157 lines
4.2 KiB
Haskell
157 lines
4.2 KiB
Haskell
{- git-annex Key data type
|
|
-
|
|
- Copyright 2011-2016 Joey Hess <id@joeyh.name>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
module Types.Key (
|
|
Key(..),
|
|
AssociatedFile,
|
|
stubKey,
|
|
key2file,
|
|
file2key,
|
|
nonChunkKey,
|
|
chunkKeyOffset,
|
|
isChunkKey,
|
|
isKeyPrefix,
|
|
|
|
prop_isomorphic_key_encode,
|
|
prop_isomorphic_key_decode
|
|
) where
|
|
|
|
import System.Posix.Types
|
|
import Data.Aeson
|
|
import qualified Data.Text as T
|
|
|
|
import Common
|
|
import Utility.QuickCheck
|
|
import Utility.Bloom
|
|
|
|
{- A Key has a unique name, which is derived from a particular backend,
|
|
- and may contain other optional metadata. -}
|
|
data Key = Key
|
|
{ keyName :: String
|
|
, keyBackendName :: String
|
|
, keySize :: Maybe Integer
|
|
, keyMtime :: Maybe EpochTime
|
|
, keyChunkSize :: Maybe Integer
|
|
, keyChunkNum :: Maybe Integer
|
|
} deriving (Eq, Ord, Read, Show)
|
|
|
|
{- A filename may be associated with a Key. -}
|
|
type AssociatedFile = Maybe FilePath
|
|
|
|
stubKey :: Key
|
|
stubKey = Key
|
|
{ keyName = ""
|
|
, keyBackendName = ""
|
|
, keySize = Nothing
|
|
, keyMtime = Nothing
|
|
, keyChunkSize = Nothing
|
|
, keyChunkNum = Nothing
|
|
}
|
|
|
|
-- Gets the parent of a chunk key.
|
|
nonChunkKey :: Key -> Key
|
|
nonChunkKey k = k
|
|
{ keyChunkSize = Nothing
|
|
, keyChunkNum = Nothing
|
|
}
|
|
|
|
-- Where a chunk key is offset within its parent.
|
|
chunkKeyOffset :: Key -> Maybe Integer
|
|
chunkKeyOffset k = (*)
|
|
<$> keyChunkSize k
|
|
<*> (pred <$> keyChunkNum k)
|
|
|
|
isChunkKey :: Key -> Bool
|
|
isChunkKey k = isJust (keyChunkSize k) && isJust (keyChunkNum k)
|
|
|
|
-- Checks if a string looks like at least the start of a key.
|
|
isKeyPrefix :: String -> Bool
|
|
isKeyPrefix s = [fieldSep, fieldSep] `isInfixOf` s
|
|
|
|
fieldSep :: Char
|
|
fieldSep = '-'
|
|
|
|
{- Converts a key to a string that is suitable for use as a filename.
|
|
- The name field is always shown last, separated by doubled fieldSeps,
|
|
- and is the only field allowed to contain the fieldSep. -}
|
|
key2file :: Key -> FilePath
|
|
key2file Key { keyBackendName = b, keySize = s, keyMtime = m, keyChunkSize = cs, keyChunkNum = cn, keyName = n } =
|
|
b +++ ('s' ?: s) +++ ('m' ?: m) +++ ('S' ?: cs) +++ ('C' ?: cn) +++ (fieldSep : n)
|
|
where
|
|
"" +++ y = y
|
|
x +++ "" = x
|
|
x +++ y = x ++ fieldSep:y
|
|
f ?: (Just v) = f : show v
|
|
_ ?: _ = ""
|
|
|
|
file2key :: FilePath -> Maybe Key
|
|
file2key s
|
|
| key == Just stubKey || (keyName <$> key) == Just "" || (keyBackendName <$> key) == Just "" = Nothing
|
|
| otherwise = key
|
|
where
|
|
key = startbackend stubKey s
|
|
|
|
startbackend k v = sepfield k v addbackend
|
|
|
|
sepfield k v a = case span (/= fieldSep) v of
|
|
(v', _:r) -> findfields r $ a k v'
|
|
_ -> Nothing
|
|
|
|
findfields (c:v) (Just k)
|
|
| c == fieldSep = Just $ k { keyName = v }
|
|
| otherwise = sepfield k v $ addfield c
|
|
findfields _ v = v
|
|
|
|
addbackend k v = Just k { keyBackendName = v }
|
|
addfield 's' k v = do
|
|
sz <- readish v
|
|
return $ k { keySize = Just sz }
|
|
addfield 'm' k v = do
|
|
mtime <- readish v
|
|
return $ k { keyMtime = Just mtime }
|
|
addfield 'S' k v = do
|
|
chunksize <- readish v
|
|
return $ k { keyChunkSize = Just chunksize }
|
|
addfield 'C' k v = case readish v of
|
|
Just chunknum | chunknum > 0 ->
|
|
return $ k { keyChunkNum = Just chunknum }
|
|
_ -> return k
|
|
addfield _ _ _ = Nothing
|
|
|
|
instance ToJSON Key where
|
|
toJSON = toJSON . key2file
|
|
|
|
instance FromJSON Key where
|
|
parseJSON (String t) = maybe mempty pure $ file2key $ T.unpack t
|
|
parseJSON _ = mempty
|
|
|
|
instance Arbitrary Key where
|
|
arbitrary = Key
|
|
<$> (listOf1 $ elements $ ['A'..'Z'] ++ ['a'..'z'] ++ ['0'..'9'] ++ "-_\r\n \t")
|
|
<*> (listOf1 $ elements ['A'..'Z']) -- BACKEND
|
|
<*> ((abs <$>) <$> arbitrary) -- size cannot be negative
|
|
<*> arbitrary
|
|
<*> ((abs <$>) <$> arbitrary) -- chunksize cannot be negative
|
|
<*> ((succ . abs <$>) <$> arbitrary) -- chunknum cannot be 0 or negative
|
|
|
|
instance Hashable Key where
|
|
hashIO32 = hashIO32 . key2file
|
|
hashIO64 = hashIO64 . key2file
|
|
|
|
prop_isomorphic_key_encode :: Key -> Bool
|
|
prop_isomorphic_key_encode k = Just k == (file2key . key2file) k
|
|
|
|
prop_isomorphic_key_decode :: FilePath -> Bool
|
|
prop_isomorphic_key_decode f
|
|
| normalfieldorder = maybe True (\k -> key2file k == f) (file2key f)
|
|
| otherwise = True
|
|
where
|
|
-- file2key will accept the fields in any order, so don't
|
|
-- try the test unless the fields are in the normal order
|
|
normalfieldorder = fields `isPrefixOf` "smSC"
|
|
fields = map (f !!) $ filter (< length f) $ map succ $
|
|
elemIndices fieldSep f
|