{-# LANGUAGE DataKinds #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE KindSignatures #-}
{-# 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 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 (Map c) where
explInit = Map <$> newIORef mempty
instance ExplGet (Map c) where
explExists (Map ref) ety = M.member ety <$> readIORef ref
explGet (Map ref) ety = fromJust . M.lookup ety <$> readIORef ref
{-# INLINE explExists #-}
{-# INLINE explGet #-}
instance ExplSet (Map c) where
{-# INLINE explSet #-}
explSet (Map ref) ety x = modifyIORef' ref $ M.insert ety x
instance ExplDestroy (Map c) where
{-# INLINE explDestroy #-}
explDestroy (Map ref) ety = modifyIORef' ref (M.delete ety)
instance ExplMembers (Map c) where
{-# INLINE explMembers #-}
explMembers (Map ref) = U.fromList . M.keys <$> readIORef ref
data Unique c = Unique (IORef Int) (IORef c)
type instance Elem (Unique c) = c
instance ExplInit (Unique c) where
explInit = Unique <$> newIORef (-1) <*> newIORef (error "Uninitialized Unique value")
instance ExplGet (Unique c) where
{-# INLINE explGet #-}
explGet (Unique _ cref) _ = readIORef cref
{-# INLINE explExists #-}
explExists (Unique eref _) ety = (==ety) <$> readIORef eref
instance ExplSet (Unique c) where
{-# INLINE explSet #-}
explSet (Unique eref cref) ety x = writeIORef eref ety >> writeIORef cref x
instance ExplDestroy (Unique c) where
{-# INLINE explDestroy #-}
explDestroy (Unique eref _) ety = do e <- readIORef eref; when (e==ety) (writeIORef eref (-1))
instance ExplMembers (Unique c) where
{-# INLINE explMembers #-}
explMembers (Unique eref _) = f <$> readIORef eref
where f (-1) = mempty
f x = U.singleton x
newtype Global c = Global (IORef c)
type instance Elem (Global c) = c
instance Monoid c => ExplInit (Global c) where
explInit = Global <$> newIORef mempty
instance ExplGet (Global c) where
explGet (Global ref) _ = readIORef ref
explExists _ _ = return True
instance ExplSet (Global c) where
explSet (Global ref) _ c = writeIORef ref c
class Cachable s
instance Cachable (Map s)
instance (KnownNat n, Cachable s) => Cachable (Cache n s)
data Cache (n :: Nat) s =
Cache Int (UM.IOVector Int) (VM.IOVector (Elem s)) s
type instance Elem (Cache n s) = Elem s
instance (ExplInit s, KnownNat n, Cachable s) => ExplInit (Cache n s) where
explInit = do
let n = fromIntegral$ natVal (Proxy @n)
tags <- UM.replicate n (-1)
cache <- VM.new n
child <- explInit
return (Cache n tags cache child)
instance ExplGet s => ExplGet (Cache n s) where
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
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 s => ExplSet (Cache n s) where
explSet (Cache n tags cache s) ety x = do
let index = ety `rem` n
tag <- UM.unsafeRead tags index
when (tag /= (-1) && tag /= ety) $ do
cached <- VM.unsafeRead cache index
explSet s tag cached
UM.unsafeWrite tags index ety
VM.unsafeWrite cache index x
instance ExplDestroy s => ExplDestroy (Cache n s) where
explDestroy (Cache n tags _ s) ety = do
tag <- UM.unsafeRead tags (ety `rem` n)
if tag == ety
then UM.unsafeWrite tags (ety `rem` n) (-1)
else explDestroy s ety
instance ExplMembers s => ExplMembers (Cache n s) where
explMembers (Cache _ tags _ s) = do
cached <- U.filter (/= (-1)) <$> U.freeze tags
stored <- explMembers s
return $! cached U.++ stored