git-annex/Remote/Directory.hs

{- A "remote" that is just a local directory.
 -
 - Copyright 2011 Joey Hess <joey@kitenet.net>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

module Remote.Directory (remote) where

import IO
import Control.Exception.Extensible (IOException)
import qualified Data.Map as M
import Control.Monad (when)
import Control.Monad.State (liftIO)
import System.Directory (doesDirectoryExist, doesFileExist, removeFile)
import System.FilePath

import RemoteClass
import Types
import qualified GitRepo as Git
import qualified Annex
import UUID
import Locations
import CopyFile
import Config
import Remote.Special

remote :: RemoteType Annex
remote = RemoteType {
	typename = "directory",
	enumerate = findSpecialRemotes "directory",
	generate = gen,
	setup = directorySetup
}

gen :: Git.Repo -> UUID -> Cost -> Maybe (M.Map String String) -> Annex (Remote Annex)
gen r u cst _ = do
	dir <- getConfig r "directory" (error "missing directory")
	return $ Remote {
		uuid = u,
		cost = cst,
		name = Git.repoDescribe r,
 		storeKey = store dir,
		retrieveKeyFile = retrieve dir,
		removeKey = remove dir,
		hasKey = checkPresent dir,
		hasKeyCheap = True,
		config = Nothing
	}

directorySetup :: UUID -> M.Map String String -> Annex (M.Map String String)
directorySetup u c = do
	-- verify configuration is sane
	let dir = case M.lookup "directory" c of
		Nothing -> error "Specify directory="
		Just d -> d
	e <- liftIO $ doesDirectoryExist dir
	when (not e) $ error $ "Directory does not exist: " ++ dir

	-- The directory is stored in git config, not in this remote's
	-- persistant state, so it can vary between hosts.
	gitConfigSpecialRemote u c "directory" dir
	return $ M.delete "directory" c

dirKey :: FilePath -> Key -> FilePath
dirKey d k = d </> show k

store :: FilePath -> Key -> Annex Bool
store d k = do
	g <- Annex.gitRepo
	liftIO $ copyFile (gitAnnexLocation g k) (dirKey d k)

retrieve :: FilePath -> Key -> FilePath -> Annex Bool
retrieve d k f = liftIO $ copyFile (dirKey d k) f

remove :: FilePath -> Key -> Annex Bool
remove d k = liftIO $ catch
	(removeFile (dirKey d k) >> return True)
	(const $ return False)

checkPresent :: FilePath -> Key -> Annex (Either IOException Bool)
checkPresent d k = liftIO $ try $ doesFileExist (dirKey d k)