git-annex/Command/Sync.hs

559 lines
17 KiB
Haskell

{- git-annex command
-
- Copyright 2011 Joachim Breitner <mail@joachim-breitner.de>
- Copyright 2011-2014 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.Sync where
import Common.Annex
import Command
import qualified Annex
import qualified Annex.Branch
import qualified Annex.Queue
import qualified Remote
import qualified Types.Remote as Remote
import Annex.Direct
import Annex.CatFile
import Annex.Link
import Annex.Hook
import qualified Git.Command
import qualified Git.LsFiles as LsFiles
import qualified Git.Merge
import qualified Git.Branch
import qualified Git.Ref
import qualified Git
import Git.Types (BlobType(..))
import qualified Types.Remote
import qualified Remote.Git
import Config
import Annex.ReplaceFile
import Git.FileMode
import Annex.Wanted
import Annex.Content
import Command.Get (getKeyFile')
import qualified Command.Move
import Logs.Location
import Annex.Drop
import Annex.UUID
import Annex.VariantFile
import qualified Data.Set as S
import Control.Concurrent.MVar
def :: [Command]
def = [withOptions syncOptions $
command "sync" (paramOptional (paramRepeating paramRemote))
seek SectionCommon "synchronize local repository with remotes"]
syncOptions :: [Option]
syncOptions = [ contentOption ]
contentOption :: Option
contentOption = flagOption [] "content" "also transfer file contents"
seek :: CommandSeek
seek rs = do
prepMerge
-- There may not be a branch checked out until after the commit,
-- or perhaps after it gets merged from the remote.
-- So only look it up once it's needed, and if once there is a
-- branch, cache it.
mvar <- liftIO newEmptyMVar
let getbranch = ifM (liftIO $ isEmptyMVar mvar)
( do
branch <- inRepo Git.Branch.current
when (isJust branch) $
liftIO $ putMVar mvar branch
return branch
, liftIO $ readMVar mvar
)
let withbranch a = a =<< getbranch
remotes <- syncRemotes rs
let gitremotes = filter Remote.gitSyncableRemote remotes
let dataremotes = filter (not . remoteAnnexIgnore . Remote.gitconfig) remotes
-- Syncing involves many actions, any of which can independently
-- fail, without preventing the others from running.
seekActions $ return $ concat
[ [ commit ]
, [ withbranch mergeLocal ]
, map (withbranch . pullRemote) gitremotes
, [ mergeAnnex ]
]
whenM (Annex.getFlag $ optionName contentOption) $
whenM (seekSyncContent dataremotes) $
-- Transferring content can take a while,
-- and other changes can be pushed to the git-annex
-- branch on the remotes in the meantime, so pull
-- and merge again to avoid our push overwriting
-- those changes.
seekActions $ return $ concat
[ map (withbranch . pullRemote) gitremotes
, [ commitAnnex, mergeAnnex ]
]
seekActions $ return $ concat
[ [ withbranch pushLocal ]
, map (withbranch . pushRemote) gitremotes
]
{- Merging may delete the current directory, so go to the top
- of the repo. This also means that sync always acts on all files in the
- repository, not just on a subdirectory. -}
prepMerge :: Annex ()
prepMerge = liftIO . setCurrentDirectory =<< fromRepo Git.repoPath
syncBranch :: Git.Ref -> Git.Ref
syncBranch = Git.Ref.under "refs/heads/synced" . fromDirectBranch
remoteBranch :: Remote -> Git.Ref -> Git.Ref
remoteBranch remote = Git.Ref.underBase $ "refs/remotes/" ++ Remote.name remote
syncRemotes :: [String] -> Annex [Remote]
syncRemotes rs = ifM (Annex.getState Annex.fast) ( nub <$> pickfast , wanted )
where
pickfast = (++) <$> listed <*> (filterM good =<< fastest <$> available)
wanted
| null rs = filterM good =<< concat . Remote.byCost <$> available
| otherwise = listed
listed = catMaybes <$> mapM (Remote.byName . Just) rs
available = filter (remoteAnnexSync . Types.Remote.gitconfig)
. filter (not . Remote.isXMPPRemote)
<$> Remote.remoteList
good r
| Remote.gitSyncableRemote r = Remote.Git.repoAvail $ Types.Remote.repo r
| otherwise = return True
fastest = fromMaybe [] . headMaybe . Remote.byCost
commit :: CommandStart
commit = next $ next $ ifM isDirect
( do
showStart "commit" ""
void stageDirect
void preCommitDirect
commitStaged commitmessage
, do
showStart "commit" ""
Annex.Branch.commit "update"
-- Commit will fail when the tree is clean, so ignore failure.
_ <- inRepo $ tryIO . Git.Command.runQuiet
[ Param "commit"
, Param "-a"
, Param "-m"
, Param commitmessage
]
return True
)
where
commitmessage = "git-annex automatic sync"
commitStaged :: String -> Annex Bool
commitStaged commitmessage = go =<< inRepo Git.Branch.currentUnsafe
where
go Nothing = return False
go (Just branch) = do
runAnnexHook preCommitAnnexHook
parent <- inRepo $ Git.Ref.sha branch
void $ inRepo $ Git.Branch.commit False commitmessage branch
(maybeToList parent)
return True
mergeLocal :: Maybe Git.Ref -> CommandStart
mergeLocal Nothing = stop
mergeLocal (Just branch) = go =<< needmerge
where
syncbranch = syncBranch branch
needmerge = ifM isBareRepo
( return False
, do
unlessM (inRepo $ Git.Ref.exists syncbranch) $
inRepo $ updateBranch syncbranch
inRepo $ Git.Branch.changed branch syncbranch
)
go False = stop
go True = do
showStart "merge" $ Git.Ref.describe syncbranch
next $ next $ mergeFrom syncbranch
pushLocal :: Maybe Git.Ref -> CommandStart
pushLocal Nothing = stop
pushLocal (Just branch) = do
-- Update the sync branch to match the new state of the branch
inRepo $ updateBranch $ syncBranch branch
-- In direct mode, we're operating on some special direct mode
-- branch, rather than the intended branch, so update the indended
-- branch.
whenM isDirect $
inRepo $ updateBranch $ fromDirectBranch branch
stop
updateBranch :: Git.Ref -> Git.Repo -> IO ()
updateBranch syncbranch g =
unlessM go $ error $ "failed to update " ++ Git.fromRef syncbranch
where
go = Git.Command.runBool
[ Param "branch"
, Param "-f"
, Param $ Git.fromRef $ Git.Ref.base syncbranch
] g
pullRemote :: Remote -> Maybe Git.Ref -> CommandStart
pullRemote remote branch = do
showStart "pull" (Remote.name remote)
next $ do
showOutput
stopUnless fetch $
next $ mergeRemote remote branch
where
fetch = inRepo $ Git.Command.runBool
[Param "fetch", Param $ Remote.name remote]
{- The remote probably has both a master and a synced/master branch.
- Which to merge from? Well, the master has whatever latest changes
- were committed (or pushed changes, if this is a bare remote),
- while the synced/master may have changes that some
- other remote synced to this remote. So, merge them both. -}
mergeRemote :: Remote -> Maybe Git.Ref -> CommandCleanup
mergeRemote remote b = case b of
Nothing -> do
branch <- inRepo Git.Branch.currentUnsafe
and <$> mapM merge (branchlist branch)
Just _ -> and <$> (mapM merge =<< tomerge (branchlist b))
where
merge = mergeFrom . remoteBranch remote
tomerge = filterM (changed remote)
branchlist Nothing = []
branchlist (Just branch) = [branch, syncBranch branch]
pushRemote :: Remote -> Maybe Git.Ref -> CommandStart
pushRemote _remote Nothing = stop
pushRemote remote (Just branch) = go =<< needpush
where
needpush
| remoteAnnexReadOnly (Types.Remote.gitconfig remote) = return False
| otherwise = anyM (newer remote) [syncBranch branch, Annex.Branch.name]
go False = stop
go True = do
showStart "push" (Remote.name remote)
next $ next $ do
showOutput
ok <- inRepo $ pushBranch remote branch
unless ok $ do
warning $ unwords [ "Pushing to " ++ Remote.name remote ++ " failed." ]
showLongNote "(non-fast-forward problems can be solved by setting receive.denyNonFastforwards to false in the remote's git config)"
return ok
{- Pushes a regular branch like master to a remote. Also pushes the git-annex
- branch.
-
- If the remote is a bare git repository, it's best to push the regular
- branch directly to it, so that cloning/pulling will get it.
- On the other hand, if it's not bare, pushing to the checked out branch
- will fail, and this is why we push to its syncBranch.
-
- Git offers no way to tell if a remote is bare or not, so both methods
- are tried.
-
- The direct push is likely to spew an ugly error message, so stderr is
- elided. Since git progress display goes to stderr too, the sync push
- is done first, and actually sends the data. Then the direct push is
- tried, with stderr discarded, to update the branch ref on the remote.
-
- The sync push forces the update of the remote synced/git-annex branch.
- This is necessary if a transition has rewritten the git-annex branch.
- Normally any changes to the git-annex branch get pulled and merged before
- this push, so this forcing is unlikely to overwrite new data pushed
- in from another repository that is also syncing.
-
- But overwriting of data on synced/git-annex can happen, in a race.
- The only difference caused by using a forced push in that case is that
- the last repository to push wins the race, rather than the first to push.
-
- The sync push will fail to overwrite if receive.denyNonFastforwards is
- set on the remote.
-}
pushBranch :: Remote -> Git.Ref -> Git.Repo -> IO Bool
pushBranch remote branch g = tryIO (directpush g) `after` syncpush g
where
syncpush = Git.Command.runBool $ pushparams
[ Git.Branch.forcePush $ refspec Annex.Branch.name
, refspec branch
]
directpush = Git.Command.runQuiet $ pushparams
[Git.fromRef $ Git.Ref.base $ fromDirectBranch branch]
pushparams branches =
[ Param "push"
, Param $ Remote.name remote
] ++ map Param branches
refspec b = concat
[ Git.fromRef $ Git.Ref.base b
, ":"
, Git.fromRef $ Git.Ref.base $ syncBranch b
]
commitAnnex :: CommandStart
commitAnnex = do
Annex.Branch.commit "update"
stop
mergeAnnex :: CommandStart
mergeAnnex = do
void Annex.Branch.forceUpdate
stop
{- Merges from a branch into the current branch. -}
mergeFrom :: Git.Ref -> Annex Bool
mergeFrom branch = do
showOutput
ifM isDirect
( maybe go godirect =<< inRepo Git.Branch.current
, go
)
where
go = runmerge $ inRepo $ Git.Merge.mergeNonInteractive branch
godirect currbranch = do
old <- inRepo $ Git.Ref.sha currbranch
d <- fromRepo gitAnnexMergeDir
r <- runmerge $ inRepo $ mergeDirect d branch
new <- inRepo $ Git.Ref.sha currbranch
case (old, new) of
(Just oldsha, Just newsha) ->
mergeDirectCleanup d oldsha newsha
_ -> noop
return r
runmerge a = ifM a
( return True
, resolveMerge
)
{- Resolves a conflicted merge. It's important that any conflicts be
- resolved in a way that itself avoids later merge conflicts, since
- multiple repositories may be doing this concurrently.
-
- Only annexed files are resolved; other files are left for the user to
- handle.
-
- This uses the Keys pointed to by the files to construct new
- filenames. So when both sides modified file foo,
- it will be deleted, and replaced with files foo.variant-A and
- foo.variant-B.
-
- On the other hand, when one side deleted foo, and the other modified it,
- it will be deleted, and the modified version stored as file
- foo.variant-A (or B).
-
- It's also possible that one side has foo as an annexed file, and
- the other as a directory or non-annexed file. The annexed file
- is renamed to resolve the merge, and the other object is preserved as-is.
-}
resolveMerge :: Annex Bool
resolveMerge = do
top <- fromRepo Git.repoPath
(fs, cleanup) <- inRepo (LsFiles.unmerged [top])
mergedfs <- catMaybes <$> mapM resolveMerge' fs
let merged = not (null mergedfs)
void $ liftIO cleanup
(deleted, cleanup2) <- inRepo (LsFiles.deleted [top])
unless (null deleted) $
Annex.Queue.addCommand "rm" [Params "--quiet -f --"] deleted
void $ liftIO cleanup2
when merged $ do
unlessM isDirect $
cleanConflictCruft mergedfs top
Annex.Queue.flush
void $ inRepo $ Git.Command.runBool
[ Param "commit"
, Param "-m"
, Param "git-annex automatic merge conflict fix"
]
showLongNote "Merge conflict was automatically resolved; you may want to examine the result."
return merged
resolveMerge' :: LsFiles.Unmerged -> Annex (Maybe FilePath)
resolveMerge' u
| issymlink LsFiles.valUs && issymlink LsFiles.valThem = do
kus <- getKey LsFiles.valUs
kthem <- getKey LsFiles.valThem
case (kus, kthem) of
-- Both sides of conflict are annexed files
(Just keyUs, Just keyThem) -> do
removeoldfile keyUs
if keyUs == keyThem
then makelink keyUs
else do
makelink keyUs
makelink keyThem
return $ Just file
-- Our side is annexed, other side is not.
(Just keyUs, Nothing) -> do
ifM isDirect
( do
removeoldfile keyUs
makelink keyUs
movefromdirectmerge file
, do
unstageoldfile
makelink keyUs
)
return $ Just file
-- Our side is not annexed, other side is.
(Nothing, Just keyThem) -> do
makelink keyThem
unstageoldfile
return $ Just file
-- Neither side is annexed; cannot resolve.
(Nothing, Nothing) -> return Nothing
| otherwise = return Nothing
where
file = LsFiles.unmergedFile u
issymlink select = select (LsFiles.unmergedBlobType u) `elem` [Just SymlinkBlob, Nothing]
makelink key = do
let dest = variantFile file key
l <- inRepo $ gitAnnexLink dest key
replaceFile dest $ makeAnnexLink l
stageSymlink dest =<< hashSymlink l
whenM isDirect $
toDirect key dest
removeoldfile keyUs = do
ifM isDirect
( removeDirect keyUs file
, liftIO $ nukeFile file
)
Annex.Queue.addCommand "rm" [Params "--quiet -f --"] [file]
unstageoldfile = Annex.Queue.addCommand "rm" [Params "--quiet -f --cached --"] [file]
getKey select = case select (LsFiles.unmergedSha u) of
Nothing -> return Nothing
Just sha -> catKey sha symLinkMode
{- Move something out of the direct mode merge directory and into
- the git work tree.
-
- On a filesystem not supporting symlinks, this is complicated
- because a directory may contain annex links, but just
- moving them into the work tree will not let git know they are
- symlinks.
-
- Also, if the content of the file is available, make it available
- in direct mode.
-}
movefromdirectmerge item = do
d <- fromRepo gitAnnexMergeDir
liftIO $ rename (d </> item) item
mapM_ setuplink =<< liftIO (dirContentsRecursive item)
setuplink f = do
v <- getAnnexLinkTarget f
case v of
Nothing -> noop
Just target -> do
unlessM (coreSymlinks <$> Annex.getGitConfig) $
addAnnexLink target f
maybe noop (`toDirect` f)
(fileKey (takeFileName target))
{- git-merge moves conflicting files away to files
- named something like f~HEAD or f~branch, but the
- exact name chosen can vary. Once the conflict is resolved,
- this cruft can be deleted. To avoid deleting legitimate
- files that look like this, only delete files that are
- A) not staged in git and B) look like git-annex symlinks.
-}
cleanConflictCruft :: [FilePath] -> FilePath -> Annex ()
cleanConflictCruft resolvedfs top = do
(fs, cleanup) <- inRepo $ LsFiles.notInRepo False [top]
mapM_ clean fs
void $ liftIO cleanup
where
clean f
| matchesresolved f = whenM (isJust <$> isAnnexLink f) $
liftIO $ nukeFile f
| otherwise = noop
s = S.fromList resolvedfs
matchesresolved f = S.member (base f) s
base f = reverse $ drop 1 $ dropWhile (/= '~') $ reverse f
changed :: Remote -> Git.Ref -> Annex Bool
changed remote b = do
let r = remoteBranch remote b
ifM (inRepo $ Git.Ref.exists r)
( inRepo $ Git.Branch.changed b r
, return False
)
newer :: Remote -> Git.Ref -> Annex Bool
newer remote b = do
let r = remoteBranch remote b
ifM (inRepo $ Git.Ref.exists r)
( inRepo $ Git.Branch.changed r b
, return True
)
{- If it's preferred content, and we don't have it, get it from one of the
- listed remotes (preferring the cheaper earlier ones).
-
- Send it to each remote that doesn't have it, and for which it's
- preferred content.
-
- Drop it locally if it's not preferred content (honoring numcopies).
-
- Drop it from each remote that has it, where it's not preferred content
- (honoring numcopies).
-
- If any file movements were generated, returns true.
-}
seekSyncContent :: [Remote] -> Annex Bool
seekSyncContent rs = do
mvar <- liftIO newEmptyMVar
mapM_ (go mvar) =<< seekHelper LsFiles.inRepo []
liftIO $ not <$> isEmptyMVar mvar
where
go mvar f = ifAnnexed f
(\v -> void (liftIO (tryPutMVar mvar ())) >> syncFile rs f v)
noop
syncFile :: [Remote] -> FilePath -> (Key, Backend) -> Annex ()
syncFile rs f (k, _) = do
locs <- loggedLocations k
let (have, lack) = partition (\r -> Remote.uuid r `elem` locs) rs
got <- anyM id =<< handleget have
putrs <- catMaybes . snd . unzip <$> (sequence =<< handleput lack)
u <- getUUID
let locs' = concat [[u | got], putrs, locs]
-- Using callCommandAction rather than commandAction for drops,
-- because a failure to drop does not mean the sync failed.
handleDropsFrom locs' rs "unwanted" True k (Just f)
Nothing callCommandAction
where
wantget have = allM id
[ pure (not $ null have)
, not <$> inAnnex k
, wantGet True (Just k) (Just f)
]
handleget have = ifM (wantget have)
( return [ get have ]
, return []
)
get have = commandAction $ do
showStart "get" f
next $ next $ getViaTmp k $ \dest -> getKeyFile' k (Just f) dest have
wantput r
| Remote.readonly r || remoteAnnexReadOnly (Types.Remote.gitconfig r) = return False
| otherwise = wantSend True (Just k) (Just f) (Remote.uuid r)
handleput lack = ifM (inAnnex k)
( map put <$> filterM wantput lack
, return []
)
put dest = do
ok <- commandAction $ do
showStart "copy" f
next $ Command.Move.toPerform dest False k (Just f)
return (ok, if ok then Just (Remote.uuid dest) else Nothing)