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module Erebos.Storage.List (
StoredList,
emptySList, fromSList, storedFromSList,
slistAdd, slistAddS,
-- TODO slistInsert, slistInsertS,
slistRemove, slistReplace, slistReplaceS,
-- TODO mapFromSList, updateOld,
-- TODO StoreUpdate(..),
-- TODO withStoredListItem, withStoredListItemS,
) where
import Data.List
import Data.Maybe
import qualified Data.Set as S
import Erebos.Storage
import Erebos.Storage.Internal
import Erebos.Storage.Merge
data List a = ListNil
| ListItem { listPrev :: [StoredList a]
, listItem :: Maybe (Stored a)
, listRemove :: Maybe (Stored (List a))
}
type StoredList a = Stored (List a)
instance Storable a => Storable (List a) where
store' ListNil = storeZero
store' x@ListItem {} = storeRec $ do
mapM_ (storeRef "PREV") $ listPrev x
mapM_ (storeRef "item") $ listItem x
mapM_ (storeRef "remove") $ listRemove x
load' = loadCurrentObject >>= \case
ZeroObject -> return ListNil
_ -> loadRec $ ListItem <$> loadRefs "PREV"
<*> loadMbRef "item"
<*> loadMbRef "remove"
instance Storable a => ZeroStorable (List a) where
fromZero _ = ListNil
emptySList :: Storable a => Storage -> IO (StoredList a)
emptySList st = wrappedStore st ListNil
groupsFromSLists :: forall a. Storable a => StoredList a -> [[Stored a]]
groupsFromSLists = helperSelect S.empty . (:[])
where
helperSelect :: S.Set (StoredList a) -> [StoredList a] -> [[Stored a]]
helperSelect rs xxs | x:xs <- sort $ filterRemoved rs xxs = helper rs x xs
| otherwise = []
helper :: S.Set (StoredList a) -> StoredList a -> [StoredList a] -> [[Stored a]]
helper rs x xs
| ListNil <- fromStored x
= []
| Just rm <- listRemove (fromStored x)
, ans <- ancestors [x]
, (other, collision) <- partition (S.null . S.intersection ans . ancestors . (:[])) xs
, cont <- helperSelect (rs `S.union` ancestors [rm]) $ concatMap (listPrev . fromStored) (x : collision) ++ other
= case catMaybes $ map (listItem . fromStored) (x : collision) of
[] -> cont
xis -> xis : cont
| otherwise = case listItem (fromStored x) of
Nothing -> helperSelect rs $ listPrev (fromStored x) ++ xs
Just xi -> [xi] : (helperSelect rs $ listPrev (fromStored x) ++ xs)
filterRemoved :: S.Set (StoredList a) -> [StoredList a] -> [StoredList a]
filterRemoved rs = filter (S.null . S.intersection rs . ancestors . (:[]))
fromSList :: Mergeable a => StoredList (Component a) -> [a]
fromSList = map merge . groupsFromSLists
storedFromSList :: (Mergeable a, Storable a) => StoredList (Component a) -> IO [Stored a]
storedFromSList = mapM storeMerge . groupsFromSLists
slistAdd :: Storable a => a -> StoredList a -> IO (StoredList a)
slistAdd x prev@(Stored (Ref st _) _) = do
sx <- wrappedStore st x
slistAddS sx prev
slistAddS :: Storable a => Stored a -> StoredList a -> IO (StoredList a)
slistAddS sx prev@(Stored (Ref st _) _) = wrappedStore st (ListItem [prev] (Just sx) Nothing)
{- TODO
slistInsert :: Storable a => Stored a -> a -> StoredList a -> IO (StoredList a)
slistInsert after x prev@(Stored (Ref st _) _) = do
sx <- wrappedStore st x
slistInsertS after sx prev
slistInsertS :: Storable a => Stored a -> Stored a -> StoredList a -> IO (StoredList a)
slistInsertS after sx prev@(Stored (Ref st _) _) = wrappedStore st $ ListItem Nothing (findSListRef after prev) (Just sx) prev
-}
slistRemove :: Storable a => Stored a -> StoredList a -> IO (StoredList a)
slistRemove rm prev@(Stored (Ref st _) _) = wrappedStore st $ ListItem [prev] Nothing (findSListRef rm prev)
slistReplace :: Storable a => Stored a -> a -> StoredList a -> IO (StoredList a)
slistReplace rm x prev@(Stored (Ref st _) _) = do
sx <- wrappedStore st x
slistReplaceS rm sx prev
slistReplaceS :: Storable a => Stored a -> Stored a -> StoredList a -> IO (StoredList a)
slistReplaceS rm sx prev@(Stored (Ref st _) _) = wrappedStore st $ ListItem [prev] (Just sx) (findSListRef rm prev)
findSListRef :: Stored a -> StoredList a -> Maybe (StoredList a)
findSListRef _ (Stored _ ListNil) = Nothing
findSListRef x cur | listItem (fromStored cur) == Just x = Just cur
| otherwise = listToMaybe $ catMaybes $ map (findSListRef x) $ listPrev $ fromStored cur
{- TODO
mapFromSList :: Storable a => StoredList a -> Map RefDigest (Stored a)
mapFromSList list = helper list M.empty
where helper :: Storable a => StoredList a -> Map RefDigest (Stored a) -> Map RefDigest (Stored a)
helper (Stored _ ListNil) cur = cur
helper (Stored _ (ListItem (Just rref) _ (Just x) rest)) cur =
let rxref = case load rref of
ListItem _ _ (Just rx) _ -> sameType rx x $ storedRef rx
_ -> error "mapFromSList: malformed list"
in helper rest $ case M.lookup (refDigest $ storedRef x) cur of
Nothing -> M.insert (refDigest rxref) x cur
Just x' -> M.insert (refDigest rxref) x' cur
helper (Stored _ (ListItem _ _ _ rest)) cur = helper rest cur
sameType :: a -> a -> b -> b
sameType _ _ x = x
updateOld :: Map RefDigest (Stored a) -> Stored a -> Stored a
updateOld m x = fromMaybe x $ M.lookup (refDigest $ storedRef x) m
data StoreUpdate a = StoreKeep
| StoreReplace a
| StoreRemove
withStoredListItem :: (Storable a) => (a -> Bool) -> StoredList a -> (a -> IO (StoreUpdate a)) -> IO (StoredList a)
withStoredListItem p list f = withStoredListItemS (p . fromStored) list (suMap (wrappedStore $ storedStorage list) <=< f . fromStored)
where suMap :: Monad m => (a -> m b) -> StoreUpdate a -> m (StoreUpdate b)
suMap _ StoreKeep = return StoreKeep
suMap g (StoreReplace x) = return . StoreReplace =<< g x
suMap _ StoreRemove = return StoreRemove
withStoredListItemS :: (Storable a) => (Stored a -> Bool) -> StoredList a -> (Stored a -> IO (StoreUpdate (Stored a))) -> IO (StoredList a)
withStoredListItemS p list f = do
case find p $ storedFromSList list of
Just sx -> f sx >>= \case StoreKeep -> return list
StoreReplace nx -> slistReplaceS sx nx list
StoreRemove -> slistRemove sx list
Nothing -> return list
-}
|