Cabal-3.6.0.0: src/Distribution/Utils/Structured.hs
{-# LANGUAGE CPP #-}
{-# LANGUAGE DefaultSignatures #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeOperators #-}
#if __GLASGOW_HASKELL__ >= 711
{-# LANGUAGE PatternSynonyms #-}
#endif
#if __GLASGOW_HASKELL__ >= 800
{-# LANGUAGE TypeInType #-}
#endif
-- |
--
-- Copyright: (c) 2019 Oleg Grenrus
--
-- Structurally tag binary serialisaton stream.
-- Useful when most 'Binary' instances are 'Generic' derived.
--
-- Say you have a data type
--
-- @
-- data Record = Record
-- { _recordFields :: HM.HashMap Text (Integer, ByteString)
-- , _recordEnabled :: Bool
-- }
-- deriving (Eq, Show, Generic)
--
-- instance 'Binary' Record
-- instance 'Structured' Record
-- @
--
-- then you can serialise and deserialise @Record@ values with a structure tag by simply
--
-- @
-- 'structuredEncode' record :: 'LBS.ByteString'
-- 'structuredDecode' lbs :: IO Record
-- @
--
-- If structure of @Record@ changes in between, deserialisation will fail early.
--
-- Technically, 'Structured' is not related to 'Binary', and may
-- be useful in other uses.
--
module Distribution.Utils.Structured (
-- * Encoding and decoding
-- | These functions operate like @binary@'s counterparts,
-- but the serialised version has a structure hash in front.
structuredEncode,
structuredEncodeFile,
structuredDecode,
structuredDecodeOrFailIO,
structuredDecodeFileOrFail,
-- * Structured class
Structured (structure),
MD5,
structureHash,
structureBuilder,
genericStructure,
GStructured,
nominalStructure,
containerStructure,
-- * Structure type
Structure (..),
TypeName,
ConstructorName,
TypeVersion,
SopStructure,
hashStructure,
typeVersion,
typeName,
) where
import Data.Int (Int16, Int32, Int64, Int8)
import Data.List.NonEmpty (NonEmpty)
import Data.Proxy (Proxy (..))
import Data.Ratio (Ratio)
import Data.Word (Word, Word16, Word32, Word64, Word8)
import qualified Control.Monad.Trans.State.Strict as State
import Control.Exception (ErrorCall (..), catch, evaluate)
import GHC.Generics
import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy as LBS
#if MIN_VERSION_bytestring(0,10,4)
import qualified Data.ByteString.Builder as Builder
#else
import qualified Data.ByteString.Lazy.Builder as Builder
#endif
import qualified Data.IntMap as IM
import qualified Data.IntSet as IS
import qualified Data.Map as Map
import qualified Data.Sequence as Seq
import qualified Data.Set as Set
import qualified Data.Text as T
import qualified Data.Text.Lazy as LT
import qualified Data.Time as Time
import qualified Distribution.Compat.Binary as Binary
#ifdef MIN_VERSION_aeson
import qualified Data.Aeson as Aeson
#endif
#if __GLASGOW_HASKELL__ >= 800
import Data.Kind (Type)
#else
#define Type *
#endif
import Distribution.Compat.Typeable (Typeable, TypeRep, typeRep)
import Distribution.Utils.MD5
import Data.Monoid (mconcat)
import qualified Data.Semigroup
import qualified Data.Foldable
#if !MIN_VERSION_base(4,8,0)
import Control.Applicative (pure)
import Data.Traversable (traverse)
#endif
#if !MIN_VERSION_base(4,7,0)
import Data.Typeable (Typeable1, typeOf1)
#endif
-------------------------------------------------------------------------------
-- Types
-------------------------------------------------------------------------------
type TypeName = String
type ConstructorName = String
-- | A sematic version of a data type. Usually 0.
type TypeVersion = Word32
-- | Structure of a datatype.
--
-- It can be infinite, as far as 'TypeRep's involved are finite.
-- (e.g. polymorphic recursion might cause troubles).
--
data Structure
= Nominal !TypeRep !TypeVersion TypeName [Structure] -- ^ nominal, yet can be parametrised by other structures.
| Newtype !TypeRep !TypeVersion TypeName Structure -- ^ a newtype wrapper
| Structure !TypeRep !TypeVersion TypeName SopStructure -- ^ sum-of-products structure
deriving (Eq, Ord, Show, Generic)
type SopStructure = [(ConstructorName, [Structure])]
-- | A MD5 hash digest of 'Structure'.
hashStructure :: Structure -> MD5
hashStructure = md5 . LBS.toStrict . Builder.toLazyByteString . structureBuilder
-- | A van-Laarhoven lens into 'TypeVersion' of 'Structure'
--
-- @
-- 'typeVersion' :: Lens' 'Structure' 'TypeVersion'
-- @
typeVersion :: Functor f => (TypeVersion -> f TypeVersion) -> Structure -> f Structure
typeVersion f (Nominal t v n s) = fmap (\v' -> Nominal t v' n s) (f v)
typeVersion f (Newtype t v n s) = fmap (\v' -> Newtype t v' n s) (f v)
typeVersion f (Structure t v n s) = fmap (\v' -> Structure t v' n s) (f v)
-- | A van-Laarhoven lens into 'TypeName' of 'Structure'
--
-- @
-- 'typeName' :: Lens' 'Structure' 'TypeName'
-- @
typeName :: Functor f => (TypeName -> f TypeName) -> Structure -> f Structure
typeName f (Nominal t v n s) = fmap (\n' -> Nominal t v n' s) (f n)
typeName f (Newtype t v n s) = fmap (\n' -> Newtype t v n' s) (f n)
typeName f (Structure t v n s) = fmap (\n' -> Structure t v n' s) (f n)
-------------------------------------------------------------------------------
-- Builder
-------------------------------------------------------------------------------
-- | Flatten 'Structure' into something we can calculate hash of.
--
-- As 'Structure' can be potentially infinite. For mutually recursive types,
-- we keep track of 'TypeRep's, and put just 'TypeRep' name when it's occurred
-- another time.
structureBuilder :: Structure -> Builder.Builder
structureBuilder s0 = State.evalState (go s0) Map.empty where
go :: Structure -> State.State (Map.Map String (NonEmpty TypeRep)) Builder.Builder
go (Nominal t v n s) = withTypeRep t $ do
s' <- traverse go s
return $ mconcat $ Builder.word8 1 : Builder.word32LE v : Builder.stringUtf8 n : s'
go (Newtype t v n s) = withTypeRep t $ do
s' <- go s
return $ mconcat [Builder.word8 2, Builder.word32LE v, Builder.stringUtf8 n, s']
go (Structure t v n s) = withTypeRep t $ do
s' <- goSop s
return $ mconcat [Builder.word8 3, Builder.word32LE v, Builder.stringUtf8 n, s']
withTypeRep t k = do
acc <- State.get
case insert t acc of
Nothing -> return $ mconcat [ Builder.word8 0, Builder.stringUtf8 (show t) ]
Just acc' -> do
State.put acc'
k
goSop :: SopStructure -> State.State (Map.Map String (NonEmpty TypeRep)) Builder.Builder
goSop sop = do
parts <- traverse part sop
return $ mconcat parts
part (cn, s) = do
s' <- traverse go s
return $ Data.Monoid.mconcat [ Builder.stringUtf8 cn, mconcat s' ]
insert :: TypeRep -> Map.Map String (NonEmpty TypeRep) -> Maybe (Map.Map String (NonEmpty TypeRep))
insert tr m = case Map.lookup trShown m of
Nothing -> inserted
Just ne | tr `Data.Foldable.elem` ne -> Nothing
| otherwise -> inserted
where
inserted = Just (Map.insertWith (Data.Semigroup.<>) trShown (pure tr) m)
trShown = show tr
-------------------------------------------------------------------------------
-- Classes
-------------------------------------------------------------------------------
-- | Class of types with a known 'Structure'.
--
-- For regular data types 'Structured' can be derived generically.
--
-- @
-- data Record = Record { a :: Int, b :: Bool, c :: [Char] } deriving ('Generic')
-- instance 'Structured' Record
-- @
--
-- @since 3.2.0.0
--
class Typeable a => Structured a where
structure :: Proxy a -> Structure
default structure :: (Generic a, GStructured (Rep a)) => Proxy a -> Structure
structure = genericStructure
-- This member is hidden. It's there to precalc
structureHash' :: Tagged a MD5
structureHash' = Tagged (hashStructure (structure (Proxy :: Proxy a)))
-- private Tagged
newtype Tagged a b = Tagged { untag :: b }
-- | Semantically @'hashStructure' . 'structure'@.
structureHash :: forall a. Structured a => Proxy a -> MD5
structureHash _ = untag (structureHash' :: Tagged a MD5)
-------------------------------------------------------------------------------
-- Functions
-------------------------------------------------------------------------------
-- | Structured 'Binary.encode'.
-- Encode a value to using binary serialisation to a lazy 'LBS.ByteString'.
-- Encoding starts with 16 byte large structure hash.
structuredEncode
:: forall a. (Binary.Binary a, Structured a)
=> a -> LBS.ByteString
structuredEncode x = Binary.encode (Tag :: Tag a, x)
-- | Lazily serialise a value to a file
structuredEncodeFile :: (Binary.Binary a, Structured a) => FilePath -> a -> IO ()
structuredEncodeFile f = LBS.writeFile f . structuredEncode
-- | Structured 'Binary.decode'.
-- Decode a value from a lazy 'LBS.ByteString', reconstructing the original structure.
-- Throws pure exception on invalid inputs.
structuredDecode
:: forall a. (Binary.Binary a, Structured a)
=> LBS.ByteString -> a
structuredDecode lbs = snd (Binary.decode lbs :: (Tag a, a))
structuredDecodeOrFailIO :: (Binary.Binary a, Structured a) => LBS.ByteString -> IO (Either String a)
structuredDecodeOrFailIO bs =
catch (evaluate (structuredDecode bs) >>= return . Right) handler
where
#if MIN_VERSION_base(4,9,0)
handler (ErrorCallWithLocation str _) = return $ Left str
#else
handler (ErrorCall str) = return $ Left str
#endif
-- | Lazily reconstruct a value previously written to a file.
structuredDecodeFileOrFail :: (Binary.Binary a, Structured a) => FilePath -> IO (Either String a)
structuredDecodeFileOrFail f = structuredDecodeOrFailIO =<< LBS.readFile f
-------------------------------------------------------------------------------
-- Helper data
-------------------------------------------------------------------------------
data Tag a = Tag
instance Structured a => Binary.Binary (Tag a) where
get = do
actual <- binaryGetMD5
if actual == expected
then return Tag
else fail $ concat
[ "Non-matching structured hashes: "
, showMD5 actual
, "; expected: "
, showMD5 expected
]
where
expected = untag (structureHash' :: Tagged a MD5)
put _ = binaryPutMD5 expected
where
expected = untag (structureHash' :: Tagged a MD5)
-------------------------------------------------------------------------------
-- Smart constructors
-------------------------------------------------------------------------------
-- | Use 'Typeable' to infer name
nominalStructure :: Typeable a => Proxy a -> Structure
nominalStructure p = Nominal tr 0 (show tr) [] where
tr = typeRep p
#if MIN_VERSION_base(4,7,0)
containerStructure :: forall f a. (Typeable f, Structured a) => Proxy (f a) -> Structure
containerStructure _ = Nominal faTypeRep 0 (show fTypeRep)
[ structure (Proxy :: Proxy a)
]
where
fTypeRep = typeRep (Proxy :: Proxy f)
faTypeRep = typeRep (Proxy :: Proxy (f a))
#else
containerStructure :: forall f a. (Typeable1 f, Structured a) => Proxy (f a) -> Structure
containerStructure _ = Nominal faTypeRep 0 (show fTypeRep)
[ structure (Proxy :: Proxy a)
]
where
fTypeRep = typeOf1 (undefined :: f ())
faTypeRep = typeRep (Proxy :: Proxy (f a))
#endif
-------------------------------------------------------------------------------
-- Generic
-------------------------------------------------------------------------------
-- | Derive 'structure' genrically.
genericStructure :: forall a. (Typeable a, Generic a, GStructured (Rep a)) => Proxy a -> Structure
genericStructure _ = gstructured (typeRep (Proxy :: Proxy a)) (Proxy :: Proxy (Rep a)) 0
-- | Used to implement 'genericStructure'.
class GStructured (f :: Type -> Type) where
gstructured :: TypeRep -> Proxy f -> TypeVersion -> Structure
instance (i ~ D, Datatype c, GStructuredSum f) => GStructured (M1 i c f) where
gstructured tr _ v = case sop of
#if MIN_VERSION_base(4,7,0)
[(_, [s])] | isNewtype p -> Newtype tr v name s
#endif
_ -> Structure tr v name sop
where
p = undefined :: M1 i c f ()
name = datatypeName p
sop = gstructuredSum (Proxy :: Proxy f) []
class GStructuredSum (f :: Type -> Type) where
gstructuredSum :: Proxy f -> SopStructure -> SopStructure
instance (i ~ C, Constructor c, GStructuredProd f) => GStructuredSum (M1 i c f) where
gstructuredSum _ xs = (name, prod) : xs
where
name = conName (undefined :: M1 i c f ())
prod = gstructuredProd (Proxy :: Proxy f) []
instance (GStructuredSum f, GStructuredSum g) => GStructuredSum (f :+: g) where
gstructuredSum _ xs
= gstructuredSum (Proxy :: Proxy f)
$ gstructuredSum (Proxy :: Proxy g) xs
instance GStructuredSum V1 where
gstructuredSum _ = id
class GStructuredProd (f :: Type -> Type) where
gstructuredProd :: Proxy f -> [Structure] -> [Structure]
instance (i ~ S, GStructuredProd f) => GStructuredProd (M1 i c f) where
gstructuredProd _ = gstructuredProd (Proxy :: Proxy f)
instance Structured c => GStructuredProd (K1 i c) where
gstructuredProd _ xs = structure (Proxy :: Proxy c) : xs
instance GStructuredProd U1 where
gstructuredProd _ = id
instance (GStructuredProd f, GStructuredProd g) => GStructuredProd (f :*: g) where
gstructuredProd _ xs
= gstructuredProd (Proxy :: Proxy f)
$ gstructuredProd (Proxy :: Proxy g) xs
-------------------------------------------------------------------------------
-- instances
-------------------------------------------------------------------------------
instance Structured ()
instance Structured Bool
instance Structured Ordering
instance Structured Char where structure = nominalStructure
instance Structured Int where structure = nominalStructure
instance Structured Integer where structure = nominalStructure
instance Structured Data.Word.Word where structure = nominalStructure
instance Structured Int8 where structure = nominalStructure
instance Structured Int16 where structure = nominalStructure
instance Structured Int32 where structure = nominalStructure
instance Structured Int64 where structure = nominalStructure
instance Structured Word8 where structure = nominalStructure
instance Structured Word16 where structure = nominalStructure
instance Structured Word32 where structure = nominalStructure
instance Structured Word64 where structure = nominalStructure
instance Structured Float where structure = nominalStructure
instance Structured Double where structure = nominalStructure
instance Structured a => Structured (Maybe a)
instance (Structured a, Structured b) => Structured (Either a b)
instance Structured a => Structured (Ratio a) where structure = containerStructure
instance Structured a => Structured [a] where structure = containerStructure
instance Structured a => Structured (NonEmpty a) where structure = containerStructure
instance (Structured a1, Structured a2) => Structured (a1, a2)
instance (Structured a1, Structured a2, Structured a3) => Structured (a1, a2, a3)
instance (Structured a1, Structured a2, Structured a3, Structured a4) => Structured (a1, a2, a3, a4)
instance (Structured a1, Structured a2, Structured a3, Structured a4, Structured a5) => Structured (a1, a2, a3, a4, a5)
instance (Structured a1, Structured a2, Structured a3, Structured a4, Structured a5, Structured a6) => Structured (a1, a2, a3, a4, a5, a6)
instance (Structured a1, Structured a2, Structured a3, Structured a4, Structured a5, Structured a6, Structured a7) => Structured (a1, a2, a3, a4, a5, a6, a7)
instance Structured BS.ByteString where structure = nominalStructure
instance Structured LBS.ByteString where structure = nominalStructure
instance Structured T.Text where structure = nominalStructure
instance Structured LT.Text where structure = nominalStructure
instance (Structured k, Structured v) => Structured (Map.Map k v) where structure _ = Nominal (typeRep (Proxy :: Proxy (Map.Map k v))) 0 "Map" [ structure (Proxy :: Proxy k), structure (Proxy :: Proxy v) ]
instance (Structured k) => Structured (Set.Set k) where structure = containerStructure
instance (Structured v) => Structured (IM.IntMap v) where structure = containerStructure
instance Structured IS.IntSet where structure = nominalStructure
instance (Structured v) => Structured (Seq.Seq v) where structure = containerStructure
instance Structured Time.UTCTime where structure = nominalStructure
instance Structured Time.DiffTime where structure = nominalStructure
instance Structured Time.UniversalTime where structure = nominalStructure
instance Structured Time.NominalDiffTime where structure = nominalStructure
instance Structured Time.Day where structure = nominalStructure
instance Structured Time.TimeZone where structure = nominalStructure
instance Structured Time.TimeOfDay where structure = nominalStructure
instance Structured Time.LocalTime where structure = nominalStructure
-- Proxy isn't Typeable in base-4.8 / base
-- #if __GLASGOW_HASKELL__ >= 800
-- instance (Typeable k, Typeable (a :: k)) => Structured (Proxy a)
-- #else
-- instance (Typeable a) => Structured (Proxy a) where
-- structure p = Structure (typeRep p) 0 "Proxy" [("Proxy",[])]
-- #endif