git-annex/Annex/Content/PointerFile.hs
2022-06-22 16:20:08 -04:00

72 lines
2.3 KiB
Haskell

{- git-annex pointer files
-
- Copyright 2010-2018 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Annex.Content.PointerFile where
import Annex.Common
import Annex.Perms
import Annex.Link
import Annex.ReplaceFile
import Annex.InodeSentinal
import Annex.Content.LowLevel
import Utility.InodeCache
import qualified Utility.RawFilePath as R
#if ! defined(mingw32_HOST_OS)
import Utility.Touch
import qualified System.Posix.Files as Posix
#endif
{- Populates a pointer file with the content of a key.
-
- If the file already has some other content, it is not modified.
-
- Returns an InodeCache if it populated the pointer file.
-}
populatePointerFile :: Restage -> Key -> RawFilePath -> RawFilePath -> Annex (Maybe InodeCache)
populatePointerFile restage k obj f = go =<< liftIO (isPointerFile f)
where
go (Just k') | k == k' = do
let f' = fromRawFilePath f
destmode <- liftIO $ catchMaybeIO $ fileMode <$> R.getFileStatus f
liftIO $ removeWhenExistsWith R.removeLink f
(ic, populated) <- replaceWorkTreeFile f' $ \tmp -> do
let tmp' = toRawFilePath tmp
ok <- linkOrCopy k obj tmp' destmode >>= \case
Just _ -> thawContent tmp' >> return True
Nothing -> liftIO (writePointerFile tmp' k destmode) >> return False
ic <- withTSDelta (liftIO . genInodeCache tmp')
return (ic, ok)
maybe noop (restagePointerFile restage f) ic
if populated
then return ic
else return Nothing
go _ = return Nothing
{- Removes the content from a pointer file, replacing it with a pointer.
-
- Does not check if the pointer file is modified. -}
depopulatePointerFile :: Key -> RawFilePath -> Annex ()
depopulatePointerFile key file = do
let file' = fromRawFilePath file
st <- liftIO $ catchMaybeIO $ getFileStatus file'
let mode = fmap fileMode st
secureErase file
liftIO $ removeWhenExistsWith R.removeLink file
ic <- replaceWorkTreeFile file' $ \tmp -> do
let tmp' = toRawFilePath tmp
liftIO $ writePointerFile tmp' key mode
#if ! defined(mingw32_HOST_OS)
-- Don't advance mtime; this avoids unncessary re-smudging
-- by git in some cases.
liftIO $ maybe noop
(\t -> touch tmp' t False)
(fmap Posix.modificationTimeHiRes st)
#endif
withTSDelta (liftIO . genInodeCache tmp')
maybe noop (restagePointerFile (Restage True) file) ic