Rather than go through the location log to see which files are present on
the remote, it simply looks at the disk contents directly.
I benchmarked this speeding up scanning 834 files, from an annex on my
phone's SSD, from 11.39 seconds to 1.31 seconds. (No files actually moved.)
Also benchmarked 8139 files, from an annex on spinning storage,
speeding up from 103.17 to 13.39 seconds.
Note that benchmarking with an encrypted annex on flash actually showed a
minor slowdown with this optimisation -- from 13.93 to 14.50 seconds. Seems
the overhead of doing the crypto needed to get the filenames to directly
check can be higher than the overhead of looking up data in the location
log. (Which says good things about how well the location log and git have
been optimised!) It *may* make sense to make encrypted local remotes not
have hasKeyCheap set; further benchmarking is called for.
Added Annex.cleanup, which is a general purpose interface for adding
actions to run at the end.
Remotes with the old git-annex-shell will commit every time, and have no
commit command, so hide stderr when running the commit command.
Now changes are staged into the branch's index, but not committed,
which avoids growing a large journal. And sync and merge always
explicitly commit, ensuring that even when they do nothing else,
they commit the staged changes.
Added a flag file to indicate that the branch's journal contains
uncommitted changes. (Could use git ls-files, but don't want to run
that every time.)
In the future, this ability to have uncommitted changes staged in the
journal might be used on remotes after a series of oneshot commands.
To avoid commits of data to the git-annex branch after each command
is run, set annex.alwayscommit=false. Its data will then be committed
less frequently, when a merge or sync is done.
I was able to reproduce this on linux using the kernel's nfs server and
mounting localhost:/. Determined that removing the directory fails when
the just-deleted file in it was locked. Considered dropping the lock
before removing the directory, but this would complicate parts of the code
that should not need to worry about locking. So instead, ignore the failure
to remove the directory in this case.
While I was at it, made it attempt to remove both levels of hash
directories, in case they're empty.
storing it in remotes/web/xx/yy/foo.log meant lots of extra directory
objects in git. Now I use xx/yy/foo.log.web, which is just as unique, but
more efficient since foo.log is there anyway.
Of course, it still looks in the old location too.
useful when adding hundreds of thousands of files on a system with plenty
of memory.
git add gets quite slow in such a large repository, so if the system has
more than the ~32 mb of memory the queue can use by default, it's a useful
optimisation to increase the queue size, in order to decrease the number
of times git add is run.
The list of files had to be retained until the end so it could be deleted.
Also, a list of update-index lines was generated and only then fed into it.
Now everything streams in constant space.
When hashing the files, the entire list of shas was read strictly.
That was entirely unnecessary, since there's a cleanup action run
after they're consumed.
Turns out that commit really made some serious improvements to memory use.
With the lazy state monad, git-annex add in a huge tree grew seemingly
without bound until it overflowed the stack. With the strict monad,
it uses 42 mb max.
It's possible another change since the 3.20120123 release fixed that,
but a964012fc3 seems most likely.
If there's no Content-Length, or the key has no size, this check is not
done, but it should happen most of the time, and protect against web
content that has changed.
Can be used to specify what file the url is added to. This can be used to
override the default filename that is used when adding an url, which is
based on the url. Or, when the file already exists, the url is recorded as
another location of the file.
Done by adding a oneshot mode, in which location log changes are written to
the journal, but not committed. Taking advantage of git-annex's existing
ability to recover in this situation.
This is used by git-annex-shell and other places where changes are made to
a remote's location log.
This drops the >>! and >>? with the nice low fixity. IfElse does have
undocumented >>=>>! and >>=>>? operators, but I deem that too fishy.
Anyway, using whenM and unlessM is easier; I sometimes mixed the operators
up.
Ssh connection caching is now enabled automatically by git-annex. Only one
ssh connection is made to each host per git-annex run, which can speed some
things up a lot, as well as avoiding repeated password prompts. Concurrent
git-annex processes also share ssh connections. Cached ssh connections are
shut down when git-annex exits.
Note: The rsync special remote does not yet participate in the ssh
connection caching.
Fscking a remote is now supported. It's done by retrieving
the contents of the specified files from the remote, and checking them,
so can be an expensive operation.
(Several optimisations are possible, to speed it up, of course.. This is
the slow and stupid remote fsck to start with.)
Still, if the remote is a special remote, or a git repository that you
cannot run fsck in locally, it's nice to have the ability to fsck it.
If you have any directory special remotes, now would be a good time to
fsck them, in case you were hit by the data loss bug fixed in the
previous release!
When moving a file to the remote failed, and partially transferred content
was left behind in the directory, re-running the same move would think it
succeeded and delete the local copy.
I reproduced data loss when moving files to a partition that was almost
full. Interrupting a transfer could have similar results.
Easily fixed by using a temp file which is then moved atomically into place
once the transfer completes.
I've audited other calls to copyFileExternal, and other special remote
file transfer code; everything else seems to use temp files correctly
(rsync, git), or otherwise use atomic transfers (bup, S3).
This way, the build log will indicate whether StatFS can be relied on.
I've tested all the failing architectures now, and on all of them,
the StatFS code now returns Nothing, rather than Just nonsense.
Also, if annex.diskreserve is set on a platform where StatFS is not
working, git-annex will complain.
Also, the Makefile was missing the sources target used when building with
cabal.
git-annex FTBFS on s390, mips, powerpc, sparc. That StatFS code is failing
on all of them. At least on s390, the failure appears as:
Just (FileSystemStats {fsStatBlockSize = 4096, fsStatBlockCount = 0,
fsStatByteCount = 0, fsStatBytesFree = 0, fsStatBytesAvailable = 0,
fsStatBytesUsed = 0})
While I don't understand why this is happening, or how to fix it,
bandaid over it by checking for obviously bad values and returning Nothing.
That disables disk free space checking, but at least git-annex will work.
Upstream bug: http://code.google.com/p/xmobar/issues/detail?id=70
This overrides the trust.log, and is overridden by the command-line trust
parameters.
It would have been nicer to have Logs.Trust.trustMap just look up the
configuration for all remotes, but a dependency loop prevented that
(Remotes depends on Logs.Trust in several ways). So instead, look up
the configuration when building remotes, storing it in the same forcetrust
field used for the command-line trust parameters.
Only set --no-tty when GPG_AGENT_INFO is set and batch mode is used.
In the test suite, set GPG_AGENT_INFO to /dev/null to avoid the test suite
relying on /dev/tty.
This needs to run git log on the location log files to get at all past
versions of the file, which tends to be a bit slow.
It would be possible to make a version optimised for showing the location
logs for every key. That would only need to run git log once, so would be
faster, but it would need to process an enormous amount of data, so
would not speed up the individual file case.
In the future it would be nice to support log --format. log --json also
doesn't work right yet.
Turns out that git will accept a .git/config containing an url with eg,
spaces in its name. Handle this by escaping the url if it's not valid.
This also fixes support for urls containing escaped characters like %20
for space. Before, the path from the url was not unescaped properly.
Dotfiles, and files inside dotdirs are not added by "git annex add" unless
the dotfile or directory is explicitly listed. So "git annex add ." will
add all untracked files in the current directory except for those in
dotdirs.
One reason for this is that it will make git-annex more usable with vcsh,
where you don't want "vcsh big annex add" to check in all the dotfiles
that are already versioned in other repositories.
(If you're using vcsh for repos that contain non-dotfiles, this won't help,
and you'll need to .gitignore such things, but this will cover the common
case.)
A more general reason why this seems like a good idea is the same reason ls
ignores dotfiles, just the unix convention that they are cruft that is kept
out of the way most of the time.
All the other git-annex commands still do deal with any dotfiles that do
get into the annex. This seemed right because if I've gone to the trouble
to add a dotfile, I will want "git annex get ." to get it along with
everything else.
Consider this git config --list case:
url.git+ssh://git@example.com/.insteadOf=gl
url.git+ssh://git@example.com/.insteadOf=shared
Since config is stored in a Map, only the last of the values for this key
was stored and available for use by the insteadOf code. But that
is wrong; git allows either "gl" or "shared" to be used in an url and
the insteadOf value to be substituted in.
To support this, it seems best to keep the existing config map as-is,
and add a second map that accumulates a list of multiple values for
config keys. This new fullconfig map can be used in the rare places where
multiple values for a key make sense, without needing to complicate
everything else.
Haskell's laziness and data sharing keep the overhead of adding
this second map low.
Rsync is only run once, with include / exclude rules used to specify
exactly what to delete. This is faster, and avoids ugly error messages
from rsync, and doesn't fail if the content already got deleted somehow.
A crash on parsing was fixed a while ago. This adds support for fully
correctly parsing multiline git config values, using git config --null.
Since git-annex-shell configlist uses normal git config output, I left in
support for that too; the two forms of config output can be easily
identified by the parser. Since configlist only prints the annex.uuid
config, there's no risk of multiline values there, so no need to change it.
Testing b9ac585454, it didn't find the
optimal union merge, the second sha was the one to use, at least in
the case I tried. Let's just try all shas to see if any can be reused.
I stopped using the expensive nub, so despite the use of sets to
sort/uniq file contents, this is probably as fast or faster than it
was before.
Always merge the git-annex branch into .git/annex/index before making a
commit from the index.
This ensures that, when the branch has been changed in any way
(by a push being received, or changes pulled directly into it, or
even by the user checking it out, and committing a change), the index
reflects those changes.
This is much too slow; it needs to be optimised to only update the
index when the branch has really changed, not every time.
Also, there is an unhandled race, when a change is made to the branch
right after the index gets updated. I left it in for now because it's
unlikely and I didn't want to complicate things with additional locking
yet.
Added files don't have to be committed before they can be unannexed.
unannex no longer commits existing staged changes
unannex of the last file in a directory now works, before it failed because
git rm deleted the directory out from under it,
There are several places where it's assumed a key can be written on one
line. One is in the format of the .git/annex/unused files. The difficult
one is that filenames derived from keys are fed into git cat-file --batch,
which has a line based input. (And no -z option.)
So, for now it's best to block such keys being created.
When storing content in bare repositories, use the hashDirLower
directories. Bare repositories can be on USB drives, which might
use the FAT filesystem, and fall afoul of recent bugs in linux's handling
of mixed case on FAT. Using hashDirLower avoids that.
The only fully supported thing is to have the main repository on one disk,
and .git/annex on another. Only commands that move data in/out of the annex
will need to copy it across devices.
There is only partial support for putting arbitrary subdirectories of
.git/annex on different devices. For one thing, but this can require more
copies to be done. For example, when .git/annex/tmp is on one device, and
.git/annex/journal on another, every journal write involves a call to
mv(1). Also, there are a few places that make hard links between various
subdirectories of .git/annex with createLink, that are not handled.
In the common case without cross-device, the new moveFile is actually
faster than renameFile, avoiding an unncessary stat to check that a file
(not a directory) is being moved. Of course if a cross-device move is
needed, it is as slow as mv(1) of the data.
The bug was that with --json, output lines were sometimes doubled. For
example, git annex init --json would output two lines, despite only running
one thing. Adding to the weirdness, this only occurred when the output
was redirected to a pipe or a file.
Strace showed two processes outputting the same buffered output.
The second process was this writer process (only needed to work around
bug #624389):
_ <- forkProcess $ do
hPutStr toh $ unlines paths
hClose toh
exitSuccess
The doubled output occurs when this process exits, and ghc flushes the
inherited stdout buffer. Why only when piping? I don't know, but ghc may
be behaving differently when stdout is not a terminal.
While this is quite possibly a ghc bug, there is a nice fix in git-annex.
Explicitly flushing after each chunk of json is output works around the
problem, and as a side effect, json is streamed rather than being output
all at the end when performing an expensive operaition.
However, note that this means all uses of putStr in git-annex must be
explicitly flushed. The others were, already.
It would be nice if command-specific options were supported. The first
difficulty is that which command is being called is not known until after
getopt; but that could be worked around by finding the first non-dashed
parameter. Storing the settings without putting them in the annex monad is
the next difficulty; it could perhaps be handled by making the seek stage
pass applicable settings into the start stage (and from there on to perform
as needed). But that still leaves a problem, what data type to use to
represent the options between getopt and seek?
Left out the backend usage graph for now, and bad/temp directory sizes
are only displayed when present. Also, disk usage is returned as a string
with units, which I can see changing later.
This is actually tricky, 45bbf210a1 added
the escaping because it's needed for rsync that does go over ssh.
So I had to detect whether the remote's rsync url will use ssh or not,
and vary the escaping.
Before, a merge was first calculated, by running various actions that
called git and built up a list of lines, which were at the end sent
to git update-index. This necessarily used space proportional to the size
of the diff between the trees being merged.
Now, lines are streamed into git update-index from each of the actions in
turn.
Runtime size of git-annex merge when merging 50000 location log files
drops from around 100 mb to a constant 4 mb.
Presumably it runs quite a lot faster, too.
Avoids doing auto-merging in commands that don't need fully current
information from the git-annex branch. In particular, git annex add no
longer needs to auto-merge. Affected commands: Anything that doesn't
look up data from the branch, but does write a change to it.
It might seem counterintuitive that we can change a value without first
making sure we have the current value. This optimisation works because
these two sequences are equivilant:
1. pull from remote
2. union merge
3. read file from branch
4. modify file and write to branch
vs.
1. read file from branch
2. modify file and write to branch
3. pull from remote
4. union merge
After either sequence, the git-annex branch contains the same logical content
for the modified file. (Possibly with lines in a different order or
additional old lines of course).
More accurately, it was supported already when map uses git-annex-shell,
but not when it does not.
Note that the user name cannot be shell escaped using git-annex's current
approach for shell escaping. I tried and some shells like dash cannot
cd ~'joey'. Rest of directory is still shell escaped, not for security but
in case a directory has a space or other weird character.
This is my own damn fault for not making UUID a real type, and then relying
on the type checker to ensure my refactoring was correct -- which it wasn't!
I should probably add code to clean up bogus entries in the uuid.log, but
right now I want to get the fix out there to prevent people experiencing
this bug.
I should also make UUID a real data type.
Thanks Valentin Haenel for a test case showing how non-fast-forward merges
could result in an ongoing pull/merge/push cycle.
While the git-annex branch is fast-forwarded, git-annex's index file is still
updated using the union merge strategy as before. There's no other way to
update the index that would be any faster.
It is possible that a union merge and a fast-forward result in different file
contents: Files should have the same lines, but a union merge may change
their order. If this happens, the next commit made to the git-annex branch
will have some unnecessary changes to line orders, but the consistency
of data should be preserved.
Note that when the journal contains changes, a fast-forward is never attempted,
which is fine, because committing those changes would be vanishingly unlikely
to leave the git-annex branch at a commit that already exists in one of
the remotes.
The real difficulty is handling the case where multiple remotes have all
changed. git-annex does find the best (ie, newest) one and fast forwards
to it. If the remotes are diverged, no fast-forward is done at all. It would
be possible to pick one, fast forward to it, and make a merge commit to
the rest, I see no benefit to adding that complexity.
Determining the best of N changed remotes requires N*2+1 calls to git-log, but
these are fast git-log calls, and N is typically small. Also, typically
some or all of the remote refs will be the same, and git-log is not called to
compare those. In the real world I expect this will almost always add only
1 git-log call to the merge process. (Which already makes N anyway.)
To get old behavior, add a .gitattributes containing: * annex.backend=WORM
I feel that SHA256 is a better default for most people, as long as their
systems are fast enough that checksumming their files isn't a problem.
git-annex should default to preserving the integrity of data as well as git
does. Checksum backends also work better with editing files via
unlock/lock.
I considered just using SHA1, but since that hash is believed to be somewhat
near to being broken, and git-annex deals with large files which would be a
perfect exploit medium, I decided to go to a SHA-2 hash.
SHA512 is annoyingly long when displayed, and git-annex displays it in a
few places (and notably it is shown in ls -l), so I picked the shorter
hash. Considered SHA224 as it's even shorter, but feel it's a bit weird.
I expect git-annex will use SHA-3 at some point in the future, but
probably not soon!
Note that systems without a sha256sum (or sha256) program will fall back to
defaulting to SHA1.
Checks location log information, and file contents.
Does not check that numcopies is satisfied, as .gitattributes information
about numcopies is not available in a bare repository. In practice, that
should not be a problem, since fsck is also run in a checkout and will
check numcopies there.
Specifically, disabled trying to update the git-annex branch on the remote,
since that data is never used by operations that act on such remotes.
Also, when copying content to such a remote, skip committing the presence
information changes to its git-annex branch. Leaving it in the journal there
is ok: Any command run on the remote that needs the info will flush the
journal.
This may partially solve this bug:
http://git-annex.branchable.com/bugs/fails_to_handle_lot_of_files/
Although I still see unreaped git processes piling up when doing a copy --to.
* This version of git-annex only works with git 1.7.7 and newer.
The breakage with old versions is subtle, and affects
annex.numcopies .gitattributes settings, so be sure to upgrade git
to 1.7.7. (Debian package now depends on that version.)
* Don't pass absolute paths to git show-attr, as it started following
symlinks when that's done in 1.7.7. Instead, use relative paths,
which show-attr only handles 100% correctly in 1.7.7. Closes: #645046
Unfortunatly I can find no way to work with the old and new gits, as
the old had bugs that require absolute paths, while the new doesn't like
them at all. And the behavior of git show-attr in 1.7.7. is the same as
eg, git add of an absolute path to a symlink, so seems entirely
intentional and not likely to change.
* git-annex now asks git-annex-shell to verify that it's operating in
the expected repository.
* Note that this git-annex will not interoperate with remotes using
older versions of git-annex-shell.
The reason for this check is to avoid git-annex getting confused about
what remote repository actually contains a value. It's a prerequisite for
supporting git insteadOf aliases.
* New or changed repository descriptions in uuid.log now have a timestamp,
which is used to ensure the newest description is used when the uuid.log
has been merged.
* Note that older versions of git-annex will display the timestamp as part
of the repository description, which is ugly but otherwise harmless.
This yields a second or so speedup in unused, find, etc. Seems that even
when the ByteString is immediately split and then converted to Strings,
it's faster.
I may try to push ByteStrings out into more of git-annex gradually,
although I suspect most of the time-critical parts are already covered
now, and many of the rest rely on libraries that only support Strings.
Added Git.ByteString which replaces Git IO methods with ones using lazy
ByteStrings. This can be more efficient when large quantities of data are
being read from git.
In Git.LsTree, parse git ls-tree output more efficiently, thanks
to ByteString. This benchmarks 25% faster, in a benchmark that includes
(probably predominately) the run time for git ls-tree itself.
In real world numbers, this makes git annex unused 2 seconds faster for
each branch it needs to check, in my usual large repo.
Using Sets is the right thing; they have constant size lookup like my
SizeList, and logn insertation, which beats nub to death.
Runs faster than --fast mode did before, and gives accurate counts.
13 seconds total runtime with a warm cache in a repository with 40 thousand
keys.
find: Rather than only showing files whose contents are present, when used
with --exclude --copies or --in, displays all files that match the
specified conditions.
Note that this is a behavior change for find --exclude! Old behavior
can be gotten with find --in . --exclude=...
get, drop: Added --auto option, which decides whether to get/drop content
as needed to work toward the configured numcopies.
The problem with bundling it up in optimize was that I then found I wanted
to run an optmize that did not drop files, only got them. Considered adding
a --only-get switch to it, but that seemed wrong. Instead, let's make
existing subcommands optionally smarter.
Note that the only actual difference between drop and drop --auto is that
the latter does not even try to drop a file if it knows of not enough
copies, and does not print any error messages about files it was unable to
drop.
It might be nice to make get avoid asking git for attributes when not in
auto mode. For now it always asks for attributes.
First, this ensures that git annex addurl, when run repeatedly with the
same url, doesn't create duplicate files, which it did before when it
fell back to the longer filename.
Secondly, the file part of an url is frequently not very descriptive on its
own.
The uri scheme, auth, and port is intentionally left out, as clutter.
This includes a generic JSONStream library built on top of Text.JSON
(somewhat hackishly).
It would be possible to stream out a single json document describing
all actions, but it's probably better for consumers if they can expect
one json document per line, so I did it that way instead.
Output from external programs used for transferring files is not
currently hidden when outputting json, which probably makes it not very
useful there. This may be dealt with if there is demand for json
output for --get or --move to be parsable.
The version, status, and find subcommands have hand-crafted output and
don't do json. The whereis subcommand needs to be modified to produce
useful json.
Using a single strictness annotation, in just the right place.
Tried several others, none of which helped and some of which potentially
hurt. This is only the second time I've really had to deal with this in
a year of using haskell, which is, I suppose not that bad.
Statting files returned by dirContents to see if they exist and are regular
files seems pretty useless. This code was originally part of fsck, and
perhaps the idea then was to avoid things returned by dirContents that were
not files. But it's certianly not needed in the current use cases for
getKeysPresent.
when a git repository is first being created. Clones will automatically
notice that git-annex is in use and automatically perform a basic
initalization. It's still recommended to run "git annex init" in any
clones, to describe them.
The tricky part about this is that to generate a key, the file must be
present already. Worked around by adding (back) an URL key type, which
is used for addurl --fast.
This was more complex than would be expected. unannex has to use git commit -a
since it's removing files from git; git commit filelist won't do.
Allow commands to be added to the Git queue that have no associated files,
and run such commands once.
This allows eg, `git-annex -c annex.rsync-options=-6 get file`
The overridden git configs are not passed on to git plumbing commands
that are run. Perhaps someone will find a need to do that, but I don't yet
and it would require storing more state to know what config settings
have been overridden and need to be passed on.
Could result in bad location log data for keys that contain [&:%] in their
names. (A workaround for this problem is to run git annex fsck.)
`git annex unused --from remote` could also run into the broken code.
Giulio Eulisse reported that on OSX, bad free space numbers were being
shown. It thought he had negative free space.
While the documentation is not clear, especially across OS's, it seems
likely that statfs uses unsigned long. It doesn't make sense for any
numbers to be negative.
This is substantially slower than using make, does not build or install
documentation, does not run the test suite, and is not particularly
recommended, but could be useful to some.
Rebenchmarked v2 vs v3, and v3 is now actually faster. Yes, storing data
in git, using git as a filesystem is actually faster than just using the
filesystem. If you do it just right. :)
All commands that often have to read a lot of information from
the git-annex branch should now be nearly as fast as before
the branch was introduced.
Before fsck was taking approximatly 3 hours, now it's running in 8 minutes.
The code is very nasty. It should be rewritten to read the header line
from git cat-file, and then read the specified number of bytes of content.
Since the logs have just been moved into the git-annex branch, don't need
to worry about backwards compatability with old versions of git-annex that
would fail to parse location logs with extra fields tacked on.
This is a new git subcommand, that does a generic union merge operation
between two refs, storing the result in a branch. It operates efficiently
without touching the working tree. It does need to write out a temporary
index file, and may need to write out some other temp files as well.
This could be useful for anything that stores data in a branch,
and needs to merge changes into that branch without actually checking the
branch out. Since conflict handling can't be done without a working copy,
the merge type is always a union merge, which is fine for data stored in
log format (as git-annex does), or in non-conflicting files
(as pristine-tar does).
This probably belongs in git proper, but it will live in git-annex for now.
---
Plan is to move .git-annex/ to a git-annex branch, and use git-union-merge
to handle merging changes when pulling from remotes.
Some preliminary benchmarking using real .git-annex/ data indicates
that it's quite fast, except for the "git add" call, which is as slow
as "git add" tends to be with a big index.
cp is still used when copying file from repos on the same filesystem, since
--reflink=auto can make it significantly faster on filesystems such as
btrfs.
Directory special remotes still use cp, not rsync. It's not clear what
tmp file should be used when rsyncing to such a remote.
get not honoring --from has surprised me a few times, so least surprise
suggests it should just behave like copy --from. This leaves the difference
between get and copy being that copy always requires the remote to copy
from, while get will decide whether to get a file from a key/value store or
a remote.
Avoid git reset here too, so I no longer need to care that it's much more
expensive than seems wise (but I asked the git list about that anyway).
It's not necessary to reset the staged file content from the index, as
the `git add` of the the symlink will replace it anyway.
`git commit` of unlocked files is still slow, since git still has to shove
their entire content into the index, only to have it be thrown away. So it's
still better to use `git annex add`
This takes advantage of the debug logging done by missingh, and I added
my own debug messages for executeFile calls. There are still some other
low-level ways git-annex runs stuff that are not shown by debugging,
but this gets most of it easily.
In particular, munge key filenames to comply with the IA's filename limits,
disable encryption, support their nonstandard way of creating buckets, and
allow x-amz-* headers to be specified in initremote to set item metadata.
Still TODO: initremote does not handle multiword metadata headers right.
Releasing before I have quite finished the code. Got a little caught
up in Anathem references. Time for a walk and then a tiny bit more coding
and possibly testing.
When it's stalled, there are 3 processes:
git annex
git ls-files
git check-attr
git-annex stalls trying to write to git check-attr, which stalls trying to
write to stdout (read by git-annex).
git ls-files does not seem to be involved directly; I've seen the stall when
it was still streaming out the file list, and after it had exited and
zombified.
The read and write are supposed to be handled by two different threads,
which pipeBoth forks off, thus avoiding deadlock. But it does deadlock.
(Certian signals unblock the deadlock for a while, then it stalls again.)
So, this is another case of WTF is the ghc IO manager doing today?
I avoid the issue by converting the writer to a separate process.
Possibly this was caused by some change in ghc 7 -- I'm offline and cannot
verify now, but I'm sure I used to be able to run git annex drop w/o it
hanging! And the code does not seem to have changed, except for commit
c1dc407941, which I tried reverting without
success. In fact, I reverted all the way back to 0.20110316 and still
saw the stall.
Update: Minimal test case:
import System.Cmd.Utils
main = do
as <- checkAttr "blah" $ map show [1..100000]
sequence $ map (putStrLn . show) as
checkAttr attr files = do
(_, s) <- pipeBoth "git" params $ unlines files
return $ lines s
where
params = ["check-attr", attr, "--stdin"]
Bug filed on ghc in debian, #624389
Fully tested and working, including resuming and encryption. (Though not
resuming when sending *with* encryption; gpg doesn't produce identical
output each time.)
Uses same layout as the directory special remote and the .git/annex/objects/
directory.
This was a real PITA to fix, since location logs can be staged in
both the current repo, as well as in local remote's repos, in
which case the cwd will not be in the repo. And git add needs different
params in both cases, when absolute paths are not used.
In passing, git annex fsck now stages location log fixes.
The test suite will not be run if it cannot be compiled.
It may be possible later to split off the quickcheck using tests into
a separate program and keep most of the tests using just hunit.
The remaining leaks are in hS3. The leak with encryption was worked around
by the use of the temp file. (And was probably originally caused by
gpgCipherHandle sparking a thread which kept a reference to the start
of the byte string.)
* Update Debian build dependencies for ghc 7.
* Debian package is now built with S3 support. Thanks Joachim Breitner for
making this possible, also thanks Greg Heartsfield for working to improve
the hS3 library for git-annex.
Also hid a conflicting new symbol from Control.Monad.State
This was a most surprising leak. It occurred in the process that is forked
off to feed data to gpg. That process was passed a lazy ByteString of
input, and ghc seemed to not GC the ByteString as it was lazily read
and consumed, so memory slowly leaked as the file was read and passed
through gpg to bup.
To fix it, I simply changed the feeder to take an IO action that returns
the lazy bytestring, and fed the result directly to hPut.
AFAICS, this should change nothing WRT buffering. But somehow it makes
ghc's GC do the right thing. Probably I triggered some weakness in ghc's
GC (version 6.12.1).
(Note that S3 still has this leak, and others too. Fixing it will involve
another dance with the type system.)
Update: One theory I have is that this has something to do with
the forking of the feeder process. Perhaps, when the ByteString
is produced before the fork, ghc decides it need to hold a pointer
to the start of it, for some reason -- maybe it doesn't realize that
it is only used in the forked process.
Stalls were caused by code that did approximatly:
content' <- liftIO $ withEncryptedContent cipher content return
store content'
The return evaluated without actually reading content from S3,
and so the cleanup code began waiting on gpg to exit before
gpg could send all its data.
Fixing it involved moving the `store` type action into the IO monad:
liftIO $ withEncryptedContent cipher content store
Which was a bit of a pain to do, thank you type system, but
avoids the problem as now the whole content is consumed, and
stored, before cleanup.
Since the queue is flushed in between subcommand actions being run,
there should be no issues with actions that expect to queue up some stuff
and have it run after they do other stuff. So I didn't have to audit for
such assumptions.
to avoid some issues with git on OSX with the mixed-case directories. No
migration is needed; the old mixed case hash directories are still read;
new information is written to the new directories.
So, it would be nicer to just use Cabal and take advantage
of its conditional compilation support. But, Cabal seems to
lack good support for a package with an internal library that is used by
multiple executables. It wants to build everything twice or more.
That's too slow for me.
Anyway, fairly soon, I expect to upgrade hS3 to a requirment, and I
can just revert this.
For example, this could happen if using SHA1 and a file with content
"foo" were added to that backend. Then a file with "content" foo were
migrated from the WORM backend.
Assume that, if a backend assigned the same key, the already annexed
content must be the same. So, the "old" content can be reused.
The space leak was somehow caused by this line:
absfiles <- mapM absPath files
I confess, I don't quite understand why this caused bad buffering,
but apparently the whole pipeline from git-ls-files backed up at that
point.
Happily, rewriting the code to only get the cwd once and use a pure
function to calculate absfiles clears it up, and should be a little more
efficient in syscalls too.
Add --fast flag, that can enable less expensive, but also less thurough versions of some commands.
* Add --fast flag, that can enable less expensive, but also less thurough
versions of some commands.
* fsck: In fast mode, avoid checking checksums.
* unused: In fast mode, just show all existing temp files as unused,
and avoid expensive scan for other unused content.
Free space checking is now done, for transfers of data for keys that have free space metadata.
(Notably, not for SHA* keys generated with git-annex 0.24 or earlier.)
The code is believed to work on Linux, FreeBSD, and OSX; check compile-time
messages to see if it is not enabled for your OS.
When adding files to the annex, the symlinks pointing at the annexed
content are made to have the same mtime as the original file. While git
does not preserve that information, this allows a tool like metastore to be
used with annexed files.
Haskell's IO layer crashes on characters > 255 when in a non-unicode (latin1)
locale. Until Haskell gets better behavior, put in an admittedly ugly
workaround for that: git-annex forces utf8 output mode no matter what
locale is selected. So if you use a non-utf8 locale, your filenames with
characters > 127 will not be displayed as you'd expect. But at least it
won't crash.
* Look for dir.git directories the same as git does.
* Support remote urls specified as relative paths.
* Support non-ssh remote paths that contain tilde expansions.
I had not taken into account that the code was written to run git and leave
zombies, for performance/laziness reasons, when I wrote the test suite.
So rather than the typical 1 zombie process that git-annex develops, test
developed dozens. Caused problems on system with low process limits.
Added a reap function to GitRepo, that waits for any zombie child processes.
Internally, the filenames are stored as un-decoded unicode.
I tried decoding them, but then haskell tries to access the wrong files.
Hmm.
So, I've unhappily chosen option "B", which is to decode filenames before
they are displayed.
Still todo:
- add repos from uuid.log that were not directly found
- group repos into their respective hosts
- display inaccessible repos and broken remote connections in red
- anonymize the url display somewhat, so the maps can be shared
- use uuid info to tell when two apparently different repos are actually
the same repo accessed in different ways
* Improved temp file handling. Transfers of content can now be resumed
from temp files later; the resume does not have to be the immediate
next git-annex run.
* unused: Include partially transferred content in the list.
Moved away from a map of flags to storing config directly in the AnnexState
structure. Got rid of most accessor functions in Annex.
This allowed supporting multiple --exclude flags.
* bugfix: Running `move --to` with a remote whose UUID was not yet known
could result in git-annex not recording on the local side where the
file was moved to. This could not result in data loss, or even a
significant problem, since the remote *did* record that it had the file.
* Also, add a general guard to detect attempts to record information
about repositories with missing UUIDs.
* fsck: Check if annex.numcopies is satisfied.
* fsck: Verify the sha1 of files when the SHA1 backend is used.
* fsck: Verify the size of files when the WORM backend is used.
* fsck: Allow specifying individual files to fsk if fscking everything
is not desired.
* fsck: Fix bug, introduced in 0.04, in detection of unused data.
isLocked was doing the expensive check before the cheap one. Let's not
fork git diff twice per file when committing, especially.
git diff is still run more than strictly necessary (ie, more than once)
if multiple unlocked files are being committed. But much better now.
