Seems I punted on this while porting before. This hack relies on DOS not
using / in filenames, it's effectively an alternate path separatr in at
least current versions of windows..
Potentially fixes some FD leak if an action on an opened file handle fails
for some reason. There have been some hard to reproduce reports of
git-annex leaking FDs, and this may solve them.
So that remotes that use a persistent network connection are restarted.
A remote might keep open a long duration network connection, and could
fail to deal well with losing the connection. This is particularly a
concern now that we have external special reotes. An external
special remote that is implemented naively might open the connection only
when PREPARE is sent, and if it loses connection, throw errors on each
request that is made.
(Note that the ssh connection caching should not have this problem; if the
long-duration ssh process loses connection, the named pipe is disconnected
and the next ssh attempt will reconnect. Also, XMPP already deals with
disconnection robustly in its own way.)
There's no way for git-annex to know if a lost network connection actually
affects a given remote, which might have a transfer in process. It does not
make sense to force kill the transferkeys process every time the NetWatcher
detects a change. (Especially because the NetWatcher sometimes polls 1
change per hour.)
In any case, the NetWatcher only detects connection to a network, not
disconnection. So if a transfer is in progress over the network, and the
network goes down, that will need to time out on its own.
An alternate approch that was considered is to use a separate transferkeys
process for each remote, and detect when a request fails, and assume that
means that process is in a failing state and restart it. The problem with
that approach is that if a resource is not available and a remote fails
every time, it degrades to starting a new transferkeys process for every
file transfer, which is too expensive.
Instead, this commit only handles the network reconnection case, and restarts
transferkeys only once the network has reconnected and another transfer needs
to be made. So, a transferkeys process will be reused for 1 hour, or until the
next network connection.
----
The NotificationBroadcaster was rewritten to use TMVars rather than MSampleVars,
to allow checking without blocking if a notification has been received.
----
This commit was sponsored by Tobias Brunner.
This has not been tested at all. It compiles!
The only known missing things are support for encryption, and for get/set
of special remote configuration, and of key state. (The latter needs
separate work to add a new per-key log file to store that state.)
Only thing I don't much like is that initremote needs to be passed both
type=external and externaltype=foo. It would be better to have just
type=foo
Most of this is quite straightforward code, that largely wrote itself given
the types. The only tricky parts were:
* Need to lock the remote when using it to eg make a request, because
in theory git-annex could have multiple threads that each try to use
a remote at the same time. I don't think that git-annex ever does
that currently, but better safe than sorry.
* Rather than starting up every external special remote program when
git-annex starts, they are started only on demand, when first used.
This will avoid slowdown, especially when running fast git-annex query
commands. Once started, they keep running until git-annex stops, currently,
which may not be ideal, but it's hard to know a better time to stop them.
* Bit of a chicken and egg problem with caching the cost of the remote,
because setting annex-cost in the git config needs the remote to already
be set up. Managed to finesse that.
This commit was sponsored by Lukas Anzinger.
The shell code was nasty, and buggy. New haskell code is much nicer,
and it's easy to do complicated calculations to properly convert possibly
absolute symlinks between libraries into relative links using it.
transferkeys had used special FDs for communication, but that would be
quite annoying to do in Windows.
Instead, use stdin and stdout. But, to avoid commands like rsync stomping
on them and messing up the communications channel, they're duplicated to a
different handle; stdin is replaced with a null handle, and stdout is
replaced with a copy of stderr. This should all work in windows too.
Stopping in progress transfers may work on windows.. if the types unify
anyway. ;) May need some more porting.
In 0.9, -v shows version, rather than controlling verbosity.
Still need to port to 0.9, this just avoids massively confusing addurl when
quvi prints its version and exits successfully, on urls that it cannot be
used with.
Allow AnyTime events that still have time to occur in the current day to
fall in a window covering the current day, instead of waiting until the
next day in the Recurrance.
Currently only implemented for local git remotes. May try to add support
to git-annex-shell for ssh remotes later. Could concevably also be
supported by some special remote, although that seems unlikely.
Cronner user this when available, and when not falls back to
fsck --fast --from remote
git annex fsck --from does not itself use this interface.
To do so, I would need to pass --fast and all other options that influence
fsck on to the git annex fsck that it runs inside the remote. And that
seems like a lot of work for a result that would be no better than
cd remote; git annex fsck
This may need to be revisited if git-annex-shell gets support, since it
may be the case that the user cannot ssh to the server to run git-annex
fsck there, but can run git-annex-shell there.
This commit was sponsored by Damien Diederen.
addurl: Improve message when adding url with wrong size to existing file.
Before the message suggested the url didn't exist.
Fixed handling of URL keys that have no recorded size. Before, if the key
has no size, the url also had to not declare any size, which was unlikely
and wrong, or it was taken to not exist. This probably would mostly affect
keys that were added to the annex with addurl --relaxed.
Turns out that forkProcess masks async exceptions. Unmask them so that the
daemon code can use them for thread IPC.
There is some risk this introduces breakage in git-annex, but it would be
breakage that would already occur when the assistant was run with
--foreground.
