git add --update cannot be used, because it'll stage typechanged direct
mode files. Intead, use ls-files to find deleted files, and stage them
ourselves.
It seems that no commit was made before when the scan staged deleted files.
(Probably masked since if files were added, a commit happened then..)
Now that I'm doing the staging, I was also able to fix that bug.
This allows it to use Build.SysConfig to always install the programs
configure detected. Amoung other fixes, this ensures the right uuid
generator and checksum programs are installed.
I also cleaned up the handling of lsof's path; configure now checks for
it in PATH, but falls back to looking for it in sbin directories.
* get/copy --auto: Transfer data even if it would exceed numcopies,
when preferred content settings want it.
* drop --auto: Fix dropping content when there are no preferred content
settings.
Noticed that when pairing, sometimes both sides start to push, and the other
side sends a PushRequest, and the two deadlock, neither doing anything.
(Timeout eventually breaks this.) So, let both run at the same time.
This should help prevent git-annex clients receiving messages that
were intended for normal clients they're sharing the account with.
Changed XMPP protocol use to always send chat messages directed at the
specific client, as the negative priority blocks less directed messages.
It might even work, although nothing yet triggers XMPP pushes.
Also added a set of deferred push messages. Only one push can run at a
time, and unrelated push messages get deferred. The set will never grow
very large, because it only puts two types of messages in there, that
can only vary in the client doing the push.
Maybe the spec allows it, but broadcasting self-directed presence info to
all buddies is just insane.
I had to bring back the IQ messages for self-pairing, while still using
directed presence for other pairing. Ugly.
Testing between Google Talk and prosody, the directed IQ messages
were not received. Google Talk probably only relays them between
clients using the same account.
I first tried even more directed presence, with each client JID being sent
a separate presence, but that didn't work on Google Talk, particularly
it was ignored when one client sent it to another client using the same
account.
So, presence directed at the user@host of the client to pair with. Tested
working between Google Talk and prosody (in both directions), as well
as between two clients with the same account on Google Talk, and
two clients with the same account on prosody.
Only problem with this form of directed presence is that if I also use it
for git pushes, more clients than are interested in a push's data will
receive it. So I may need some better approach, or a hybrid between
directed IQ and directed presence.
Still wait 1 minute after a change before waiting on the next change, but don't
wait at the start, when we might get a pull that contains config changes
right away.
Currently have three old versions of functions that more reworking is
needed to remove: getDaemonStatusOld, modifyDaemonStatusOld_, and
modifyDaemonStatusOld
This is a nice win; much less code runs in Annex, so other threads have
more chances to run concurrently.
I do notice that renaming a file has gone from 1 to 2 commits. I think this
is due to the above improvement letting the committer run more frequently,
so it commits the rm first.
Converted several threads to run in the monad.
Added a lot of useful combinators for working with the monad.
Now the monad includes the name of the thread.
Some debugging messages are disabled pending converting other threads.
I now have this topology working:
assistant ---> {bare repo, special remote} <--- assistant
And, I think, also this one:
+----------- bare repo --------+
v v
assistant ---> special remote <--- assistant
While before with assistant <---> assistant connections, both sides got
location info updated after a transfer, in this topology, the bare repo
*might* get its location info updated, but the other assistant has no way to
know that it did. And a special remote doesn't record location info,
so transfers to it won't propigate out location log changes at all.
So, for these to work, after a transfer succeeds, the git-annex branch
needs to be pushed. This is done by recording a synthetic commit has
occurred, which lets the pusher handle pushing out the change (which will
include actually committing any still journalled changes to the git-annex
branch).
Of course, this means rather a lot more syncing action than happened
before. At least the pusher bundles together very close together pushes,
somewhat. Currently it just waits 2 seconds between each push.
Adjust build deps to ensure that only a fixed version of the library will
be used.
Also, removed the bound thread stuff, which I now think was (probably)
a red herring.
MountWatcher can't do this, because it uses the session dbus,
and won't have access to the new DBUS_SESSION_BUS_ADDRESS if a new session
is started.
Bumped dbus library version, FD leak in it is fixed.
Currently relies on SRV being set, or the JID's hostname being the server
hostname and the port being default. Future work: Allow manual
configuration of user name, hostname, and port.
Now when the dbus connection is dropped, it'll fall back to polling.
I could make it try to reconnect, but there's a FD leak in the dbus
library, so not yet.
This *may* solve the segfault I was seeing when the XMPP library called
startTLS. My hypothesis is as follows:
* TLS is documented
(http://www.gnu.org/software/gnutls/manual/gnutls.html#Thread-safety)
thread safe, but only when a single thread accesses it.
* forkIO threads are not bound to an OS thread, so it was possible for
the threaded runtime to run part of the XMPP code on one thread, and
then switch to another thread later.
So, forkOS, with its bound threads, should be used for the XMPP thread.
Since the crash doesn't happen reliably, I am not yet sure about this fix.
Note that I kept all the other threads in the assistant unbound, because
bound threads have significantly higher overhead.
Seems presence notifications are not sent to clients that have marked
themselves unavailable. (Testing with google talk.)
This is the death knell for the presence hack, because it has to stay
available, and even the toggle to unavailable and back could cause it to
miss a notification. Still, flipped it so it basically works, for now.
Lacking error handling, reconnection, credentials configuration,
and doesn't actually do anything when it receives an incoming notification.
Other than that, it might work! :)
Hooked up everything that needs to notify on pushes. Note that
syncNewRemote does not notify. This is probably ok, and I'd need to thread
more state through to make it do so.
This is only set up to support a single push notification method; I didn't
use a NotificationBroadcaster. Partly because I don't yet know what info
about pushes needs to be communicated, so my data types are only
preliminary.
Monitors git-annex branch for changes, which are noticed by the Merger
thread whenever the branch ref is changed (either due to an incoming push,
or a local change), and refreshes cached config values for modified config
files.
Rate limited to run no more often than once per minute. This is important
because frequent git-annex branch changes happen when files are being
added, or transferred, etc.
A primary use case is that, when preferred content changes are made,
and get pushed to remotes, the remotes start honoring those settings.
Other use cases include propigating repository description and trust
changes to remotes, and learning when a remote has added a new special
remote, so the webapp can present the GUI to enable that special remote
locally.
Also added a uuid.log cache. All other config files already had caches.
This can result in the file being dropped, or being downloaded, or even
being dropped from some other repo.
It's even possible to create a file in a directory where content is not
wanted, which will make the assistant immediately send it elsewhere, and
then drop it.
This was complicated quite a bit by needing to check numcopies. I optimised
that, so it only looks up numcopies once per file, no matter how many
remotes it checks to drop from. Although it did just occur to me that
it might be better to first check if it wants to drop content, and only
then check numcopies..
This avoids the expensive transfer scan relying on its list of remotes
to scan being accurate throughout, which it will not be when the user
pauses syncing to a remote.
I feel it's ok to queue transfers to *any* known remote, not just the ones
being scanned.
Note that there are still small races where after syncing to a remote is
paused, a transfer can be queued for it. Not just in the expensive transfer
scan, but in the cheap failed transfer scan, and elsewhere.
I noticed this while offline (so that lack of solar power is good for something).
Apparently it tries to bind multicast to lo, and that fails.
If this happens, catch it, and retry until a real network interface becomes
available.
It may be that this should tie into the NetWatcher, and rebind whenever
an interface comes up. Needs testing..
Both when queueing downloads, and uploads, consults the preferred content
settings.
I didn't make it check yet when requeing failed transfers or queuing
deferred downloads; dealing with the preferred content settings (or indeed,
other settings) changing while the assistant is running still needs work.
Makes it safe to use git annex unlock with the watcher/assistant.
And also to mix use of the watcher/assistant with regular files stored in git.
Long ago, I had avoided doing this check, except during the startup scan,
because it would be slow to run ls-files repeatedly.
But then I added the lsof check, and to make that fast, got it to detect
batch file adds. So let's move the ls-files check to also occur when it'll
have a batch, and can check them all with one call.
This does slow down adding a single file by just a bit, but really only
a little bit. (The lsof check is probably more expensive.) It also
speeds up the startup scan, especially when there are lots of new files
found by the scan.
Also, fixed the sleep for annex.delayadd to not run while the threadstate
lock is held, so it doesn't unnecessarily freeze everything else.
Also, --force no longer makes it skip the lsof check, which was not
documented, and seems never a good idea.
This is handled differently for inotify, which can track modifications of
existing files, and kqueue, which cannot (TTBOMK). On the inotify side,
the TransferWatcher just waits for the file to be updated and reads the new
bytesComplete. On the kqueue side, the TransferPoller has to re-read the
file every update (currently 0.5 seconds, might need to increase that).
I did think about working around kqueue's limitations by somehow creating
a new file each time the size changed. But cleaning up all the files that
would result seemed difficult. And really, this is not a lot worse than
the TransferWatcher's behavior for downloads, which stats a file every 0.5
seconds. As long as the OS has decent file caching behavior..
cp is used here, but we can just watch the size of the destination file
This commit made from within the ruins of an old mill, overlooking a
beautiful waterfall.
This doesn't avoid it sometimes attempting to commit when there are no
changes. Typically that happens when a change is pushed in from another
repo; the watcher sees the file and tries to stage it, resulting in an
empty commit. Really fixing that would probably use more CPU than
occasionally trying to make an empty commit.
However, this does save a lot of unnecessary work, as those empty commits
had to be synced out, which no longer happens.
This ensures file propigate takes place in situations such as: Usb drive A
is connected to B. A's master branch is already in sync with B, but it is
being used to sneakernet some files around, so B downloads those. There is no
master branch change, so C does not request these files. B needs to upload
the files it just downloaded on to C, etc.
My first try at this, I saw loops happen. B uploaded to C, which then
tried to upload back to B (because it had not received the updated
git-annex branch from B yet). B already had the file, but it still created
a transfer info file from the incoming transfer, and its watcher saw
that be removed, and tried to upload back to C.
These loops should have been fixed by my previous commit. (They never
affected ssh remotes, only local ones, it seemed.) While C might still try
to upload to B, or to some other remote that already has the file, the
extra work dies out there.
I was seeing some interesting crashes after the previous commit,
when making file changes slightly faster than the assistant could keep up.
error: Ref refs/heads/master is at 7074f8e0a11110c532d06746e334f2fec6af6ab4 but expected 95ea86008d72a40d97a81cfc8fb47a0da92166bd
fatal: cannot lock HEAD ref
Committer crashed: git commit [Param "--allow-empty-message",Param "-m",Param "",Param "--allow-empty",Param "--quiet"] failed
Pusher crashed: thread blocked indefinitely in an STM transaction
Clearly the the merger ended up running at the same time as the committer,
and with both modifying HEAD the committer crashed. I fixed that by
making the Merger run its merge inside the annex monad, which avoids
it running concurrently with other git operations. Also by making
the committer not crash if git fails.
What I don't understand is why the pusher then crashed with a STM deadlock.
That must be in either the DaemonStatusHandle or the FailedPushMap,
and the latter is only used by the pusher. Did the committer's crash somehow
break STM?
The BlockedIndefinitelyOnSTM exception is described as:
-- |The thread is waiting to retry an STM transaction, but there are no
-- other references to any @TVar@s involved, so it can't ever continue.
If the Committer had a reference to a TVar and crashed, I can sort of see
this leading to that exception..
The crash was quite easy to reproduce after the previous commit, but
after making the above change, I have yet to see it again. Here's hoping.
Now when a download is queued and there's no known remote to get it from,
it's added to a deferred download list, which will be retried later.
The Merger thread tries to queue any deferred downloads when it receives
a push to the git-annex branch.
Note that the Merger thread now also forces an update of the git-annex
branch. The assistant was not updating this branch before, and it saw a
(mostly) correct view of state, but now that incoming pushes go to
synced/git-annex, it needs to be merged in.
Don't expose these as branches in refs/heads/. Instead hide them away in
refs/synced/ where only show-ref will find them.
Make unused only look at branches and tags, not these other things,
so it won't care if some stale sync ref used to use a file.
This means they don't need to be deleted, which could have
led to an incoming sync being missed.
The fallback branches pushed to contain the uuid of the pusher, which is
ugly. That's why syncing doesn't normally use this method.
The merger deletes fallback branches after merging them, to contain the
ugliness, and so unused doesn't look at data from these branches.
(The fallback git-annex branch is left behind for now.)
Finally.
Last bug fixes here: Send PairResp with same UUID in the PairReq.
Fix off-by-one in code that filters out our own pairing messages.
Also reworked the pairing alerts, which are still slightly buggy.
Pair requests the the same UUID are part of the same pairing session,
which allows us to detect attempts to brute force the shared secret,
as that will result in pair requests with the same UUID that are
not verified with the right secret.
