git-annex/Command/Add.hs
Joey Hess d8fb97806c support all filename encodings with ghc 7.4
Under ghc 7.4, this seems to be able to handle all filename encodings
again. Including filename encodings that do not match the LANG setting.
I think this will not work with earlier versions of ghc, it uses some ghc
internals.

Turns out that ghc 7.4 has a special filesystem encoding that it uses when
reading/writing filenames (as FilePaths). This encoding is documented
to allow  "arbitrary undecodable bytes to be round-tripped through it".

So, to get FilePaths from eg, git ls-files, set the Handle that is reading
from git to use this encoding. Then things basically just work.

However, I have not found a way to make Text read using this encoding.
Text really does assume unicode. So I had to switch back to using String
when reading/writing data to git. Which is a pity, because it's some
percent slower, but at least it works.

Note that stdout and stderr also have to be set to this encoding, or
printing out filenames that contain undecodable bytes causes a crash.
IMHO this is a misfeature in ghc, that the user can pass you a filename,
which you can readFile, etc, but that default, putStr of filename may
cause a crash!

Git.CheckAttr gave me special trouble, because the filenames I got back
from git, after feeding them in, had further encoding breakage.
Rather than try to deal with that, I just zip up the input filenames
with the attributes. Which must be returned in the same order queried
for this to work.

Also of note is an apparent GHC bug I worked around in Git.CheckAttr. It
used to forkProcess and feed git from the child process.  Unfortunatly,
after this forkProcess, accessing the `files` variable from the parent
returns []. Not the value that was passed into the function. This screams
of a bad bug, that's clobbering a variable, but for now I just avoid
forkProcess there to work around it. That forkProcess was itself only added
because of a ghc bug, #624389. I've confirmed that the test case for that
bug doesn't reproduce it with ghc 7.4. So that's ok, except for the new ghc
bug I have not isolated and reported. Why does this simple bit of code
magnet the ghc bugs? :)

Also, the symlink touching code is currently broken, when used on utf-8
filenames in a non-utf-8 locale, or probably on any filename containing
undecodable bytes, and I temporarily commented it out.
2012-02-03 16:23:20 -04:00

95 lines
2.7 KiB
Haskell

{- git-annex command
-
- Copyright 2010 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.Add where
import Common.Annex
import Annex.Exception
import Command
import qualified Annex
import qualified Annex.Queue
import qualified Backend
import Logs.Location
import Annex.Content
import Utility.Touch
import Backend
def :: [Command]
def = [command "add" paramPaths seek "add files to annex"]
{- Add acts on both files not checked into git yet, and unlocked files. -}
seek :: [CommandSeek]
seek = [withFilesNotInGit start, withFilesUnlocked start]
{- The add subcommand annexes a file, storing it in a backend, and then
- moving it into the annex directory and setting up the symlink pointing
- to its content. -}
start :: BackendFile -> CommandStart
start p@(_, file) = notBareRepo $ ifAnnexed file fixup add
where
add = do
s <- liftIO $ getSymbolicLinkStatus file
if isSymbolicLink s || not (isRegularFile s)
then stop
else do
showStart "add" file
next $ perform p
fixup (key, _) = do
-- fixup from an interrupted add; the symlink
-- is present but not yet added to git
showStart "add" file
liftIO $ removeFile file
next $ next $ cleanup file key =<< inAnnex key
perform :: BackendFile -> CommandPerform
perform (backend, file) = Backend.genKey file backend >>= go
where
go Nothing = stop
go (Just (key, _)) = do
handle (undo file key) $ moveAnnex key file
next $ cleanup file key True
{- On error, put the file back so it doesn't seem to have vanished.
- This can be called before or after the symlink is in place. -}
undo :: FilePath -> Key -> IOException -> Annex a
undo file key e = do
unlessM (inAnnex key) rethrow -- no cleanup to do
liftIO $ whenM (doesFileExist file) $ removeFile file
handle tryharder $ fromAnnex key file
logStatus key InfoMissing
rethrow
where
rethrow = throw e
-- fromAnnex could fail if the file ownership is weird
tryharder :: IOException -> Annex ()
tryharder _ = do
src <- inRepo $ gitAnnexLocation key
liftIO $ moveFile src file
cleanup :: FilePath -> Key -> Bool -> CommandCleanup
cleanup file key hascontent = do
handle (undo file key) $ do
link <- calcGitLink file key
liftIO $ createSymbolicLink link file
when hascontent $ do
logStatus key InfoPresent
-- touch the symlink to have the same mtime as the
-- file it points to
-- XXX Currently broken on non-utf8 locales when
-- dealing with utf-8 filenames.
--liftIO $ do
--mtime <- modificationTime <$> getFileStatus file
--touch file (TimeSpec mtime) False
force <- Annex.getState Annex.force
if force
then Annex.Queue.add "add" [Param "-f", Param "--"] [file]
else Annex.Queue.add "add" [Param "--"] [file]
return True