git-annex/Annex.hs
2010-10-10 19:00:08 -04:00

74 lines
2.1 KiB
Haskell

{- git-annex toplevel code
-}
module Annex where
import System.Posix.Files
import System.Directory
import GitRepo
import Utility
import Locations
import Types
import Backend
import BackendList
{- On startup, examine the git repo, prepare it, and record state for
- later. -}
startAnnex :: IO State
startAnnex = do
r <- currentRepo
gitPrep r
-- TODO query git repo for configuration
return State { repo = r, backends = supportedBackends }
{- Annexes a file, storing it in a backend, and then moving it into
- the annex directory and setting up the symlink pointing to its content. -}
annexFile :: State -> FilePath -> IO ()
annexFile state file = do
checkExists file
checkLegal file
alreadyannexed <- lookupBackend (backends state) (repo state) file
case (alreadyannexed) of
Just _ -> error $ "already annexed " ++ file
Nothing -> do
stored <- storeFile (backends state) (repo state) file
case (stored) of
Nothing -> error $ "no backend could store " ++ file
Just key -> symlink key
where
symlink key = do
dest <- annexDir (repo state) key
createDirectoryIfMissing True (parentDir dest)
renameFile file dest
createSymbolicLink dest file
gitAdd (repo state) file
checkExists file = do
exists <- doesFileExist file
case (exists) of
False -> error $ "does not exist: " ++ file
True -> return ()
checkLegal file = do
s <- getFileStatus file
case (not (isSymbolicLink s) && not (isRegularFile s)) of
False -> error $ "not a regular file: " ++ file
True -> return ()
{- Sets up a git repo for git-annex. May be called repeatedly. -}
gitPrep :: GitRepo -> IO ()
gitPrep repo = do
-- configure git to use union merge driver on state files
let attrLine = stateLoc ++ "/* merge=union"
attributes <- gitAttributes repo
exists <- doesFileExist attributes
if (not exists)
then do
writeFile attributes $ attrLine ++ "\n"
gitAdd repo attributes
else do
content <- readFile attributes
if (all (/= attrLine) (lines content))
then do
appendFile attributes $ attrLine ++ "\n"
gitAdd repo attributes
else return ()