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author | Joey Hess <joey@kitenet.net> | 2013-02-17 15:05:55 -0400 |
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committer | Joey Hess <joey@kitenet.net> | 2013-02-17 16:43:14 -0400 |
commit | 6d8b95d6bf0d7b5666efc02379fe55e8d02e1ebe (patch) | |
tree | b93747a1bad6f2ca2456d4ac95d5cf177855f98d /Annex/Link.hs | |
parent | 898a39429f750bd05898df9a4b8dae371ddc9d68 (diff) |
fully support core.symlinks=false in all relevant symlink handling code
Refactored annex link code into nice clean new library.
Audited and dealt with calls to createSymbolicLink.
Remaining calls are all safe, because:
Annex/Link.hs: ( liftIO $ createSymbolicLink linktarget file
only when core.symlinks=true
Assistant/WebApp/Configurators/Local.hs: createSymbolicLink link link
test if symlinks can be made
Command/Fix.hs: liftIO $ createSymbolicLink link file
command only works in indirect mode
Command/FromKey.hs: liftIO $ createSymbolicLink link file
command only works in indirect mode
Command/Indirect.hs: liftIO $ createSymbolicLink l f
refuses to run if core.symlinks=false
Init.hs: createSymbolicLink f f2
test if symlinks can be made
Remote/Directory.hs: go [file] = catchBoolIO $ createSymbolicLink file f >> return True
fast key linking; catches failure to make symlink and falls back to copy
Remote/Git.hs: liftIO $ catchBoolIO $ createSymbolicLink loc file >> return True
ditto
Upgrade/V1.hs: liftIO $ createSymbolicLink link f
v1 repos could not be on a filesystem w/o symlinks
Audited and dealt with calls to readSymbolicLink.
Remaining calls are all safe, because:
Annex/Link.hs: ( liftIO $ catchMaybeIO $ readSymbolicLink file
only when core.symlinks=true
Assistant/Threads/Watcher.hs: ifM ((==) (Just link) <$> liftIO (catchMaybeIO $ readSymbolicLink file))
code that fixes real symlinks when inotify sees them
It's ok to not fix psdueo-symlinks.
Assistant/Threads/Watcher.hs: mlink <- liftIO (catchMaybeIO $ readSymbolicLink file)
ditto
Command/Fix.hs: stopUnless ((/=) (Just link) <$> liftIO (catchMaybeIO $ readSymbolicLink file)) $ do
command only works in indirect mode
Upgrade/V1.hs: getsymlink = takeFileName <$> readSymbolicLink file
v1 repos could not be on a filesystem w/o symlinks
Audited and dealt with calls to isSymbolicLink.
(Typically used with getSymbolicLinkStatus, but that is just used because
getFileStatus is not as robust; it also works on pseudolinks.)
Remaining calls are all safe, because:
Assistant/Threads/SanityChecker.hs: | isSymbolicLink s -> addsymlink file ms
only handles staging of symlinks that were somehow not staged
(might need to be updated to support pseudolinks, but this is
only a belt-and-suspenders check anyway, and I've never seen the code run)
Command/Add.hs: if isSymbolicLink s || not (isRegularFile s)
avoids adding symlinks to the annex, so not relevant
Command/Indirect.hs: | isSymbolicLink s -> void $ flip whenAnnexed f $
only allowed on systems that support symlinks
Command/Indirect.hs: whenM (liftIO $ not . isSymbolicLink <$> getSymbolicLinkStatus f) $ do
ditto
Seek.hs:notSymlink f = liftIO $ not . isSymbolicLink <$> getSymbolicLinkStatus f
used to find unlocked files, only relevant in indirect mode
Utility/FSEvents.hs: | Files.isSymbolicLink s = runhook addSymlinkHook $ Just s
Utility/FSEvents.hs: | Files.isSymbolicLink s ->
Utility/INotify.hs: | Files.isSymbolicLink s ->
Utility/INotify.hs: checkfiletype Files.isSymbolicLink addSymlinkHook f
Utility/Kqueue.hs: | Files.isSymbolicLink s = callhook addSymlinkHook (Just s) change
all above are lower-level, not relevant
Audited and dealt with calls to isSymLink.
Remaining calls are all safe, because:
Annex/Direct.hs: | isSymLink (getmode item) =
This is looking at git diff-tree objects, not files on disk
Command/Unused.hs: | isSymLink (LsTree.mode l) = do
This is looking at git ls-tree, not file on disk
Utility/FileMode.hs:isSymLink :: FileMode -> Bool
Utility/FileMode.hs:isSymLink = checkMode symbolicLinkMode
low-level
Done!!
Diffstat (limited to 'Annex/Link.hs')
-rw-r--r-- | Annex/Link.hs | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/Annex/Link.hs b/Annex/Link.hs new file mode 100644 index 000000000..f35c069ee --- /dev/null +++ b/Annex/Link.hs @@ -0,0 +1,74 @@ +{- git-annex links to content + - + - On file systems that support them, symlinks are used. + - + - On other filesystems, git instead stores the symlink target in a regular + - file. + - + - Copyright 2013 Joey Hess <joey@kitenet.net> + - + - Licensed under the GNU GPL version 3 or higher. + -} + +module Annex.Link where + +import Common.Annex +import qualified Annex +import qualified Git.HashObject +import qualified Git.UpdateIndex +import qualified Annex.Queue +import Git.Types + +{- Checks if a file is a link to a key. -} +isAnnexLink :: FilePath -> Annex (Maybe Key) +isAnnexLink file = maybe Nothing (fileKey . takeFileName) <$> getAnnexLinkTarget file + +{- Gets the link target of a symlink. + - + - On a filesystem that does not support symlinks, get the link + - target by looking inside the file. (Only return at first 8k of the file, + - more than enough for any symlink target.) + - + - Returns Nothing if the file is not a symlink, or not a link to annex + - content. + -} +getAnnexLinkTarget :: FilePath -> Annex (Maybe String) +getAnnexLinkTarget file = do + v <- ifM (coreSymlinks <$> Annex.getGitConfig) + ( liftIO $ catchMaybeIO $ readSymbolicLink file + , liftIO $ catchMaybeIO $ take 8192 <$> readFile file + ) + case v of + Nothing -> return Nothing + Just l + | isLinkToAnnex l -> return v + | otherwise -> return Nothing + +{- Creates a link on disk. + - + - On a filesystem that does not support symlinks, writes the link target + - to a file. Note that git will only treat the file as a symlink if + - it's staged as such, so use addAnnexLink when adding a new file or + - modified link to git. + -} +makeAnnexLink :: String -> FilePath -> Annex () +makeAnnexLink linktarget file = ifM (coreSymlinks <$> Annex.getGitConfig) + ( liftIO $ createSymbolicLink linktarget file + , liftIO $ writeFile file linktarget + ) + +{- Creates a link on disk, and additionally stages it in git. -} +addAnnexLink :: String -> FilePath -> Annex () +addAnnexLink linktarget file = do + makeAnnexLink linktarget file + stageSymlink file =<< hashSymlink linktarget + +{- Injects a symlink target into git, returning its Sha. -} +hashSymlink :: String -> Annex Sha +hashSymlink linktarget = inRepo $ Git.HashObject.hashObject BlobObject linktarget + +{- Stages a symlink to the annex, using a Sha of its target. -} +stageSymlink :: FilePath -> Sha -> Annex () +stageSymlink file sha = + Annex.Queue.addUpdateIndex =<< + inRepo (Git.UpdateIndex.stageSymlink file sha) |