git-annex/Annex/ReplaceFile.hs
Joey Hess 6111958440
fix test suite
14683da9eb caused a test suite failure.
When the content of a key is not present, a LinkAnnexFailed is returned,
but replaceFile then tried to move the file into place, and since it was
not written, that crashed.

Sponsored-by: Boyd Stephen Smith Jr. on Patreon
2021-08-02 13:59:23 -04:00

87 lines
2.9 KiB
Haskell

{- git-annex file replacing
-
- Copyright 2013-2021 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Annex.ReplaceFile (
replaceGitAnnexDirFile,
replaceGitDirFile,
replaceWorkTreeFile,
replaceFile,
replaceFile',
) where
import Annex.Common
import Annex.Tmp
import Annex.Perms
import Git
import Utility.Tmp.Dir
import Utility.Directory.Create
#ifndef mingw32_HOST_OS
import Utility.Path.Max
#endif
{- replaceFile on a file located inside the gitAnnexDir. -}
replaceGitAnnexDirFile :: FilePath -> (FilePath -> Annex a) -> Annex a
replaceGitAnnexDirFile = replaceFile createAnnexDirectory
{- replaceFile on a file located inside the .git directory. -}
replaceGitDirFile :: FilePath -> (FilePath -> Annex a) -> Annex a
replaceGitDirFile = replaceFile $ \dir -> do
top <- fromRepo localGitDir
liftIO $ createDirectoryUnder top dir
{- replaceFile on a worktree file. -}
replaceWorkTreeFile :: FilePath -> (FilePath -> Annex a) -> Annex a
replaceWorkTreeFile = replaceFile createWorkTreeDirectory
{- Replaces a possibly already existing file with a new version,
- atomically, by running an action.
-
- The action is passed the name of temp file, in a temp directory,
- which it can write to, and once done the temp file is moved into place
- and anything else in the temp directory is deleted.
-
- The action can throw an exception, in which case the temp directory
- will be deleted, and the existing file will be preserved.
-
- Throws an IO exception when it was unable to replace the file.
-
- The createdirectory action is only run when moving the file into place
- fails, and can create any parent directory structure needed.
-}
replaceFile :: (RawFilePath -> Annex ()) -> FilePath -> (FilePath -> Annex a) -> Annex a
replaceFile createdirectory file action = replaceFile' createdirectory file (const True) action
replaceFile' :: (RawFilePath -> Annex ()) -> FilePath -> (a -> Bool) -> (FilePath -> Annex a) -> Annex a
replaceFile' createdirectory file checkres action = withOtherTmp $ \othertmpdir -> do
let othertmpdir' = fromRawFilePath othertmpdir
#ifndef mingw32_HOST_OS
-- Use part of the filename as the template for the temp
-- directory. This does not need to be unique, but it
-- makes it more clear what this temp directory is for.
filemax <- liftIO $ fileNameLengthLimit othertmpdir'
let basetmp = take (filemax `div` 2) (takeFileName file)
#else
-- Windows has limits on the whole path length, so keep
-- it short.
let basetmp = "t"
#endif
withTmpDirIn othertmpdir' basetmp $ \tmpdir -> do
let tmpfile = tmpdir </> basetmp
r <- action tmpfile
when (checkres r) $
replaceFileFrom tmpfile file createdirectory
return r
replaceFileFrom :: FilePath -> FilePath -> (RawFilePath -> Annex ()) -> Annex ()
replaceFileFrom src dest createdirectory = go `catchIO` fallback
where
go = liftIO $ moveFile src dest
fallback _ = do
createdirectory (parentDir (toRawFilePath dest))
go