{- adjusted branch - - Copyright 2016 Joey Hess - - Licensed under the GNU GPL version 3 or higher. -} {-# LANGUAGE BangPatterns #-} module Annex.AdjustedBranch ( Adjustment(..), OrigBranch, AdjBranch(..), originalToAdjusted, adjustedToOriginal, fromAdjustedBranch, getAdjustment, enterAdjustedBranch, adjustBranch, adjustToCrippledFileSystem, updateAdjustedBranch, propigateAdjustedCommits, AdjustedClone(..), checkAdjustedClone, isGitVersionSupported, checkVersionSupported, ) where import Annex.Common import qualified Annex import Git import Git.Types import qualified Git.Branch import qualified Git.Ref import qualified Git.Command import qualified Git.Tree import qualified Git.DiffTree import qualified Git.Merge import Git.Tree (TreeItem(..)) import Git.Sha import Git.Env import Git.Index import Git.FilePath import qualified Git.LockFile import qualified Git.Version import Annex.Version import Annex.CatFile import Annex.Link import Annex.AutoMerge import Annex.Content import Annex.Perms import Annex.GitOverlay import Utility.Tmp import qualified Database.Keys import Config import qualified Data.Map as M data Adjustment = UnlockAdjustment | LockAdjustment | FixAdjustment | UnFixAdjustment | HideMissingAdjustment | ShowMissingAdjustment deriving (Show, Eq) reverseAdjustment :: Adjustment -> Adjustment reverseAdjustment UnlockAdjustment = LockAdjustment reverseAdjustment LockAdjustment = UnlockAdjustment reverseAdjustment HideMissingAdjustment = ShowMissingAdjustment reverseAdjustment ShowMissingAdjustment = HideMissingAdjustment reverseAdjustment FixAdjustment = UnFixAdjustment reverseAdjustment UnFixAdjustment = FixAdjustment {- How to perform various adjustments to a TreeItem. -} adjustTreeItem :: Adjustment -> TreeItem -> Annex (Maybe TreeItem) adjustTreeItem UnlockAdjustment = ifSymlink adjustToPointer noAdjust adjustTreeItem LockAdjustment = ifSymlink noAdjust adjustToSymlink adjustTreeItem FixAdjustment = ifSymlink adjustToSymlink noAdjust adjustTreeItem UnFixAdjustment = ifSymlink (adjustToSymlink' gitAnnexLinkCanonical) noAdjust adjustTreeItem HideMissingAdjustment = \ti@(TreeItem _ _ s) -> do mk <- catKey s case mk of Just k -> ifM (inAnnex k) ( return (Just ti) , return Nothing ) Nothing -> return (Just ti) adjustTreeItem ShowMissingAdjustment = noAdjust ifSymlink :: (TreeItem -> Annex a) -> (TreeItem -> Annex a) -> TreeItem -> Annex a ifSymlink issymlink notsymlink ti@(TreeItem _f m _s) | toBlobType m == Just SymlinkBlob = issymlink ti | otherwise = notsymlink ti noAdjust :: TreeItem -> Annex (Maybe TreeItem) noAdjust = return . Just adjustToPointer :: TreeItem -> Annex (Maybe TreeItem) adjustToPointer ti@(TreeItem f _m s) = do mk <- catKey s case mk of Just k -> do Database.Keys.addAssociatedFile k f Just . TreeItem f (fromBlobType FileBlob) <$> hashPointerFile k Nothing -> return (Just ti) adjustToSymlink :: TreeItem -> Annex (Maybe TreeItem) adjustToSymlink = adjustToSymlink' gitAnnexLink adjustToSymlink' :: (FilePath -> Key -> Git.Repo -> GitConfig -> IO FilePath) -> TreeItem -> Annex (Maybe TreeItem) adjustToSymlink' gitannexlink ti@(TreeItem f _m s) = do mk <- catKey s case mk of Just k -> do absf <- inRepo $ \r -> absPath $ fromTopFilePath f r linktarget <- calcRepo $ gitannexlink absf k Just . TreeItem f (fromBlobType SymlinkBlob) <$> hashSymlink linktarget Nothing -> return (Just ti) type OrigBranch = Branch newtype AdjBranch = AdjBranch { adjBranch :: Branch } -- This is a hidden branch ref, that's used as the basis for the AdjBranch, -- since pushes can overwrite the OrigBranch at any time. So, changes -- are propigated from the AdjBranch to the head of the BasisBranch. newtype BasisBranch = BasisBranch Ref -- The basis for refs/heads/adjusted/master(unlocked) is -- refs/basis/adjusted/master(unlocked). basisBranch :: AdjBranch -> BasisBranch basisBranch (AdjBranch adjbranch) = BasisBranch $ Ref ("refs/basis/" ++ fromRef (Git.Ref.base adjbranch)) adjustedBranchPrefix :: String adjustedBranchPrefix = "refs/heads/adjusted/" serialize :: Adjustment -> String serialize UnlockAdjustment = "unlocked" serialize LockAdjustment = "locked" serialize HideMissingAdjustment = "present" serialize ShowMissingAdjustment = "showmissing" serialize FixAdjustment = "fixed" serialize UnFixAdjustment = "unfixed" deserialize :: String -> Maybe Adjustment deserialize "unlocked" = Just UnlockAdjustment deserialize "locked" = Just UnlockAdjustment deserialize "present" = Just HideMissingAdjustment deserialize "fixed" = Just FixAdjustment deserialize "unfixed" = Just UnFixAdjustment deserialize _ = Nothing originalToAdjusted :: OrigBranch -> Adjustment -> AdjBranch originalToAdjusted orig adj = AdjBranch $ Ref $ adjustedBranchPrefix ++ base ++ '(' : serialize adj ++ ")" where base = fromRef (Git.Ref.base orig) adjustedToOriginal :: Branch -> Maybe (Adjustment, OrigBranch) adjustedToOriginal b | adjustedBranchPrefix `isPrefixOf` bs = do let (base, as) = separate (== '(') (drop prefixlen bs) adj <- deserialize (takeWhile (/= ')') as) Just (adj, Git.Ref.underBase "refs/heads" (Ref base)) | otherwise = Nothing where bs = fromRef b prefixlen = length adjustedBranchPrefix getAdjustment :: Branch -> Maybe Adjustment getAdjustment = fmap fst . adjustedToOriginal fromAdjustedBranch :: Branch -> OrigBranch fromAdjustedBranch b = maybe b snd (adjustedToOriginal b) originalBranch :: Annex (Maybe OrigBranch) originalBranch = fmap fromAdjustedBranch <$> inRepo Git.Branch.current {- Enter an adjusted version of current branch (or, if already in an - adjusted version of a branch, changes the adjustment of the original - branch). - - Can fail, if no branch is checked out, or if the adjusted branch already - exists, or perhaps if staged changes conflict with the adjusted branch. -} enterAdjustedBranch :: Adjustment -> Annex Bool enterAdjustedBranch adj = go =<< originalBranch where go (Just origbranch) = do let adjbranch = adjBranch $ originalToAdjusted origbranch adj ifM (inRepo (Git.Ref.exists adjbranch) <&&> (not <$> Annex.getState Annex.force)) ( do mapM_ (warning . unwords) [ [ "adjusted branch" , Git.Ref.describe adjbranch , "already exists." ] , [ "Aborting because that branch may have changes that have not yet reached" , Git.Ref.describe origbranch ] , [ "You can check out the adjusted branch manually to enter it," , "or delete the adjusted branch and re-run this command." ] ] return False , do AdjBranch b <- preventCommits $ const $ adjustBranch adj origbranch showOutput -- checkout can have output in large repos inRepo $ Git.Command.runBool [ Param "checkout" , Param $ fromRef $ Git.Ref.base b ] ) go Nothing = do warning "not on any branch!" return False adjustToCrippledFileSystem :: Annex () adjustToCrippledFileSystem = do warning "Entering an adjusted branch where files are unlocked as this filesystem does not support locked files." whenM (isNothing <$> originalBranch) $ void $ inRepo $ Git.Branch.commitCommand Git.Branch.AutomaticCommit [ Param "--quiet" , Param "--allow-empty" , Param "-m" , Param "commit before entering adjusted unlocked branch" ] unlessM (enterAdjustedBranch UnlockAdjustment) $ warning "Failed to enter adjusted branch!" setBasisBranch :: BasisBranch -> Ref -> Annex () setBasisBranch (BasisBranch basis) new = inRepo $ Git.Branch.update' basis new setAdjustedBranch :: String -> AdjBranch -> Ref -> Annex () setAdjustedBranch msg (AdjBranch b) r = inRepo $ Git.Branch.update msg b r adjustBranch :: Adjustment -> OrigBranch -> Annex AdjBranch adjustBranch adj origbranch = do -- Start basis off with the current value of the origbranch. setBasisBranch basis origbranch sha <- adjustCommit adj basis setAdjustedBranch "entering adjusted branch" adjbranch sha return adjbranch where adjbranch = originalToAdjusted origbranch adj basis = basisBranch adjbranch adjustCommit :: Adjustment -> BasisBranch -> Annex Sha adjustCommit adj basis = do treesha <- adjustTree adj basis commitAdjustedTree treesha basis adjustTree :: Adjustment -> BasisBranch -> Annex Sha adjustTree adj (BasisBranch basis) = do let toadj = adjustTreeItem adj treesha <- Git.Tree.adjustTree toadj [] [] basis =<< Annex.gitRepo return treesha type CommitsPrevented = Git.LockFile.LockHandle {- Locks git's index file, preventing git from making a commit, merge, - or otherwise changing the HEAD ref while the action is run. - - Throws an IO exception if the index file is already locked. -} preventCommits :: (CommitsPrevented -> Annex a) -> Annex a preventCommits = bracket setup cleanup where setup = do lck <- fromRepo indexFileLock liftIO $ Git.LockFile.openLock lck cleanup = liftIO . Git.LockFile.closeLock {- Commits a given adjusted tree, with the provided parent ref. - - This should always yield the same value, even if performed in different - clones of a repo, at different times. The commit message and other - metadata is based on the parent. -} commitAdjustedTree :: Sha -> BasisBranch -> Annex Sha commitAdjustedTree treesha parent@(BasisBranch b) = commitAdjustedTree' treesha parent [b] commitAdjustedTree' :: Sha -> BasisBranch -> [Ref] -> Annex Sha commitAdjustedTree' treesha (BasisBranch basis) parents = go =<< catCommit basis where go Nothing = inRepo mkcommit go (Just basiscommit) = inRepo $ commitWithMetaData (commitAuthorMetaData basiscommit) (commitCommitterMetaData basiscommit) mkcommit mkcommit = Git.Branch.commitTree Git.Branch.AutomaticCommit adjustedBranchCommitMessage parents treesha {- This message should never be changed. -} adjustedBranchCommitMessage :: String adjustedBranchCommitMessage = "git-annex adjusted branch" findAdjustingCommit :: AdjBranch -> Annex (Maybe Commit) findAdjustingCommit (AdjBranch b) = go =<< catCommit b where go Nothing = return Nothing go (Just c) | commitMessage c == adjustedBranchCommitMessage = return (Just c) | otherwise = case commitParent c of [p] -> go =<< catCommit p _ -> return Nothing {- Update the currently checked out adjusted branch, merging the provided - branch into it. Note that the provided branch should be a non-adjusted - branch. -} updateAdjustedBranch :: Branch -> (OrigBranch, Adjustment) -> [Git.Merge.MergeConfig] -> Git.Branch.CommitMode -> Annex Bool updateAdjustedBranch tomerge (origbranch, adj) mergeconfig commitmode = catchBoolIO $ join $ preventCommits go where adjbranch@(AdjBranch currbranch) = originalToAdjusted origbranch adj basis = basisBranch adjbranch go commitsprevented = ifM (inRepo $ Git.Branch.changed currbranch tomerge) ( do (updatedorig, _) <- propigateAdjustedCommits' origbranch adj commitsprevented changestomerge updatedorig , nochangestomerge ) nochangestomerge = return $ return True {- Since the adjusted branch changes files, merging tomerge - directly into it would likely result in unncessary merge - conflicts. To avoid those conflicts, instead merge tomerge into - updatedorig. The result of the merge can the be - adjusted to yield the final adjusted branch. - - In order to do a merge into a ref that is not checked out, - set the work tree to a temp directory, and set GIT_DIR - to another temp directory, in which HEAD contains the - updatedorig sha. GIT_COMMON_DIR is set to point to the real - git directory, and so git can read and write objects from there, - but will use GIT_DIR for HEAD and index. - - (Doing the merge this way also lets it run even though the main - index file is currently locked.) -} changestomerge (Just updatedorig) = do misctmpdir <- fromRepo gitAnnexTmpMiscDir void $ createAnnexDirectory misctmpdir tmpwt <- fromRepo gitAnnexMergeDir withTmpDirIn misctmpdir "git" $ \tmpgit -> withWorkTreeRelated tmpgit $ withemptydir tmpwt $ withWorkTree tmpwt $ do liftIO $ writeFile (tmpgit "HEAD") (fromRef updatedorig) -- This reset makes git merge not care -- that the work tree is empty; otherwise -- it will think that all the files have -- been staged for deletion, and sometimes -- the merge includes these deletions -- (for an unknown reason). -- http://thread.gmane.org/gmane.comp.version-control.git/297237 inRepo $ Git.Command.run [Param "reset", Param "HEAD", Param "--quiet"] showAction $ "Merging into " ++ fromRef (Git.Ref.base origbranch) merged <- inRepo (Git.Merge.merge' [] tomerge mergeconfig commitmode) <||> (resolveMerge (Just updatedorig) tomerge True <&&> commitResolvedMerge commitmode) if merged then do !mergecommit <- liftIO $ extractSha <$> readFile (tmpgit "HEAD") -- This is run after the commit lock is dropped. return $ postmerge mergecommit else return $ return False changestomerge Nothing = return $ return False withemptydir d a = bracketIO setup cleanup (const a) where setup = do whenM (doesDirectoryExist d) $ removeDirectoryRecursive d createDirectoryIfMissing True d cleanup _ = removeDirectoryRecursive d {- A merge commit has been made between the basisbranch and - tomerge. Update the basisbranch and origbranch to point - to that commit, adjust it to get the new adjusted branch, - and check it out. - - But, there may be unstaged work tree changes that conflict, - so the check out is done by making a normal merge of - the new adjusted branch. -} postmerge (Just mergecommit) = do setBasisBranch basis mergecommit inRepo $ Git.Branch.update' origbranch mergecommit adjtree <- adjustTree adj (BasisBranch mergecommit) adjmergecommit <- commitAdjustedTree adjtree (BasisBranch mergecommit) -- Make currbranch be the parent, so that merging -- this commit will be a fast-forward. adjmergecommitff <- commitAdjustedTree' adjtree (BasisBranch mergecommit) [currbranch] showAction "Merging into adjusted branch" ifM (autoMergeFrom adjmergecommitff (Just currbranch) mergeconfig commitmode) ( reparent adjtree adjmergecommit =<< getcurrentcommit , return False ) postmerge Nothing = return False -- Now that the merge into the adjusted branch is complete, -- take the tree from that merge, and attach it on top of the -- adjmergecommit, if it's different. reparent adjtree adjmergecommit (Just currentcommit) = do if (commitTree currentcommit /= adjtree) then do c <- inRepo $ Git.Branch.commitTree Git.Branch.AutomaticCommit ("Merged " ++ fromRef tomerge) [adjmergecommit] (commitTree currentcommit) inRepo $ Git.Branch.update "updating adjusted branch" currbranch c propigateAdjustedCommits origbranch adj else inRepo $ Git.Branch.update "updating adjusted branch" currbranch adjmergecommit return True reparent _ _ Nothing = return False getcurrentcommit = do v <- inRepo Git.Branch.currentUnsafe case v of Nothing -> return Nothing Just c -> catCommit c {- Check for any commits present on the adjusted branch that have not yet - been propigated to the basis branch, and propigate them to the basis - branch and from there on to the orig branch. - - After propigating the commits back to the basis banch, - rebase the adjusted branch on top of the updated basis branch. -} propigateAdjustedCommits :: OrigBranch -> Adjustment -> Annex () propigateAdjustedCommits origbranch adj = preventCommits $ \commitsprevented -> join $ snd <$> propigateAdjustedCommits' origbranch adj commitsprevented {- Returns sha of updated basis branch, and action which will rebase - the adjusted branch on top of the updated basis branch. -} propigateAdjustedCommits' :: OrigBranch -> Adjustment -> CommitsPrevented -> Annex (Maybe Sha, Annex ()) propigateAdjustedCommits' origbranch adj _commitsprevented = do ov <- inRepo $ Git.Ref.sha basis case ov of Just origsha -> do cv <- catCommit currbranch case cv of Just currcommit -> do v <- newcommits >>= go origsha False case v of Left e -> do warning e return (Nothing, return ()) Right newparent -> return ( Just newparent , rebase currcommit newparent ) Nothing -> return (Nothing, return ()) Nothing -> return (Nothing, return ()) where (BasisBranch basis) = basisBranch adjbranch adjbranch@(AdjBranch currbranch) = originalToAdjusted origbranch adj newcommits = inRepo $ Git.Branch.changedCommits basis currbranch -- Get commits oldest first, so they can be processed -- in order made. [Param "--reverse"] go parent _ [] = do setBasisBranch (BasisBranch basis) parent inRepo $ Git.Branch.update' origbranch parent return (Right parent) go parent pastadjcommit (sha:l) = do mc <- catCommit sha case mc of Just c | commitMessage c == adjustedBranchCommitMessage -> go parent True l | pastadjcommit -> do v <- reverseAdjustedCommit parent adj (sha, c) origbranch case v of Left e -> return (Left e) Right commit -> go commit pastadjcommit l _ -> go parent pastadjcommit l rebase currcommit newparent = do -- Reuse the current adjusted tree, and reparent it -- on top of the newparent. commitAdjustedTree (commitTree currcommit) (BasisBranch newparent) >>= inRepo . Git.Branch.update rebaseOnTopMsg currbranch rebaseOnTopMsg :: String rebaseOnTopMsg = "rebasing adjusted branch on top of updated original branch" {- Reverses an adjusted commit, and commit with provided commitparent, - yielding a commit sha. - - Adjusts the tree of the commitparent, changing only the files that the - commit changed, and reverse adjusting those changes. - - The commit message, and the author and committer metadata are - copied over from the basiscommit. However, any gpg signature - will be lost, and any other headers are not copied either. -} reverseAdjustedCommit :: Sha -> Adjustment -> (Sha, Commit) -> OrigBranch -> Annex (Either String Sha) reverseAdjustedCommit commitparent adj (csha, basiscommit) origbranch | length (commitParent basiscommit) > 1 = return $ Left $ "unable to propigate merge commit " ++ show csha ++ " back to " ++ show origbranch | otherwise = do treesha <- reverseAdjustedTree commitparent adj csha revadjcommit <- inRepo $ commitWithMetaData (commitAuthorMetaData basiscommit) (commitCommitterMetaData basiscommit) $ Git.Branch.commitTree Git.Branch.AutomaticCommit (commitMessage basiscommit) [commitparent] treesha return (Right revadjcommit) {- Adjusts the tree of the basis, changing only the files that the - commit changed, and reverse adjusting those changes. - - commitDiff does not support merge commits, so the csha must not be a - merge commit. -} reverseAdjustedTree :: Sha -> Adjustment -> Sha -> Annex Sha reverseAdjustedTree basis adj csha = do (diff, cleanup) <- inRepo (Git.DiffTree.commitDiff csha) let (adds, others) = partition (\dti -> Git.DiffTree.srcsha dti == nullSha) diff let (removes, changes) = partition (\dti -> Git.DiffTree.dstsha dti == nullSha) others adds' <- catMaybes <$> mapM (adjustTreeItem reverseadj) (map diffTreeToTreeItem adds) treesha <- Git.Tree.adjustTree (propchanges changes) adds' (map Git.DiffTree.file removes) basis =<< Annex.gitRepo void $ liftIO cleanup return treesha where reverseadj = reverseAdjustment adj propchanges changes ti@(TreeItem f _ _) = case M.lookup (norm f) m of Nothing -> return (Just ti) -- not changed Just change -> adjustTreeItem reverseadj change where m = M.fromList $ map (\i@(TreeItem f' _ _) -> (norm f', i)) $ map diffTreeToTreeItem changes norm = normalise . getTopFilePath diffTreeToTreeItem :: Git.DiffTree.DiffTreeItem -> TreeItem diffTreeToTreeItem dti = TreeItem (Git.DiffTree.file dti) (Git.DiffTree.dstmode dti) (Git.DiffTree.dstsha dti) data AdjustedClone = InAdjustedClone | NotInAdjustedClone | NeedUpgradeForAdjustedClone {- Cloning a repository that has an adjusted branch checked out will - result in the clone having the same adjusted branch checked out -- but - the origbranch won't exist in the clone, nor will the basis. So - to properly set up the adjusted branch, the origbranch and basis need - to be set. - - We can't trust that the origin's origbranch matches up with the currently - checked out adjusted branch; the origin could have the two branches - out of sync (eg, due to another branch having been pushed to the origin's - origbranch), or due to a commit on its adjusted branch not having been - propigated back to origbranch. - - So, find the adjusting commit on the currently checked out adjusted - branch, and use the parent of that commit as the basis, and set the - origbranch to it. - - The repository may also need to be upgraded to a new version, if the - current version is too old to support adjusted branches. -} checkAdjustedClone :: Annex AdjustedClone checkAdjustedClone = ifM isBareRepo ( return NotInAdjustedClone , go =<< inRepo Git.Branch.current ) where go Nothing = return NotInAdjustedClone go (Just currbranch) = case adjustedToOriginal currbranch of Nothing -> return NotInAdjustedClone Just (adj, origbranch) -> do let basis@(BasisBranch bb) = basisBranch (originalToAdjusted origbranch adj) unlessM (inRepo $ Git.Ref.exists bb) $ do unlessM (inRepo $ Git.Ref.exists origbranch) $ do let remotebranch = Git.Ref.underBase "refs/remotes/origin" origbranch inRepo $ Git.Branch.update' origbranch remotebranch aps <- fmap commitParent <$> findAdjustingCommit (AdjBranch currbranch) case aps of Just [p] -> setBasisBranch basis p _ -> error $ "Unable to clean up from clone of adjusted branch; perhaps you should check out " ++ Git.Ref.describe origbranch ifM versionSupportsUnlockedPointers ( return InAdjustedClone , return NeedUpgradeForAdjustedClone ) -- git 2.2.0 needed for GIT_COMMON_DIR which is needed -- by updateAdjustedBranch to use withWorkTreeRelated. isGitVersionSupported :: IO Bool isGitVersionSupported = not <$> Git.Version.older "2.2.0" checkVersionSupported :: Annex () checkVersionSupported = do unlessM versionSupportsAdjustedBranch $ error "Adjusted branches are only supported in v6 or newer repositories." unlessM (liftIO isGitVersionSupported) $ error "Your version of git is too old; upgrade it to 2.2.0 or newer to use adjusted branches."