git-annex/Annex/Direct.hs
2015-01-21 12:50:09 -04:00

456 lines
15 KiB
Haskell

{- git-annex direct mode
-
- Copyright 2012-2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.Direct where
import Common.Annex
import qualified Annex
import qualified Git
import qualified Git.LsFiles
import qualified Git.Merge
import qualified Git.DiffTree as DiffTree
import qualified Git.Config
import qualified Git.Ref
import qualified Git.Branch
import Git.Sha
import Git.FilePath
import Git.Types
import Config
import Annex.CatFile
import qualified Annex.Queue
import Logs.Location
import Backend
import Types.KeySource
import Annex.Content
import Annex.Content.Direct
import Annex.Link
import Utility.InodeCache
import Utility.CopyFile
import Annex.Perms
import Annex.ReplaceFile
import Annex.VariantFile
import Git.Index
import Annex.Index
import Annex.LockFile
{- Uses git ls-files to find files that need to be committed, and stages
- them into the index. Returns True if some changes were staged. -}
stageDirect :: Annex Bool
stageDirect = do
Annex.Queue.flush
top <- fromRepo Git.repoPath
(l, cleanup) <- inRepo $ Git.LsFiles.stagedOthersDetails [top]
forM_ l go
void $ liftIO cleanup
staged <- Annex.Queue.size
Annex.Queue.flush
return $ staged /= 0
where
{- Determine what kind of modified or deleted file this is, as
- efficiently as we can, by getting any key that's associated
- with it in git, as well as its stat info. -}
go (file, Just sha, Just mode) = withTSDelta $ \delta -> do
shakey <- catKey sha mode
mstat <- liftIO $ catchMaybeIO $ getSymbolicLinkStatus file
mcache <- liftIO $ maybe (pure Nothing) (toInodeCache delta file) mstat
filekey <- isAnnexLink file
case (shakey, filekey, mstat, mcache) of
(_, Just key, _, _)
| shakey == filekey -> noop
{- A changed symlink. -}
| otherwise -> stageannexlink file key
(Just key, _, _, Just cache) -> do
{- All direct mode files will show as
- modified, so compare the cache to see if
- it really was. -}
oldcache <- recordedInodeCache key
case oldcache of
[] -> modifiedannexed file key cache
_ -> unlessM (elemInodeCaches cache oldcache) $
modifiedannexed file key cache
(Just key, _, Nothing, _) -> deletedannexed file key
(Nothing, _, Nothing, _) -> deletegit file
(_, _, Just _, _) -> addgit file
go _ = noop
modifiedannexed file oldkey cache = do
void $ removeAssociatedFile oldkey file
void $ addDirect file cache
deletedannexed file key = do
void $ removeAssociatedFile key file
deletegit file
stageannexlink file key = do
l <- inRepo $ gitAnnexLink file key
stageSymlink file =<< hashSymlink l
void $ addAssociatedFile key file
addgit file = Annex.Queue.addCommand "add" [Param "-f"] [file]
deletegit file = Annex.Queue.addCommand "rm" [Param "-qf"] [file]
{- Run before a commit to update direct mode bookeeping to reflect the
- staged changes being committed. -}
preCommitDirect :: Annex Bool
preCommitDirect = do
(diffs, clean) <- inRepo $ DiffTree.diffIndex Git.Ref.headRef
makeabs <- flip fromTopFilePath <$> gitRepo
forM_ diffs (go makeabs)
liftIO clean
where
go makeabs diff = do
withkey (DiffTree.srcsha diff) (DiffTree.srcmode diff) removeAssociatedFile
withkey (DiffTree.dstsha diff) (DiffTree.dstmode diff) addAssociatedFile
where
withkey sha mode a = when (sha /= nullSha) $ do
k <- catKey sha mode
case k of
Nothing -> noop
Just key -> void $ a key $
makeabs $ DiffTree.file diff
{- Adds a file to the annex in direct mode. Can fail, if the file is
- modified or deleted while it's being added. -}
addDirect :: FilePath -> InodeCache -> Annex Bool
addDirect file cache = do
showStart "add" file
let source = KeySource
{ keyFilename = file
, contentLocation = file
, inodeCache = Just cache
}
got =<< genKey source =<< chooseBackend file
where
got Nothing = do
showEndFail
return False
got (Just (key, _)) = ifM (sameInodeCache file [cache])
( do
l <- inRepo $ gitAnnexLink file key
stageSymlink file =<< hashSymlink l
addInodeCache key cache
void $ addAssociatedFile key file
logStatus key InfoPresent
showEndOk
return True
, do
showEndFail
return False
)
{- In direct mode, git merge would usually refuse to do anything, since it
- sees present direct mode files as type changed files.
-
- So, to handle a merge, it's run with the work tree set to a temp
- directory, and the merge is staged into a copy of the index.
- Then the work tree is updated to reflect the merge, and
- finally, the merge is committed and the real index updated.
-
- A lock file is used to avoid races with any other caller of mergeDirect.
-
- To avoid other git processes from making change to the index while our
- merge is in progress, the index lock file is used as the temp index
- file. This is the same as what git does when updating the index
- normally.
-}
mergeDirect :: Maybe Git.Ref -> Maybe Git.Ref -> Git.Branch -> Annex Bool -> Git.Branch.CommitMode -> Annex Bool
mergeDirect startbranch oldref branch resolvemerge commitmode = exclusively $ do
reali <- liftIO . absPath =<< fromRepo indexFile
tmpi <- liftIO . absPath =<< fromRepo indexFileLock
liftIO $ copyFile reali tmpi
d <- fromRepo gitAnnexMergeDir
liftIO $ do
whenM (doesDirectoryExist d) $
removeDirectoryRecursive d
createDirectoryIfMissing True d
withIndexFile tmpi $ do
merged <- stageMerge d branch commitmode
r <- if merged
then return True
else resolvemerge
mergeDirectCleanup d (fromMaybe Git.Sha.emptyTree oldref)
mergeDirectCommit merged startbranch branch commitmode
liftIO $ rename tmpi reali
return r
where
exclusively = withExclusiveLock gitAnnexMergeLock
{- Stage a merge into the index, avoiding changing HEAD or the current
- branch. -}
stageMerge :: FilePath -> Git.Branch -> Git.Branch.CommitMode -> Annex Bool
stageMerge d branch commitmode = do
-- XXX A bug in git makes stageMerge unsafe to use if the git repo
-- is configured with core.symlinks=false
-- Using mergeNonInteractive is not ideal though, since it will
-- update the current branch immediately, before the work tree
-- has been updated, which would leave things in an inconsistent
-- state if mergeDirectCleanup is interrupted.
-- <http://marc.info/?l=git&m=140262402204212&w=2>
merger <- ifM (coreSymlinks <$> Annex.getGitConfig)
( return Git.Merge.stageMerge
, return $ \ref -> Git.Merge.mergeNonInteractive ref commitmode
)
inRepo $ \g -> do
wd <- liftIO $ absPath d
gd <- liftIO $ absPath $ Git.localGitDir g
merger branch $
g { location = Local { gitdir = gd, worktree = Just (addTrailingPathSeparator wd) } }
{- Commits after a direct mode merge is complete, and after the work
- tree has been updated by mergeDirectCleanup.
-}
mergeDirectCommit :: Bool -> Maybe Git.Ref -> Git.Branch -> Git.Branch.CommitMode -> Annex ()
mergeDirectCommit allowff old branch commitmode = do
void preCommitDirect
d <- fromRepo Git.localGitDir
let merge_head = d </> "MERGE_HEAD"
let merge_msg = d </> "MERGE_MSG"
let merge_mode = d </> "MERGE_MODE"
ifM (pure allowff <&&> canff)
( inRepo $ Git.Branch.update Git.Ref.headRef branch -- fast forward
, do
msg <- liftIO $
catchDefaultIO ("merge " ++ fromRef branch) $
readFile merge_msg
void $ inRepo $ Git.Branch.commit commitmode False msg
Git.Ref.headRef [Git.Ref.headRef, branch]
)
liftIO $ mapM_ nukeFile [merge_head, merge_msg, merge_mode]
where
canff = maybe (return False) (\o -> inRepo $ Git.Branch.fastForwardable o branch) old
mergeDirectCleanup :: FilePath -> Git.Ref -> Annex ()
mergeDirectCleanup d oldref = do
updateWorkTree d oldref
liftIO $ removeDirectoryRecursive d
{- Updates the direct mode work tree to reflect the changes staged in the
- index by a git command, that was run in a temporary work tree.
-
- Uses diff-index to compare the staged changes with provided ref
- which should be the tree before the merge, and applies those
- changes to the work tree.
-
- There are really only two types of changes: An old item can be deleted,
- or a new item added. Two passes are made, first deleting and then
- adding. This is to handle cases where eg, a file is deleted and a
- directory is added. (The diff-tree output may list these in the opposite
- order, but we cannot add the directory until the file with the
- same name is removed.)
-}
updateWorkTree :: FilePath -> Git.Ref -> Annex ()
updateWorkTree d oldref = do
(items, cleanup) <- inRepo $ DiffTree.diffIndex oldref
makeabs <- flip fromTopFilePath <$> gitRepo
let fsitems = zip (map (makeabs . DiffTree.file) items) items
forM_ fsitems $
go makeabs DiffTree.srcsha DiffTree.srcmode moveout moveout_raw
forM_ fsitems $
go makeabs DiffTree.dstsha DiffTree.dstmode movein movein_raw
void $ liftIO cleanup
where
go makeabs getsha getmode a araw (f, item)
| getsha item == nullSha = noop
| otherwise = void $
tryNonAsync . maybe (araw item makeabs f) (\k -> void $ a item makeabs k f)
=<< catKey (getsha item) (getmode item)
moveout _ _ = removeDirect
{- Files deleted by the merge are removed from the work tree.
- Empty work tree directories are removed, per git behavior. -}
moveout_raw _ _ f = liftIO $ do
nukeFile f
void $ tryIO $ removeDirectory $ parentDir f
{- If the file is already present, with the right content for the
- key, it's left alone.
-
- If the file is already present, and does not exist in the
- oldref, preserve this local file.
-
- Otherwise, create the symlink and then if possible, replace it
- with the content. -}
movein item makeabs k f = unlessM (goodContent k f) $ do
preserveUnannexed item makeabs f oldref
l <- inRepo $ gitAnnexLink f k
replaceFile f $ makeAnnexLink l
toDirect k f
{- Any new, modified, or renamed files were written to the temp
- directory by the merge, and are moved to the real work tree. -}
movein_raw item makeabs f = do
preserveUnannexed item makeabs f oldref
liftIO $ do
createDirectoryIfMissing True $ parentDir f
void $ tryIO $ rename (d </> getTopFilePath (DiffTree.file item)) f
{- If the file that's being moved in is already present in the work
- tree, but did not exist in the oldref, preserve this
- local, unannexed file (or directory), as "variant-local".
-
- It's also possible that the file that's being moved in
- is in a directory that collides with an exsting, non-annexed
- file (not a directory), which should be preserved.
-}
preserveUnannexed :: DiffTree.DiffTreeItem -> (TopFilePath -> FilePath) -> FilePath -> Ref -> Annex ()
preserveUnannexed item makeabs absf oldref = do
whenM (liftIO (collidingitem absf) <&&> unannexed absf) $
liftIO $ findnewname absf 0
checkdirs (DiffTree.file item)
where
checkdirs from = case upFrom (getTopFilePath from) of
Nothing -> noop
Just p -> do
let d = asTopFilePath p
let absd = makeabs d
whenM (liftIO (colliding_nondir absd) <&&> unannexed absd) $
liftIO $ findnewname absd 0
checkdirs d
collidingitem f = isJust
<$> catchMaybeIO (getSymbolicLinkStatus f)
colliding_nondir f = maybe False (not . isDirectory)
<$> catchMaybeIO (getSymbolicLinkStatus f)
unannexed f = (isNothing <$> isAnnexLink f)
<&&> (isNothing <$> catFileDetails oldref f)
findnewname :: FilePath -> Int -> IO ()
findnewname f n = do
let localf = mkVariant f
("local" ++ if n > 0 then show n else "")
ifM (collidingitem localf)
( findnewname f (n+1)
, rename f localf
`catchIO` const (findnewname f (n+1))
)
{- If possible, converts a symlink in the working tree into a direct
- mode file. If the content is not available, leaves the symlink
- unchanged. -}
toDirect :: Key -> FilePath -> Annex ()
toDirect k f = fromMaybe noop =<< toDirectGen k f
toDirectGen :: Key -> FilePath -> Annex (Maybe (Annex ()))
toDirectGen k f = do
loc <- calcRepo $ gitAnnexLocation k
ifM (liftIO $ doesFileExist loc)
( return $ Just $ fromindirect loc
, do
{- Copy content from another direct file. -}
absf <- liftIO $ absPath f
dlocs <- filterM (goodContent k) =<<
filterM (\l -> isNothing <$> getAnnexLinkTarget l) =<<
(filter (/= absf) <$> addAssociatedFile k f)
case dlocs of
[] -> return Nothing
(dloc:_) -> return $ Just $ fromdirect dloc
)
where
fromindirect loc = do
{- Move content from annex to direct file. -}
updateInodeCache k loc
void $ addAssociatedFile k f
modifyContent loc $ do
thawContent loc
liftIO (replaceFileFrom loc f)
`catchIO` (\_ -> freezeContent loc)
fromdirect loc = do
replaceFile f $
liftIO . void . copyFileExternal CopyAllMetaData loc
updateInodeCache k f
{- Removes a direct mode file, while retaining its content in the annex
- (unless its content has already been changed). -}
removeDirect :: Key -> FilePath -> Annex ()
removeDirect k f = do
void $ removeAssociatedFileUnchecked k f
unlessM (inAnnex k) $
ifM (goodContent k f)
( moveAnnex k f
, logStatus k InfoMissing
)
liftIO $ do
nukeFile f
void $ tryIO $ removeDirectory $ parentDir f
{- Called when a direct mode file has been changed. Its old content may be
- lost. -}
changedDirect :: Key -> FilePath -> Annex ()
changedDirect oldk f = do
locs <- removeAssociatedFile oldk f
whenM (pure (null locs) <&&> not <$> inAnnex oldk) $
logStatus oldk InfoMissing
{- Enable/disable direct mode. -}
setDirect :: Bool -> Annex ()
setDirect wantdirect = do
if wantdirect
then do
switchHEAD
setbare
else do
setbare
switchHEADBack
setConfig (annexConfig "direct") val
Annex.changeGitConfig $ \c -> c { annexDirect = wantdirect }
where
val = Git.Config.boolConfig wantdirect
setbare = setConfig (ConfigKey Git.Config.coreBare) val
{- Since direct mode sets core.bare=true, incoming pushes could change
- the currently checked out branch. To avoid this problem, HEAD
- is changed to a internal ref that nothing is going to push to.
-
- For refs/heads/master, use refs/heads/annex/direct/master;
- this way things that show HEAD (eg shell prompts) will
- hopefully show just "master". -}
directBranch :: Ref -> Ref
directBranch orighead = case split "/" $ fromRef orighead of
("refs":"heads":"annex":"direct":_) -> orighead
("refs":"heads":rest) ->
Ref $ "refs/heads/annex/direct/" ++ intercalate "/" rest
_ -> Ref $ "refs/heads/" ++ fromRef (Git.Ref.base orighead)
{- Converts a directBranch back to the original branch.
-
- Any other ref is left unchanged.
-}
fromDirectBranch :: Ref -> Ref
fromDirectBranch directhead = case split "/" $ fromRef directhead of
("refs":"heads":"annex":"direct":rest) ->
Ref $ "refs/heads/" ++ intercalate "/" rest
_ -> directhead
switchHEAD :: Annex ()
switchHEAD = maybe noop switch =<< inRepo Git.Branch.currentUnsafe
where
switch orighead = do
let newhead = directBranch orighead
maybe noop (inRepo . Git.Branch.update newhead)
=<< inRepo (Git.Ref.sha orighead)
inRepo $ Git.Branch.checkout newhead
switchHEADBack :: Annex ()
switchHEADBack = maybe noop switch =<< inRepo Git.Branch.currentUnsafe
where
switch currhead = do
let orighead = fromDirectBranch currhead
v <- inRepo $ Git.Ref.sha currhead
case v of
Just headsha
| orighead /= currhead -> do
inRepo $ Git.Branch.update orighead headsha
inRepo $ Git.Branch.checkout orighead
inRepo $ Git.Branch.delete currhead
_ -> inRepo $ Git.Branch.checkout orighead