126 lines
3.1 KiB
Haskell
126 lines
3.1 KiB
Haskell
{- git-annex SHA backend
|
|
-
|
|
- Copyright 2011 Joey Hess <joey@kitenet.net>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
module Backend.SHA (backends) where
|
|
|
|
import Control.Monad.State
|
|
import Data.String.Utils
|
|
import System.Cmd.Utils
|
|
import System.IO
|
|
import System.Directory
|
|
import Data.Maybe
|
|
import System.Posix.Files
|
|
import System.FilePath
|
|
|
|
import Messages
|
|
import qualified Annex
|
|
import Locations
|
|
import Content
|
|
import Types
|
|
import Types.Backend
|
|
import Types.Key
|
|
import Utility
|
|
import qualified SysConfig
|
|
|
|
type SHASize = Int
|
|
|
|
sizes :: [Int]
|
|
sizes = [1, 256, 512, 224, 384]
|
|
|
|
backends :: [Backend Annex]
|
|
-- order is slightly significant; want sha1 first ,and more general
|
|
-- sizes earlier
|
|
backends = catMaybes $ map genBackend sizes ++ map genBackendE sizes
|
|
|
|
genBackend :: SHASize -> Maybe (Backend Annex)
|
|
genBackend size
|
|
| shaCommand size == Nothing = Nothing
|
|
| otherwise = Just b
|
|
where
|
|
b = Types.Backend.Backend
|
|
{ name = shaName size
|
|
, getKey = keyValue size
|
|
, fsckKey = checkKeyChecksum size
|
|
}
|
|
|
|
genBackendE :: SHASize -> Maybe (Backend Annex)
|
|
genBackendE size =
|
|
case genBackend size of
|
|
Nothing -> Nothing
|
|
Just b -> Just $ b
|
|
{ name = shaNameE size
|
|
, getKey = keyValueE size
|
|
}
|
|
|
|
shaCommand :: SHASize -> Maybe String
|
|
shaCommand 1 = SysConfig.sha1
|
|
shaCommand 256 = SysConfig.sha256
|
|
shaCommand 224 = SysConfig.sha224
|
|
shaCommand 384 = SysConfig.sha384
|
|
shaCommand 512 = SysConfig.sha512
|
|
shaCommand _ = Nothing
|
|
|
|
shaName :: SHASize -> String
|
|
shaName size = "SHA" ++ show size
|
|
|
|
shaNameE :: SHASize -> String
|
|
shaNameE size = shaName size ++ "E"
|
|
|
|
shaN :: SHASize -> FilePath -> Annex String
|
|
shaN size file = do
|
|
showAction "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 = fromJust $ shaCommand size
|
|
|
|
{- A key is a checksum of its contents. -}
|
|
keyValue :: SHASize -> FilePath -> Annex (Maybe Key)
|
|
keyValue size file = do
|
|
s <- shaN size file
|
|
stat <- liftIO $ getFileStatus file
|
|
return $ Just $ stubKey
|
|
{ keyName = s
|
|
, keyBackendName = shaName size
|
|
, keySize = Just $ fromIntegral $ fileSize stat
|
|
}
|
|
|
|
{- Extension preserving keys. -}
|
|
keyValueE :: SHASize -> FilePath -> Annex (Maybe Key)
|
|
keyValueE size file = keyValue size file >>= maybe (return Nothing) addE
|
|
where
|
|
addE k = return $ Just $ k
|
|
{ keyName = keyName k ++ extension
|
|
, keyBackendName = shaNameE size
|
|
}
|
|
naiveextension = takeExtension file
|
|
extension =
|
|
if length naiveextension > 6
|
|
then "" -- probably not really an extension
|
|
else naiveextension
|
|
|
|
-- A key's checksum is checked during fsck.
|
|
checkKeyChecksum :: SHASize -> Key -> Annex Bool
|
|
checkKeyChecksum size key = do
|
|
g <- Annex.gitRepo
|
|
fast <- Annex.getState Annex.fast
|
|
let file = gitAnnexLocation g key
|
|
present <- liftIO $ doesFileExist file
|
|
if not present || fast
|
|
then return True
|
|
else do
|
|
s <- shaN size file
|
|
if s == dropExtension (keyName key)
|
|
then return True
|
|
else do
|
|
dest <- moveBad key
|
|
warning $ "Bad file content; moved to " ++ dest
|
|
return False
|