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diff --git a/src/Erebos/Storage.hs b/src/Erebos/Storage.hs
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+module Erebos.Storage (
+ Storage, PartialStorage, StorageCompleteness,
+ openStorage, memoryStorage,
+ deriveEphemeralStorage, derivePartialStorage,
+
+ Ref, PartialRef, RefDigest,
+ refDigest,
+ readRef, showRef, showRefDigest,
+ refDigestFromByteString, hashToRefDigest,
+ copyRef, partialRef, partialRefFromDigest,
+
+ Object, PartialObject, Object'(..), RecItem, RecItem'(..),
+ serializeObject, deserializeObject, deserializeObjects,
+ ioLoadObject, ioLoadBytes,
+ storeRawBytes, lazyLoadBytes,
+ storeObject,
+ collectObjects, collectStoredObjects,
+
+ Head, HeadType(..),
+ HeadTypeID, mkHeadTypeID,
+ headId, headStorage, headRef, headObject, headStoredObject,
+ loadHeads, loadHead, reloadHead,
+ storeHead, replaceHead, updateHead, updateHead_,
+
+ WatchedHead,
+ watchHead, watchHeadWith, unwatchHead,
+
+ MonadStorage(..),
+
+ Storable(..), ZeroStorable(..),
+ StorableText(..), StorableDate(..), StorableUUID(..),
+
+ Store, StoreRec,
+ evalStore, evalStoreObject,
+ storeBlob, storeRec, storeZero,
+ storeEmpty, storeInt, storeNum, storeText, storeBinary, storeDate, storeUUID, storeRef, storeRawRef,
+ storeMbEmpty, storeMbInt, storeMbNum, storeMbText, storeMbBinary, storeMbDate, storeMbUUID, storeMbRef, storeMbRawRef,
+ storeZRef,
+
+ Load, LoadRec,
+ evalLoad,
+ loadCurrentRef, loadCurrentObject,
+ loadRecCurrentRef, loadRecItems,
+
+ loadBlob, loadRec, loadZero,
+ loadEmpty, loadInt, loadNum, loadText, loadBinary, loadDate, loadUUID, loadRef, loadRawRef,
+ loadMbEmpty, loadMbInt, loadMbNum, loadMbText, loadMbBinary, loadMbDate, loadMbUUID, loadMbRef, loadMbRawRef,
+ loadTexts, loadBinaries, loadRefs, loadRawRefs,
+ loadZRef,
+
+ Stored,
+ fromStored, storedRef,
+ wrappedStore, wrappedLoad,
+ copyStored,
+ unsafeMapStored,
+
+ StoreInfo(..), makeStoreInfo,
+
+ StoredHistory,
+ fromHistory, fromHistoryAt, storedFromHistory, storedHistoryList,
+ beginHistory, modifyHistory,
+) where
+
+import Control.Applicative
+import Control.Arrow
+import Control.Concurrent
+import Control.Exception
+import Control.Monad
+import Control.Monad.Except
+import Control.Monad.Reader
+import Control.Monad.Writer
+
+import Crypto.Hash
+
+import Data.ByteString (ByteString)
+import qualified Data.ByteArray as BA
+import qualified Data.ByteString as B
+import qualified Data.ByteString.Char8 as BC
+import qualified Data.ByteString.Lazy as BL
+import qualified Data.ByteString.Lazy.Char8 as BLC
+import Data.Char
+import Data.Function
+import qualified Data.HashTable.IO as HT
+import Data.List
+import qualified Data.Map as M
+import Data.Maybe
+import Data.Ratio
+import Data.Set (Set)
+import qualified Data.Set as S
+import Data.Text (Text)
+import qualified Data.Text as T
+import Data.Text.Encoding
+import Data.Text.Encoding.Error
+import Data.Time.Calendar
+import Data.Time.Clock
+import Data.Time.Format
+import Data.Time.LocalTime
+import Data.Typeable
+import Data.UUID (UUID)
+import qualified Data.UUID as U
+import qualified Data.UUID.V4 as U
+
+import System.Directory
+import System.FilePath
+import System.INotify
+import System.IO.Error
+import System.IO.Unsafe
+
+import Erebos.Storage.Internal
+
+
+type Storage = Storage' Complete
+type PartialStorage = Storage' Partial
+
+storageVersion :: String
+storageVersion = "0.1"
+
+openStorage :: FilePath -> IO Storage
+openStorage path = modifyIOError annotate $ do
+ let versionPath = path </> "erebos-storage"
+ doesFileExist versionPath >>= \case
+ True -> readFile versionPath >>= \case
+ content | (ver:_) <- lines content, ver == storageVersion -> return ()
+ | otherwise -> fail "unsupported storage version"
+ False -> do
+ doesDirectoryExist path >>= \case
+ True -> do
+ listDirectory path >>= \case
+ contents@(_:_) | "objects" `notElem` contents || "heads" `notElem` contents
+ -> fail "directory is neither empty, nor an existing erebos storage"
+ _ -> return ()
+ False -> do
+ createDirectoryIfMissing True $ path
+ writeFile versionPath $ storageVersion <> "\n"
+
+ createDirectoryIfMissing True $ path </> "objects"
+ createDirectoryIfMissing True $ path </> "heads"
+ watchers <- newMVar ([], WatchList 1 [])
+ refgen <- newMVar =<< HT.new
+ refroots <- newMVar =<< HT.new
+ return $ Storage
+ { stBacking = StorageDir path watchers
+ , stParent = Nothing
+ , stRefGeneration = refgen
+ , stRefRoots = refroots
+ }
+ where
+ annotate e = annotateIOError e "failed to open storage" Nothing (Just path)
+
+memoryStorage' :: IO (Storage' c')
+memoryStorage' = do
+ backing <- StorageMemory <$> newMVar [] <*> newMVar M.empty <*> newMVar M.empty <*> newMVar (WatchList 1 [])
+ refgen <- newMVar =<< HT.new
+ refroots <- newMVar =<< HT.new
+ return $ Storage
+ { stBacking = backing
+ , stParent = Nothing
+ , stRefGeneration = refgen
+ , stRefRoots = refroots
+ }
+
+memoryStorage :: IO Storage
+memoryStorage = memoryStorage'
+
+deriveEphemeralStorage :: Storage -> IO Storage
+deriveEphemeralStorage parent = do
+ st <- memoryStorage
+ return $ st { stParent = Just parent }
+
+derivePartialStorage :: Storage -> IO PartialStorage
+derivePartialStorage parent = do
+ st <- memoryStorage'
+ return $ st { stParent = Just parent }
+
+type Ref = Ref' Complete
+type PartialRef = Ref' Partial
+
+zeroRef :: Storage' c -> Ref' c
+zeroRef s = Ref s (RefDigest h)
+ where h = case digestFromByteString $ B.replicate (hashDigestSize $ digestAlgo h) 0 of
+ Nothing -> error $ "Failed to create zero hash"
+ Just h' -> h'
+ digestAlgo :: Digest a -> a
+ digestAlgo = undefined
+
+isZeroRef :: Ref' c -> Bool
+isZeroRef (Ref _ h) = all (==0) $ BA.unpack h
+
+
+refFromDigest :: Storage' c -> RefDigest -> IO (Maybe (Ref' c))
+refFromDigest st dgst = fmap (const $ Ref st dgst) <$> ioLoadBytesFromStorage st dgst
+
+readRef :: Storage -> ByteString -> IO (Maybe Ref)
+readRef s b =
+ case readRefDigest b of
+ Nothing -> return Nothing
+ Just dgst -> refFromDigest s dgst
+
+copyRef' :: forall c c'. (StorageCompleteness c, StorageCompleteness c') => Storage' c' -> Ref' c -> IO (c (Ref' c'))
+copyRef' st ref'@(Ref _ dgst) = refFromDigest st dgst >>= \case Just ref -> return $ return ref
+ Nothing -> doCopy
+ where doCopy = do mbobj' <- ioLoadObject ref'
+ mbobj <- sequence $ copyObject' st <$> mbobj'
+ sequence $ unsafeStoreObject st <$> join mbobj
+
+copyObject' :: forall c c'. (StorageCompleteness c, StorageCompleteness c') => Storage' c' -> Object' c -> IO (c (Object' c'))
+copyObject' _ (Blob bs) = return $ return $ Blob bs
+copyObject' st (Rec rs) = fmap Rec . sequence <$> mapM copyItem rs
+ where copyItem :: (ByteString, RecItem' c) -> IO (c (ByteString, RecItem' c'))
+ copyItem (n, item) = fmap (n,) <$> case item of
+ RecEmpty -> return $ return $ RecEmpty
+ RecInt x -> return $ return $ RecInt x
+ RecNum x -> return $ return $ RecNum x
+ RecText x -> return $ return $ RecText x
+ RecBinary x -> return $ return $ RecBinary x
+ RecDate x -> return $ return $ RecDate x
+ RecUUID x -> return $ return $ RecUUID x
+ RecRef x -> fmap RecRef <$> copyRef' st x
+copyObject' _ ZeroObject = return $ return ZeroObject
+
+copyRef :: forall c c' m. (StorageCompleteness c, StorageCompleteness c', MonadIO m) => Storage' c' -> Ref' c -> m (LoadResult c (Ref' c'))
+copyRef st ref' = liftIO $ returnLoadResult <$> copyRef' st ref'
+
+copyObject :: forall c c'. (StorageCompleteness c, StorageCompleteness c') => Storage' c' -> Object' c -> IO (LoadResult c (Object' c'))
+copyObject st obj' = returnLoadResult <$> copyObject' st obj'
+
+partialRef :: PartialStorage -> Ref -> PartialRef
+partialRef st (Ref _ dgst) = Ref st dgst
+
+partialRefFromDigest :: PartialStorage -> RefDigest -> PartialRef
+partialRefFromDigest st dgst = Ref st dgst
+
+
+data Object' c
+ = Blob ByteString
+ | Rec [(ByteString, RecItem' c)]
+ | ZeroObject
+ deriving (Show)
+
+type Object = Object' Complete
+type PartialObject = Object' Partial
+
+data RecItem' c
+ = RecEmpty
+ | RecInt Integer
+ | RecNum Rational
+ | RecText Text
+ | RecBinary ByteString
+ | RecDate ZonedTime
+ | RecUUID UUID
+ | RecRef (Ref' c)
+ deriving (Show)
+
+type RecItem = RecItem' Complete
+
+serializeObject :: Object' c -> BL.ByteString
+serializeObject = \case
+ Blob cnt -> BL.fromChunks [BC.pack "blob ", BC.pack (show $ B.length cnt), BC.singleton '\n', cnt]
+ Rec rec -> let cnt = BL.fromChunks $ concatMap (uncurry serializeRecItem) rec
+ in BL.fromChunks [BC.pack "rec ", BC.pack (show $ BL.length cnt), BC.singleton '\n'] `BL.append` cnt
+ ZeroObject -> BL.empty
+
+-- |Serializes and stores object data without ony dependencies, so is safe only
+-- if all the referenced objects are already stored or reference is partial.
+unsafeStoreObject :: Storage' c -> Object' c -> IO (Ref' c)
+unsafeStoreObject storage = \case
+ ZeroObject -> return $ zeroRef storage
+ obj -> unsafeStoreRawBytes storage $ serializeObject obj
+
+storeObject :: PartialStorage -> PartialObject -> IO PartialRef
+storeObject = unsafeStoreObject
+
+storeRawBytes :: PartialStorage -> BL.ByteString -> IO PartialRef
+storeRawBytes = unsafeStoreRawBytes
+
+serializeRecItem :: ByteString -> RecItem' c -> [ByteString]
+serializeRecItem name (RecEmpty) = [name, BC.pack ":e", BC.singleton ' ', BC.singleton '\n']
+serializeRecItem name (RecInt x) = [name, BC.pack ":i", BC.singleton ' ', BC.pack (show x), BC.singleton '\n']
+serializeRecItem name (RecNum x) = [name, BC.pack ":n", BC.singleton ' ', BC.pack (showRatio x), BC.singleton '\n']
+serializeRecItem name (RecText x) = [name, BC.pack ":t", BC.singleton ' ', escaped, BC.singleton '\n']
+ where escaped = BC.concatMap escape $ encodeUtf8 x
+ escape '\n' = BC.pack "\n\t"
+ escape c = BC.singleton c
+serializeRecItem name (RecBinary x) = [name, BC.pack ":b ", showHex x, BC.singleton '\n']
+serializeRecItem name (RecDate x) = [name, BC.pack ":d", BC.singleton ' ', BC.pack (formatTime defaultTimeLocale "%s %z" x), BC.singleton '\n']
+serializeRecItem name (RecUUID x) = [name, BC.pack ":u", BC.singleton ' ', U.toASCIIBytes x, BC.singleton '\n']
+serializeRecItem name (RecRef x) = [name, BC.pack ":r ", showRef x, BC.singleton '\n']
+
+lazyLoadObject :: forall c. StorageCompleteness c => Ref' c -> LoadResult c (Object' c)
+lazyLoadObject = returnLoadResult . unsafePerformIO . ioLoadObject
+
+ioLoadObject :: forall c. StorageCompleteness c => Ref' c -> IO (c (Object' c))
+ioLoadObject ref | isZeroRef ref = return $ return ZeroObject
+ioLoadObject ref@(Ref st rhash) = do
+ file' <- ioLoadBytes ref
+ return $ do
+ file <- file'
+ let chash = hashToRefDigest file
+ when (chash /= rhash) $ error $ "Hash mismatch on object " ++ BC.unpack (showRef ref) {- TODO throw -}
+ return $ case runExcept $ unsafeDeserializeObject st file of
+ Left err -> error $ err ++ ", ref " ++ BC.unpack (showRef ref) {- TODO throw -}
+ Right (x, rest) | BL.null rest -> x
+ | otherwise -> error $ "Superfluous content after " ++ BC.unpack (showRef ref) {- TODO throw -}
+
+lazyLoadBytes :: forall c. StorageCompleteness c => Ref' c -> LoadResult c BL.ByteString
+lazyLoadBytes ref | isZeroRef ref = returnLoadResult (return BL.empty :: c BL.ByteString)
+lazyLoadBytes ref = returnLoadResult $ unsafePerformIO $ ioLoadBytes ref
+
+unsafeDeserializeObject :: Storage' c -> BL.ByteString -> Except String (Object' c, BL.ByteString)
+unsafeDeserializeObject _ bytes | BL.null bytes = return (ZeroObject, bytes)
+unsafeDeserializeObject st bytes =
+ case BLC.break (=='\n') bytes of
+ (line, rest) | Just (otype, len) <- splitObjPrefix line -> do
+ let (content, next) = first BL.toStrict $ BL.splitAt (fromIntegral len) $ BL.drop 1 rest
+ guard $ B.length content == len
+ (,next) <$> case otype of
+ _ | otype == BC.pack "blob" -> return $ Blob content
+ | otype == BC.pack "rec" -> maybe (throwError $ "Malformed record item ")
+ (return . Rec) $ sequence $ map parseRecLine $ mergeCont [] $ BC.lines content
+ | otherwise -> throwError $ "Unknown object type"
+ _ -> throwError $ "Malformed object"
+ where splitObjPrefix line = do
+ [otype, tlen] <- return $ BLC.words line
+ (len, rest) <- BLC.readInt tlen
+ guard $ BL.null rest
+ return (BL.toStrict otype, len)
+
+ mergeCont cs (a:b:rest) | Just ('\t', b') <- BC.uncons b = mergeCont (b':BC.pack "\n":cs) (a:rest)
+ mergeCont cs (a:rest) = B.concat (a : reverse cs) : mergeCont [] rest
+ mergeCont _ [] = []
+
+ parseRecLine line = do
+ colon <- BC.elemIndex ':' line
+ space <- BC.elemIndex ' ' line
+ guard $ colon < space
+ let name = B.take colon line
+ itype = B.take (space-colon-1) $ B.drop (colon+1) line
+ content = B.drop (space+1) line
+
+ val <- case BC.unpack itype of
+ "e" -> do guard $ B.null content
+ return RecEmpty
+ "i" -> do (num, rest) <- BC.readInteger content
+ guard $ B.null rest
+ return $ RecInt num
+ "n" -> RecNum <$> parseRatio content
+ "t" -> return $ RecText $ decodeUtf8With lenientDecode content
+ "b" -> RecBinary <$> readHex content
+ "d" -> RecDate <$> parseTimeM False defaultTimeLocale "%s %z" (BC.unpack content)
+ "u" -> RecUUID <$> U.fromASCIIBytes content
+ "r" -> RecRef . Ref st <$> readRefDigest content
+ _ -> Nothing
+ return (name, val)
+
+deserializeObject :: PartialStorage -> BL.ByteString -> Except String (PartialObject, BL.ByteString)
+deserializeObject = unsafeDeserializeObject
+
+deserializeObjects :: PartialStorage -> BL.ByteString -> Except String [PartialObject]
+deserializeObjects _ bytes | BL.null bytes = return []
+deserializeObjects st bytes = do (obj, rest) <- deserializeObject st bytes
+ (obj:) <$> deserializeObjects st rest
+
+
+collectObjects :: Object -> [Object]
+collectObjects obj = obj : map fromStored (fst $ collectOtherStored S.empty obj)
+
+collectStoredObjects :: Stored Object -> [Stored Object]
+collectStoredObjects obj = obj : (fst $ collectOtherStored S.empty $ fromStored obj)
+
+collectOtherStored :: Set RefDigest -> Object -> ([Stored Object], Set RefDigest)
+collectOtherStored seen (Rec items) = foldr helper ([], seen) $ map snd items
+ where helper (RecRef ref) (xs, s) | r <- refDigest ref
+ , r `S.notMember` s
+ = let o = wrappedLoad ref
+ (xs', s') = collectOtherStored (S.insert r s) $ fromStored o
+ in ((o : xs') ++ xs, s')
+ helper _ (xs, s) = (xs, s)
+collectOtherStored seen _ = ([], seen)
+
+
+type Head = Head' Complete
+
+headId :: Head a -> HeadID
+headId (Head uuid _) = uuid
+
+headStorage :: Head a -> Storage
+headStorage = refStorage . headRef
+
+headRef :: Head a -> Ref
+headRef (Head _ sx) = storedRef sx
+
+headObject :: Head a -> a
+headObject (Head _ sx) = fromStored sx
+
+headStoredObject :: Head a -> Stored a
+headStoredObject (Head _ sx) = sx
+
+deriving instance StorableUUID HeadID
+deriving instance StorableUUID HeadTypeID
+
+mkHeadTypeID :: String -> HeadTypeID
+mkHeadTypeID = maybe (error "Invalid head type ID") HeadTypeID . U.fromString
+
+class Storable a => HeadType a where
+ headTypeID :: proxy a -> HeadTypeID
+
+
+headTypePath :: FilePath -> HeadTypeID -> FilePath
+headTypePath spath (HeadTypeID tid) = spath </> "heads" </> U.toString tid
+
+headPath :: FilePath -> HeadTypeID -> HeadID -> FilePath
+headPath spath tid (HeadID hid) = headTypePath spath tid </> U.toString hid
+
+loadHeads :: forall a m. MonadIO m => HeadType a => Storage -> m [Head a]
+loadHeads s@(Storage { stBacking = StorageDir { dirPath = spath }}) = liftIO $ do
+ let hpath = headTypePath spath $ headTypeID @a Proxy
+
+ files <- filterM (doesFileExist . (hpath </>)) =<<
+ handleJust (\e -> guard (isDoesNotExistError e)) (const $ return [])
+ (getDirectoryContents hpath)
+ fmap catMaybes $ forM files $ \hname -> do
+ case U.fromString hname of
+ Just hid -> do
+ (h:_) <- BC.lines <$> B.readFile (hpath </> hname)
+ Just ref <- readRef s h
+ return $ Just $ Head (HeadID hid) $ wrappedLoad ref
+ Nothing -> return Nothing
+loadHeads Storage { stBacking = StorageMemory { memHeads = theads } } = liftIO $ do
+ let toHead ((tid, hid), ref) | tid == headTypeID @a Proxy = Just $ Head hid $ wrappedLoad ref
+ | otherwise = Nothing
+ 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
+ handleJust (guard . isDoesNotExistError) (const $ return Nothing) $ do
+ (h:_) <- BC.lines <$> B.readFile (headPath spath (headTypeID @a Proxy) 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
+
+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
+ let tid = headTypeID @a Proxy
+ hid <- HeadID <$> U.nextRandom
+ stored <- wrappedStore st obj
+ case stBacking st of
+ StorageDir { dirPath = spath } -> do
+ Right () <- writeFileChecked (headPath spath tid hid) Nothing $
+ showRef (storedRef stored) `B.append` BC.singleton '\n'
+ return ()
+ StorageMemory { memHeads = theads } -> do
+ modifyMVar_ theads $ return . (((tid, hid), storedRef stored) :)
+ return $ Head hid stored
+
+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'
+ 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
+ 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
+
+ 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)
+ case res of
+ Right (h, ws) -> mapM_ ($ headRef h) ws >> return (Right h)
+ Left x -> return $ Left x
+
+updateHead :: (HeadType a, MonadIO m) => Head a -> (Stored a -> m (Stored a, b)) -> m (Maybe (Head a), b)
+updateHead h f = do
+ (o, x) <- f $ headStoredObject h
+ replaceHead h o >>= \case
+ Right h' -> return (Just h', x)
+ Left Nothing -> return (Nothing, x)
+ Left (Just h') -> updateHead h' f
+
+updateHead_ :: (HeadType a, MonadIO m) => Head a -> (Stored a -> m (Stored a)) -> m (Maybe (Head a))
+updateHead_ h = fmap fst . updateHead h . (fmap (,()) .)
+
+
+data WatchedHead = forall a. WatchedHead Storage WatchID (MVar a)
+
+watchHead :: forall a. HeadType a => Head a -> (Head a -> IO ()) -> IO WatchedHead
+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
+ memo <- newEmptyMVar
+ let tid = headTypeID @a Proxy
+ 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
+ modifyMVar_ memo $ \prev -> do
+ when (x /= prev) $ cb x
+ return x
+ } : wlList wl
+ }
+
+ watched <- case stBacking st of
+ StorageDir { dirPath = spath, dirWatchers = mvar } -> modifyMVar mvar $ \(ilist, wl) -> do
+ ilist' <- case lookup tid ilist of
+ Just _ -> return ilist
+ Nothing -> 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
+ Nothing -> return ()
+ _ -> return ()
+ return $ (tid, inotify) : ilist
+ return $ first (ilist',) $ addWatcher wl
+
+ StorageMemory { memWatchers = mvar } -> modifyMVar mvar $ return . addWatcher
+
+ cur <- sel . maybe oh id <$> reloadHead oh
+ cb cur
+ putMVar memo cur
+
+ return watched
+
+unwatchHead :: WatchedHead -> IO ()
+unwatchHead (WatchedHead st wid _) = do
+ let delWatcher wl = wl { wlList = filter ((/=wid) . wlID) $ wlList wl }
+ case stBacking st of
+ StorageDir { dirWatchers = mvar } -> modifyMVar_ mvar $ return . second delWatcher
+ StorageMemory { memWatchers = mvar } -> modifyMVar_ mvar $ return . delWatcher
+
+
+class Monad m => MonadStorage m where
+ getStorage :: m Storage
+ mstore :: Storable a => a -> m (Stored a)
+
+ default mstore :: MonadIO m => Storable a => a -> m (Stored a)
+ mstore x = do
+ st <- getStorage
+ wrappedStore st x
+
+instance MonadIO m => MonadStorage (ReaderT Storage m) where
+ getStorage = ask
+
+instance MonadIO m => MonadStorage (ReaderT (Head a) m) where
+ getStorage = asks $ headStorage
+
+
+class Storable a where
+ store' :: a -> Store
+ load' :: Load a
+
+ store :: StorageCompleteness c => Storage' c -> a -> IO (Ref' c)
+ store st = evalStore st . store'
+ load :: Ref -> a
+ load = evalLoad load'
+
+class Storable a => ZeroStorable a where
+ fromZero :: Storage -> a
+
+data Store = StoreBlob ByteString
+ | StoreRec (forall c. StorageCompleteness c => Storage' c -> [IO [(ByteString, RecItem' c)]])
+ | StoreZero
+
+evalStore :: StorageCompleteness c => Storage' c -> Store -> IO (Ref' c)
+evalStore st = unsafeStoreObject st <=< evalStoreObject st
+
+evalStoreObject :: StorageCompleteness c => Storage' c -> Store -> IO (Object' c)
+evalStoreObject _ (StoreBlob x) = return $ Blob x
+evalStoreObject s (StoreRec f) = Rec . concat <$> sequence (f s)
+evalStoreObject _ StoreZero = return ZeroObject
+
+newtype StoreRecM c a = StoreRecM (ReaderT (Storage' c) (Writer [IO [(ByteString, RecItem' c)]]) a)
+ deriving (Functor, Applicative, Monad)
+
+type StoreRec c = StoreRecM c ()
+
+newtype Load a = Load (ReaderT (Ref, Object) (Except String) a)
+ deriving (Functor, Applicative, Alternative, Monad, MonadPlus, MonadError String)
+
+evalLoad :: Load a -> Ref -> a
+evalLoad (Load f) ref = either (error {- TODO throw -} . ((BC.unpack (showRef ref) ++ ": ")++)) id $ runExcept $ runReaderT f (ref, lazyLoadObject ref)
+
+loadCurrentRef :: Load Ref
+loadCurrentRef = Load $ asks fst
+
+loadCurrentObject :: Load Object
+loadCurrentObject = Load $ asks snd
+
+newtype LoadRec a = LoadRec (ReaderT (Ref, [(ByteString, RecItem)]) (Except String) a)
+ deriving (Functor, Applicative, Alternative, Monad, MonadPlus, MonadError String)
+
+loadRecCurrentRef :: LoadRec Ref
+loadRecCurrentRef = LoadRec $ asks fst
+
+loadRecItems :: LoadRec [(ByteString, RecItem)]
+loadRecItems = LoadRec $ asks snd
+
+
+instance Storable Object where
+ store' (Blob bs) = StoreBlob bs
+ store' (Rec xs) = StoreRec $ \st -> return $ do
+ Rec xs' <- copyObject st (Rec xs)
+ return xs'
+ store' ZeroObject = StoreZero
+
+ load' = loadCurrentObject
+
+ store st = unsafeStoreObject st <=< copyObject st
+ load = lazyLoadObject
+
+instance Storable ByteString where
+ store' = storeBlob
+ load' = loadBlob id
+
+instance Storable a => Storable [a] where
+ store' [] = storeZero
+ store' (x:xs) = storeRec $ do
+ storeRef "i" x
+ storeRef "n" xs
+
+ load' = loadCurrentObject >>= \case
+ ZeroObject -> return []
+ _ -> loadRec $ (:)
+ <$> loadRef "i"
+ <*> loadRef "n"
+
+instance Storable a => ZeroStorable [a] where
+ fromZero _ = []
+
+
+storeBlob :: ByteString -> Store
+storeBlob = StoreBlob
+
+storeRec :: (forall c. StorageCompleteness c => StoreRec c) -> Store
+storeRec sr = StoreRec $ do
+ let StoreRecM r = sr
+ execWriter . runReaderT r
+
+storeZero :: Store
+storeZero = StoreZero
+
+
+class StorableText a where
+ toText :: a -> Text
+ fromText :: MonadError String m => Text -> m a
+
+instance StorableText Text where
+ toText = id; fromText = return
+
+instance StorableText [Char] where
+ toText = T.pack; fromText = return . T.unpack
+
+
+class StorableDate a where
+ toDate :: a -> ZonedTime
+ fromDate :: ZonedTime -> a
+
+instance StorableDate ZonedTime where
+ toDate = id; fromDate = id
+
+instance StorableDate UTCTime where
+ toDate = utcToZonedTime utc
+ fromDate = zonedTimeToUTC
+
+instance StorableDate Day where
+ toDate day = toDate $ UTCTime day 0
+ fromDate = utctDay . fromDate
+
+
+class StorableUUID a where
+ toUUID :: a -> UUID
+ fromUUID :: UUID -> a
+
+instance StorableUUID UUID where
+ toUUID = id; fromUUID = id
+
+
+storeEmpty :: String -> StoreRec c
+storeEmpty name = StoreRecM $ tell [return [(BC.pack name, RecEmpty)]]
+
+storeMbEmpty :: String -> Maybe () -> StoreRec c
+storeMbEmpty name = maybe (return ()) (const $ storeEmpty name)
+
+storeInt :: Integral a => String -> a -> StoreRec c
+storeInt name x = StoreRecM $ tell [return [(BC.pack name, RecInt $ toInteger x)]]
+
+storeMbInt :: Integral a => String -> Maybe a -> StoreRec c
+storeMbInt name = maybe (return ()) (storeInt name)
+
+storeNum :: (Real a, Fractional a) => String -> a -> StoreRec c
+storeNum name x = StoreRecM $ tell [return [(BC.pack name, RecNum $ toRational x)]]
+
+storeMbNum :: (Real a, Fractional a) => String -> Maybe a -> StoreRec c
+storeMbNum name = maybe (return ()) (storeNum name)
+
+storeText :: StorableText a => String -> a -> StoreRec c
+storeText name x = StoreRecM $ tell [return [(BC.pack name, RecText $ toText x)]]
+
+storeMbText :: StorableText a => String -> Maybe a -> StoreRec c
+storeMbText name = maybe (return ()) (storeText name)
+
+storeBinary :: BA.ByteArrayAccess a => String -> a -> StoreRec c
+storeBinary name x = StoreRecM $ tell [return [(BC.pack name, RecBinary $ BA.convert x)]]
+
+storeMbBinary :: BA.ByteArrayAccess a => String -> Maybe a -> StoreRec c
+storeMbBinary name = maybe (return ()) (storeBinary name)
+
+storeDate :: StorableDate a => String -> a -> StoreRec c
+storeDate name x = StoreRecM $ tell [return [(BC.pack name, RecDate $ toDate x)]]
+
+storeMbDate :: StorableDate a => String -> Maybe a -> StoreRec c
+storeMbDate name = maybe (return ()) (storeDate name)
+
+storeUUID :: StorableUUID a => String -> a -> StoreRec c
+storeUUID name x = StoreRecM $ tell [return [(BC.pack name, RecUUID $ toUUID x)]]
+
+storeMbUUID :: StorableUUID a => String -> Maybe a -> StoreRec c
+storeMbUUID name = maybe (return ()) (storeUUID name)
+
+storeRef :: Storable a => StorageCompleteness c => String -> a -> StoreRec c
+storeRef name x = StoreRecM $ do
+ s <- ask
+ tell $ (:[]) $ do
+ ref <- store s x
+ return [(BC.pack name, RecRef ref)]
+
+storeMbRef :: Storable a => StorageCompleteness c => String -> Maybe a -> StoreRec c
+storeMbRef name = maybe (return ()) (storeRef name)
+
+storeRawRef :: StorageCompleteness c => String -> Ref -> StoreRec c
+storeRawRef name ref = StoreRecM $ do
+ st <- ask
+ tell $ (:[]) $ do
+ ref' <- copyRef st ref
+ return [(BC.pack name, RecRef ref')]
+
+storeMbRawRef :: StorageCompleteness c => String -> Maybe Ref -> StoreRec c
+storeMbRawRef name = maybe (return ()) (storeRawRef name)
+
+storeZRef :: (ZeroStorable a, StorageCompleteness c) => String -> a -> StoreRec c
+storeZRef name x = StoreRecM $ do
+ s <- ask
+ tell $ (:[]) $ do
+ ref <- store s x
+ return $ if isZeroRef ref then []
+ else [(BC.pack name, RecRef ref)]
+
+
+loadBlob :: (ByteString -> a) -> Load a
+loadBlob f = loadCurrentObject >>= \case
+ Blob x -> return $ f x
+ _ -> throwError "Expecting blob"
+
+loadRec :: LoadRec a -> Load a
+loadRec (LoadRec lrec) = loadCurrentObject >>= \case
+ Rec rs -> do
+ ref <- loadCurrentRef
+ either throwError return $ runExcept $ runReaderT lrec (ref, rs)
+ _ -> throwError "Expecting record"
+
+loadZero :: a -> Load a
+loadZero x = loadCurrentObject >>= \case
+ ZeroObject -> return x
+ _ -> throwError "Expecting zero"
+
+
+loadEmpty :: String -> LoadRec ()
+loadEmpty name = maybe (throwError $ "Missing record item '"++name++"'") return =<< loadMbEmpty name
+
+loadMbEmpty :: String -> LoadRec (Maybe ())
+loadMbEmpty name = (lookup (BC.pack name) <$> loadRecItems) >>= \case
+ Nothing -> return Nothing
+ Just (RecEmpty) -> return (Just ())
+ Just _ -> throwError $ "Expecting type int of record item '"++name++"'"
+
+loadInt :: Num a => String -> LoadRec a
+loadInt name = maybe (throwError $ "Missing record item '"++name++"'") return =<< loadMbInt name
+
+loadMbInt :: Num a => String -> LoadRec (Maybe a)
+loadMbInt name = (lookup (BC.pack name) <$> loadRecItems) >>= \case
+ Nothing -> return Nothing
+ Just (RecInt x) -> return (Just $ fromInteger x)
+ Just _ -> throwError $ "Expecting type int of record item '"++name++"'"
+
+loadNum :: (Real a, Fractional a) => String -> LoadRec a
+loadNum name = maybe (throwError $ "Missing record item '"++name++"'") return =<< loadMbNum name
+
+loadMbNum :: (Real a, Fractional a) => String -> LoadRec (Maybe a)
+loadMbNum name = (lookup (BC.pack name) <$> loadRecItems) >>= \case
+ Nothing -> return Nothing
+ Just (RecNum x) -> return (Just $ fromRational x)
+ Just _ -> throwError $ "Expecting type number of record item '"++name++"'"
+
+loadText :: StorableText a => String -> LoadRec a
+loadText name = maybe (throwError $ "Missing record item '"++name++"'") return =<< loadMbText name
+
+loadMbText :: StorableText a => String -> LoadRec (Maybe a)
+loadMbText name = (lookup (BC.pack name) <$> loadRecItems) >>= \case
+ Nothing -> return Nothing
+ Just (RecText x) -> Just <$> fromText x
+ Just _ -> throwError $ "Expecting type text of record item '"++name++"'"
+
+loadTexts :: StorableText a => String -> LoadRec [a]
+loadTexts name = do
+ items <- map snd . filter ((BC.pack name ==) . fst) <$> loadRecItems
+ forM items $ \case RecText x -> fromText x
+ _ -> throwError $ "Expecting type text of record item '"++name++"'"
+
+loadBinary :: BA.ByteArray a => String -> LoadRec a
+loadBinary name = maybe (throwError $ "Missing record item '"++name++"'") return =<< loadMbBinary name
+
+loadMbBinary :: BA.ByteArray a => String -> LoadRec (Maybe a)
+loadMbBinary name = (lookup (BC.pack name) <$> loadRecItems) >>= \case
+ Nothing -> return Nothing
+ Just (RecBinary x) -> return $ Just $ BA.convert x
+ Just _ -> throwError $ "Expecting type binary of record item '"++name++"'"
+
+loadBinaries :: BA.ByteArray a => String -> LoadRec [a]
+loadBinaries name = do
+ items <- map snd . filter ((BC.pack name ==) . fst) <$> loadRecItems
+ forM items $ \case RecBinary x -> return $ BA.convert x
+ _ -> throwError $ "Expecting type binary of record item '"++name++"'"
+
+loadDate :: StorableDate a => String -> LoadRec a
+loadDate name = maybe (throwError $ "Missing record item '"++name++"'") return =<< loadMbDate name
+
+loadMbDate :: StorableDate a => String -> LoadRec (Maybe a)
+loadMbDate name = (lookup (BC.pack name) <$> loadRecItems) >>= \case
+ Nothing -> return Nothing
+ Just (RecDate x) -> return $ Just $ fromDate x
+ Just _ -> throwError $ "Expecting type date of record item '"++name++"'"
+
+loadUUID :: StorableUUID a => String -> LoadRec a
+loadUUID name = maybe (throwError $ "Missing record iteem '"++name++"'") return =<< loadMbUUID name
+
+loadMbUUID :: StorableUUID a => String -> LoadRec (Maybe a)
+loadMbUUID name = (lookup (BC.pack name) <$> loadRecItems) >>= \case
+ Nothing -> return Nothing
+ Just (RecUUID x) -> return $ Just $ fromUUID x
+ Just _ -> throwError $ "Expecting type UUID of record item '"++name++"'"
+
+loadRawRef :: String -> LoadRec Ref
+loadRawRef name = maybe (throwError $ "Missing record item '"++name++"'") return =<< loadMbRawRef name
+
+loadMbRawRef :: String -> LoadRec (Maybe Ref)
+loadMbRawRef name = (lookup (BC.pack name) <$> loadRecItems) >>= \case
+ Nothing -> return Nothing
+ Just (RecRef x) -> return (Just x)
+ Just _ -> throwError $ "Expecting type ref of record item '"++name++"'"
+
+loadRawRefs :: String -> LoadRec [Ref]
+loadRawRefs name = do
+ items <- map snd . filter ((BC.pack name ==) . fst) <$> loadRecItems
+ forM items $ \case RecRef x -> return x
+ _ -> throwError $ "Expecting type ref of record item '"++name++"'"
+
+loadRef :: Storable a => String -> LoadRec a
+loadRef name = load <$> loadRawRef name
+
+loadMbRef :: Storable a => String -> LoadRec (Maybe a)
+loadMbRef name = fmap load <$> loadMbRawRef name
+
+loadRefs :: Storable a => String -> LoadRec [a]
+loadRefs name = map load <$> loadRawRefs name
+
+loadZRef :: ZeroStorable a => String -> LoadRec a
+loadZRef name = loadMbRef name >>= \case
+ Nothing -> do Ref st _ <- loadRecCurrentRef
+ return $ fromZero st
+ Just x -> return x
+
+
+type Stored a = Stored' Complete a
+
+instance Storable a => Storable (Stored a) where
+ store st = copyRef st . storedRef
+ store' (Stored _ x) = store' x
+ load' = Stored <$> loadCurrentRef <*> load'
+
+instance ZeroStorable a => ZeroStorable (Stored a) where
+ fromZero st = Stored (zeroRef st) $ fromZero st
+
+fromStored :: Stored a -> a
+fromStored (Stored _ x) = x
+
+storedRef :: Stored a -> Ref
+storedRef (Stored ref _) = ref
+
+wrappedStore :: MonadIO m => Storable a => Storage -> a -> m (Stored a)
+wrappedStore st x = do ref <- liftIO $ store st x
+ return $ Stored ref x
+
+wrappedLoad :: Storable a => Ref -> Stored a
+wrappedLoad ref = Stored ref (load ref)
+
+copyStored :: forall c c' m a. (StorageCompleteness c, StorageCompleteness c', MonadIO m) =>
+ Storage' c' -> Stored' c a -> m (LoadResult c (Stored' c' a))
+copyStored st (Stored ref' x) = liftIO $ returnLoadResult . fmap (flip Stored x) <$> copyRef' st ref'
+
+-- |Passed function needs to preserve the object representation to be safe
+unsafeMapStored :: (a -> b) -> Stored a -> Stored b
+unsafeMapStored f (Stored ref x) = Stored ref (f x)
+
+
+data StoreInfo = StoreInfo
+ { infoDate :: ZonedTime
+ , infoNote :: Maybe Text
+ }
+ deriving (Show)
+
+makeStoreInfo :: IO StoreInfo
+makeStoreInfo = StoreInfo
+ <$> getZonedTime
+ <*> pure Nothing
+
+storeInfoRec :: StoreInfo -> StoreRec c
+storeInfoRec info = do
+ storeDate "date" $ infoDate info
+ storeMbText "note" $ infoNote info
+
+loadInfoRec :: LoadRec StoreInfo
+loadInfoRec = StoreInfo
+ <$> loadDate "date"
+ <*> loadMbText "note"
+
+
+data History a = History StoreInfo (Stored a) (Maybe (StoredHistory a))
+ deriving (Show)
+
+type StoredHistory a = Stored (History a)
+
+instance Storable a => Storable (History a) where
+ store' (History si x prev) = storeRec $ do
+ storeInfoRec si
+ storeMbRef "prev" prev
+ storeRef "item" x
+
+ load' = loadRec $ History
+ <$> loadInfoRec
+ <*> loadRef "item"
+ <*> loadMbRef "prev"
+
+fromHistory :: StoredHistory a -> a
+fromHistory = fromStored . storedFromHistory
+
+fromHistoryAt :: ZonedTime -> StoredHistory a -> Maybe a
+fromHistoryAt zat = fmap (fromStored . snd) . listToMaybe . dropWhile ((at<) . zonedTimeToUTC . fst) . storedHistoryTimedList
+ where at = zonedTimeToUTC zat
+
+storedFromHistory :: StoredHistory a -> Stored a
+storedFromHistory sh = let History _ item _ = fromStored sh
+ in item
+
+storedHistoryList :: StoredHistory a -> [Stored a]
+storedHistoryList = map snd . storedHistoryTimedList
+
+storedHistoryTimedList :: StoredHistory a -> [(ZonedTime, Stored a)]
+storedHistoryTimedList sh = let History hinfo item prev = fromStored sh
+ in (infoDate hinfo, item) : maybe [] storedHistoryTimedList prev
+
+beginHistory :: Storable a => Storage -> StoreInfo -> a -> IO (StoredHistory a)
+beginHistory st si x = do sx <- wrappedStore st x
+ wrappedStore st $ History si sx Nothing
+
+modifyHistory :: Storable a => StoreInfo -> (a -> a) -> StoredHistory a -> IO (StoredHistory a)
+modifyHistory si f prev@(Stored (Ref st _) _) = do
+ sx <- wrappedStore st $ f $ fromHistory prev
+ wrappedStore st $ History si sx (Just prev)
+
+
+showRatio :: Rational -> String
+showRatio r = case decimalRatio r of
+ Just (n, 1) -> show n
+ Just (n', d) -> let n = abs n'
+ in (if n' < 0 then "-" else "") ++ show (n `div` d) ++ "." ++
+ (concatMap (show.(`mod` 10).snd) $ reverse $ takeWhile ((>1).fst) $ zip (iterate (`div` 10) d) (iterate (`div` 10) (n `mod` d)))
+ Nothing -> show (numerator r) ++ "/" ++ show (denominator r)
+
+decimalRatio :: Rational -> Maybe (Integer, Integer)
+decimalRatio r = do
+ let n = numerator r
+ d = denominator r
+ (c2, d') = takeFactors 2 d
+ (c5, d'') = takeFactors 5 d'
+ guard $ d'' == 1
+ let m = if c2 > c5 then 5 ^ (c2 - c5)
+ else 2 ^ (c5 - c2)
+ return (n * m, d * m)
+
+takeFactors :: Integer -> Integer -> (Integer, Integer)
+takeFactors f n | n `mod` f == 0 = let (c, n') = takeFactors f (n `div` f)
+ in (c+1, n')
+ | otherwise = (0, n)
+
+parseRatio :: ByteString -> Maybe Rational
+parseRatio bs = case BC.groupBy ((==) `on` isNumber) bs of
+ (m:xs) | m == BC.pack "-" -> negate <$> positive xs
+ xs -> positive xs
+ where positive = \case
+ [bx] -> fromInteger . fst <$> BC.readInteger bx
+ [bx, op, by] -> do
+ (x, _) <- BC.readInteger bx
+ (y, _) <- BC.readInteger by
+ case BC.unpack op of
+ "." -> return $ (x % 1) + (y % (10 ^ BC.length by))
+ "/" -> return $ x % y
+ _ -> Nothing
+ _ -> Nothing
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-05 18:21:32 +0000