git-annex/Annex/CatFile.hs
Joey Hess 1c83b6c439 work around a very strange git-cat-file behavior
Sometimes it seems that git-cat-file --batch stops getting info for
files in the current repo, when ":file" is fed to it. I have not reproduced
this at the command line, but only when using git annex whereis and git
annex move inside a direct mode repo. Those failed, because cat-file
returned "file missing". OTOH, git annex find works fine, despite passing
the same file to cat-file. It seems that the failing commands first asked
cat-file to show a file on the git-annex branch. Perhaps it got "stuck" on
that branch? But I cannot repoduce it running cat-file by hand. Most
strange. HEAD is a workaround for this extreme weirdness, since I spent a
good 2 hours struggling with it already.
2013-01-05 17:06:24 -04:00

62 lines
1.6 KiB
Haskell

{- git cat-file interface, with handle automatically stored in the Annex monad
-
- Copyright 2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.CatFile (
catFile,
catObject,
catObjectDetails,
catFileHandle,
catKey,
catKeyFile,
) where
import qualified Data.ByteString.Lazy as L
import Common.Annex
import qualified Git
import qualified Git.CatFile
import qualified Annex
import Git.Types
catFile :: Git.Branch -> FilePath -> Annex L.ByteString
catFile branch file = do
h <- catFileHandle
liftIO $ Git.CatFile.catFile h branch file
catObject :: Git.Ref -> Annex L.ByteString
catObject ref = do
h <- catFileHandle
liftIO $ Git.CatFile.catObject h ref
catObjectDetails :: Git.Ref -> Annex (Maybe (L.ByteString, Sha))
catObjectDetails ref = do
h <- catFileHandle
liftIO $ Git.CatFile.catObjectDetails h ref
catFileHandle :: Annex Git.CatFile.CatFileHandle
catFileHandle = maybe startup return =<< Annex.getState Annex.catfilehandle
where
startup = do
h <- inRepo Git.CatFile.catFileStart
Annex.changeState $ \s -> s { Annex.catfilehandle = Just h }
return h
{- From the Sha or Ref of a symlink back to the key. -}
catKey :: Ref -> Annex (Maybe Key)
catKey ref = do
l <- encodeW8 . L.unpack <$> catObject ref
return $ if isLinkToAnnex l
then fileKey $ takeFileName l
else Nothing
{- From a file in git back to the key.
-
- Prefixing the file with ./ makes this work even if in a subdirectory
- of a repo. For some reason, HEAD is sometimes needed.
-}
catKeyFile :: FilePath -> Annex (Maybe Key)
catKeyFile f = catKey $ Ref $ "HEAD:./" ++ f