diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. 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If not, see . + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + Copyright (C) + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/avers.cabal b/avers.cabal new file mode 100644 --- /dev/null +++ b/avers.cabal @@ -0,0 +1,61 @@ +name: avers +version: 0.0.1 +license: GPL-3 +license-file: LICENSE +author: Tomas Carnecky +maintainer: tomas.carnecky@gmail.com +category: Avers +build-type: Simple +cabal-version: >= 1.10 + +synopsis: empty +description: empty + + +library + hs-source-dirs: src + default-language: Haskell2010 + + ghc-options: + -threaded -Wall + + + -- For the time being everything is exported. + exposed-modules: + Avers + , Avers.Metrics + , Avers.Patching + , Avers.Storage + , Avers.Storage.Backend + , Avers.Storage.Expressions + , Avers.TH + , Avers.Types + , Avers.Views + + + -- Standard dependencies, stuff that is or should be in the platform. + build-depends: + aeson + , attoparsec + , base <= 9999 + , bytestring + , containers + , mtl + , network + , stm + , template-haskell + , text + , time + , unordered-containers + , vector + + -- More exotic dependencies which people may not immediately recognize. + build-depends: + MonadRandom + , base16-bytestring + , cryptohash + , inflections + , influxdb + , resource-pool + , rethinkdb-client-driver >= 0.0.11 + , scrypt diff --git a/src/Avers.hs b/src/Avers.hs new file mode 100644 --- /dev/null +++ b/src/Avers.hs @@ -0,0 +1,107 @@ +{-# LANGUAGE NoImplicitPrelude #-} + +module Avers + ( + -- * The Avers Monad + Avers + , evalAvers + + -- * Types + , Path(..) + , Pk(..) + + , ObjId(..) + , rootObjId + + , RevId(..) + , zeroRevId + + , ObjectId(..) + , Operation(..) + + -- * Object + , Object(..) + , exists + , createObject + , lookupObject + , deleteObject + , pruneObject + , objectsOfType + , allObjectsOfType + + -- * Patch + , Patch(..) + , PatchError(..) + , lookupPatch + + -- * Snapshot + , Snapshot(..) + , lookupLatestSnapshot + , objectContent + + -- * Release + , Release(..) + , lookupRelease + , createRelease + , lookupLatestRelease + + -- * Patching + , resolvePathIn + + -- * Session + , SessionId(..) + , Session(..) + , saveSession + , lookupSession + , dropSession + + , ObjectType(..) + , SomeObjectType(..) + , lookupObjectType + + , AversError(..) + , AversConfig(..) + , AversState + , newState + , strErr + , parseValueAs + + -- * Blob + , BlobId(..) + , Blob(..) + , createBlob + , lookupBlob + + -- * Secret + , SecretId(..) + , Secret(..) + , updateSecret + , verifySecret + + , applyObjectUpdates + , runQuery + , runQueryCollect + , parseValue + , parseDatum + , newId + + , objectsTable + , blobsTable + + , validateObject + + -- * Views + , View(..) + , SomeView(..) + , viewTable + , updateView + + ) where + + + +import Avers.Patching +import Avers.Storage +import Avers.Storage.Backend +import Avers.Types +import Avers.Views diff --git a/src/Avers/Metrics.hs b/src/Avers/Metrics.hs new file mode 100644 --- /dev/null +++ b/src/Avers/Metrics.hs @@ -0,0 +1,39 @@ +{-# LANGUAGE TemplateHaskell #-} +{-# LANGUAGE OverloadedStrings #-} + +module Avers.Metrics where + +import Control.Concurrent +import Control.Monad.State + +import Data.Text (Text) + +import Network.BSD + +import Database.InfluxDB +import Database.InfluxDB.TH + +import Avers.Types + + +data Point = Point + { pointMachine :: String + , pointComponent :: Text + , pointValue :: Double + } + + +reportPoint :: Text -> Double -> Avers () +reportPoint series value = do + ac <- gets config + case influxConfig ac of + Nothing -> return () + Just cfg -> void $ liftIO $ forkIO $ do + h <- getHostName + postWithPrecision cfg "rmx" SecondsPrecision $ withSeries series $ do + writePoints $ Point h "api" value + + +deriveSeriesData defaultOptions + { fieldLabelModifier = stripPrefixLower "point" } + ''Point diff --git a/src/Avers/Patching.hs b/src/Avers/Patching.hs new file mode 100644 --- /dev/null +++ b/src/Avers/Patching.hs @@ -0,0 +1,223 @@ +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE RecordWildCards #-} + +module Avers.Patching + ( applyOperation + , opOT + , rebaseOperation + , resolvePathIn + ) where + + +import Data.Monoid + +import Data.Text (Text) +import qualified Data.Text as T + +import qualified Data.Vector as V +import qualified Data.HashMap.Strict as M + +import Data.Aeson +import Data.Aeson.Types + +import Avers.Types (Patch(..), Path(..), Operation(..), PatchM, PatchError(..)) + +import Control.Monad + + +-- | Apply the given op on the value. Can throw an exception if the operation +-- is invalid. +applyOperation :: Value -> Operation -> PatchM Value +applyOperation value Set{..} = changeObject value opPath $ \key -> + maybe (M.delete key) (M.insert key) opValue + +applyOperation value Splice{..} = changeArray value opPath $ \a -> do + + -- Check if the indices are within the allowed range. + when (V.length a < opIndex + opRemove) $ + Left $ UnknownPatchError $ mconcat + [ "Index out of range (" + , T.pack (show $ V.length a) + , "," + , T.pack (show opIndex) + , "," + , T.pack (show opRemove) + , ")" + ] + + -- The existing array and the elements we want to insert must match + -- structurally (have the same type). Furthermore, if the array consists + -- of objects, each object is required to have an "id" field. + unless (isStructurallyEquivalent opInsert a) $ + Left $ UnknownPatchError "Array doesn't match structure" + + return $ V.take opIndex a V.++ V.fromList opInsert V.++ V.drop (opIndex + opRemove) a + + where + isStructurallyEquivalent :: [Value] -> V.Vector Value -> Bool + isStructurallyEquivalent a b = strings a b || validObjects a b + + strings a b = all isString a && V.all isString b + validObjects a b = all hasObjectId a && V.all hasObjectId b + + +isString :: Value -> Bool +isString (String _) = True +isString _ = False + +hasObjectId :: Value -> Bool +hasObjectId (Object o) = M.member "id" o +hasObjectId _ = False + +pathElements :: Path -> [Text] +pathElements = T.split ('.' ==) . unPath + +changeObject :: Value -> Path -> (Text -> Object -> Object) -> PatchM Value +changeObject value path f = changeObjectAt value (init (pathElements path)) $ \x -> + case x of + Object o -> Right $ Object $ f (last (pathElements path)) o + _ -> Left $ UnknownPatchError "Can not change a non-object" + +changeArray :: Value -> Path -> (Array -> PatchM Array) -> PatchM Value +changeArray value path f = changeObjectAt value (pathElements path) $ \x -> + case x of + Array a -> fmap Array $ f a + _ -> Left $ UnknownPatchError "Can not change a non-array" + + +changeObjectAt :: Value -> [Text] -> (Value -> PatchM Value) -> PatchM Value +changeObjectAt container [] f = f container + +changeObjectAt (Object o) (x:xs) f = + case parse (const $ o .: x) o of + Error _ -> Left $ UnknownPatchError $ "Key '" <> T.pack (show x) <> "' does not exist inside the object" + Success a -> do + new <- changeObjectAt a xs f + return $ Object $ M.insert x new o + + +changeObjectAt (Array a) (x:xs) f = + case V.findIndex (matchObjectId x) a of + Nothing -> Left $ UnknownPatchError $ "Can not find item with id " <> T.pack (show x) <> " in the array" + Just index -> do + new <- changeObjectAt (a V.! index) xs f + return $ Array $ a V.// [(index, new)] + +changeObjectAt _ _ _ = Left $ UnknownPatchError "Can not descend into primitive values" + + +matchObjectId :: Text -> Value -> Bool +matchObjectId itemId (Object o) = Just (String itemId) == M.lookup "id" o +matchObjectId _ _ = False + + + +-- | Resolve the path in the object. +resolvePathIn :: Path -> Value -> Maybe Value +resolvePathIn path = go (pathElements path) + where + go [] value = Just value + go [""] value = Just value + + go (x:xs) (Object o) = + case parse (const $ o .: x) o of + Error _ -> Nothing + Success a -> go xs a + + go (x:xs) (Array a) = + maybe Nothing (go xs) $ V.find (matchObjectId x) a + + go _ _ = Nothing + + + +-- Set (foo) -> Set (foo) = ok +-- Set (foo) -> Set (foo.bar) = drop +-- Set (foo.bar) -> Set (foo) = ok +-- Set (foo) -> Set (bar) = ok +-- +-- Set (foo) -> Splice (foo) = drop +-- Set (foo) -> Splice (foo.bar) = drop +-- Set (foo.bar) -> Splice (foo) = ok +-- Set (foo) -> Splice (bar) = ok +-- +-- Splice (foo) -> Set (foo) = ok +-- Splice (foo) -> Set (foo.bar) = ok if foo.bar exists +-- Splice (foo.bar) -> Set (foo) = ok +-- Splice (foo) -> Set (bar) = ok +-- +-- Splice (foo) -> Splice (foo) = drop -- todo: ok (adjust) +-- Splice (foo) -> Splice (foo.bar) = ok if foo.bar exists +-- Splice (foo.bar) -> Splice (foo) = ok +-- Splice (foo) -> Splice (bar) = ok + +opOT :: Value -> Operation -> Operation -> Maybe Operation +opOT content base op + + -- Duplicate ops are dropped. + | base == op = Nothing + + -- If neither is a prefix of the other (they touch distinct parts of the + -- object) then it's safe to accept the op. + | not ((opPath base `isPrefixOf` opPath op) || (opPath op `isPrefixOf` opPath base)) = + Just op + + | otherwise = case base of + Set{..} -> setOT opPath + Splice{..} -> spliceOT opPath + + where + setOT path = case op of + Set{..} -- Set -> Set + | path == opPath -> Just op + | path `isPrefixOf` opPath -> Nothing + | otherwise -> Just op + + Splice{..} -- Set -> Splice + | path == opPath -> Nothing + | path `isPrefixOf` opPath -> Nothing + | otherwise -> Just op + + spliceOT path = case op of + Set{..} -- Splice -> Set + | path == opPath -> Just op + | path `isPrefixOf` opPath -> onlyIfPresent opPath + | otherwise -> Just op + + Splice{..} -- Splice -> Splice + | path == opPath -> spliceOnSplice base op + | path `isPrefixOf` opPath -> onlyIfPresent opPath + | otherwise -> Nothing + + onlyIfPresent path = case resolvePathIn path content of + Nothing -> Nothing + Just _ -> Just op + + (Path a) `isPrefixOf` (Path b) = a `T.isPrefixOf` b + + -- Both ops are 'Splice' on the same path. + spliceOnSplice op1 op2 + | opIndex op1 + opRemove op1 <= opIndex op2 + = Just $ op2 { opIndex = opIndex op2 + (length $ opInsert op1) - opRemove op2 } + + | opIndex op2 + opRemove op2 < opIndex op1 + = Just op2 + + | otherwise = Nothing + + + +-- | Given an 'Operation' which was created against a particular 'Value' +-- (content), rebase it on top of patches which were created against the very +-- same content in parallel. +-- +-- This function assumes that the patches apply cleanly to the content. +-- Failure to do so results in a fatal error. + +rebaseOperation :: Value -> Operation -> [Patch] -> Maybe Operation +rebaseOperation _ op [] = Just op +rebaseOperation content op (x:xs) = case applyOperation content (patchOperation x) of + Left e -> error $ "Unexpected failure: " ++ (show e) + Right newContent -> case opOT newContent (patchOperation x) op of + Nothing -> Nothing + Just op' -> rebaseOperation newContent op' xs diff --git a/src/Avers/Storage.hs b/src/Avers/Storage.hs new file mode 100644 --- /dev/null +++ b/src/Avers/Storage.hs @@ -0,0 +1,608 @@ +{-# LANGUAGE BangPatterns #-} +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TemplateHaskell #-} + +{-| + +This module abstracts the storage engine and provides functions to +manipulate objects stored in it. + +-} + +module Avers.Storage where + +import Control.Applicative +import Control.Concurrent.STM + +import Control.Monad.Random (getRandomR, evalRandIO) +import Control.Monad.State +import Control.Monad.Except + +import Data.Char +import Data.Monoid +import Data.Maybe +import qualified Data.ByteString.Lazy as BL +import qualified Data.ByteString.Base16 as BS16 + +import Data.Vector (Vector) +import qualified Data.Vector as V + +import Data.Text (Text) +import qualified Data.Text as T +import qualified Data.Text.Encoding as T + +import qualified Data.Map as M + +import Data.Time +import Data.List (find) +import Data.Aeson (Value) +import Data.Aeson.Types (emptyObject) + +import qualified Crypto.Hash.SHA3 as SHA3 + +import qualified Database.RethinkDB as R + +import Crypto.Scrypt + +import Avers.Metrics +import Avers.Types +import Avers.Patching +import Avers.TH +import Avers.Views + +import Avers.Storage.Backend +import Avers.Storage.Expressions + + +requireResult :: AversError -> Maybe a -> Avers a +requireResult err Nothing = throwError err +requireResult _ (Just v) = return v + + +-- All the tables which this storage engine uses. +objectsTable, sessionsTable, snapshotsTable, patchesTable, secretsTable, blobsTable :: R.Exp R.Table +blobsTable = R.Table Nothing $ R.lift ("blobs" :: Text) +objectsTable = R.Table Nothing $ R.lift ("objects" :: Text) +patchesTable = R.Table Nothing $ R.lift ("patches" :: Text) +secretsTable = R.Table Nothing $ R.lift ("secrets" :: Text) +sessionsTable = R.Table Nothing $ R.lift ("sessions" :: Text) +snapshotsTable = R.Table Nothing $ R.lift ("snapshots" :: Text) + + +trace :: String -> Avers a -> Avers a +trace label act = do + start <- liftIO $ getCurrentTime + ret <- act + end <- liftIO $ getCurrentTime + + reportPoint + ("avers.storage." <> (T.pack label) <> ".duration") + (realToFrac $ diffUTCTime end start) + + return ret + + +-- | True if the object exists. +exists :: ObjId -> Avers Bool +exists objId = trace "exists" $ + existsDocument objectsTable (BaseObjectId objId) + + +-- | Lookup an 'Object' by its 'ObjId'. Throws 'ObjectNotFound' if the object +-- doesn't exist. +lookupObject :: ObjId -> Avers Object +lookupObject objId = trace "lookupObject" $ do + mbObject <- lookupDocument objectsTable (BaseObjectId objId) + requireResult (ObjectNotFound objId) mbObject + + +-- | Create a new object of the given type. An initial snapshot ('RevId' 0) +-- is created from the supplied content. +createObject :: (ToJSON a) => ObjectType a -> ObjId -> a -> Avers ObjId +createObject ot@ObjectType{..} createdBy content = do + objId <- otId + now <- liftIO $ getCurrentTime + + let object = Object objId otType now createdBy Nothing + boId = BaseObjectId objId + snapshot = Snapshot boId zeroRevId (toJSON content) + + insertDocument objectsTable object + insertDocument snapshotsTable snapshot + + updateObjectViews ot objId (Just content) + + return objId + + +-- | Mark the object as deleted. +deleteObject :: ObjId -> Avers () +deleteObject objId = do + obj <- lookupObject objId + upsertDocument objectsTable (obj { objectDeleted = Just True }) + + SomeObjectType objType <- lookupObjectType (objectType obj) + updateObjectViews objType objId Nothing + + + +-- | Prune the object from the database. This is only allowed if the object is +-- marked as deleted. Note that this is a very dangerous operation, it can not +-- be undone. +pruneObject :: ObjId -> Avers () +pruneObject objId = do + obj <- lookupObject objId + SomeObjectType objType <- lookupObjectType (objectType obj) + + unless (objectDeleted obj == Just True) $ + strErr $ "pruneObject: object " ++ show objId ++ " is not deleted" + + -- Drop all related patches. Note that there will never be a patch with + -- revision zero, so it's safe to use 'patchesAfterRevision'. + patches <- patchesAfterRevision (BaseObjectId objId) zeroRevId + void $ mapM (deleteDocument patchesTable) patches + + -- Drop all related snapshots. + snapshotDatums <- runQueryCollect $ + R.BetweenIndexed + "objectSnapshotSequence" + ( R.Closed $ R.Array $ V.fromList [R.String $ toPk objId, R.Number $ fromIntegral (0 :: Int)] + , R.Open $ R.Array $ V.fromList [R.String $ toPk objId, R.Number $ fromIntegral (99999999 :: Int)] + ) + + snapshotsTable + snapshots <- V.mapM parseDatum snapshotDatums :: Avers (Vector Snapshot) + void $ V.mapM (deleteDocument snapshotsTable) snapshots + + -- Remove related entries from all views. + forM_ (otViews objType) $ \(SomeView view) -> do + deleteDocument (viewTable view) objId + + -- Drop the object itself. + void $ deleteDocument objectsTable objId + + + +----------------------------------------------------------------------------- +-- | Fetch the content of the object and try to parse it. +-- +-- This function will fail with a 'ParseError' if the content can not be +-- decoded into the desired type. + +objectContent :: (FromJSON a) => ObjectId -> Avers a +objectContent objId = do + Snapshot{..} <- lookupLatestSnapshot objId + parseValue snapshotContent + + + +----------------------------------------------------------------------------- +-- | Get the snapshot of the newest revision of the given object. + +lookupLatestSnapshot :: ObjectId -> Avers Snapshot +lookupLatestSnapshot objId = trace "lookupLatestSnapshot" $ do + snapshot <- newestSnapshot objId + patches <- patchesAfterRevision objId (snapshotRevisionId snapshot) + applyPatches snapshot patches + + +-- TODO: Verify that the patch is applicable to the snapshot, ie. +-- snapshot revId == patch revId + 1 +applyPatchToSnapshot :: Snapshot -> Patch -> Avers Snapshot +applyPatchToSnapshot snapshot@Snapshot{..} Patch{..} = + case applyOperation snapshotContent patchOperation of + Left e -> patchError e + Right v -> return $ snapshot { snapshotContent = v + , snapshotRevisionId = patchRevisionId + } + + +applyPatches :: Snapshot -> [Patch] -> Avers Snapshot +applyPatches snapshot patches = + foldM applyPatchToSnapshot snapshot patches + + +lookupRecentRevision :: ObjectId -> Avers (Maybe RevId) +lookupRecentRevision objId = do + m <- liftIO . atomically . readTVar =<< gets recentRevisionCache + return $ M.lookup objId m + +updateRecentRevision :: ObjectId -> RevId -> Avers () +updateRecentRevision objId revId = do + cache <- gets recentRevisionCache + liftIO $ atomically $ modifyTVar' cache $ + M.insertWith max objId revId + + + + +----------------------------------------------------------------------------- +-- | Get the newest snapshot which is stored in the database. The object may +-- be at a higher revision if the later snapshots are missing from the +-- database. +-- +-- This is an internal function. If you want the latest snapshot, you should +-- use 'lookupLatestSnapshot'. + +newestSnapshot :: ObjectId -> Avers Snapshot +newestSnapshot objId = trace "newestSnapshot" $ do + (RevId revId) <- fromMaybe zeroRevId <$> lookupRecentRevision objId + snapshot <- runQueryDatum $ headE $ + R.OrderByIndexed (R.Descending "objectSnapshotSequence") $ + R.BetweenIndexed "objectSnapshotSequence" ((lowerBound revId), upperBound) $ + snapshotsTable + + updateRecentRevision objId (snapshotRevisionId snapshot) + return snapshot + + where + lowerBound revId = R.Closed $ R.Array $ V.fromList [R.String $ toPk objId, R.Number $ fromIntegral revId] + upperBound = R.Open $ R.Array $ V.fromList [R.String $ toPk objId, R.Number $ fromIntegral (99999999 :: Int)] + + + +lookupSnapshot :: ObjectId -> RevId -> Avers Snapshot +lookupSnapshot objId (RevId revId) = trace "lookupSnapshot" $ do + snapshot <- runQueryDatum $ headE $ + R.OrderByIndexed (R.Descending "objectSnapshotSequence") $ + R.BetweenIndexed "objectSnapshotSequence" (lowerBound, upperBound) $ + snapshotsTable + + -- Get all patches which we need to apply on top of the snapshot to + -- arrive at the desired revision. + patches0 <- patchesAfterRevision objId (snapshotRevisionId snapshot) + let patches = filter (\Patch{..} -> patchRevisionId <= RevId revId) patches0 + + foldM applyPatchToSnapshot snapshot patches + + where + lowerBound = R.Closed $ R.Array $ V.fromList [R.String $ toPk objId, R.Number 0] + upperBound = R.Closed $ R.Array $ V.fromList [R.String $ toPk objId, R.Number $ fromIntegral revId] + + + +savePatch :: Patch -> Avers () +savePatch = insertDocument patchesTable + +saveSnapshot :: Snapshot -> Avers () +saveSnapshot = insertDocument snapshotsTable + + + +----------------------------------------------------------------------------- +-- Update the secret value. If a secret with the given 'SecretId' does not +-- exist yet, one will be created (IOW this function has upsert semantics). + +updateSecret :: SecretId -> Text -> Avers () +updateSecret secId secret = do + ep <- liftIO $ encryptPassIO defaultParams (Pass $ T.encodeUtf8 secret) + saveSecretValue secId ep + + + +----------------------------------------------------------------------------- +-- | Verify the value against the secret. If that fails, then this function +-- throws an error. +-- +-- This function automatically updates the secret in the database if the +-- scrypt params have changed. + +verifySecret :: SecretId -> Text -> Avers () +verifySecret secId secret = do + Secret{..} <- requireResult (DocumentNotFound $ toPk secId) =<< + lookupDocument secretsTable secId + + let ep = EncryptedPass $ T.encodeUtf8 secretValue + let (ok, new) = verifyPass defaultParams (Pass $ T.encodeUtf8 secret) ep + + -- If the secret doens't match, return NotFound + when (not ok) $ strErr $ "Not Found" + + -- Update the database if we got a new value from the verify step. This + -- is the case when the scrypt params have changed. See documentation of + -- 'verifyPass'. + maybe (return ()) (saveSecretValue secId) new + + + +----------------------------------------------------------------------------- +-- | Internal function which actually saves a secret in the database. + +saveSecretValue :: SecretId -> EncryptedPass -> Avers () +saveSecretValue secId (EncryptedPass x) = do + upsertDocument secretsTable $ Secret secId $ T.decodeUtf8 x + + + + +patchesAfterRevision :: ObjectId -> RevId -> Avers [Patch] +patchesAfterRevision objId (RevId revId) = trace "patchesAfterRevision" $ do + res <- runQuery $ + R.OrderBy [R.Ascending "revisionId"] $ + R.BetweenIndexed "objectPatchSequence" (lowerBound, upperBound) $ + patchesTable + + V.toList <$> V.mapM parseDatum res + + where + lowerBound = R.Open $ R.Array $ V.fromList [R.String $ toPk objId, R.Number $ fromIntegral revId] + upperBound = R.Open $ R.Array $ V.fromList [R.String $ toPk objId, R.Number $ fromIntegral (revId + 999999)] + + +lookupPatch :: ObjectId -> RevId -> Avers Patch +lookupPatch objId revId = trace "lookupPatch" $ do + runQuerySingleSelection $ R.Get patchesTable $ R.lift $ + toPk objId <> "@" <> toPk revId + + + +-- | Lookup an object type which is registered in the Avers monad. +lookupObjectType :: Text -> Avers SomeObjectType +lookupObjectType objType = do + types <- objectTypes <$> gets config + case find (\(SomeObjectType ObjectType{..}) -> otType == objType) types of + Nothing -> throwError $ UnknownObjectType objType + Just x -> return x + + + +applyObjectUpdates + :: ObjectId -- ^ The object which you want to update + -> RevId -- ^ The 'RevId' against which the operations were created + -> ObjId -- ^ Committer + -> [Operation] -- ^ The operations to apply + -> Bool -- ^ True if validation should be skipped + -> Avers ([Patch], Int, [Patch]) + +applyObjectUpdates objId revId committerId ops novalidate = trace "applyObjectUpdates" $ do + -- First check that the object exists. We'll need its metadata later. + obj <- lookupObject baseObjId + SomeObjectType ot <- lookupObjectType (objectType obj) + + -- The 'Snapshot' against which the submitted operations were created. + baseSnapshot <- lookupSnapshot objId revId + + -- If there are any patches which the client doesn't know about we need + -- to let her know. + previousPatches <- patchesAfterRevision objId revId + + latestSnapshot <- applyPatches baseSnapshot previousPatches + + -- Apply the operations and get the final snapshot. + (Snapshot{..}, PatchState{..}) <- runStateT (patchHandler novalidate) $ + PatchState ot objId revId committerId ops 0 + baseSnapshot latestSnapshot previousPatches [] + + -- Update object views. + unless novalidate $ do + content <- parseValue snapshotContent + updateObjectViews ot baseObjId (Just content) + + return (previousPatches, psNumConsumedOperations, psPatches) + + where + baseObjId = objectIdBase objId + + + +data PatchState a = PatchState + { psObjectType :: ObjectType a + , psObjectId :: ObjectId + , psRevisionId :: RevId + , psCommitterId :: ObjId + , psOperations :: [ Operation ] + , psNumConsumedOperations :: Int + , psBaseSnapshot :: Snapshot + , psLatestSnapshot :: Snapshot + , psPreviousPatches :: [ Patch ] + , psPatches :: [ Patch ] + } + + +type AversPatch a b = StateT (PatchState a) Avers b + + +patchHandler :: (FromJSON a) => Bool -> AversPatch a Snapshot +patchHandler novalidate = do + PatchState{..} <- get + foldM (saveOperation $ snapshotContent psBaseSnapshot) + psLatestSnapshot psOperations + + where + + saveOperation baseContent snapshot@Snapshot{..} op = do + PatchState{..} <- get + + case rebaseOperation baseContent op psPreviousPatches of + Nothing -> return snapshot + Just op' -> do + now <- liftIO $ getCurrentTime + + let revId = succ snapshotRevisionId + patch = Patch psObjectId revId psCommitterId now op' + + case applyOperation snapshotContent op' of + Left e -> error $ "Failure: " ++ (show e) + Right newContent + | newContent /= snapshotContent -> do + unless novalidate $ do + lift $ validateWithType psObjectType newContent + + let newSnapshot = snapshot { snapshotContent = newContent + , snapshotRevisionId = revId + } + + -- Now we know that the patch can be applied cleanly, so + -- we can save it in the database. + lift $ savePatch patch + + modify $ \s -> s + { psPatches = psPatches ++ [patch] + , psNumConsumedOperations = psNumConsumedOperations + 1 + } + + lift $ saveSnapshot newSnapshot + return newSnapshot + | otherwise -> return snapshot + + +existsBlob :: BlobId -> Avers Bool +existsBlob = existsDocument blobsTable + +lookupBlob :: BlobId -> Avers Blob +lookupBlob bId = lookupDocument blobsTable bId >>= + requireResult (DocumentNotFound $ toPk bId) + +insertBlob :: Blob -> Avers () +insertBlob = insertDocument blobsTable + +saveBlobContent :: Blob -> BL.ByteString -> Avers () +saveBlobContent Blob{..} content = do + cfg <- gets config + liftIO $ (putBlob cfg) blobId blobContentType content + + +saveSession :: Session -> Avers () +saveSession = insertDocument sessionsTable + +lookupSession :: SessionId -> Avers Session +lookupSession sessId = lookupDocument sessionsTable sessId >>= + requireResult (DocumentNotFound $ toPk sessId) + +dropSession :: SessionId -> Avers () +dropSession sessId = void $ deleteDocument sessionsTable sessId + + + +newId :: Int -> IO Text +newId n = T.pack <$> take n <$> randomAlphanumericSequence + where + randomAlphanumericSequence :: IO String + randomAlphanumericSequence = map alnum <$> + evalRandIO (sequence $ repeat $ getRandomR (0, 61)) + + alnum :: Int -> Char + alnum x + | x < 26 = chr ((x ) + 65) + | x < 52 = chr ((x - 26) + 97) + | x < 62 = chr ((x - 52) + 48) + | otherwise = error $ "Out of range: " ++ show x + + +validateObject :: Text -> Value -> Avers () +validateObject objType value = do + (SomeObjectType ot) <- lookupObjectType objType + validateWithType ot value + +validateWithType :: (FromJSON a) => ObjectType a -> Value -> Avers () +validateWithType ot value = case parseValueAs ot value of + Left e -> throwError e + Right _ -> return () + + +lookupRelease :: ObjId -> RevId -> Avers Release +lookupRelease objId revId = objectContent (ReleaseObjectId objId revId) + + +-- | Create a new release of the given revision. If the object doesn't exist, +-- it will fail with 'ObjectNotFound'. +createRelease :: ObjId -> RevId -> Avers () +createRelease objId revId = do + -- The object must exist. + objectExists <- exists objId + unless objectExists $ throwError (ObjectNotFound objId) + + -- The release objects are not patchable at the moment. If one already + -- exists, then there is nothing to do. Otherwise create the initial + -- snapshot with empty content. + exists' <- existsDocument snapshotsTable (toPk snapshot) + unless exists' $ insertDocument snapshotsTable snapshot + + where + objectId = ReleaseObjectId objId revId + snapshot = Snapshot objectId zeroRevId emptyObject + + +lookupLatestRelease :: ObjId -> Avers (Maybe RevId) +lookupLatestRelease objId = do + let match = R.lift $ "^" <> toPk objId <> "/release/" + + predicate :: R.Exp R.Object -> R.Exp Bool + predicate x = R.Coerce + (R.Match (objectFieldE "objectId" x) match) + (R.lift ("bool"::Text)) + + oId <- runQueryDatum $ + (objectFieldE "objectId" :: R.Exp R.Object -> R.Exp R.Datum) $ + headE $ + R.OrderBy [R.Descending "objectId"] $ + R.Filter predicate snapshotsTable + + case oId of + ReleaseObjectId objId1 revId -> do + when (objId /= objId1) $ databaseError "lookupLatestRelease: objId do not match" + return $ Just revId + + _ -> return Nothing + + + +------------------------------------------------------------------------- +-- Blobs +------------------------------------------------------------------------- + +createBlob :: BL.ByteString -> Text -> Avers Blob +createBlob body contentType = do + -- Only create the blob if it doesn't already exist. That way we can + -- avoid having to upload the blob to the storage. + ex <- existsBlob (blobId blob) + unless ex $ do + saveBlobContent blob body + insertBlob blob + + return blob + + where + size = fromIntegral $ BL.length body + hash = BS16.encode $ SHA3.hashlazy 256 body + blob = Blob (BlobId $ T.decodeUtf8 hash) size contentType + + +objectsOfType :: ObjectType a -> Avers (Vector ObjId) +objectsOfType objType = do + let predicate :: R.Exp R.Object -> R.Exp Bool + predicate = objectFieldEqE "type" (otType objType) + + res <- runQueryCollect $ + R.Map mapId $ + R.OrderBy [R.Descending "createdAt", R.Ascending "id"] $ + R.Filter isNotDeleted $ + R.Filter predicate objectsTable + + return $ V.map ObjId res + + +allObjectsOfType :: ObjectType a -> Avers (Vector ObjId) +allObjectsOfType objType = do + let predicate :: R.Exp R.Object -> R.Exp Bool + predicate = objectFieldEqE "type" (otType objType) + + res <- runQueryCollect $ + R.Map mapId $ + R.OrderBy [R.Descending "createdAt", R.Ascending "id"] $ + R.Filter predicate objectsTable + + return $ V.map ObjId res + + +isNotDeleted :: R.Exp R.Object -> R.Exp Bool +isNotDeleted x = R.Any + [ R.Not $ R.HasFields ["deleted"] x + , objectFieldEqE "deleted" False x + ] + +mapId:: R.Exp R.Object -> R.Exp Text +mapId = R.GetField "id" diff --git a/src/Avers/Storage/Backend.hs b/src/Avers/Storage/Backend.hs new file mode 100644 --- /dev/null +++ b/src/Avers/Storage/Backend.hs @@ -0,0 +1,159 @@ +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE TemplateHaskell #-} +{-# LANGUAGE TypeFamilies #-} + + +{-| + +Low-level implementation of the storage backend. + +-} + +module Avers.Storage.Backend + ( parseValue + , parseDatum + + , runQuery + , runQueryDatum + , runQuerySingleSelection + , runQueryCollect + + , existsDocument + , lookupDocument + , insertDocument + , upsertDocument + , deleteDocument + ) where + + +import Prelude hiding (lookup) + +import Control.Monad.Except +import Control.Monad.State + +import Data.Monoid +import Data.Aeson (Value, Result(..)) +import Data.Aeson.Types (parse, parseEither) +import Data.Pool +import qualified Data.Text as T +import qualified Data.HashMap.Strict as HMS +import qualified Data.Vector as V + +import qualified Database.RethinkDB as R +import Database.RethinkDB.TH + +import Avers.TH +import Avers.Types +import Avers.Storage.Expressions + + + +parseValue :: (FromJSON a, MonadError AversError m) => Value -> m a +parseValue value = case parseEither parseJSON value of + Left e -> parseError value (T.pack e) + Right x -> return x + + +parseDatum :: (R.FromDatum a, MonadError AversError m) => R.Datum -> m a +parseDatum datum = case parse R.parseDatum datum of + Error e -> parseError (toJSON datum) (T.pack e) + Success x -> return x + + + +data WriteResponse = WriteResponse + { writeResponseInserted :: Int + , writeResponseDeleted :: Int + , writeResponseReplaced :: Int + , writeResponseUnchanged :: Int + , writeResponseSkipped :: Int + , writeResponseErrors :: Int + } deriving (Show) + + +checkWriteResponse :: Maybe R.Datum -> Avers () +checkWriteResponse resp = do + case resp of + Nothing -> strErr "Error" + Just x -> + case parseEither R.parseDatum x of + Left err -> strErr err + Right WriteResponse{..} -> + if writeResponseErrors == 0 + then return () + else databaseError $ "Errors during write operation: " <> T.pack (show resp) + +mergePk :: (R.ToDatum a, Pk a) => a -> R.Object +mergePk doc = HMS.insert primaryKeyField (R.String $ toPk doc) hms + where (R.Object hms) = R.toDatum doc + + +runQuerySingleSelection :: (R.FromDatum a) => R.Exp R.SingleSelection -> Avers a +runQuerySingleSelection query = do + res <- runQuery query + case res of + Nothing -> documentNotFound "..." + Just x -> parseDatum x + +runQueryDatum :: (R.FromDatum a) => R.Exp R.Datum -> Avers a +runQueryDatum query = do + res <- runQuery query + parseDatum res + +runQuery :: (R.FromResponse (R.Result a)) => R.Exp a -> Avers (R.Result a) +runQuery query = do + pool <- gets databaseHandlePool + res <- liftIO $ withResource pool $ \handle -> do + R.run handle query + + case res of + Left e -> databaseError (T.pack $ show e) + Right r -> return r + +runQueryCollect :: (R.FromDatum a, R.IsSequence e, R.Result e ~ R.Sequence a) => R.Exp e -> Avers (V.Vector a) +runQueryCollect query = do + pool <- gets databaseHandlePool + res <- liftIO $ withResource pool $ \handle -> do + r0 <- R.run handle query + case r0 of + Left e -> return $ Left e + Right x -> R.collect handle x + + case res of + Left e -> databaseError (T.pack $ show e) + Right r -> return r + + + +existsDocument :: (Pk k) => R.Exp R.Table -> k -> Avers Bool +existsDocument table key = do + res <- runQuery $ R.IsEmpty $ R.Filter (primaryKeyEqE (toPk key)) table + return $ not res + + +lookupDocument :: (Pk k, R.FromDatum a) => R.Exp R.Table -> k -> Avers (Maybe a) +lookupDocument table key = do + res <- runQuery $ R.Get table (R.lift (toPk key)) + maybe (return Nothing) parseDatum res + + +insertDocument :: (R.ToDatum a, Pk a) => R.Exp R.Table -> a -> Avers () +insertDocument table doc = do + resp <- runQuery $ R.InsertObject R.CRError table (mergePk doc) + checkWriteResponse $ Just $ R.Object resp + + +deleteDocument :: (Pk k) => R.Exp R.Table -> k -> Avers () +deleteDocument table key = do + resp <- runQuery $ R.Delete $ R.Get table (R.lift $ toPk key) + checkWriteResponse $ Just $ R.Object resp + + +upsertDocument :: (R.ToDatum a, Pk a) => R.Exp R.Table -> a -> Avers () +upsertDocument table doc = do + resp <- runQuery $ R.InsertObject R.CRReplace table (mergePk doc) + checkWriteResponse $ Just $ R.Object resp + +$(deriveDatum (deriveJSONOptions "writeResponse") ''WriteResponse) diff --git a/src/Avers/Storage/Expressions.hs b/src/Avers/Storage/Expressions.hs new file mode 100644 --- /dev/null +++ b/src/Avers/Storage/Expressions.hs @@ -0,0 +1,52 @@ +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE TemplateHaskell #-} +{-# LANGUAGE TypeFamilies #-} + + +{-| + +This module contains RethinkDB Expressions which are used to build queries. + +-} + +module Avers.Storage.Expressions where + + +import Prelude hiding (lookup) + +import Data.Text (Text) +import Database.RethinkDB as R + + +-- | The primary key in all our documents is the default "id". +primaryKeyField :: Text +primaryKeyField = "id" + + +-- | Expression which represents the primary key field. +primaryKeyFieldE :: Exp Text +primaryKeyFieldE = lift primaryKeyField + + +-- | Expression which represents the value of a field inside of an Object. +objectFieldE :: (IsDatum a) => Text -> Exp Object -> Exp a +objectFieldE field obj = GetField (lift field) obj + + +-- | True if the object field matches the given value. +objectFieldEqE :: (ToDatum a) => Text -> a -> Exp Object -> Exp Bool +objectFieldEqE field value obj = Eq + (objectFieldE field obj :: Exp Datum) + (lift $ toDatum value) + + +-- | True if the object's primary key matches the given string. +primaryKeyEqE :: Text -> Exp Object -> Exp Bool +primaryKeyEqE = objectFieldEqE primaryKeyField + + +-- | Take the first item out of a sequence. +headE :: (IsSequence a, IsDatum r) => Exp a -> Exp r +headE = Nth 0 diff --git a/src/Avers/TH.hs b/src/Avers/TH.hs new file mode 100644 --- /dev/null +++ b/src/Avers/TH.hs @@ -0,0 +1,234 @@ +{-# LANGUAGE TemplateHaskell #-} + +module Avers.TH + ( deriveJSON + , deriveJSONOptions + , variantOptions + , defaultVariantOptions + + , deriveEncoding + , deriveRecordEncoding + + , FromJSON(..) + , ToJSON(..) + ) where + + +import Language.Haskell.TH + +import Control.Applicative +import Control.Monad + +import Data.Char + +import qualified Data.HashMap.Strict as HM +import qualified Data.Text as T + +import Data.Aeson +import Data.Aeson.TH +import qualified Data.Aeson.Types as A + +import Text.Inflections + +import qualified Database.RethinkDB as R +import Database.RethinkDB (toDatum, FromDatum(..)) +import Database.RethinkDB.TH + + + +dropPrefix :: String -> String -> String +dropPrefix prefix x = toLower (head rest) : tail rest + where rest = drop (length prefix) x + + +-- FIXME: Should dasherize and drop the prefix from the constructor as well! +deriveJSONOptions :: String -> Options +deriveJSONOptions prefix = defaultOptions + { fieldLabelModifier = dropPrefix prefix + , constructorTagModifier = map toLower + } + +dasherizeTag :: String -> String +dasherizeTag x = case parseCamelCase [] x of + Left err -> error $ show err + Right res -> map toLower $ dasherize res + +variantOptions :: String -> String -> String -> Options +variantOptions tagField contentsField prefix = defaultOptions + { constructorTagModifier = dasherizeTag . dropPrefix prefix + , sumEncoding = TaggedObject tagField contentsField + } + +defaultVariantOptions :: String -> Options +defaultVariantOptions = variantOptions "type" "content" + + +deriveEncoding :: Options -> Name -> Q [Dec] +deriveEncoding opts name = + liftM2 (++) + (deriveJSON opts name) + (deriveDatum opts name) + + +deriveEncodingWithDefaults :: Options -> Name -> [(String, Q Exp)] -> Q [Dec] +deriveEncodingWithDefaults options typeN defaults = + liftM2 (++) + (deriveJSONWithDefaults options typeN defaults) + (deriveDatumWithDefaults options typeN defaults) + + +deriveRecordEncoding :: Name -> String -> [(String, Q Exp)] -> Q [Dec] +deriveRecordEncoding typeN prefix defaults = + deriveEncodingWithDefaults (deriveJSONOptions prefix) typeN defaults + + + +------------------------------------------------------------------------------ +-- JSON + +deriveJSONWithDefaults :: Options -> Name -> [(String, Q Exp)] -> Q [Dec] +deriveJSONWithDefaults options typeN defaults = liftM2 (++) + (deriveToJSON options typeN) + (deriveFromJSONWithDefaults options typeN defaults) + +deriveFromJSONWithDefaults :: Options -> Name -> [(String, Q Exp)] -> Q [Dec] +deriveFromJSONWithDefaults options typeN defaults = do + xN <- newName "x" + (tyVarsBndrs, fieldNames) <- getTyInfo typeN + parseJsonE <- mkParseJSON options typeN + insertDefaultsE <- mkInsertDefaults defaults + modifyObjectE <- [|modifyObject|] + let tyVars = tyVarBndrNames tyVarsBndrs + fieldNames' = map (fieldLabelModifier options . nameBase) fieldNames + + forM_ defaults $ \(name, _) -> + when (name `notElem` fieldNames') $ fail $ + "Avers.TH.deriveFromJSONWithDefaults: default " ++ + "specified for " ++ show name ++ " but this field does not exist." + + return + [ InstanceD [ClassP ''FromJSON [VarT tv] | tv <- tyVars] + (AppT fromJsonT (mkAppTys (typeT : map VarT tyVars))) + [ FunD 'parseJSON + [ Clause [VarP xN] + (NormalB (AppE parseJsonE (mkApps + [modifyObjectE, insertDefaultsE, VarE xN]))) + [] + ] + ] + ] + where + typeT = ConT typeN + fromJsonT = ConT ''FromJSON + +modifyObject :: (A.Object -> A.Object) -> A.Value -> A.Value +modifyObject f (A.Object o) = A.Object (f o) +modifyObject _ v = v +{-# INLINE modifyObject #-} + +mkInsertDefaults :: [(String, Q Exp)] -> Q Exp +mkInsertDefaults defaults = do + yN <- newName "y" + bodyE <- foldM insertDefault (VarE yN) defaults + return $ LamE [VarP yN] bodyE + where + flipE = VarE 'flip + constE = VarE 'const + insertWithE = VarE 'HM.insertWith + toJsonE = VarE 'toJSON + + insertDefault hmE (field, expQ) = do + textE <- [|T.pack field|] + defaultE <- expQ + return $ mkApps [insertWithE, AppE flipE constE, + textE, AppE toJsonE defaultE, hmE] + + +------------------------------------------------------------------------------ +-- Datum + +deriveDatumWithDefaults :: Options -> Name -> [(String, Q Exp)] -> Q [Dec] +deriveDatumWithDefaults options typeN defaults = liftM2 (++) + (deriveToDatum options typeN) + (deriveFromDatumWithDefaults options typeN defaults) + +deriveFromDatumWithDefaults :: Options -> Name -> [(String, Q Exp)] -> Q [Dec] +deriveFromDatumWithDefaults options typeN defaults = do + xN <- newName "x" + (tyVarsBndrs, fieldNames) <- getTyInfo typeN + parseJsonE <- mkParseDatum options typeN + insertDefaultsE <- mkInsertDatumDefaults defaults + modifyObjectE <- [|modifyDatumObject|] + let tyVars = tyVarBndrNames tyVarsBndrs + fieldNames' = map (fieldLabelModifier options . nameBase) fieldNames + + forM_ defaults $ \(name, _) -> + when (name `notElem` fieldNames') $ fail $ + "Avers.TH.deriveFromDatumWithDefaults: default " ++ + "specified for " ++ show name ++ " but this field does not exist." + + return + [ InstanceD [ClassP ''FromDatum [VarT tv] | tv <- tyVars] + (AppT fromDatumT (mkAppTys (typeT : map VarT tyVars))) + [ FunD 'parseDatum + [ Clause [VarP xN] + (NormalB (AppE parseJsonE (mkApps + [modifyObjectE, insertDefaultsE, VarE xN]))) + [] + ] + ] + ] + where + typeT = ConT typeN + fromDatumT = ConT ''FromDatum + +modifyDatumObject :: (R.Object -> R.Object) -> R.Datum -> R.Datum +modifyDatumObject f (R.Object o) = R.Object (f o) +modifyDatumObject _ v = v +{-# INLINE modifyDatumObject #-} + +mkInsertDatumDefaults :: [(String, Q Exp)] -> Q Exp +mkInsertDatumDefaults defaults = do + yN <- newName "y" + bodyE <- foldM insertDefault (VarE yN) defaults + return $ LamE [VarP yN] bodyE + where + flipE = VarE 'flip + constE = VarE 'const + insertWithE = VarE 'HM.insertWith + toJsonE = VarE 'toDatum + + insertDefault hmE (field, expQ) = do + textE <- [|T.pack field|] + defaultE <- expQ + return $ mkApps [insertWithE, AppE flipE constE, + textE, AppE toJsonE defaultE, hmE] + + + +mkApps :: [Exp] -> Exp +mkApps = foldl1 AppE + +mkAppTys :: [Type] -> Type +mkAppTys = foldl1 AppT + +getTyInfo :: Name -> Q ([TyVarBndr], [Name]) +getTyInfo typeN = do + info <- reify typeN + case info of + TyConI (DataD _ _ tvbs cons _) -> pure (tvbs, getFieldNames =<< cons) + TyConI (NewtypeD _ _ tvbs con _) -> pure (tvbs, getFieldNames con) + _ -> fail $ + "Avers.TH.getTyInfo: only simple data/newtype " ++ + "constructors are supported." + +tyVarBndrNames :: [TyVarBndr] -> [Name] +tyVarBndrNames = map $ \tvb -> case tvb of + PlainTV n -> n + KindedTV n _ -> n + +getFieldNames :: Con -> [Name] +getFieldNames (NormalC _ _) = [] +getFieldNames (InfixC _ _ _) = [] +getFieldNames (ForallC _ _ con) = getFieldNames con +getFieldNames (RecC _ fields) = [name | (name, _, _) <- fields] diff --git a/src/Avers/Types.hs b/src/Avers/Types.hs new file mode 100644 --- /dev/null +++ b/src/Avers/Types.hs @@ -0,0 +1,604 @@ +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE GeneralizedNewtypeDeriving #-} +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE TemplateHaskell #-} + +module Avers.Types where + +import Control.Applicative + +import Control.Monad.Except +import Control.Monad.State + +import Control.Concurrent.STM + +import Data.Time.Clock +import Data.String +import Data.ByteString.Lazy (ByteString) + +import Data.Text (Text) +import qualified Data.Text as T + +import Data.Map (Map) +import qualified Data.Map as M + +import Data.Monoid +import Data.Char + +import Data.Attoparsec.Text + +import qualified Data.Aeson as Aeson +import qualified Data.Aeson.Types as Aeson +import Data.Aeson (Value(String)) +import Data.Aeson.Types (parseEither) + +import qualified Database.RethinkDB as R +import Database.RethinkDB.TH + +import qualified Database.InfluxDB as InfluxDB + +import Data.Pool + +import Avers.TH +import Avers.Index + + + +----------------------------------------------------------------------------- +-- | Pk - Types which can be converted to a database primary key. + +class Pk a where + toPk :: a -> Text + +instance Pk Text where + toPk = id + + + +----------------------------------------------------------------------------- +-- | Path + +newtype Path = Path { unPath :: Text } + deriving (Eq, Ord, Show) + +instance IsString Path where + fromString = Path . T.pack + +instance ToJSON Path where + toJSON = toJSON . unPath + +instance FromJSON Path where + parseJSON (String s) = return $ Path s + parseJSON _ = fail "Path" + +instance R.FromDatum Path where + parseDatum (R.String s) = return $ Path s + parseDatum _ = fail "Path" + +instance R.ToDatum Path where + toDatum = R.toDatum . unPath + + + +----------------------------------------------------------------------------- +-- | ObjId + +newtype ObjId = ObjId { unObjId :: Text } + deriving (Eq, Ord, Show) + +instance Pk ObjId where + toPk = unObjId + +instance ToJSON ObjId where + toJSON = toJSON . unObjId + +instance FromJSON ObjId where + parseJSON x = ObjId <$> parseJSON x + +instance R.FromDatum ObjId where + parseDatum x = ObjId <$> R.parseDatum x + +instance R.ToDatum ObjId where + toDatum = R.toDatum . unObjId + + +-- | The root object id is used for object created internally or when there +-- is no applicable creator. +rootObjId :: ObjId +rootObjId = ObjId "" + + + +----------------------------------------------------------------------------- +-- | RevId + +newtype RevId = RevId { unRevId :: Int } + deriving (Eq, Ord, Show) + +instance Enum RevId where + succ (RevId x) = RevId (succ x) + pred (RevId x) = RevId (pred x) + toEnum = RevId + fromEnum = unRevId + +instance Pk RevId where + toPk = T.pack . show . unRevId + +instance ToJSON RevId where + toJSON = toJSON . unRevId + +instance FromJSON RevId where + parseJSON x = RevId <$> parseJSON x + +instance R.FromDatum RevId where + parseDatum x = RevId <$> R.parseDatum x + +instance R.ToDatum RevId where + toDatum = R.toDatum . unRevId + + +-- | The 'RevId' which is used for the initial snapshot. +zeroRevId :: RevId +zeroRevId = RevId 0 + + + +----------------------------------------------------------------------------- +-- | ObjectId + +data ObjectId + + = BaseObjectId !ObjId + -- ^ The base object whose snapshots contain the actual content. + + | ReleaseObjectId !ObjId !RevId + -- ^ An object describing a particualar release of the base object. + + | AuthorizationObjectId !ObjId + -- ^ Object which contains authorization rules. + + deriving (Eq, Ord, Show) + + +instance Pk ObjectId where + toPk (BaseObjectId objId) = toPk objId + toPk (ReleaseObjectId objId revId) = toPk objId <> "/release/" <> toPk revId + toPk (AuthorizationObjectId objId) = toPk objId <> "/authorization" + +instance ToJSON ObjectId where + toJSON = toJSON . toPk + +instance FromJSON ObjectId where + parseJSON (String x) = either fail return $ parseOnly objectIdParser x + parseJSON _ = fail "ObjectId" + +instance R.FromDatum ObjectId where + parseDatum (R.String x) = either fail return $ parseOnly objectIdParser x + parseDatum _ = fail "ObjectId" + +instance R.ToDatum ObjectId where + toDatum = R.toDatum . toPk + + +objectIdParser :: Parser ObjectId +objectIdParser = (releaseObjectId <|> authorizationObjectId <|> baseObjectId) <* endOfInput + where + objId = ObjId <$> takeWhile1 isAlphaNum + revId = RevId <$> decimal + + baseObjectId = BaseObjectId + <$> objId + + releaseObjectId = ReleaseObjectId + <$> objId + <* string "/release/" + <*> revId + + authorizationObjectId = AuthorizationObjectId + <$> objId + <* string "/authorization" + + +parseObjectId :: Text -> Maybe ObjectId +parseObjectId text = case parseOnly objectIdParser text of + Left _ -> Nothing + Right v -> Just v + + +objectIdBase :: ObjectId -> ObjId +objectIdBase (BaseObjectId objId ) = objId +objectIdBase (ReleaseObjectId objId _) = objId +objectIdBase (AuthorizationObjectId objId ) = objId + + + +----------------------------------------------------------------------------- +-- | The operations that can be applied to JSON values. +data Operation + -- | Set is applied to 'Object's. It is used for adding, updating + -- and deleting properties from the object. + = Set + { opPath :: !Path + , opValue :: !(Maybe Value) + } + + -- | Splice is used to manipulate 'Array's. It can remove and insert + -- multiple elements in a single operation. + | Splice + { opPath :: !Path + , opIndex :: !Int + , opRemove :: !Int + , opInsert :: ![ Value ] + } + + deriving (Eq, Show) + +$(deriveEncoding (deriveJSONOptions "op"){ + omitNothingFields = True, + sumEncoding = TaggedObject "type" "content" +} ''Operation) + + + +data PatchError + = UnknownPatchError !Text + deriving (Show) + +type PatchM a = Either PatchError a + + +data Object = Object + { objectId :: !ObjId + , objectType :: !Text + , objectCreatedAt :: !UTCTime + , objectCreatedBy :: !ObjId + , objectDeleted :: !(Maybe Bool) + } deriving (Show) + +instance Pk Object where + toPk = toPk . objectId + +$(deriveEncoding (deriveJSONOptions "object") ''Object) + + + +----------------------------------------------------------------------------- +-- | Patch + +data Patch = Patch + { patchObjectId :: !ObjectId + , patchRevisionId :: !RevId + , patchAuthorId :: !ObjId + , patchCreatedAt :: !UTCTime + , patchOperation :: !Operation + } deriving (Show) + +instance Pk Patch where + toPk Patch{..} = toPk patchObjectId <> "@" <> toPk patchRevisionId + +$(deriveEncoding (deriveJSONOptions "patch") ''Patch) + + + +----------------------------------------------------------------------------- +-- | Snapshot + +data Snapshot = Snapshot + { snapshotObjectId :: !ObjectId + , snapshotRevisionId :: !RevId + , snapshotContent :: !Value + } deriving (Show) + +instance Pk Snapshot where + toPk Snapshot{..} = toPk snapshotObjectId <> "@" <> toPk snapshotRevisionId + +$(deriveEncoding (deriveJSONOptions "snapshot") ''Snapshot) + + + +----------------------------------------------------------------------------- +-- | Release + +data Release = Release + +instance ToJSON Release where + toJSON = const Aeson.emptyObject + +instance FromJSON Release where + parseJSON (Aeson.Object _) = return Release + parseJSON _ = fail "Release" + +-- $(deriveEncoding (deriveJSONOptions "release") ''Release) + + + +----------------------------------------------------------------------------- +-- | SecretId + +newtype SecretId = SecretId { unSecretId :: Text } + deriving (Show) + +instance Pk SecretId where + toPk = unSecretId + +instance ToJSON SecretId where + toJSON = toJSON . unSecretId + +instance FromJSON SecretId where + parseJSON x = SecretId <$> parseJSON x + +instance R.FromDatum SecretId where + parseDatum x = SecretId <$> R.parseDatum x + +instance R.ToDatum SecretId where + toDatum = R.toDatum . unSecretId + + + +----------------------------------------------------------------------------- +-- | Secret + +data Secret = Secret + { secretId :: !SecretId + , secretValue :: !Text + } + +instance Pk Secret where + toPk = toPk . secretId + +$(deriveEncoding (deriveJSONOptions "secret") ''Secret) + + + +----------------------------------------------------------------------------- +-- | BlobId + +newtype BlobId = BlobId { unBlobId :: Text } + deriving (Show) + +instance Pk BlobId where + toPk = unBlobId + +instance ToJSON BlobId where + toJSON = toJSON . unBlobId + +instance FromJSON BlobId where + parseJSON x = BlobId <$> parseJSON x + +instance R.FromDatum BlobId where + parseDatum x = BlobId <$> R.parseDatum x + +instance R.ToDatum BlobId where + toDatum = R.toDatum . unBlobId + + + +----------------------------------------------------------------------------- +-- | Blob + +data Blob = Blob + { blobId :: !BlobId + , blobSize :: !Int + , blobContentType :: !Text + } deriving (Show) + +instance Pk Blob where + toPk = toPk . blobId + +$(deriveEncoding (deriveJSONOptions "blob") ''Blob) + + + +----------------------------------------------------------------------------- +-- | SessionId + +newtype SessionId = SessionId { unSessionId :: Text } + +instance Pk SessionId where + toPk = unSessionId + +instance ToJSON SessionId where + toJSON = toJSON . unSessionId + +instance FromJSON SessionId where + parseJSON x = SessionId <$> parseJSON x + +instance R.FromDatum SessionId where + parseDatum x = SessionId <$> R.parseDatum x + +instance R.ToDatum SessionId where + toDatum = R.toDatum . unSessionId + + + +----------------------------------------------------------------------------- +-- | The record that is stored in the database. + +data Session = Session + { sessionId :: !SessionId + , sessionAccountId :: !ObjId + , sessionCreatedAt :: !UTCTime + , sessionLastAccessedAt :: !UTCTime + } + +instance Pk Session where + toPk Session{..} = toPk sessionId + +$(deriveEncoding (deriveJSONOptions "session") ''Session) + + + +data AversError + = InternalError !AversError + | DatabaseError !Text + | PatchError !PatchError + | ParseError !Value !Text + | UnknownObjectType !Text + | ObjectNotFound !ObjId + | DocumentNotFound !Text + | AversError !Text + | NotAuthorized + deriving (Show) + + +internalError :: AversError -> Avers a +internalError = throwError . InternalError + +internal :: Avers a -> Avers a +internal m = m `catchError` internalError + +databaseError :: Text -> Avers a +databaseError = throwError . DatabaseError + +patchError :: PatchError -> Avers a +patchError = throwError . PatchError + +parseError :: (MonadError AversError m) => Value -> Text -> m a +parseError value text = throwError $ ParseError value text + +documentNotFound :: Text -> Avers a +documentNotFound = throwError . DocumentNotFound + +strErr :: String -> Avers a +strErr = throwError . AversError . T.pack + + +-- | An 'ObjectType' describes a particular type of object that is managed by +-- Avers. +data ObjectType a = ObjectType + { otType :: !Text + -- ^ The value of the @type@ field of the 'Object'. + + , otId :: Avers ObjId + -- ^ Action which generates a new id. This is so that object types can + -- have different strategies how to generate ids. + + , otViews :: [SomeView a] + } + +data SomeObjectType where + SomeObjectType :: (R.ToDatum a, R.FromDatum a, FromJSON a, ToJSON a) + => ObjectType a -> SomeObjectType + +parseValueAs :: (FromJSON a) => ObjectType a -> Value -> Either AversError a +parseValueAs ObjectType{..} value = case parseEither parseJSON value of + Left e -> parseError value (T.pack $ show e) + Right x -> return x + + + +-- | Configuration of the 'Avers' monad. +data AversConfig = AversConfig + + { databaseHost :: !Text + -- ^ The hostname where RethinkDB is running. The port is currently not + -- configurable. + + , databaseName :: !Text + -- ^ RethinkDB supports multiple databases. This is the name of the one + -- which should be used. + + , influxConfig :: !(Maybe InfluxDB.Config) + -- ^ The influx server where avers reports metrics to. + + , putBlob :: BlobId -> Text -> ByteString -> IO () + -- ^ Function which saves the given blob in the blob store. This can be + -- the local filesystem or an external services such as Amazon S3. + -- + -- TODO: Propagate errors back to the caller. + + , objectTypes :: ![SomeObjectType] + -- ^ All the object types which Avers knows about. + } + + +data AversState = AversState + { config :: !AversConfig + -- ^ A reference to the config, just in case we need it. + + , databaseHandlePool :: !(Pool R.Handle) + -- ^ A pool of handles which are used to access the database. + + , recentRevisionCache :: !(TVar (Map ObjectId RevId)) + -- ^ Map from 'ObjectId' to a recent 'RevId'. It may be the latest or + -- a few revisions behind. + } + + + +newDatabaseHandlePool :: AversConfig -> IO (Pool R.Handle) +newDatabaseHandlePool AversConfig{..} = + createPool create destroy numStripes idleTime maxResources + + where + create = do + putStrLn $ mconcat + [ "Creating a new RethinkDB handle to " + , T.unpack databaseHost + , ":28015" + , " database " + , T.unpack databaseName + ] + + R.newHandle databaseHost 28015 Nothing (R.Database (R.lift databaseName)) + + destroy handle = do + putStrLn "Closing RethinkDB handle" + R.close handle + + numStripes = 1 + idleTime = fromIntegral $ (60 * 60 :: Int) + maxResources = 10 + + +newState :: AversConfig -> IO AversState +newState config = do + AversState + <$> pure config + <*> newDatabaseHandlePool config + <*> newTVarIO M.empty + + +newtype Avers a = Avers + { runAvers :: StateT AversState (ExceptT AversError IO) a + } deriving (Functor, Applicative, Monad, MonadIO, MonadError AversError, MonadState AversState) + +class (Monad m) => MonadAvers m where + liftAvers :: Avers a -> m a + +instance MonadAvers Avers where + liftAvers = id + +instance MonadAvers m => MonadAvers (StateT s m) where + liftAvers = lift . liftAvers + +evalAvers :: AversState -> Avers a -> IO (Either AversError a) +evalAvers h m = runExceptT $ evalStateT (runAvers m) h + + + +------------------------------------------------------------------------------ +-- View + +data View obj a = View + { viewName :: Text + -- ^ The table name is derived from the view name. Therefore it should + -- be unique amongst all views. + + , viewParser :: R.Datum -> Either AversError a + -- ^ Function which parses objects stored in this view. + + , viewObjectTransformer :: obj -> Avers (Maybe a) + -- ^ Function which transforms an Avers Object into a type stored + -- in the view. + + , viewIndices :: [Index] + -- ^ Secondary indices defined on the view. + } + + +data SomeView obj where + SomeView :: (R.ToDatum a, R.FromDatum a, FromJSON obj, ToJSON a) + => View obj a -> SomeView obj diff --git a/src/Avers/Views.hs b/src/Avers/Views.hs new file mode 100644 --- /dev/null +++ b/src/Avers/Views.hs @@ -0,0 +1,66 @@ +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE GeneralizedNewtypeDeriving #-} +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE RecordWildCards #-} +{-# LANGUAGE TemplateHaskell #-} + +module Avers.Views where + + +import Control.Monad + +import Data.Aeson as Aeson +import Data.Monoid +import qualified Data.HashMap.Strict as HMS + +import qualified Database.RethinkDB as R + +import Avers.Types +import Avers.Storage.Backend + + + +-- | Construct the table name for the given view. The table names look +-- something like this: "view_openGames" +viewTable :: View obj a -> R.Exp R.Table +viewTable View{..} = R.Table Nothing $ R.lift $ mconcat + [ "view_" + , viewName + ] + + +data Record a = Record + { recId :: ObjId + , recContent :: a + } + +instance Pk (Record a) where + toPk = toPk . recId + +instance (ToJSON a) => ToJSON (Record a) where + toJSON Record{..} = Aeson.Object $ HMS.insert "id" (Aeson.String $ toPk recId) hms + where (Aeson.Object hms) = toJSON recContent + +instance (R.ToDatum a) => R.ToDatum (Record a) where + toDatum Record{..} = R.Object $ HMS.insert "id" (R.String $ toPk recId) $ + HMS.fromList $ map (\(k,v) -> (k, R.toDatum v)) $ HMS.toList hms + where (R.Object hms) = R.toDatum recContent + + + +updateObjectViews :: ObjectType a -> ObjId -> Maybe a -> Avers () +updateObjectViews ObjectType{..} objId mbObj = do + forM_ otViews $ \(SomeView view) -> do + updateView view objId mbObj + + +updateView :: (R.ToDatum a) => View obj a -> ObjId -> Maybe obj -> Avers () +updateView view@View{..} objId mbObj = do + case mbObj of + Nothing -> deleteDocument (viewTable view) objId + Just obj -> do + mbRecord <- viewObjectTransformer obj + case mbRecord of + Nothing -> deleteDocument (viewTable view) objId + Just rec -> upsertDocument (viewTable view) (Record objId rec)