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Command/DropUnused.hs

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+{- git-annex command
+ -
+ - Copyright 2010 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Command.DropUnused where
+
+import Control.Monad.State (liftIO)
+import qualified Data.Map as M
+
+import Command
+import Types
+import Messages
+import Locations
+import qualified Annex
+import qualified Command.Drop
+import Backend
+
+seek :: [SubCmdSeek]
+seek = [withStrings start]
+
+{- Drops unused content by number. -} 
+start :: SubCmdStartString
+start s = do
+	m <- readUnusedLog
+	case M.lookup s m of
+		Nothing -> return Nothing
+		Just key -> do
+			showStart "dropunused" s
+			backend <- keyBackend key
+			-- force drop, even if this is the only copy
+			Annex.flagChange "force" $ FlagBool True
+			return $ Just $ Command.Drop.perform key backend
+
+readUnusedLog :: Annex (M.Map String Key)
+readUnusedLog = do
+	g <- Annex.gitRepo
+	l <- liftIO $ readFile (annexUnusedLog g)
+	return $ M.fromList $ map parse $ lines l
+	where
+		parse line = (head ws, tokey $ unwords $ tail ws)
+			where
+				ws = words line
+				tokey s = read s :: Key