git-annex/Git/UpdateIndex.hs
Joey Hess 438dbe3b66
convert to withCreateProcess for async exception safety
This handles all sites where checkSuccessProcess/ignoreFailureProcess
is used, except for one: Git.Command.pipeReadLazy
That one will be significantly more work to convert to bracketing.

(Also skipped Command.Assistant.autoStart, but it does not need to
shut down the processes it started on exception because they are
git-annex assistant daemons..)

forceSuccessProcess is done, except for createProcessSuccess.
All call sites of createProcessSuccess will need to be converted
to bracketing.

(process pools still todo also)
2020-06-04 12:44:09 -04:00

159 lines
4.4 KiB
Haskell

{- git-update-index library
-
- Copyright 2011-2020 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.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 -> FilePath -> Repo -> IO Streamer
stageFile sha treeitemtype file repo = do
p <- toTopFilePath (toRawFilePath file) repo
return $ pureStreamer $ updateIndexLine sha treeitemtype p
{- A streamer that removes a file from the index. -}
unstageFile :: FilePath -> Repo -> IO Streamer
unstageFile file repo = do
p <- toTopFilePath (toRawFilePath 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 :: FilePath -> Sha -> Repo -> IO Streamer
stageSymlink file sha repo = do
!line <- updateIndexLine
<$> pure sha
<*> pure TreeSymlink
<*> toTopFilePath (toRawFilePath 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. -}
refreshIndex :: Repo -> ((FilePath -> IO ()) -> IO ()) -> IO Bool
refreshIndex repo feeder = withCreateProcess p 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
feeder $ \f -> do
hPutStr h f
hPutStr h "\0"
hFlush h
hClose h
checkSuccessProcess pid
go _ _ _ _ = error "internal"