Implemented with no additional overhead of compares etc.
This is safe to do for presence logs because of their locality of change;
a given repo's presence logs are only ever changed in that repo, or in a
repo that has just been actively changing the content of that repo.
So, we don't need to worry about a split-brain situation where there'd
be disagreement about the location of a key in a repo. And so, it's ok to
not update the timestamp when that's the only change that would be made
due to logging presence info.
I want this as fast as possible, so it can be added to code paths without
slowing them down.
Avoid the set lookup, and rely on laziness,
drops runtime from 14.37 ns to 11.03 ns according to this criterion benchmark:
import Criterion.Main
import qualified Types.Difference as New
import qualified Types.DifferenceOld as Old
main :: IO ()
main = defaultMain
[ bgroup "hasDifference"
[ bench "new" $ whnf (New.hasDifference New.OneLevelObjectHash) new
, bench "old" $ whnf (Old.hasDifference Old.OneLevelObjectHash) old
]
]
where
s = "fromList [ObjectHashLower, OneLevelObjectHash, OneLevelBranchHash]"
new = New.readDifferences s
old = Old.readDifferences s
A little bit of added boilerplate, but I suppose it's worth it to not
need to worry about set lookup overhead. Note that adding more differences
would slow down the old implementation; the new implementation will run
the same speed.
A dead key is both not present at the location that thinks it has a copy,
and also is assumed to probably not be present anywhere else. Although
there may be lurking disconnected repos that somehow still have a copy.
Suprisingly few changes needed for this! This is because the presence log
code only really concerns itself with keys that are present, and dead keys
are not present.
Note that both the location and web log can be parsed as having a dead key.
I don't see any value to having keys listed as dead in the web log, but
since it doesn't change any behavior, there was no point in not parsing it.
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 is a little optimisation; avoid loading the info file for the
download of the current key when checking for other downloads.
The reversion it fixes is sorta strange.
a812d598ef broke checking for transfers
that were already in progress. Indeed, the transfer lock was not held
after getTransfers was called.
Why? I think it's magic in ghc's handling of getLock and setLock,
although it's hard to tell since those functions are almost entirely
undocumented as to their semantics.
Something, either the RTS (or maybe it's linux?) notices that the
same process has taken a lock and is now calling getLock on a FD attached
to the same file. So, it drops the lock.
So, this optimisation avoids that problematic behavior.
Useful for things like ipfs that don't use regular urls.
An external special remote can add a regular url to a key, and then
git-annex get will download it from the web. But for ipfs, we want to
instead tell git-annex that the uri uses OtherDownloader. Before this
change, the external special remote protocol lacked a way to do that.
I hope this doesn't impact speed much -- it does have to pull out a value
from Annex state every time it accesses the branch now.
The test case I dropped has never caught any problems that I can remember,
and would have been rather difficult to convert.
Eliminated complexity and future proofed. The most important change is that
all functions over Difference are now total; any Difference that can be
expressed should be handled. Avoids needs for sanity checking of inputs,
and version skew with the future.
Also, the difference.log now serializes a [Difference], not a Differences.
This saves space and keeps it simpler.
Note that [Difference] might contain conflicting differences (eg,
[Version5, Version6]. In this case, one of them needs to consistently win
over the others, probably based on Ord.
* init: Repository tuning parameters can now be passed when initializing a
repository for the first time. For details, see
http://git-annex.branchable.com/tuning/
* merge: Refuse to merge changes from a git-annex branch of a repo
that has been tuned in incompatable ways.
Reverts 965e106f24
Unfortunately, this caused breakage on Windows, and possibly elsewhere,
because parentDir and takeDirectory do not behave the same when there is a
trailing directory separator.
parentDir is less safe than takeDirectory, especially when working
with relative FilePaths. It's really only useful in loops that
want to terminate at /
This commit was sponsored by Audric SCHILTKNECHT.
The url log could have an url for a key, while the location log thinks it's
not present in the web. In this case, addurl --file url would not do
anything. Fixed it to re-add the web as a location.
I don't know how this situation could arise, but I saw it in the wild in
the conference_proceedings repo, affecting key
URL-s17806003--http://mirror.linux.org.au/pub/linux.conf.au/2014/Wednesday/53-Building_Effective_Alliances_around_the_Trans-Pacific_Partnershi-c0505b631127ccc67e38e637344d988e
Investigating the presence log, it looked like that key
was originally listed as present in the web, then in commit
56abf9e9f3e691ed9d83513037d4019313321ca3 someone else's git-annex
set it and some other things to not present in the web. It would be
interesting to know what that user did, but I doubt I'll be able to find
out. All I can tell from this investigation is that the inconsistency was
not introduced when originally addurl-ing the url.
addurl behavior change: When downloading an url ending in .torrent,
it will download files from bittorrent, instead of the old behavior
of adding the torrent file to the repository.
Added Recommends on aria2 and bittornado | bittorrent.
This commit was sponsored by Asbjørn Sloth Tønnesen.
