preserve unlocked file mtime when dropping

When dropping an unlocked file, preserve its mtime, which avoids git status
unncessarily running the clean filter on the file.

If the index file has close to the same mtime as a work tree file, git will
not trust the index to be up-to-date, and re-runs the clean filter
unncessarily. Preserving the mtime when depopulating a pointer file avoids
git status doing a little (or maybe a lot) of unncessary work.

There are other places that the mtime could be preserved, including other
places where pointer files are written perhaps, but also
populatePointerFile. But, I don't know of cases where those lead to git
status doing unncessary work, so I just fixed the one I'm aware of for now.
This commit is contained in:
Joey Hess 2019-10-08 14:01:12 -04:00
parent 7c91eb35f7
commit 1113caa53e
No known key found for this signature in database
GPG key ID: DB12DB0FF05F8F38
6 changed files with 88 additions and 2 deletions

View file

@ -9,15 +9,20 @@
module Annex.Content.PointerFile where
#if ! defined(mingw32_HOST_OS)
import System.Posix.Files
#else
import System.PosixCompat.Files
#endif
import Annex.Common
import Annex.Perms
import Annex.Link
import Annex.ReplaceFile
import Annex.InodeSentinal
import Utility.InodeCache
import Annex.Content.LowLevel
import Utility.InodeCache
import Utility.Touch
{- Populates a pointer file with the content of a key.
-
@ -48,10 +53,18 @@ populatePointerFile restage k obj f = go =<< liftIO (isPointerFile f)
- Does not check if the pointer file is modified. -}
depopulatePointerFile :: Key -> FilePath -> Annex ()
depopulatePointerFile key file = do
mode <- liftIO $ catchMaybeIO $ fileMode <$> getFileStatus file
st <- liftIO $ catchMaybeIO $ getFileStatus file
let mode = fmap fileMode st
secureErase file
liftIO $ nukeFile file
ic <- replaceFile file $ \tmp -> do
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 modificationTimeHiRes st)
#endif
withTSDelta (liftIO . genInodeCache tmp)
maybe noop (restagePointerFile (Restage True) file) ic