git-annex/Backend/URL.hs
Joey Hess 8f9b501515 handle really long urls
Using the whole url as a key can make the filename too long. Truncate
and use a md5sum for uniqueness if necessary.
2012-02-16 02:05:06 -04:00

41 lines
867 B
Haskell

{- git-annex "URL" backend -- keys whose content is available from urls.
-
- Copyright 2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Backend.URL (
backends,
fromUrl
) where
import Data.Hash.MD5
import Common.Annex
import Types.Backend
import Types.Key
backends :: [Backend]
backends = [backend]
backend :: Backend
backend = Backend {
name = "URL",
getKey = const (return Nothing),
fsckKey = Nothing
}
fromUrl :: String -> Maybe Integer -> Key
fromUrl url size = stubKey
{ keyName = key
, keyBackendName = "URL"
, keySize = size
}
where
-- when it's not too long, use the url as the key name
-- 256 is the absolute filename max, but use a shorter
-- length because this is not the entire key filename.
key
| length url < 128 = url
| otherwise = take 128 url ++ "-" ++ md5s (Str url)