git-annex/Command/ReKey.hs
Joey Hess 94fcd0cf59 add routes to pause/start/cancel transfers
This commit includes a paydown on technical debt incurred two years ago,
when I didn't know that it was bad to make custom Read and Show instances
for types. As the routes need Read and Show for Transfer, which includes a
Key, and deriving my own Read instance of key was not practical,
I had to finally clean that up.

So the compact Key read and show functions are now file2key and key2file,
and Read and Show are now derived instances.

Changed all code that used the old instances, compiler checked.
(There were a few places, particularly in Command.Unused, and the test
suite where the Show instance continue to be used for legitimate
comparisons; ie show key_x == show key_y (though really in a bloom filter))
2012-08-08 16:20:24 -04:00

64 lines
1.7 KiB
Haskell

{- git-annex command
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.ReKey where
import Common.Annex
import Command
import qualified Annex
import Types.Key
import Annex.Content
import qualified Command.Add
import Logs.Web
def :: [Command]
def = [command "rekey"
(paramOptional $ paramRepeating $ paramPair paramPath paramKey)
seek "change keys used for files"]
seek :: [CommandSeek]
seek = [withPairs start]
start :: (FilePath, String) -> CommandStart
start (file, keyname) = ifAnnexed file go stop
where
newkey = fromMaybe (error "bad key") $ file2key keyname
go (oldkey, _)
| oldkey == newkey = stop
| otherwise = do
showStart "rekey" file
next $ perform file oldkey newkey
perform :: FilePath -> Key -> Key -> CommandPerform
perform file oldkey newkey = do
present <- inAnnex oldkey
_ <- if present
then linkKey oldkey newkey
else do
unlessM (Annex.getState Annex.force) $
error $ file ++ " is not available (use --force to override)"
return True
next $ cleanup file oldkey newkey
{- Make a hard link to the old key content, to avoid wasting disk space. -}
linkKey :: Key -> Key -> Annex Bool
linkKey oldkey newkey = getViaTmpUnchecked newkey $ \tmp -> do
src <- inRepo $ gitAnnexLocation oldkey
liftIO $ unlessM (doesFileExist tmp) $ createLink src tmp
return True
cleanup :: FilePath -> Key -> Key -> CommandCleanup
cleanup file oldkey newkey = do
-- If the old key had some associated urls, record them for
-- the new key as well.
urls <- getUrls oldkey
unless (null urls) $
mapM_ (setUrlPresent newkey) urls
-- Update symlink to use the new key.
liftIO $ removeFile file
Command.Add.cleanup file newkey True