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.
This allows eg, putting .git/annex/tmp on a ram disk, if the disk IO
of temp object files is too annoying (and if you don't want to keep
partially transferred objects across reboots).
.git/annex/misctmp must be on the same filesystem as the git work tree,
since files are moved to there in a way that will not work cross-device,
as well as symlinked into there.
I first wanted to put the tmp objects in .git/annex/objects/tmp, but
that would pose transition problems on upgrade when partially transferred
objects existed.
git annex info does not currently show the size of .git/annex/misctemp,
since it should stay small. It would also be ok to make something clean it
out, periodically.
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.
Fixed up a number of things that had worked around there not being a way to
get that.
Most notably, transfer info files on windows now include the process id,
since no locking is currently done. This means the file format varies
between windows and unix.
Windows has a larger (unsigned) PID space, so cannot use the unix CInt
there.
Note that TransferInfo does not yet ever get the TransferPid populated,
as there is missing locking.
This is motivated by a user report that the assistant was repeatedly
retrying transfers of files that had been deleted (in direct mode, so
removing the only copy).
Note that the glacier code retries failed transfers after a while to retry
downloads that have aged long enough to be available. This is ok; if we're
doing a full transfer scan we'll retry on every file that is still in the
git tree.
Also note that this makes the assistant less likely to get every file
referenced by old revs of the git tree. Not something the assistant tries
to ensure anyway, so I feel this is acceptable.
Made fromDirect check that a file in the tree has good content (and is not
a broken symlink either) before copying it to another file that has the
same key.
Made replaceFile clean up the temp file if the action that creates it, or
the file replacement action fails.
Most remotes have meters in their implementations of retrieveKeyFile
already. Simply hooking these up to the transfer log makes that information
available. Easy peasy.
This is particularly valuable information for encrypted remotes, which
otherwise bypass the assistant's polling of temp files, and so don't have
good progress bars yet.
Still some work to do here (see progressbars.mdwn changes), but this
is entirely an improvement from the lack of progress bars for encrypted
downloads.
There was confusion in different parts of the progress bar code about
whether an update contained the total number of bytes transferred, or the
number of bytes transferred since the last update. One way this bug
showed up was progress bars that seemed to stick at zero for a long time.
In order to fix it comprehensively, I add a new BytesProcessed data type,
that is explicitly a total quantity of bytes, not a delta.
Note that this doesn't necessarily fix every problem with progress bars.
Particularly, buffering can now cause progress bars to seem to run ahead
of transfers, reaching 100% when data is still being uploaded.
Rather than forking a git-annex transferkey only to have it fail,
just immediately record the failed transfer (so when the drive is plugged
in, the scan will retry it).
The newline after the filename was included in it.
This was generally benign -- mostly these filenames are just displayed,
and the newline didn't matter.
But in the assistant, it caused unexpected dropping of preferred
content.
A characteristic of this bug is that the drop was displayed like this:
drop some_file
ok
Fix resuming of downloads, which do not have a transfer info file to read.
When checking upload progress, use the MVar, rather than re-reading
the info file.
Catch exceptions in the transfer action. Required a tryAnnex.
When a transfer fails, the progress info can be used to intelligently
retry it. If the transfer managed to make some progress, but did not
fully complete, then there's a good chance that a retry will finish it
(or at least make more progress).
Transfer info files are updated when the callback is called, updating
the number of bytes transferred.
Left unused p variables at every place the callback should be used.
Which is rather a lot..
