gameServer/Store.hs
author Wuzzy <Wuzzy2@mail.ru>
Mon, 17 Sep 2018 22:37:47 +0200
changeset 13785 4ed202f0428e
parent 11046 47a8c19ecb60
permissions -rw-r--r--
Easier back jumps in Basic Movement Training (fixes bug #692) The explanation of Back Jumping (2/2) has been simplified and the "hard" part has been made easier by lowering the girders. The original idea was that I wanted to force players to learn how to jump higher by delaying the 2nd backspace keypress. But this turned out that this section was too unfair and we have lost at least one player due to rage-quitting, according to feedback.

{-
 * Hedgewars, a free turn based strategy game
 * Copyright (c) 2004-2015 Andrey Korotaev <unC0Rr@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 \-}

{-# LANGUAGE BangPatterns, GeneralizedNewtypeDeriving #-}
module Store(
    ElemIndex(),
    MStore(),
    IStore(),
    newStore,
    addElem,
    removeElem,
    readElem,
    writeElem,
    modifyElem,
    elemExists,
    firstIndex,
    indicesM,
    withIStore,
    withIStore2,
    (!),
    indices
    ) where

import qualified Data.IntSet as IntSet
import qualified Data.Vector as V
import qualified Data.Vector.Mutable as MV
import Data.IORef
import Control.Monad
import Control.DeepSeq


newtype ElemIndex = ElemIndex Int
    deriving (Eq, Show, Read, Ord, NFData)
newtype MStore e = MStore (IORef (IntSet.IntSet, IntSet.IntSet, MV.IOVector e))
newtype IStore e = IStore (IntSet.IntSet, V.Vector e)


firstIndex :: ElemIndex
firstIndex = ElemIndex 0

-- MStore code
initialSize :: Int
initialSize = 16


growFunc :: Int -> Int
growFunc a = a * 3 `div` 2

truncFunc :: Int -> Int
truncFunc a | a > growFunc initialSize = (a `div` 2)
            | otherwise = a


newStore :: IO (MStore e)
newStore = do
    newar <- MV.new initialSize
    new <- newIORef (IntSet.empty, IntSet.fromAscList [0..initialSize - 1], newar)
    return (MStore new)


growStore :: MStore e -> IO ()
growStore (MStore ref) = do
    (busyElems, freeElems, arr) <- readIORef ref
    let oldSize = MV.length arr
    let newSize = growFunc oldSize
    newArr <- MV.grow arr (newSize - oldSize)
    writeIORef ref (busyElems, freeElems `IntSet.union` IntSet.fromAscList [oldSize .. newSize-1], newArr)


growIfNeeded :: MStore e -> IO ()
growIfNeeded m@(MStore ref) = do
    (_, freeElems, _) <- readIORef ref
    when (IntSet.null freeElems) $ growStore m


truncateIfNeeded :: MStore e -> IO ()
truncateIfNeeded (MStore ref) = do
    (busyElems, _, arr) <- readIORef ref
    let oldSize = MV.length arr
    let newSize = truncFunc oldSize
    when (newSize < oldSize && (not $ IntSet.null busyElems) && IntSet.findMax busyElems < newSize) $ do
        writeIORef ref (busyElems, IntSet.fromAscList [0..newSize - 1] `IntSet.difference` busyElems, MV.take newSize arr)


addElem :: MStore e -> e -> IO ElemIndex
addElem m@(MStore ref) element = do
    growIfNeeded m
    (busyElems, freeElems, arr) <- readIORef ref
    let (!n, freeElems') = IntSet.deleteFindMin freeElems
    MV.write arr n element
    writeIORef ref (IntSet.insert n busyElems, freeElems', arr)
    return $ ElemIndex n


removeElem :: MStore e -> ElemIndex -> IO ()
removeElem m@(MStore ref) (ElemIndex n) = do
    (busyElems, freeElems, arr) <- readIORef ref
    MV.write arr n (error $ "Store: no element " ++ show n)
    writeIORef ref (IntSet.delete n busyElems, IntSet.insert n freeElems, arr)
    truncateIfNeeded m


readElem :: MStore e -> ElemIndex -> IO e
readElem (MStore ref) (ElemIndex n) = readIORef ref >>= \(_, _, arr) -> MV.read arr n


writeElem :: MStore e -> ElemIndex -> e -> IO ()
writeElem (MStore ref) (ElemIndex n) el = readIORef ref >>= \(_, _, arr) -> MV.write arr n el


modifyElem :: MStore e -> (e -> e) -> ElemIndex -> IO ()
modifyElem (MStore ref) f (ElemIndex n) = do
    (_, _, arr) <- readIORef ref
    MV.read arr n >>= MV.write arr n . f

elemExists :: MStore e -> ElemIndex -> IO Bool
elemExists (MStore ref) (ElemIndex n) = do
    (_, !free, _) <- readIORef ref
    return $ n `IntSet.notMember` free

indicesM :: MStore e -> IO [ElemIndex]
indicesM (MStore ref) = do
    (!busy, _, _) <- readIORef ref
    return $ map ElemIndex $ IntSet.toList busy


-- A way to see MStore elements in pure code via IStore
m2i :: MStore e -> IO (IStore e)
m2i (MStore ref) = do
    (a, _, c') <- readIORef ref
    c <- V.unsafeFreeze c'
    return $ IStore (a, c)

i2m :: MStore e -> IStore e -> IO ()
i2m (MStore ref) (IStore (_, arr)) = do
    (b, e, _) <- readIORef ref
    a <- V.unsafeThaw arr
    writeIORef ref (b, e, a)

withIStore :: MStore e -> (IStore e -> a) -> IO a
withIStore m f = do
    i <- m2i m
    let res = f i
    res `seq` i2m m i
    return res


withIStore2 :: MStore e1 -> MStore e2 -> (IStore e1 -> IStore e2 -> a) -> IO a
withIStore2 m1 m2 f = do
    i1 <- m2i m1
    i2 <- m2i m2
    let res = f i1 i2
    res `seq` i2m m1 i1
    i2m m2 i2
    return res


-- IStore code
(!) :: IStore e -> ElemIndex -> e
(!) (IStore (_, arr)) (ElemIndex i) = (V.!) arr i

indices :: IStore e -> [ElemIndex]
indices (IStore (busy, _)) = map ElemIndex $ IntSet.toList busy