This avoids all the complication about redundant work discussed in
the previous try at fixing this. At the expense of needing each command
that could have the problem to be patched to simply wrap the action in
onlyActionOn once the key is known. But there do not seem to be many
such commands.
onlyActionOn' should not be used with a CommandStart (or CommandPerform),
although the types do allow it. onlyActionOn handles running the whole
CommandStart chain. I couldn't immediately see a way to avoid mistken
use of onlyActionOn'.
This commit was supported by the NSF-funded DataLad project.
After a false start, I found a fairly non-intrusive way to deal with it.
Although it only handles transfers -- there may be issues with eg
concurrent dropping of the same key, or other operations.
There is no added overhead when -J is not used, other than an added
inAnnex check. When -J is used, it has to maintain and check a small
Set, which should be negligible overhead.
It could output some message saying that the transfer is being done by
another thread. Or it could even display the same progress info for both
files that are being downloaded since they have the same content. But I
opted to keep it simple, since this is rather an edge case, so it just
doesn't say anything about the transfer of the file until the other
thread finishes.
Since the deferred transfer action still runs, actions that do more than
transfer content will still get a chance to do their other work. (An
example of something that needs to do such other work is P2P.Annex,
where the download always needs to receive the content from the peer.)
And, if the first thread fails to complete a transfer, the second thread
can resume it.
But, this unfortunately means that there's a risk of redundant work
being done to transfer a key that just got transferred.
That's not ideal, but should never cause breakage; the same
thing can occur when running two separate git-annex processes.
The get/move/copy/mirror --from commands had extra inAnnex checks added,
inside the download actions. Without those checks, the first thread
downloaded the content, and then the second thread woke up and
downloaded the same content redundantly.
move/copy/mirror --to is left doing redundant uploads for now. It
would need a second checkPresent of the remote inside the upload
to avoid them, which would be expensive. A better way to avoid
redundant work needs to be found..
This commit was supported by the NSF-funded DataLad project.
Added remote configuration settings annex-ignore-command and
annex-sync-command, which are dynamic equivilants of the annex-ignore
and annex-sync configurations.
For this I needed a new DynamicConfig infrastructure. Its implementation
should be as fast as before when there is no dynamic config, and it caches
so shell commands are only run once.
Note that annex-ignore-command exits nonzero when the remote should be ignored.
While that may seem backwards, it allows using the same command for it as
for annex-sync-command when you want to disable both.
This commit was sponsored by Trenton Cronholm on Patreon.
When ssh connection caching is enabled (and when GIT_ANNEX_USE_GIT_SSH is
not set), only one ssh password prompt will be made per host, and only one
ssh password prompt will be made at a time.
This also fixes a race in prepSocket's stale ssh connection stopping
when run with -J. It was possible for one thread to start a cached ssh
connection, and another thread to immediately stop it, resulting in excess
connections being made.
This commit was supported by the NSF-funded DataLad project.
It takes a single key-value backend, rather than the unncessary and confusing list.
The old option still works if set.
Simplified some old old code too.
This commit was sponsored by Thomas Hochstein on Patreon.
It was distributing jobs to remotes that were not being used by any other
job. But, suppose that there are only 2 remotes, and -J10. In such a case,
the first 2 downloads would be distributed amoung the 2 remotes, but
the other 8 would all go to remote #1. Improved by keeping a counter
of how many jobs are assigned to a remote, and prefer remotes with fewer
jobs.
Note use of Data.Map.Strict to avoid blowing up space. I kept the
bang-patterns as-is, although probably not needed with Data.Map.Strict.
This commit was sponsored by Jack Hill on Patreon.
... to control the default behavior in all clones of a repository.
This includes a new Configurable data type, so the GitConfig type indicates
which values can be configured this way.
The implementation should be quite efficient; the config log is only read
once, and only when a Configurable value has not already been set by
git-config.
Indeed, it would be nice in the future to extend this, so that git-config
is itself only read on demand. Some commands may not need to look at the
git configuration at all.
This commit was sponsored by Trenton Cronholm on Patreon.
Any config names can be set using this; git-annex commands will only look
at specific ones that make sense and are worth the overhead of querying the
branch.
This might also be useful for storing whatever other config-type stuff the
user might want to shove into the git-annex branch.
This commit was sponsored by Jochen Bartl on Patreon.
Speeds up commands like "git-annex find --in remote" by over 50%.
Profiling showed that adjustGitEnv was 21% of the time and 37% of the
allocations of that command. It copied the environment each time with
getEnvironment.
The only repeated use of adjustGitEnv is in withIndexFile, which tends to
be run at least once per file. So, it was optimised by keeping a cache of
the environment, which can be reused.
There could be other better ways to optimise this. Maybe get the while
environment once at startup. But, then it would have to be serialized back
out each time running a child process, so I doubt that would be a net win.
It might be better to cache a version of the environment that is
pre-modified to use .git-annex/index. But, profiling doesn't show that
modifying the enviroment is taking any significant time.
This makes -Jn work with --json and --quiet, where before
setting -Jn disabled those options.
Concurrent json output is currently a mess though since threads output
chunks over top of one-another.
Only done in -J mode because only if there's concurrency can downloading
from two remotes be faster. Without concurrency, it's likely the case that
sequential downloads from the same remote are faster than switching back
and forth between two remotes.
There is some hairy MVar code here, but basically it just keeps
the activeremotes MVar full except when deciding which remote to assign
to a thread.
Also affects gets by sync --content -J
This commit was sponsored by Jochen Bartl.
* Removed the webapp-secure build flag, rolling it into the webapp build
flag.
* Removed the quvi and tahoe build flags, which only adds aeson to
the core dependencies.
* Removed the feed build flag, which only adds feed to the core
dependencies.
Build flags have cost in both code complexity and also make Setup configure
have to work harder to find a usable set of build flags when some
dependencies are missing.
When Config.setConfig runs, it throws away the old Repo and loads a new
one. So, add an action to adjust the Repo so that -c settings will persist
across that.
Writes are optimised by queueing up multiple writes when possible.
The queue is flushed after the Annex monad action finishes. That makes it
happen on program termination, and also whenever a nested Annex monad action
finishes.
Reads are optimised by checking once (per AnnexState) if the database
exists. If the database doesn't exist yet, all reads return mempty.
Reads also cause queued writes to be flushed, so reads will always be
consistent with writes (as long as they're made inside the same Annex monad).
A future optimisation path would be to determine when that's not necessary,
which is probably most of the time, and avoid flushing unncessarily.
Design notes for this commit:
- separate reads from writes
- reuse a handle which is left open until program
exit or until the MVar goes out of scope (and autoclosed then)
- writes are queued
- queue is flushed periodically
- immediate queue flush before any read
- auto-flush queue when database handle is garbage collected
- flush queue on exit from Annex monad
(Note that this may happen repeatedly for a single database connection;
or a connection may be reused for multiple Annex monad actions,
possibly even concurrent ones.)
- if database does not exist (or is empty) the handle
is not opened by reads; reads instead return empty results
- writes open the handle if it was not open previously
The problem is that shutdown is not always called, particularly in the test
suite. So, a database connection would be opened, possibly some changes
queued, and then not shut down.
One way this can happen is when using Annex.eval or Annex.run with a new
state. A better fix might be to make both of them call Keys.shutdown
(and be sure to do it even if the annex action threw an error).
Complication: Sometimes they're run reusing an existing state, so shutting
down a database connection could cause problems for other users of that
same state. I think this would need a MVar holding the database handle,
so it could be emptied once shut down, and another user of the database
connection could then start up a new one if it got shut down. But, what if
2 threads were concurrently using the same database handle and one shut it
down while the other was writing to it? Urgh.
Might have to go that route eventually to get the database access to run
fast enough. For now, a quick fix to get the test suite happier, at the
expense of speed.
Renamed the db to keys, since it is various info about a Keys.
Dropping a key will update its pointer files, as long as their content can
be verified to be unmodified. This falls back to checksum verification, but
I want it to use an InodeCache of the key, for speed. But, I have not made
anything populate that cache yet.
Commands that want to use it have to run their seek action inside
allowConcurrentOutput. Which seems reasonable; perhaps some future command
will want to support the -J flag but not use regions.
The region state moved from Annex to MessageState. This makes sense
organizationally, and note that some uses of onLocal use a different Annex
state, but pass the MessageState into it, which is what is needed.
The one exception is in Utility.Daemon. As long as a process only
daemonizes once, which seems reasonable, and as long as it avoids calling
checkDaemon once it's already running as a daemon, the fcntl locking
gotchas won't be a problem there.
Annex.LockFile has it's own separate lock pool layer, which has been
renamed to LockCache. This is a persistent cache of locks that persist
until closed.
This is not quite done; lockContent stil needs to be converted.
This works, and seems fairly robust. Clean get of 20 files at -J3. At -J10,
there are some messages about ssh multiplexing, probably due to a race
spinning up the ssh connection cacher. But, it manages to get all the files
ok regardless.
The progress bars are a scrambled mess though, due to bugs in
ascii-progress, which I've already filed. Particularly this one:
https://github.com/yamadapc/haskell-ascii-progress/issues/8
Seems to work, but still experimental until it's been tested more.
When repositories are on filesystems not supporting symlinks, the .git dir
symlink trick cannot be used. Since we're going to be in direct mode
anyway, the .git dir symlink is not strictly needed.
However, I have not fixed the code that creates new annex symlinks to
handle this case -- the committed symlinks will be wrong.
git annex sync happens to currently fail in a submodule using direct mode,
because there's no HEAD ref. That also needs to be dealt with to get
this fully working in crippled filesystems.
Leaving http://github.com/datalad/datalad/issues/44 open until these issues
are dealt with.
I think this is the last problimatic setCurrentDirectory. I also audited
for extrnal commands that git-annex might run with cwd = foo, and did not
find any that were passed any FilePath that might be absolute.
This allows the git repository to be moved while git-annex is running in
it, with fewer problems.
On Windows, this avoids some of the problems with the absurdly small
MAX_PATH of 260 bytes. In particular, git-annex repositories should
work in deeper/longer directory structures than before. See
http://git-annex.branchable.com/bugs/__34__git-annex:_direct:_1_failed__34___on_Windows/
There are several possible ways this change could break git-annex:
1. If it changes its working directory while it's running, that would
be Bad News. Good news everyone! git-annex never does so. It would also
break thread safety, so all such things were stomped out long ago.
2. parentDir "." -> "" which is not a valid path. I had to fix one
instace of this, and I should probably wipe all calls to parentDir out
of the git-annex code base; it was never a good idea.
3. Things like relPathDirToFile require absolute input paths,
and code assumes that the git repo path is absolute and passes it to it
as-is. In the case of relPathDirToFile, I converted it to not make
this assumption.
Currently, the test suite has 16 failures.
This does mean that eg, copying multiple files to a local remote will
become slightly slower, since it now restarts git-cat-file after each copy.
Should not be significant slowdown.
The reason git-cat-file is run on the remote at all is to update its
location log. In order to add an item to it, it needs to get the current
content of the log. Finding a way to avoid needing to do that would be a
good path to avoiding this slowdown if it does become a problem somehow.
This commit was sponsored by Evan Deaubl.
Removed old extensible-exceptions, only needed for very old ghc.
Made webdav use Utility.Exception, to work after some changes in DAV's
exception handling.
Removed Annex.Exception. Mostly this was trivial, but note that
tryAnnex is replaced with tryNonAsync and catchAnnex replaced with
catchNonAsync. In theory that could be a behavior change, since the former
caught all exceptions, and the latter don't catch async exceptions.
However, in practice, nothing in the Annex monad uses async exceptions.
Grepping for throwTo and killThread only find stuff in the assistant,
which does not seem related.
Command.Add.undo is changed to accept a SomeException, and things
that use it for rollback now catch non-async exceptions, rather than
only IOExceptions.
On Windows, changing the time zone causes the apparent mtime of files to
change. This confuses git-annex, which natually thinks this means the files
have actually been modified (since THAT'S WHAT A MTIME IS FOR, BILL <sheesh>).
Work around this stupidity, by using the inode sentinal file to detect if
the timezone has changed, and calculate a TSDelta, which will be applied
when generating InodeCaches.
This should add no overhead at all on unix. Indeed, I sped up a few
things slightly in the refactoring.
Seems to basically work! But it has a big known problem:
If the timezone changes while the assistant (or a long-running command)
runs, it won't notice, since it only checks the inode cache once, and
so will use the old delta for all new inode caches it generates for new
files it's added. Which will result in them seeming changed the next time
it runs.
This commit was sponsored by Vincent Demeester.
Motivation: Hook scripts for nautilus or other file managers
need to provide the user with feedback that a file is being downloaded.
This commit was sponsored by THM Schoemaker.
Benchmarking this with 1000 small files being copied, the time reduced from
15.98s to 14.64s -- an 8% improvement in the non-data-transfer overhead of
git-annex copy.
