Now gitattributes are looked up, efficiently, in only the places that
really need them, using the same approach used for cat-file.
The old CheckAttr code seemed very fragile, in the way it streamed files
through git check-attr.
I actually found that cad8824852
was still deadlocking with ghc 7.4, at the end of adding a lot of files.
This should fix that problem, and avoid future ones.
The best part is that this removes withAttrFilesInGit and withNumCopies,
which were complicated Seek methods, as well as simplfying the types
for several other Seek methods that had a Backend tupled in.
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.
Many functions took the repo as their first parameter. Changing it
consistently to be the last parameter allows doing some useful things with
currying, that reduce boilerplate.
In particular, g <- gitRepo is almost never needed now, instead
use inRepo to run an IO action in the repo, and fromRepo to get
a value from the repo.
This also provides more opportunities to use monadic and applicative
combinators.
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.
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.
The only remaining vestiage of backends is different types of keys. These
are still called "backends", mostly to avoid needing to change user interface
and configuration. But everything to do with storing keys in different
backends was gone; instead different types of remotes are used.
In the refactoring, lots of code was moved out of odd corners like
Backend.File, to closer to where it's used, like Command.Drop and
Command.Fsck. Quite a lot of dead code was removed. Several data structures
became simpler, which may result in better runtime efficiency. There should
be no user-visible changes.
* 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
It compiles. It sorta works. Several subcommands are FIXME marked and
broken, because things that used to accept separate --backend and --key
params need to be changed to accept just a --key that encodes all the key
info, now that there is metadata in keys.
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.
