git-annex/Types/UUID.hs
Joey Hess fa62c98910
simplify and speed up Utility.FileSystemEncoding
This eliminates the distinction between decodeBS and decodeBS', encodeBS
and encodeBS', etc. The old implementation truncated at NUL, and the
primed versions had to do extra work to avoid that problem. The new
implementation does not truncate at NUL, and is also a lot faster.
(Benchmarked at 2x faster for decodeBS and 3x for encodeBS; more for the
primed versions.)

Note that filepath-bytestring 1.4.2.1.8 contains the same optimisation,
and upgrading to it will speed up to/fromRawFilePath.

AFAIK, nothing relied on the old behavior of truncating at NUL. Some
code used the faster versions in places where I was sure there would not
be a NUL. So this change is unlikely to break anything.

Also, moved s2w8 and w82s out of the module, as they do not involve
filesystem encoding really.

Sponsored-by: Shae Erisson on Patreon
2021-08-11 12:13:31 -04:00

98 lines
2.4 KiB
Haskell

{- git-annex UUID type
-
- Copyright 2011-2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE TypeSynonymInstances, FlexibleInstances, GeneralizedNewtypeDeriving #-}
module Types.UUID where
import qualified Data.ByteString as B
import qualified Data.Map as M
import qualified Data.UUID as U
import Data.Maybe
import Data.String
import Data.ByteString.Builder
import qualified Data.Semigroup as Sem
import Git.Types (ConfigValue(..))
import Utility.FileSystemEncoding
import Utility.QuickCheck
import qualified Utility.SimpleProtocol as Proto
-- A UUID is either an arbitrary opaque string, or UUID info may be missing.
data UUID = NoUUID | UUID B.ByteString
deriving (Eq, Ord, Show, Read)
class FromUUID a where
fromUUID :: UUID -> a
class ToUUID a where
toUUID :: a -> UUID
instance FromUUID UUID where
fromUUID = id
instance ToUUID UUID where
toUUID = id
instance FromUUID B.ByteString where
fromUUID (UUID u) = u
fromUUID NoUUID = B.empty
instance ToUUID B.ByteString where
toUUID b
| B.null b = NoUUID
| otherwise = UUID b
instance FromUUID String where
fromUUID s = decodeBS (fromUUID s)
instance ToUUID String where
toUUID s = toUUID (encodeBS s)
instance FromUUID ConfigValue where
fromUUID s = (ConfigValue (fromUUID s))
instance ToUUID ConfigValue where
toUUID (ConfigValue v) = toUUID v
toUUID NoConfigValue = NoUUID
-- There is no matching FromUUID U.UUID because a git-annex UUID may
-- be NoUUID or perhaps contain something not allowed in a canonical UUID.
instance ToUUID U.UUID where
toUUID = toUUID . U.toASCIIBytes
buildUUID :: UUID -> Builder
buildUUID (UUID b) = byteString b
buildUUID NoUUID = mempty
isUUID :: String -> Bool
isUUID = isJust . U.fromString
-- A description of a UUID.
newtype UUIDDesc = UUIDDesc B.ByteString
deriving (Eq, Sem.Semigroup, Monoid, IsString)
fromUUIDDesc :: UUIDDesc -> String
fromUUIDDesc (UUIDDesc d) = decodeBS d
toUUIDDesc :: String -> UUIDDesc
toUUIDDesc = UUIDDesc . encodeBS
buildUUIDDesc :: UUIDDesc -> Builder
buildUUIDDesc (UUIDDesc b) = byteString b
type UUIDDescMap = M.Map UUID UUIDDesc
instance Proto.Serializable UUID where
serialize = fromUUID
deserialize = Just . toUUID
instance Arbitrary UUID where
arbitrary = frequency [(1, return NoUUID), (3, UUID <$> arb)]
where
arb = encodeBS <$> listOf1 (elements uuidchars)
uuidchars = '-' : ['a'..'z'] ++ ['A'..'Z'] ++ ['0'..'9']