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-rw-r--r--src/Erebos/Storage.hs74
1 files changed, 46 insertions, 28 deletions
diff --git a/src/Erebos/Storage.hs b/src/Erebos/Storage.hs
index 95ef649..6526f40 100644
--- a/src/Erebos/Storage.hs
+++ b/src/Erebos/Storage.hs
@@ -21,9 +21,11 @@ module Erebos.Storage (
headId, headStorage, headRef, headObject, headStoredObject,
loadHeads, loadHead, reloadHead,
storeHead, replaceHead, updateHead, updateHead_,
+ loadHeadRaw, storeHeadRaw, replaceHeadRaw,
WatchedHead,
watchHead, watchHeadWith, unwatchHead,
+ watchHeadRaw,
MonadStorage(..),
@@ -62,7 +64,6 @@ module Erebos.Storage (
) where
import Control.Applicative
-import Control.Arrow
import Control.Concurrent
import Control.Exception
import Control.Monad
@@ -72,6 +73,7 @@ import Control.Monad.Writer
import Crypto.Hash
+import Data.Bifunctor
import Data.ByteString (ByteString)
import qualified Data.ByteArray as BA
import qualified Data.ByteString as B
@@ -436,57 +438,70 @@ loadHeads Storage { stBacking = StorageMemory { memHeads = theads } } = liftIO $
catMaybes . map toHead <$> readMVar theads
loadHead :: forall a m. (HeadType a, MonadIO m) => Storage -> HeadID -> m (Maybe (Head a))
-loadHead s@(Storage { stBacking = StorageDir { dirPath = spath }}) hid = liftIO $ do
+loadHead st hid = fmap (Head hid . wrappedLoad) <$> loadHeadRaw st (headTypeID @a Proxy) hid
+
+loadHeadRaw :: forall m. MonadIO m => Storage -> HeadTypeID -> HeadID -> m (Maybe Ref)
+loadHeadRaw s@(Storage { stBacking = StorageDir { dirPath = spath }}) tid hid = liftIO $ do
handleJust (guard . isDoesNotExistError) (const $ return Nothing) $ do
- (h:_) <- BC.lines <$> B.readFile (headPath spath (headTypeID @a Proxy) hid)
+ (h:_) <- BC.lines <$> B.readFile (headPath spath tid hid)
Just ref <- readRef s h
- return $ Just $ Head hid $ wrappedLoad ref
-loadHead Storage { stBacking = StorageMemory { memHeads = theads } } hid = liftIO $ do
- fmap (Head hid . wrappedLoad) . lookup (headTypeID @a Proxy, hid) <$> readMVar theads
+ return $ Just ref
+loadHeadRaw Storage { stBacking = StorageMemory { memHeads = theads } } tid hid = liftIO $ do
+ lookup (tid, hid) <$> readMVar theads
reloadHead :: (HeadType a, MonadIO m) => Head a -> m (Maybe (Head a))
reloadHead (Head hid (Stored (Ref st _) _)) = loadHead st hid
storeHead :: forall a m. MonadIO m => HeadType a => Storage -> a -> m (Head a)
-storeHead st obj = liftIO $ do
+storeHead st obj = do
let tid = headTypeID @a Proxy
- hid <- HeadID <$> U.nextRandom
stored <- wrappedStore st obj
+ hid <- storeHeadRaw st tid (storedRef stored)
+ return $ Head hid stored
+
+storeHeadRaw :: forall m. MonadIO m => Storage -> HeadTypeID -> Ref -> m HeadID
+storeHeadRaw st tid ref = liftIO $ do
+ hid <- HeadID <$> U.nextRandom
case stBacking st of
StorageDir { dirPath = spath } -> do
Right () <- writeFileChecked (headPath spath tid hid) Nothing $
- showRef (storedRef stored) `B.append` BC.singleton '\n'
+ showRef ref `B.append` BC.singleton '\n'
return ()
StorageMemory { memHeads = theads } -> do
- modifyMVar_ theads $ return . (((tid, hid), storedRef stored) :)
- return $ Head hid stored
+ modifyMVar_ theads $ return . (((tid, hid), ref) :)
+ return hid
replaceHead :: forall a m. (HeadType a, MonadIO m) => Head a -> Stored a -> m (Either (Maybe (Head a)) (Head a))
replaceHead prev@(Head hid pobj) stored' = liftIO $ do
let st = headStorage prev
tid = headTypeID @a Proxy
stored <- copyStored st stored'
+ bimap (fmap $ Head hid . wrappedLoad) (const $ Head hid stored) <$>
+ replaceHeadRaw st tid hid (storedRef pobj) (storedRef stored)
+
+replaceHeadRaw :: forall m. MonadIO m => Storage -> HeadTypeID -> HeadID -> Ref -> Ref -> m (Either (Maybe Ref) Ref)
+replaceHeadRaw st tid hid prev new = liftIO $ do
case stBacking st of
StorageDir { dirPath = spath } -> do
let filename = headPath spath tid hid
showRefL r = showRef r `B.append` BC.singleton '\n'
- writeFileChecked filename (Just $ showRefL $ headRef prev) (showRefL $ storedRef stored) >>= \case
+ writeFileChecked filename (Just $ showRefL prev) (showRefL new) >>= \case
Left Nothing -> return $ Left Nothing
Left (Just bs) -> do Just oref <- readRef st $ BC.takeWhile (/='\n') bs
- return $ Left $ Just $ Head hid $ wrappedLoad oref
- Right () -> return $ Right $ Head hid stored
+ return $ Left $ Just oref
+ Right () -> return $ Right new
StorageMemory { memHeads = theads, memWatchers = twatch } -> do
res <- modifyMVar theads $ \hs -> do
ws <- map wlFun . filter ((==(tid, hid)) . wlHead) . wlList <$> readMVar twatch
return $ case partition ((==(tid, hid)) . fst) hs of
([] , _ ) -> (hs, Left Nothing)
- ((_, r):_, hs') | r == storedRef pobj -> (((tid, hid), storedRef stored) : hs',
- Right (Head hid stored, ws))
- | otherwise -> (hs, Left $ Just $ Head hid $ wrappedLoad r)
+ ((_, r):_, hs') | r == prev -> (((tid, hid), new) : hs',
+ Right (new, ws))
+ | otherwise -> (hs, Left $ Just r)
case res of
- Right (h, ws) -> mapM_ ($ headRef h) ws >> return (Right h)
+ Right (r, ws) -> mapM_ ($ r) ws >> return (Right r)
Left x -> return $ Left x
updateHead :: (HeadType a, MonadIO m) => Head a -> (Stored a -> m (Stored a, b)) -> m (Maybe (Head a), b)
@@ -507,19 +522,22 @@ watchHead :: forall a. HeadType a => Head a -> (Head a -> IO ()) -> IO WatchedHe
watchHead h = watchHeadWith h id
watchHeadWith :: forall a b. (HeadType a, Eq b) => Head a -> (Head a -> b) -> (b -> IO ()) -> IO WatchedHead
-watchHeadWith oh@(Head hid (Stored (Ref st _) _)) sel cb = do
+watchHeadWith (Head hid (Stored (Ref st _) _)) sel cb = do
+ watchHeadRaw st (headTypeID @a Proxy) hid (sel . Head hid . wrappedLoad) cb
+
+watchHeadRaw :: forall b. Eq b => Storage -> HeadTypeID -> HeadID -> (Ref -> b) -> (b -> IO ()) -> IO WatchedHead
+watchHeadRaw st tid hid sel cb = do
memo <- newEmptyMVar
- let tid = headTypeID @a Proxy
- addWatcher wl = (wl', WatchedHead st (wlNext wl) memo)
+ let addWatcher wl = (wl', WatchedHead st (wlNext wl) memo)
where wl' = wl { wlNext = wlNext wl + 1
, wlList = WatchListItem
{ wlID = wlNext wl
, wlHead = (tid, hid)
, wlFun = \r -> do
- let x = sel $ Head hid $ wrappedLoad r
+ let x = sel r
modifyMVar_ memo $ \prev -> do
- when (x /= prev) $ cb x
- return x
+ when (Just x /= prev) $ cb x
+ return $ Just x
} : wlList wl
}
@@ -531,8 +549,8 @@ watchHeadWith oh@(Head hid (Stored (Ref st _) _)) sel cb = do
inotify <- initINotify
void $ addWatch inotify [Move] (BC.pack $ headTypePath spath tid) $ \case
MovedIn { filePath = fpath } | Just ihid <- HeadID <$> U.fromASCIIBytes fpath -> do
- loadHead @a st ihid >>= \case
- Just h -> mapM_ ($ headRef h) . map wlFun . filter ((== (tid, ihid)) . wlHead) . wlList . snd =<< readMVar mvar
+ loadHeadRaw st tid ihid >>= \case
+ Just ref -> mapM_ ($ ref) . map wlFun . filter ((== (tid, ihid)) . wlHead) . wlList . snd =<< readMVar mvar
Nothing -> return ()
_ -> return ()
return $ (tid, inotify) : ilist
@@ -540,8 +558,8 @@ watchHeadWith oh@(Head hid (Stored (Ref st _) _)) sel cb = do
StorageMemory { memWatchers = mvar } -> modifyMVar mvar $ return . addWatcher
- cur <- sel . maybe oh id <$> reloadHead oh
- cb cur
+ cur <- fmap sel <$> loadHeadRaw st tid hid
+ maybe (return ()) cb cur
putMVar memo cur
return watched
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-05 17:03:21 +0000