git-annex/Annex/ReplaceFile.hs
Joey Hess e213ef310f git-annex (5.20140717) unstable; urgency=high
* Fix minor FD leak in journal code. Closes: #754608
  * direct: Fix handling of case where a work tree subdirectory cannot
    be written to due to permissions.
  * migrate: Avoid re-checksumming when migrating from hashE to hash backend.
  * uninit: Avoid failing final removal in some direct mode repositories
    due to file modes.
  * S3: Deal with AWS ACL configurations that do not allow creating or
    checking the location of a bucket, but only reading and writing content to
    it.
  * resolvemerge: New plumbing command that runs the automatic merge conflict
    resolver.
  * Deal with change in git 2.0 that made indirect mode merge conflict
    resolution leave behind old files.
  * sync: Fix git sync with local git remotes even when they don't have an
    annex.uuid set. (The assistant already did so.)
  * Set gcrypt-publish-participants when setting up a gcrypt repository,
    to avoid unncessary passphrase prompts.
    This is a security/usability tradeoff. To avoid exposing the gpg key
    ids who can decrypt the repository, users can unset
    gcrypt-publish-participants.
  * Install nautilus hooks even when ~/.local/share/nautilus/ does not yet
    exist, since it is not automatically created for Gnome 3 users.
  * Windows: Move .vbs files out of git\bin, to avoid that being in the
    PATH, which caused some weird breakage. (Thanks, divB)
  * Windows: Fix locking issue that prevented the webapp starting
    (since 5.20140707).

# imported from the archive
2014-07-17 11:27:25 -04:00

44 lines
1.5 KiB
Haskell

{- git-annex file replacing
-
- Copyright 2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.ReplaceFile where
import Common.Annex
import Annex.Perms
import Annex.Exception
{- Replaces a possibly already existing file with a new version,
- atomically, by running an action.
-
- The action is passed a temp file, which it can write to, and once
- done the temp file is moved into place.
-
- The action can throw an IO exception, in which case the temp file
- will be deleted, and the existing file will be preserved.
-
- Throws an IO exception when it was unable to replace the file.
-}
replaceFile :: FilePath -> (FilePath -> Annex ()) -> Annex ()
replaceFile file action = replaceFileOr file action (liftIO . nukeFile)
{- If unable to replace the file with the temp file, runs the
- rollback action, which is responsible for cleaning up the temp file. -}
replaceFileOr :: FilePath -> (FilePath -> Annex ()) -> (FilePath -> Annex ()) -> Annex ()
replaceFileOr file action rollback = do
tmpdir <- fromRepo gitAnnexTmpMiscDir
void $ createAnnexDirectory tmpdir
bracketAnnex (liftIO $ setup tmpdir) rollback $ \tmpfile -> do
action tmpfile
liftIO $ catchIO (rename tmpfile file) (fallback tmpfile)
where
setup tmpdir = do
(tmpfile, h) <- openTempFileWithDefaultPermissions tmpdir "tmp"
hClose h
return tmpfile
fallback tmpfile _ = do
createDirectoryIfMissing True $ parentDir file
moveFile tmpfile file