git-annex/Git/UpdateIndex.hs
2023-02-27 15:06:32 -04:00

169 lines
4.7 KiB
Haskell

{- git-update-index library
-
- Copyright 2011-2022 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE BangPatterns, OverloadedStrings, CPP #-}
module Git.UpdateIndex (
Streamer,
pureStreamer,
streamUpdateIndex,
streamUpdateIndex',
withUpdateIndex,
lsTree,
lsSubTree,
updateIndexLine,
stageFile,
unstageFile,
stageSymlink,
stageDiffTreeItem,
refreshIndex,
) where
import Common
import Git
import Git.Types
import Git.Command
import Git.FilePath
import Git.Sha
import qualified Git.DiffTreeItem as Diff
import qualified Data.ByteString as S
import qualified Data.ByteString.Lazy as L
import Control.Monad.IO.Class
{- Streamers are passed a callback and should feed it lines in the form
- read by update-index, and generated by ls-tree. -}
type Streamer = (L.ByteString -> IO ()) -> IO ()
{- A streamer with a precalculated value. -}
pureStreamer :: L.ByteString -> Streamer
pureStreamer !s = \streamer -> streamer s
{- Streams content into update-index from a list of Streamers. -}
streamUpdateIndex :: Repo -> [Streamer] -> IO ()
streamUpdateIndex repo as = withUpdateIndex repo $ \h ->
forM_ as $ streamUpdateIndex' h
data UpdateIndexHandle = UpdateIndexHandle Handle
streamUpdateIndex' :: UpdateIndexHandle -> Streamer -> IO ()
streamUpdateIndex' (UpdateIndexHandle h) a = a $ \s -> do
L.hPutStr h s
L.hPutStr h "\0"
withUpdateIndex :: (MonadIO m, MonadMask m) => Repo -> (UpdateIndexHandle -> m a) -> m a
withUpdateIndex repo a = bracket setup cleanup go
where
params = map Param ["update-index", "-z", "--index-info"]
setup = liftIO $ createProcess $
(gitCreateProcess params repo)
{ std_in = CreatePipe }
go p = do
r <- a (UpdateIndexHandle (stdinHandle p))
liftIO $ do
hClose (stdinHandle p)
void $ checkSuccessProcess (processHandle p)
return r
cleanup = liftIO . cleanupProcess
{- A streamer that adds the current tree for a ref. Useful for eg, copying
- and modifying branches. -}
lsTree :: Ref -> Repo -> Streamer
lsTree (Ref x) repo streamer = do
(s, cleanup) <- pipeNullSplit params repo
mapM_ streamer s
void $ cleanup
where
params = map Param ["ls-tree", "-z", "-r", "--full-tree", decodeBS x]
lsSubTree :: Ref -> FilePath -> Repo -> Streamer
lsSubTree (Ref x) p repo streamer = do
(s, cleanup) <- pipeNullSplit params repo
mapM_ streamer s
void $ cleanup
where
params = map Param ["ls-tree", "-z", "-r", "--full-tree", decodeBS x, p]
{- Generates a line suitable to be fed into update-index, to add
- a given file with a given sha. -}
updateIndexLine :: Sha -> TreeItemType -> TopFilePath -> L.ByteString
updateIndexLine sha treeitemtype file = L.fromStrict $
fmtTreeItemType treeitemtype
<> " blob "
<> fromRef' sha
<> "\t"
<> indexPath file
stageFile :: Sha -> TreeItemType -> RawFilePath -> Repo -> IO Streamer
stageFile sha treeitemtype file repo = do
p <- toTopFilePath file repo
return $ pureStreamer $ updateIndexLine sha treeitemtype p
{- A streamer that removes a file from the index. -}
unstageFile :: RawFilePath -> Repo -> IO Streamer
unstageFile file repo = do
p <- toTopFilePath file repo
return $ unstageFile' p
unstageFile' :: TopFilePath -> Streamer
unstageFile' p = pureStreamer $ L.fromStrict $
"0 "
<> fromRef' deleteSha
<> "\t"
<> indexPath p
{- A streamer that adds a symlink to the index. -}
stageSymlink :: RawFilePath -> Sha -> Repo -> IO Streamer
stageSymlink file sha repo = do
!line <- updateIndexLine
<$> pure sha
<*> pure TreeSymlink
<*> toTopFilePath file repo
return $ pureStreamer line
{- A streamer that applies a DiffTreeItem to the index. -}
stageDiffTreeItem :: Diff.DiffTreeItem -> Streamer
stageDiffTreeItem d = case toTreeItemType (Diff.dstmode d) of
Nothing -> unstageFile' (Diff.file d)
Just t -> pureStreamer $ updateIndexLine (Diff.dstsha d) t (Diff.file d)
indexPath :: TopFilePath -> InternalGitPath
indexPath = toInternalGitPath . getTopFilePath
{- Refreshes the index, by checking file stat information.
-
- The action is passed a callback that it can use to send filenames to
- update-index. Sending Nothing will wait for update-index to finish
- updating the index.
-}
refreshIndex :: (MonadIO m, MonadMask m) => Repo -> ((Maybe RawFilePath -> IO ()) -> m ()) -> m ()
refreshIndex repo feeder = bracket
(liftIO $ createProcess p)
(liftIO . cleanupProcess)
go
where
params =
[ Param "update-index"
, Param "-q"
, Param "--refresh"
, Param "-z"
, Param "--stdin"
]
p = (gitCreateProcess params repo)
{ std_in = CreatePipe }
go (Just h, _, _, pid) = do
let closer = do
hClose h
forceSuccessProcess p pid
feeder $ \case
Just f -> S.hPut h (S.snoc f 0)
Nothing -> closer
liftIO $ closer
go _ = error "internal"