git-annex/Git/DiffTree.hs
2023-04-12 17:22:03 -04:00

138 lines
4.3 KiB
Haskell

{- git diff-tree interface
-
- Copyright 2012-2020 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Git.DiffTree (
DiffTreeItem(..),
isDiffOf,
diffTree,
diffTreeRecursive,
diffIndex,
diffWorkTree,
diffFiles,
diffLog,
commitDiff,
parseDiffRaw,
) where
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as L
import qualified Data.Attoparsec.ByteString.Lazy as A
import qualified Data.Attoparsec.ByteString.Char8 as A8
import Common
import Git
import Git.Sha
import Git.Command
import Git.FilePath
import Git.DiffTreeItem
import qualified Git.Quote
import qualified Git.Ref
import Utility.Attoparsec
{- Checks if the DiffTreeItem modifies a file with a given name
- or under a directory by that name. -}
isDiffOf :: DiffTreeItem -> TopFilePath -> Bool
isDiffOf diff f =
let f' = getTopFilePath f
in if B.null f'
then True -- top of repo contains all
else f' `dirContains` getTopFilePath (file diff)
{- Diffs two tree Refs. -}
diffTree :: Ref -> Ref -> Repo -> IO ([DiffTreeItem], IO Bool)
diffTree src dst = getdiff (Param "diff-tree")
[Param (fromRef src), Param (fromRef dst), Param "--"]
{- 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 (fromRef src), Param (fromRef dst), Param "--"]
{- Diffs between a tree and the index. Does nothing if there is not yet a
- commit in the repository. -}
diffIndex :: Ref -> Repo -> IO ([DiffTreeItem], IO Bool)
diffIndex ref = diffIndex' ref [Param "--cached"]
{- Diffs between a tree and the working tree. Does nothing if there is not
- yet a commit in the repository, or if the repository is bare. -}
diffWorkTree :: Ref -> Repo -> IO ([DiffTreeItem], IO Bool)
diffWorkTree ref repo =
ifM (Git.Ref.headExists repo)
( diffIndex' ref [] repo
, return ([], return True)
)
diffIndex' :: Ref -> [CommandParam] -> Repo -> IO ([DiffTreeItem], IO Bool)
diffIndex' ref params repo =
ifM (Git.Ref.headExists repo)
( getdiff (Param "diff-index")
( params ++ [Param $ fromRef ref] ++ [Param "--"] )
repo
, return ([], return True)
)
{- Diff between the index and work tree. -}
diffFiles :: [CommandParam] -> Repo -> IO ([DiffTreeItem], IO Bool)
diffFiles = getdiff (Param "diff-files")
{- Runs git log in --raw mode to get the changes that were made in
- a particular commit to particular files. The output format
- is adjusted to be the same as diff-tree --raw._-}
diffLog :: [CommandParam] -> Repo -> IO ([DiffTreeItem], IO Bool)
diffLog params = getdiff (Param "log")
(Param "-n1" : Param "--no-abbrev" : Param "--pretty=format:" : params)
{- Uses git show to get the changes made by a commit.
-
- Does not support merge commits, and will fail on them. -}
commitDiff :: Sha -> Repo -> IO ([DiffTreeItem], IO Bool)
commitDiff ref = getdiff (Param "show")
[ Param "--no-abbrev", Param "--pretty=", Param "--raw", Param (fromRef ref) ]
getdiff :: CommandParam -> [CommandParam] -> Repo -> IO ([DiffTreeItem], IO Bool)
getdiff command params repo = do
(diff, cleanup) <- pipeNullSplit ps repo
return (parseDiffRaw diff, cleanup)
where
ps =
command :
Param "-z" :
Param "--raw" :
Param "--no-renames" :
Param "-l0" :
params
{- Parses --raw output used by diff-tree and git-log. -}
parseDiffRaw :: [L.ByteString] -> [DiffTreeItem]
parseDiffRaw l = go l
where
go [] = []
go (info:f:rest) = case A.parse (parserDiffRaw (L.toStrict f)) info of
A.Done _ r -> r : go rest
A.Fail _ _ err -> giveup $ "diff-tree parse error: " ++ err
go (s:[]) = giveup $ "diff-tree parse error near \"" ++ decodeBL s ++ "\""
-- :<srcmode> SP <dstmode> SP <srcsha> SP <dstsha> SP <status>
--
-- May be prefixed with a newline, which git log --pretty=format
-- adds to the first line of the diff, even with -z.
parserDiffRaw :: RawFilePath -> A.Parser DiffTreeItem
parserDiffRaw f = DiffTreeItem
<$ A.option '\n' (A8.char '\n')
<* A8.char ':'
<*> octal
<* A8.char ' '
<*> octal
<* A8.char ' '
<*> (maybe (fail "bad srcsha") return . extractSha =<< nextword)
<* A8.char ' '
<*> (maybe (fail "bad dstsha") return . extractSha =<< nextword)
<* A8.char ' '
<*> A.takeByteString
<*> pure (asTopFilePath $ fromInternalGitPath $ Git.Quote.unquote f)
where
nextword = A8.takeTill (== ' ')