git-annex/Backend/Utilities.hs
Joey Hess b3c69eaaf8
strict bytestring encoders and decoders
Only had lazy ones before.

Already sped up a few parts of the code.
2019-01-01 14:55:15 -04:00

31 lines
805 B
Haskell

{- git-annex backend utilities
-
- Copyright 2012 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Backend.Utilities where
import Annex.Common
import Utility.FileSystemEncoding
import Utility.Hash
{- Generates a keyName from an input string. Takes care of sanitizing it.
- If it's not too long, the full string is used as the keyName.
- Otherwise, it's truncated, and its md5 is prepended to ensure a unique
- key. -}
genKeyName :: String -> String
genKeyName s
-- Avoid making keys longer than the length of a SHA256 checksum.
| bytelen > sha256len =
truncateFilePath (sha256len - md5len - 1) s' ++ "-" ++
show (md5 (encodeBL s))
| otherwise = s'
where
s' = preSanitizeKeyName s
bytelen = length (decodeW8 s')
sha256len = 64
md5len = 32