches. The value does get cached, but still large queries will be
slower in a read-only repository when there are unmerged git-annex
branches.
When annex.merge-annex-branches=false, updateTo skips doing anything,
and so the read-only repository code does not get triggered. So a user who
is bothered by the extra work can set that.
Other writes to the repository can still result in permissions errors.
This includes the initial creation of the git-annex branch, and of course
any writes to the git-annex branch.
Joey Hess [Thu, 23 Dec 2021 18:44:03 +0000 (14:44 -0400)]
improve sync message in export edge case
sync: Better error message when unable to export to a remote because
remote.name.annex-tracking-branch is configured to a ref that does not
exist.
It does not suggest how to fix the problem because there are several
possible solutions: Change the git config to point to something that does
exist, git add some files, or put files on the special remote that will be
imported and so populate the ref.
I considered just silently not doing anything, which is what it does
when annex-tracking-branch = master and nothing has been committed to
master yet. But it seems better to be explicit about it, since this is a
fairly confusing situation to find yourself in.
Joey Hess [Tue, 14 Dec 2021 15:48:07 +0000 (11:48 -0400)]
improve git command queue flushing with time limit
So that eg, addurl of several large files that take time to download will
update the index for each file, rather than deferring the index updates to
the end.
In cases like an add of many smallish files, where a new file is being
added every few seconds. In that case, the queue will still build up a
lot of changes which are flushed at once, for best performance. Since
the default queue size is 10240, often it only gets flushed once at the
end, same as before. (Notice that updateQueue updated _lastchanged
when adding a new item to the queue without flushing it; that is
necessary to avoid it flushing the queue every 5 minutes in this case.)
But, when it takes more than a 5 minutes to add a file, the overhead of
updating the index immediately is probably small, so do it after each
file. This avoids git-annex potentially taking a very very long time
indeed to stage newly added files, which can be annoying to the user who
would like to get on with doing something with the files it's already
added, eg using git mv to rename them to a better name.
This is only likely to cause a problem if it takes say, 30 seconds to
update the index; doing an extra 30 seconds of work after every 5
minute file add would be less optimal. Normally, updating the index takes
significantly less time than that. On a SSD with 100k files it takes
less than 1 second, and the index write time is bound by disk read and
write so is not too much worse on a hard drive. So I hope this will not
impact users, although if it does turn out to, the time limit could be
made configurable.
A perhaps better way to do it would be to have a background worker
thread that wakes up every 60 seconds or so and flushes the queue.
That is made somewhat difficult because the queue can contain Annex
actions and so this would add a new source of concurrency issues.
So I'm trying to avoid that approach if possible.
Joey Hess [Thu, 9 Dec 2021 19:25:59 +0000 (15:25 -0400)]
fix error message
Was "failed to generate a key" when key generation did not fail
(it never does anymore) but the actual problem was it failed to stat
the source file, perhaps due to it being deleted while the key was being
generated.
A user reported this, in a comment I followed up on in 262400fe0417f447ab48ab6be799c43d3222a233, although I don't know
what they did to trigger the error message.
Joey Hess [Wed, 8 Dec 2021 19:08:02 +0000 (15:08 -0400)]
Fix build with ghc 9.0.1
Continuing along the same lines as commit 2739adc25814633b18174982977e00e809cb789e, it seems that
while Remote -> Retriever expands to the same data type this changes
it to, ghc 9.0.1 refuses to consider them equiviant. I guess it has
something to do with the forall?
The rest of the build all succeeds, although the stack build then crashes:
Linking .stack-work/dist/x86_64-linux-tinfo6/Cabal-3.4.0.0/build/git-annex/git-annex ...
Completed 233 action(s).
Prelude.chr: bad argument: 2214592520
This issue seems likely to be about it:
https://github.com/commercialhaskell/stack/pull/5508
I'm building with stack from debian, version 2.3.3, so a newer stack
probably avoids that. Anyway, despite that stack problem,
the git-annex binary is built, and works.
The stack.yaml I used for this build was patched as follows:
Joey Hess [Mon, 6 Dec 2021 19:01:39 +0000 (15:01 -0400)]
close pid lock only once no threads use it
This fixes a FD leak when annex.pidlock is set and -J is used. Also, it
fixes bugs where the pid lock file got deleted because one thread was
done with it, while another thread was still holding it open.
The LockPool now has two distinct types of resources,
one is per-LockHandle and is used for file Handles, which get closed
when the associated LockHandle is closed. The other one is per lock
file, and gets closed when no more LockHandles use that lock file,
including other shared locks of the same file.
That latter kind is used for the pid lock file, so it's opened by the
first thread to use a lock, and closed when the last thread closes a lock.
In practice, this means that eg git-annex get of several files opens and
closes the pidlock file a few times per file. While with -J5 it will open
the pidlock file, process a number of files, until all the threads happen to
finish together, at which point the pidlock file gets closed, and then
that repeats. So in either case, another process still gets a chance to
take the pidlock.
registerPostRelease has a rather intricate dance, there are fine-grained
STM locks, a STM lock of the pidfile itself, and the actual pidlock file
on disk that are all resolved in stages by it.
A LockHandle contains an action that will close the underlying lock
file, and that action is run when it is closed. In the case of a shared
lock, the lock file is opened once for each LockHandle, and only
the one for the LockHandle that is being closed will be closed.
Joey Hess [Fri, 3 Dec 2021 21:20:21 +0000 (17:20 -0400)]
fine-grained locking when annex.pidlock is enabled
This locking has been missing from the beginning of annex.pidlock.
It used to be possble, when two threads are doing conflicting things,
for both to run at the same time despite using locking. Seems likely
that nothing actually had a problem, but it was possible, and this
eliminates that possible source of failure.
projects / git-annex.git / log