broke out Git/Branch.hs and reorganized
This commit is contained in:
Joey Hess
parent
543d0d2501
commit
31a0c07ee9
2 changed files with 242 additions and 225 deletions
407
Annex/Branch.hs
407
Annex/Branch.hs
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@ -6,15 +6,15 @@
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-}
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module Annex.Branch (
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name,
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hasOrigin,
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hasSibling,
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create,
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update,
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get,
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change,
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commit,
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files,
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name,
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hasOrigin,
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hasSibling,
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) where
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import System.Exit
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@ -27,6 +27,7 @@ import Annex.Journal
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import qualified Git
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import qualified Git.UnionMerge
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import qualified Git.Ref
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import qualified Git.Branch
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import Annex.CatFile
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{- Name of the branch that is used to store git-annex's information. -}
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@ -41,57 +42,132 @@ fullname = Git.Ref $ "refs/heads/" ++ show name
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originname :: Git.Ref
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originname = Git.Ref $ "origin/" ++ show name
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{- Populates the branch's index file with the current branch contents.
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-
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- This is only done when the index doesn't yet exist, and the index
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- is used to build up changes to be commited to the branch, and merge
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- in changes from other branches.
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-}
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genIndex :: Git.Repo -> IO ()
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genIndex g = Git.UnionMerge.stream_update_index g
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[Git.UnionMerge.ls_tree fullname g]
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{- Does origin/git-annex exist? -}
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hasOrigin :: Annex Bool
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hasOrigin = inRepo $ Git.Ref.exists originname
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{- Merges the specified branches into the index.
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- Any changes staged in the index will be preserved. -}
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mergeIndex :: [Git.Ref] -> Annex ()
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mergeIndex branches = do
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h <- catFileHandle
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inRepo $ \g -> Git.UnionMerge.merge_index h g branches
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{- Does the git-annex branch or a sibling foo/git-annex branch exist? -}
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hasSibling :: Annex Bool
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hasSibling = not . null <$> siblingBranches
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{- Runs an action using the branch's index file. -}
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withIndex :: Annex a -> Annex a
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withIndex = withIndex' False
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withIndex' :: Bool -> Annex a -> Annex a
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withIndex' bootstrapping a = do
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f <- fromRepo gitAnnexIndex
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bracketIO (Git.useIndex f) id $ do
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unlessM (liftIO $ doesFileExist f) $ do
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unless bootstrapping create
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liftIO $ createDirectoryIfMissing True $ takeDirectory f
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unless bootstrapping $ inRepo genIndex
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a
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{- List of git-annex (refs, branches), including the main one and any
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- from remotes. Duplicate refs are filtered out. -}
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siblingBranches :: Annex [(Git.Ref, Git.Branch)]
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siblingBranches = inRepo $ Git.Ref.matching name
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{- Updates the branch's index to reflect the current contents of the branch.
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- Any changes staged in the index will be preserved.
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{- Creates the branch, if it does not already exist. -}
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create :: Annex ()
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create = do
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_ <- getBranch
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return ()
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{- Returns the ref of the branch, creating it first if necessary. -}
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getBranch :: Annex (Git.Ref)
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getBranch = maybe (hasOrigin >>= go >>= use) (return) =<< branchsha
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where
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go True = do
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inRepo $ Git.run "branch"
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[Param $ show name, Param $ show originname]
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fromMaybe (error $ "failed to create " ++ show name)
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<$> branchsha
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go False = withIndex' True $ do
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inRepo $ Git.commit "branch created" fullname []
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use sha = do
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setIndexSha sha
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return sha
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branchsha = inRepo $ Git.Ref.sha fullname
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{- Ensures that the branch and index are is up-to-date; should be
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- called before data is read from it. Runs only once per git-annex run.
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-
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- Compares the ref stored in the lock file with the current
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- ref of the branch to see if an update is needed.
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- Before refs are merged into the index, it's important to first stage the
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- journal into the index. Otherwise, any changes in the journal would
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- later get staged, and might overwrite changes made during the merge.
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-
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- (It would be cleaner to handle the merge by updating the journal, not the
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- index, with changes from the branches.)
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-
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- The branch is fast-forwarded if possible, otherwise a merge commit is
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- made.
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-}
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updateIndex :: Git.Ref -> Annex ()
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updateIndex branchref = do
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lock <- fromRepo gitAnnexIndexLock
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lockref <- Git.Ref . firstLine <$>
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liftIO (catchDefaultIO (readFileStrict lock) "")
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when (lockref /= branchref) $ do
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withIndex $ mergeIndex [fullname]
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setIndexSha branchref
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update :: Annex ()
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update = runUpdateOnce $ do
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-- ensure branch exists, and get its current ref
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branchref <- getBranch
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-- check what needs updating before taking the lock
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dirty <- journalDirty
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(refs, branches) <- unzip <$> newerSiblings
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if (not dirty && null refs)
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then updateIndex branchref
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else withIndex $ lockJournal $ do
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when dirty stageJournal
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let merge_desc = if null branches
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then "update"
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else "merging " ++
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unwords (map Git.Ref.describe branches) ++
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" into " ++ show name
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unless (null branches) $ do
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showSideAction merge_desc
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mergeIndex branches
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ff <- if dirty
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then return False
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else inRepo $ Git.Branch.fastForward fullname refs
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if ff
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then updateIndex branchref
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else commitBranch branchref merge_desc
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(nub $ fullname:refs)
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invalidateCache
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where
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newerSiblings = filterM isnewer =<< siblingBranches
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isnewer (_, b) = inRepo $ Git.Branch.changed fullname b
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{- Record that the branch's index has been updated to correspond to a
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- given ref of the branch. -}
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setIndexSha :: Git.Ref -> Annex ()
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setIndexSha ref = do
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lock <- fromRepo gitAnnexIndexLock
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liftIO $ writeFile lock $ show ref ++ "\n"
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{- Gets the content of a file on the branch, or content from the journal, or
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- staged in the index.
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-
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- Returns an empty string if the file doesn't exist yet. -}
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get :: FilePath -> Annex String
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get = get' False
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{- Like get, but does not merge the branch, so the info returned may not
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- reflect changes in remotes. (Changing the value this returns, and then
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- merging is always the same as using get, and then changing its value.) -}
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getStale :: FilePath -> Annex String
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getStale = get' True
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get' :: Bool -> FilePath -> Annex String
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get' staleok file = fromcache =<< getCache file
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where
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fromcache (Just content) = return content
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fromcache Nothing = fromjournal =<< getJournalFile file
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fromjournal (Just content) = cache content
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fromjournal Nothing
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| staleok = withIndex frombranch
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| otherwise = withIndexUpdate $ frombranch >>= cache
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frombranch = L.unpack <$> catFile fullname file
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cache content = do
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setCache file content
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return content
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{- Applies a function to modifiy the content of a file.
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-
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- Note that this does not cause the branch to be merged, it only
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- modifes the current content of the file on the branch.
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-}
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change :: FilePath -> (String -> String) -> Annex ()
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change file a = lockJournal $ getStale file >>= return . a >>= set file
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{- Records new content of a file into the journal and cache. -}
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set :: FilePath -> String -> Annex ()
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set file content = do
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setJournalFile file content
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setCache file content
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{- Stages the journal, and commits staged changes to the branch. -}
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commit :: String -> Annex ()
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commit message = whenM journalDirty $ lockJournal $ do
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stageJournal
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ref <- getBranch
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withIndex $ commitBranch ref message [fullname]
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{- Commits the staged changes in the index to the branch.
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-
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@ -141,183 +217,6 @@ commitBranch branchref message parents = do
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racemessage = message ++ " (recovery from race)"
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{- Runs an action using the branch's index file, first making sure that
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- the branch and index are up-to-date. -}
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withIndexUpdate :: Annex a -> Annex a
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withIndexUpdate a = update >> withIndex a
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{- Creates the branch, if it does not already exist. -}
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create :: Annex ()
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create = do
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_ <- getBranch
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return ()
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{- Returns the ref of the branch, creating it first if necessary. -}
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getBranch :: Annex (Git.Ref)
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getBranch = maybe (hasOrigin >>= go >>= use) (return) =<< branchsha
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where
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go True = do
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inRepo $ Git.run "branch"
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[Param $ show name, Param $ show originname]
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fromMaybe (error $ "failed to create " ++ show name)
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<$> branchsha
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go False = withIndex' True $ do
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inRepo $ Git.commit "branch created" fullname []
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use sha = do
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setIndexSha sha
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return sha
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branchsha = inRepo $ Git.Ref.sha fullname
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{- Stages the journal, and commits staged changes to the branch. -}
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commit :: String -> Annex ()
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commit message = whenM journalDirty $ lockJournal $ do
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stageJournal
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ref <- getBranch
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withIndex $ commitBranch ref message [fullname]
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{- Ensures that the branch and index are is up-to-date; should be
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- called before data is read from it. Runs only once per git-annex run.
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-
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- Before refs are merged into the index, it's important to first stage the
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- journal into the index. Otherwise, any changes in the journal would
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- later get staged, and might overwrite changes made during the merge.
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-
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- (It would be cleaner to handle the merge by updating the journal, not the
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- index, with changes from the branches.)
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-
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- The branch is fast-forwarded if possible, otherwise a merge commit is
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- made.
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-}
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update :: Annex ()
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update = runUpdateOnce $ do
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-- ensure branch exists, and get its current ref
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branchref <- getBranch
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-- check what needs updating before taking the lock
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dirty <- journalDirty
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c <- filterM (changedBranch fullname . snd) =<< siblingBranches
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let (refs, branches) = unzip c
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if (not dirty && null refs)
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then updateIndex branchref
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else withIndex $ lockJournal $ do
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when dirty stageJournal
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let merge_desc = if null branches
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then "update"
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else "merging " ++
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unwords (map Git.Ref.describe branches) ++
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" into " ++ show name
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unless (null branches) $ do
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showSideAction merge_desc
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mergeIndex branches
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ff <- if dirty then return False else tryFastForwardTo refs
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if ff
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then updateIndex branchref
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else commitBranch branchref merge_desc
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(nub $ fullname:refs)
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invalidateCache
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{- Checks if the second branch has any commits not present on the first
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- branch. -}
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changedBranch :: Git.Branch -> Git.Branch -> Annex Bool
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changedBranch origbranch newbranch
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| origbranch == newbranch = return False
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| otherwise = not . L.null <$> diffs
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where
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diffs = inRepo $ Git.pipeRead
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[ Param "log"
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, Param (show origbranch ++ ".." ++ show newbranch)
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, Params "--oneline -n1"
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]
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{- Given a set of refs that are all known to have commits not
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- on the git-annex branch, tries to update the branch by a
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- fast-forward.
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-
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- In order for that to be possible, one of the refs must contain
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- every commit present in all the other refs, as well as in the
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- git-annex branch.
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-}
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tryFastForwardTo :: [Git.Ref] -> Annex Bool
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tryFastForwardTo [] = return True
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tryFastForwardTo (first:rest) = do
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-- First, check that the git-annex branch does not contain any
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-- new commits that are not in the first other branch. If it does,
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-- cannot fast-forward.
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diverged <- changedBranch first fullname
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if diverged
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then no_ff
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else maybe no_ff do_ff =<< findbest first rest
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where
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no_ff = return False
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do_ff branch = do
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inRepo $ Git.run "update-ref"
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[Param $ show fullname, Param $ show branch]
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return True
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findbest c [] = return $ Just c
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findbest c (r:rs)
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| c == r = findbest c rs
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| otherwise = do
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better <- changedBranch c r
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worse <- changedBranch r c
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case (better, worse) of
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(True, True) -> return Nothing -- divergent fail
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(True, False) -> findbest r rs -- better
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(False, True) -> findbest c rs -- worse
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(False, False) -> findbest c rs -- same
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{- Does origin/git-annex exist? -}
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hasOrigin :: Annex Bool
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hasOrigin = inRepo $ Git.Ref.exists originname
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{- Does the git-annex branch or a sibling foo/git-annex branch exist? -}
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hasSibling :: Annex Bool
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hasSibling = not . null <$> siblingBranches
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{- List of git-annex (refs, branches), including the main one and any
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- from remotes. Duplicate refs are filtered out. -}
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siblingBranches :: Annex [(Git.Ref, Git.Branch)]
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siblingBranches = inRepo $ Git.Ref.matching name
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{- Applies a function to modifiy the content of a file.
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-
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- Note that this does not cause the branch to be merged, it only
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- modifes the current content of the file on the branch.
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-}
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change :: FilePath -> (String -> String) -> Annex ()
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change file a = lockJournal $ getStale file >>= return . a >>= set file
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{- Records new content of a file into the journal and cache. -}
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set :: FilePath -> String -> Annex ()
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set file content = do
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setJournalFile file content
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setCache file content
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{- Gets the content of a file on the branch, or content from the journal, or
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- staged in the index.
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-
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- Returns an empty string if the file doesn't exist yet. -}
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get :: FilePath -> Annex String
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get = get' False
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{- Like get, but does not merge the branch, so the info returned may not
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- reflect changes in remotes. (Changing the value this returns, and then
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- merging is always the same as using get, and then changing its value.) -}
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getStale :: FilePath -> Annex String
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getStale = get' True
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get' :: Bool -> FilePath -> Annex String
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get' staleok file = fromcache =<< getCache file
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where
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fromcache (Just content) = return content
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fromcache Nothing = fromjournal =<< getJournalFile file
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fromjournal (Just content) = cache content
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fromjournal Nothing
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| staleok = withIndex frombranch
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| otherwise = withIndexUpdate $ frombranch >>= cache
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frombranch = L.unpack <$> catFile fullname file
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cache content = do
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setCache file content
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return content
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{- Lists all files on the branch. There may be duplicates in the list. -}
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files :: Annex [FilePath]
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files = withIndexUpdate $ do
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@ -326,6 +225,64 @@ files = withIndexUpdate $ do
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jfiles <- getJournalledFiles
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return $ jfiles ++ bfiles
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{- Populates the branch's index file with the current branch contents.
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-
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- This is only done when the index doesn't yet exist, and the index
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- is used to build up changes to be commited to the branch, and merge
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- in changes from other branches.
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-}
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genIndex :: Git.Repo -> IO ()
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genIndex g = Git.UnionMerge.stream_update_index g
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[Git.UnionMerge.ls_tree fullname g]
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{- Merges the specified branches into the index.
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- Any changes staged in the index will be preserved. -}
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mergeIndex :: [Git.Ref] -> Annex ()
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mergeIndex branches = do
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h <- catFileHandle
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inRepo $ \g -> Git.UnionMerge.merge_index h g branches
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{- Runs an action using the branch's index file. -}
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withIndex :: Annex a -> Annex a
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withIndex = withIndex' False
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withIndex' :: Bool -> Annex a -> Annex a
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withIndex' bootstrapping a = do
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f <- fromRepo gitAnnexIndex
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bracketIO (Git.useIndex f) id $ do
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unlessM (liftIO $ doesFileExist f) $ do
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unless bootstrapping create
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liftIO $ createDirectoryIfMissing True $ takeDirectory f
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unless bootstrapping $ inRepo genIndex
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a
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{- Runs an action using the branch's index file, first making sure that
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- the branch and index are up-to-date. -}
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withIndexUpdate :: Annex a -> Annex a
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withIndexUpdate a = update >> withIndex a
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{- Updates the branch's index to reflect the current contents of the branch.
|
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- Any changes staged in the index will be preserved.
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-
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- Compares the ref stored in the lock file with the current
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- ref of the branch to see if an update is needed.
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-}
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updateIndex :: Git.Ref -> Annex ()
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updateIndex branchref = do
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lock <- fromRepo gitAnnexIndexLock
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lockref <- Git.Ref . firstLine <$>
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liftIO (catchDefaultIO (readFileStrict lock) "")
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when (lockref /= branchref) $ do
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withIndex $ mergeIndex [fullname]
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setIndexSha branchref
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|
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{- Record that the branch's index has been updated to correspond to a
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- given ref of the branch. -}
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setIndexSha :: Git.Ref -> Annex ()
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setIndexSha ref = do
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lock <- fromRepo gitAnnexIndexLock
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liftIO $ writeFile lock $ show ref ++ "\n"
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|
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{- Stages the journal into the index. -}
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stageJournal :: Annex ()
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stageJournal = do
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|
|
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60
Git/Branch.hs
Normal file
60
Git/Branch.hs
Normal file
|
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@ -0,0 +1,60 @@
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{- git branch stuff
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-
|
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- Copyright 2011 Joey Hess <joey@kitenet.net>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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module Git.Branch where
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import qualified Data.ByteString.Lazy.Char8 as L
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import Common
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import Git
|
||||
|
||||
{- Checks if the second branch has any commits not present on the first
|
||||
- branch. -}
|
||||
changed :: Branch -> Branch -> Repo -> IO Bool
|
||||
changed origbranch newbranch repo
|
||||
| origbranch == newbranch = return False
|
||||
| otherwise = not . L.null <$> diffs
|
||||
where
|
||||
diffs = Git.pipeRead
|
||||
[ Param "log"
|
||||
, Param (show origbranch ++ ".." ++ show newbranch)
|
||||
, Params "--oneline -n1"
|
||||
] repo
|
||||
|
||||
{- Given a set of refs that are all known to have commits not
|
||||
- on the branch, tries to update the branch by a fast-forward.
|
||||
-
|
||||
- In order for that to be possible, one of the refs must contain
|
||||
- every commit present in all the other refs.
|
||||
-}
|
||||
fastForward :: Branch -> [Ref] -> Repo -> IO Bool
|
||||
fastForward _ [] _ = return True
|
||||
fastForward branch (first:rest) repo = do
|
||||
-- First, check that the branch does not contain any
|
||||
-- new commits that are not in the first ref. If it does,
|
||||
-- cannot fast-forward.
|
||||
diverged <- changed first branch repo
|
||||
if diverged
|
||||
then no_ff
|
||||
else maybe no_ff do_ff =<< findbest first rest
|
||||
where
|
||||
no_ff = return False
|
||||
do_ff to = do
|
||||
Git.run "update-ref"
|
||||
[Param $ show branch, Param $ show to] repo
|
||||
return True
|
||||
findbest c [] = return $ Just c
|
||||
findbest c (r:rs)
|
||||
| c == r = findbest c rs
|
||||
| otherwise = do
|
||||
better <- changed c r repo
|
||||
worse <- changed r c repo
|
||||
case (better, worse) of
|
||||
(True, True) -> return Nothing -- divergent fail
|
||||
(True, False) -> findbest r rs -- better
|
||||
(False, True) -> findbest c rs -- worse
|
||||
(False, False) -> findbest c rs -- same
|
||||
Loading…
Reference in a new issue