71 lines
1.7 KiB
Haskell
71 lines
1.7 KiB
Haskell
{- git-annex SHA abstract backend
|
|
-
|
|
- Copyright 2011 Joey Hess <joey@kitenet.net>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
module Backend.SHA (genBackend) where
|
|
|
|
import Control.Monad.State
|
|
import Data.String.Utils
|
|
import System.Cmd.Utils
|
|
import System.IO
|
|
import System.Directory
|
|
|
|
import qualified Backend.File
|
|
import BackendTypes
|
|
import Messages
|
|
import qualified Annex
|
|
import Locations
|
|
import Content
|
|
import Types
|
|
import Utility
|
|
|
|
type SHASize = Int
|
|
|
|
-- Constructor for Backends using a given SHASize.
|
|
genBackend :: SHASize -> Backend Annex
|
|
genBackend size = Backend.File.backend
|
|
{ name = shaName size
|
|
, getKey = keyValue size
|
|
, fsckKey = Backend.File.checkKey $ checkKeyChecksum size
|
|
}
|
|
|
|
shaName :: SHASize -> String
|
|
shaName size = "SHA" ++ show size
|
|
|
|
shaN :: SHASize -> FilePath -> Annex String
|
|
shaN size file = do
|
|
showNote "checksum..."
|
|
liftIO $ pOpen ReadFromPipe command (toCommand [File file]) $ \h -> do
|
|
line <- hGetLine h
|
|
let bits = split " " line
|
|
if null bits
|
|
then error $ command ++ " parse error"
|
|
else return $ head bits
|
|
where
|
|
command = "sha" ++ (show size) ++ "sum"
|
|
|
|
-- A key is a checksum of its contents.
|
|
keyValue :: SHASize -> FilePath -> Annex (Maybe Key)
|
|
keyValue size file = do
|
|
s <- shaN size file
|
|
return $ Just $ Key (shaName size, s)
|
|
|
|
-- A key's checksum is checked during fsck.
|
|
checkKeyChecksum :: SHASize -> Key -> Annex Bool
|
|
checkKeyChecksum size key = do
|
|
g <- Annex.gitRepo
|
|
let file = gitAnnexLocation g key
|
|
present <- liftIO $ doesFileExist file
|
|
if not present
|
|
then return True
|
|
else do
|
|
s <- shaN size file
|
|
if s == keyName key
|
|
then return True
|
|
else do
|
|
dest <- moveBad key
|
|
warning $ "Bad file content; moved to " ++ filePathToString dest
|
|
return False
|