git-annex/Git/DiffTree.hs
Joey Hess 547d7745fb pre-commit: Update direct mode mappings.
Making the pre-commit hook look at git diff-index to find changed direct
mode files and update the mappings works pretty well.

One case where it does not work is when a file is git annex added, and then
git rmed, and then this is committed. That's a no-op commit, so the hook
probably doesn't even run, and it certianly never notices that the file
was deleted, so the mapping will still have the original filename in it.

For this and other reasons, it's important that the mappings still be
treated as possibly inconsistent.

Also, the assistant now allows the pre-commit hook to run when in direct
mode, so the mappings also get updated there.
2013-02-06 12:44:19 -04:00

86 lines
2.5 KiB
Haskell

{- git diff-tree interface
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Git.DiffTree (
DiffTreeItem(..),
diffTree,
diffTreeRecursive,
diffIndex,
) where
import Numeric
import System.Posix.Types
import Common
import Git
import Git.Sha
import Git.Command
import qualified Git.Filename
import qualified Git.Ref
data DiffTreeItem = DiffTreeItem
{ srcmode :: FileMode
, dstmode :: FileMode
, srcsha :: Sha -- nullSha if file was added
, dstsha :: Sha -- nullSha if file was deleted
, status :: String
, file :: FilePath
} deriving Show
{- Diffs two tree Refs. -}
diffTree :: Ref -> Ref -> Repo -> IO ([DiffTreeItem], IO Bool)
diffTree src dst = getdiff (Param "diff-tree")
[Param (show src), Param (show dst)]
{- Diffs two tree Refs, recursing into sub-trees -}
diffTreeRecursive :: Ref -> Ref -> Repo -> IO ([DiffTreeItem], IO Bool)
diffTreeRecursive src dst = getdiff (Param "diff-tree")
[Param "-r", Param (show src), Param (show dst)]
{- Diffs between the repository and index. Does nothing if there is not
- yet a commit in the repository. -}
diffIndex :: Repo -> IO ([DiffTreeItem], IO Bool)
diffIndex repo = do
ifM (Git.Ref.headExists repo)
( getdiff (Param "diff-index") [Param "--cached", Param "HEAD"] repo
, return ([], return True)
)
getdiff :: CommandParam -> [CommandParam] -> Repo -> IO ([DiffTreeItem], IO Bool)
getdiff command params repo = do
(diff, cleanup) <- pipeNullSplit ps repo
return (parseDiffTree diff, cleanup)
where
ps = command : Params "-z --raw --no-renames -l0" : params
{- Parses diff-tree output. -}
parseDiffTree :: [String] -> [DiffTreeItem]
parseDiffTree l = go l []
where
go [] c = c
go (info:f:rest) c = go rest (mk info f : c)
go (s:[]) _ = error $ "diff-tree parse error " ++ s
mk info f = DiffTreeItem
{ srcmode = readmode srcm
, dstmode = readmode dstm
, srcsha = fromMaybe (error "bad srcsha") $ extractSha ssha
, dstsha = fromMaybe (error "bad dstsha") $ extractSha dsha
, status = s
, file = Git.Filename.decode f
}
where
readmode = fst . Prelude.head . readOct
-- info = :<srcmode> SP <dstmode> SP <srcsha> SP <dstsha> SP <status>
-- All fields are fixed, so we can pull them out of
-- specific positions in the line.
(srcm, past_srcm) = splitAt 7 $ drop 1 info
(dstm, past_dstm) = splitAt 7 past_srcm
(ssha, past_ssha) = splitAt shaSize past_dstm
(dsha, past_dsha) = splitAt shaSize $ drop 1 past_ssha
s = drop 1 past_dsha