{-# LANGUAGE DataKinds #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE Strict #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE TypeFamilies #-}
module Apecs.Stores
( Map, Cache, Unique,
Global,
Cachable,
) where
import Control.Monad.Reader
import qualified Data.IntMap.Strict as M
import qualified Data.IntSet as S
import Data.IORef
import Data.Maybe (fromJust)
import Data.Proxy
import qualified Data.Vector.Mutable as VM
import qualified Data.Vector.Unboxed as U
import qualified Data.Vector.Unboxed.Mutable as UM
import GHC.TypeLits
import Apecs.Core
newtype Map c = Map (IORef (M.IntMap c))
type instance Elem (Map c) = c
instance ExplInit IO (Map c) where
explInit = Map <$> newIORef mempty
instance ExplGet IO (Map c) where
explExists (Map ref) ety = M.member ety <$> readIORef ref
explGet (Map ref) ety =
fromJust . M.lookup ety <$> readIORef ref
{-# INLINE explExists #-}
{-# INLINE explGet #-}
instance ExplSet IO (Map c) where
{-# INLINE explSet #-}
explSet (Map ref) ety x =
modifyIORef' ref (M.insert ety x)
instance ExplDestroy IO (Map c) where
{-# INLINE explDestroy #-}
explDestroy (Map ref) ety =
readIORef ref >>= writeIORef ref . M.delete ety
instance ExplMembers IO (Map c) where
{-# INLINE explMembers #-}
explMembers (Map ref) = U.fromList . M.keys <$> readIORef ref
newtype Unique c = Unique (IORef (Maybe (Int, c)))
type instance Elem (Unique c) = c
instance ExplInit IO (Unique c) where
explInit = Unique <$> newIORef Nothing
instance ExplGet IO (Unique c) where
{-# INLINE explGet #-}
explGet (Unique ref) _ = flip fmap (readIORef ref) $ \case
Nothing -> error "Reading empty Unique"
Just (_, c) -> c
{-# INLINE explExists #-}
explExists (Unique ref) ety = maybe False ((==ety) . fst) <$> readIORef ref
instance ExplSet IO (Unique c) where
{-# INLINE explSet #-}
explSet (Unique ref) ety c = writeIORef ref (Just (ety, c))
instance ExplDestroy IO (Unique c) where
{-# INLINE explDestroy #-}
explDestroy (Unique ref) ety = readIORef ref >>=
mapM_ (flip when (writeIORef ref Nothing) . (==ety) . fst)
instance ExplMembers IO (Unique c) where
{-# INLINE explMembers #-}
explMembers (Unique ref) = flip fmap (readIORef ref) $ \case
Nothing -> mempty
Just (ety, _) -> U.singleton ety
newtype Global c = Global (IORef c)
type instance Elem (Global c) = c
instance Monoid c => ExplInit IO (Global c) where
{-# INLINE explInit #-}
explInit = Global <$> newIORef mempty
instance ExplGet IO (Global c) where
{-# INLINE explGet #-}
explGet (Global ref) _ = readIORef ref
{-# INLINE explExists #-}
explExists _ _ = return True
instance ExplSet IO (Global c) where
{-# INLINE explSet #-}
explSet (Global ref) _ c = writeIORef ref c
class Cachable s
instance Cachable (Map s)
instance (KnownNat n, Cachable s) => Cachable (Cache n s)
data Cache (n :: Nat) s =
Cache Int (UM.IOVector Int) (VM.IOVector (Elem s)) s
cacheMiss :: t
cacheMiss = error "Cache miss!"
type instance Elem (Cache n s) = Elem s
instance (ExplInit IO s, KnownNat n, Cachable s) => ExplInit IO (Cache n s) where
{-# INLINE explInit #-}
explInit = do
let n = fromIntegral$ natVal (Proxy @n)
tags <- UM.replicate n (-2)
cache <- VM.replicate n cacheMiss
child <- explInit
return (Cache n tags cache child)
instance ExplGet IO s => ExplGet IO (Cache n s) where
{-# INLINE explGet #-}
explGet (Cache n tags cache s) ety = do
let index = ety `rem` n
tag <- UM.unsafeRead tags index
if tag == ety
then VM.unsafeRead cache index
else explGet s ety
{-# INLINE explExists #-}
explExists (Cache n tags _ s) ety = do
tag <- UM.unsafeRead tags (ety `rem` n)
if tag == ety then return True else explExists s ety
instance ExplSet IO s => ExplSet IO (Cache n s) where
{-# INLINE explSet #-}
explSet (Cache n tags cache s) ety x = do
let index = ety `rem` n
tag <- UM.unsafeRead tags index
when (tag /= (-2) && tag /= ety) $ do
cached <- VM.unsafeRead cache index
explSet s tag cached
UM.unsafeWrite tags index ety
VM.unsafeWrite cache index x
instance ExplDestroy IO s => ExplDestroy IO (Cache n s) where
{-# INLINE explDestroy #-}
explDestroy (Cache n tags cache s) ety = do
let index = ety `rem` n
tag <- UM.unsafeRead tags (ety `rem` n)
if tag == ety
then do
UM.unsafeWrite tags index (-2)
VM.unsafeWrite cache index cacheMiss
else explDestroy s ety
instance ExplMembers IO s => ExplMembers IO (Cache n s) where
{-# INLINE explMembers #-}
explMembers (Cache _ tags _ s) = do
cached <- U.filter (/= (-2)) <$> U.freeze tags
stored <- explMembers s
return $! cached U.++ stored