{-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE OverloadedStrings #-} {-# LANGUAGE RecordWildCards #-} {-# LANGUAGE ScopedTypeVariables #-} -------------------------------------------------------------------------------- -- | -- Module : Database.EventStore.Internal.Types -- Copyright : (C) 2014 Yorick Laupa -- License : (see the file LICENSE) -- -- Maintainer : Yorick Laupa <yo.eight@gmail.com> -- Stability : provisional -- Portability : non-portable -- -------------------------------------------------------------------------------- module Database.EventStore.Internal.Types where -------------------------------------------------------------------------------- import Data.Maybe import Data.Monoid (Endo(..)) import Foreign.C.Types (CTime(..)) -------------------------------------------------------------------------------- import ClassyPrelude hiding (Builder) import qualified Data.Aeson as A import Data.Aeson.Types (Object, ToJSON(..), Pair, Parser, (.=)) import Data.DotNet.TimeSpan import Data.HashMap.Strict (filterWithKey) import Data.ProtocolBuffers import Data.Time (NominalDiffTime) import Data.Time.Clock.POSIX import Data.UUID (UUID, fromByteString, toByteString) import Network.Connection (TLSSettings) -------------------------------------------------------------------------------- import Database.EventStore.Internal.Command import Database.EventStore.Logging -------------------------------------------------------------------------------- -- Exceptions -------------------------------------------------------------------------------- -- | Represent a class of error where the user is not at fault. It could be -- either the client or the server. data InternalException = ConnectionClosedByServer -- ^ Happens when the server deliberately close the connection. This -- probably happens if the client didn't respect EventStore -- communication error. For instance, the client takes too much time to -- respond to a heartbeat request. deriving (Show, Typeable) -------------------------------------------------------------------------------- instance Exception InternalException -------------------------------------------------------------------------------- -- Event -------------------------------------------------------------------------------- -- | Contains event information like its type and data. Only used for write -- queries. data Event = Event { eventType :: !Text , eventId :: !(Maybe UUID) , eventData :: !EventData } deriving (Eq, Show) -------------------------------------------------------------------------------- -- | Create an 'Event' meant to be persisted. createEvent :: Text -- ^ Event type -> Maybe UUID -- ^ Event ID, generated if 'Nothing' -> EventData -- ^ Event data -> Event createEvent = Event -------------------------------------------------------------------------------- -- | Holds event data. data EventData = Json A.Value (Maybe A.Value) | Binary ByteString (Maybe ByteString) deriving (Eq, Show) -------------------------------------------------------------------------------- -- | Maps 'Event' inner data type to an 'Int32' understandable by the server. eventDataType :: EventData -> Int32 eventDataType (Json _ _) = 1 eventDataType _ = 0 -------------------------------------------------------------------------------- -- | Maps 'Event' inner metadata type to an 'Int32' understandable by the -- server. eventMetadataType :: EventData -> Int32 eventMetadataType _ = 0 -------------------------------------------------------------------------------- -- | Creates an event using JSON format withJson :: ToJSON a => a -> EventData withJson value = Json (toJSON value) Nothing -------------------------------------------------------------------------------- -- | Creates an event using a binary format. withBinary :: ByteString -> EventData withBinary bs = Binary bs Nothing -------------------------------------------------------------------------------- -- | Creates an event with metadata using JSON format. withJsonAndMetadata :: (ToJSON a, ToJSON b) => a -> b -> EventData withJsonAndMetadata value metadata = Json (toJSON value) (Just $ toJSON metadata) -------------------------------------------------------------------------------- -- | Creates an event with metadata using binary format. withBinaryAndMetadata :: ByteString -> ByteString -> EventData withBinaryAndMetadata value metadata = Binary value (Just metadata) -------------------------------------------------------------------------------- -- | Serializes 'EventData''s data to a raw 'ByteString'. eventDataBytes :: EventData -> ByteString eventDataBytes (Json value _) = toStrict $ A.encode value eventDataBytes (Binary value _) = value -------------------------------------------------------------------------------- -- | Serializes 'EventData' metadata to a raw 'ByteString'. eventMetadataBytes :: EventData -> Maybe ByteString eventMetadataBytes (Json _ meta_m) = fmap (toStrict . A.encode) meta_m eventMetadataBytes (Binary _ meta_m) = meta_m -------------------------------------------------------------------------------- -- Expected Version -------------------------------------------------------------------------------- -- | Constants used for expected version control. -- -- The use of expected version can be a bit tricky especially when discussing -- idempotency assurances given by the EventStore. -- -- The EventStore will assure idempotency for all operations using any value -- in 'ExpectedVersion' except for 'anyStream'. When using 'anyStream' the -- EventStore will do its best to assure idempotency but will not guarantee -- idempotency. data ExpectedVersion = Any | NoStream | EmptyStream | Exact Int32 | StreamExists deriving (Eq, Show) -------------------------------------------------------------------------------- -- | Maps a 'ExpectedVersion' to an 'Int32' understandable by the server. expVersionInt32 :: ExpectedVersion -> Int32 expVersionInt32 Any = -2 expVersionInt32 NoStream = -1 expVersionInt32 EmptyStream = -1 expVersionInt32 (Exact i) = i expVersionInt32 StreamExists = -4 -------------------------------------------------------------------------------- -- | This write should not conflict with anything and should always succeed. anyVersion :: ExpectedVersion anyVersion = Any -------------------------------------------------------------------------------- -- | The stream being written to should not yet exist. If it does exist -- treat that as a concurrency problem. noStreamVersion :: ExpectedVersion noStreamVersion = NoStream -------------------------------------------------------------------------------- -- | The stream should exist and should be empty. If it does not exist or -- is not empty, treat that as a concurrency problem. emptyStreamVersion :: ExpectedVersion emptyStreamVersion = EmptyStream -------------------------------------------------------------------------------- -- | States that the last event written to the stream should have a -- sequence number matching your expected value. exactEventVersion :: Int32 -> ExpectedVersion exactEventVersion i | i < 0 = error $ "expected version must be >= 0, but is " ++ show i | otherwise = Exact i -------------------------------------------------------------------------------- -- | The stream should exist. If it or a metadata stream does not exist treat -- that as a concurrency problem. streamExists :: ExpectedVersion streamExists = StreamExists -------------------------------------------------------------------------------- -- EventStore Messages -------------------------------------------------------------------------------- -- | Serializes form of an 'Event'. data NewEvent = NewEvent { newEventId :: Required 1 (Value ByteString) , newEventType :: Required 2 (Value Text) , newEventDataType :: Required 3 (Value Int32) , newEventMetadataType :: Required 4 (Value Int32) , newEventData :: Required 5 (Value ByteString) , newEventMetadata :: Optional 6 (Value ByteString) } deriving (Generic, Show) -------------------------------------------------------------------------------- instance Encode NewEvent -------------------------------------------------------------------------------- -- | 'NewEvent' smart constructor. newEvent :: Text -- ^ Event type -> UUID -- ^ Event ID -> Int32 -- ^ Data content type -> Int32 -- ^ Metadata content type -> ByteString -- ^ Event data -> Maybe ByteString -- ^ Metadata -> NewEvent newEvent evt_type evt_id data_type meta_type evt_data evt_meta = let uuid_bytes = toStrict $ toByteString evt_id new_evt = NewEvent { newEventId = putField uuid_bytes , newEventType = putField evt_type , newEventDataType = putField data_type , newEventMetadataType = putField meta_type , newEventData = putField evt_data , newEventMetadata = putField evt_meta } in new_evt -------------------------------------------------------------------------------- -- | Represents a serialized event coming from the server. data EventRecord = EventRecord { eventRecordStreamId :: Required 1 (Value Text) , eventRecordNumber :: Required 2 (Value Int32) , eventRecordId :: Required 3 (Value ByteString) , eventRecordType :: Required 4 (Value Text) , eventRecordDataType :: Required 5 (Value Int32) , eventRecordMetadataType :: Required 6 (Value Int32) , eventRecordData :: Required 7 (Value ByteString) , eventRecordMetadata :: Optional 8 (Value ByteString) , eventRecordCreated :: Optional 9 (Value Int64) , eventRecordCreatedEpoch :: Optional 10 (Value Int64) } deriving (Generic, Show) -------------------------------------------------------------------------------- instance Decode EventRecord -------------------------------------------------------------------------------- -- | Represents a serialized event representiong either an event or a link -- event. data ResolvedIndexedEvent = ResolvedIndexedEvent { resolvedIndexedRecord :: Optional 1 (Message EventRecord) , resolvedIndexedLink :: Optional 2 (Message EventRecord) } deriving (Generic, Show) -------------------------------------------------------------------------------- instance Decode ResolvedIndexedEvent -------------------------------------------------------------------------------- -- | Represents a serialized event sent by the server in a subscription context. data ResolvedEventBuf = ResolvedEventBuf { resolvedEventBufEvent :: Required 1 (Message EventRecord) , resolvedEventBufLink :: Optional 2 (Message EventRecord) , resolvedEventBufCommitPosition :: Required 3 (Value Int64) , resolvedEventBufPreparePosition :: Required 4 (Value Int64) } deriving (Generic, Show) -------------------------------------------------------------------------------- instance Decode ResolvedEventBuf -------------------------------------------------------------------------------- -- Result -------------------------------------------------------------------------------- -- | A structure referring to a potential logical record position in the -- EventStore transaction file. data Position = Position { positionCommit :: !Int64 -- ^ Commit position of the record , positionPrepare :: !Int64 -- ^ Prepare position of the record } deriving Show -------------------------------------------------------------------------------- instance Eq Position where Position ac aap == Position bc bp = ac == bc && aap == bp -------------------------------------------------------------------------------- instance Ord Position where compare (Position ac aap) (Position bc bp) = if ac < bc || (ac == bc && aap < bp) then LT else if ac > bc || (ac == bc && aap > bp) then GT else EQ -------------------------------------------------------------------------------- -- | Representing the start of the transaction file. positionStart :: Position positionStart = Position 0 0 -------------------------------------------------------------------------------- -- | Representing the end of the transaction file. positionEnd :: Position positionEnd = Position (-1) (-1) -------------------------------------------------------------------------------- -- | Represents a previously written event. data RecordedEvent = RecordedEvent { recordedEventStreamId :: !Text -- ^ The event stream that this event belongs to. , recordedEventId :: !UUID -- ^ Unique identifier representing this event. , recordedEventNumber :: !Int32 -- ^ Number of this event in the stream. , recordedEventType :: !Text -- ^ Type of this event. , recordedEventData :: !ByteString -- ^ Representing the data of this event. , recordedEventMetadata :: !(Maybe ByteString) -- ^ Representing the metadada associated with this event. , recordedEventIsJson :: !Bool -- ^ Indicates whether the content is internally marked as json. , recordedEventCreated :: !(Maybe UTCTime) -- ^ Representing when this event was created in the system. } deriving Show -------------------------------------------------------------------------------- -- | Tries to parse JSON object from the given 'RecordedEvent'. recordedEventDataAsJson :: A.FromJSON a => RecordedEvent -> Maybe a recordedEventDataAsJson = A.decode . fromStrict . recordedEventData -------------------------------------------------------------------------------- -- | Converts a raw 'Int64' into an 'UTCTime' -- fromIntegral should be a no-op in GHC and allow eventstore to compile w GHCJS -- GHCJS maps CTime to Int32 (cf PR https://github.com/YoEight/eventstore/pull/47) toUTC :: Int64 -> UTCTime toUTC = posixSecondsToUTCTime . (/1000) . realToFrac . CTime . fromIntegral -------------------------------------------------------------------------------- -- | Constructs a 'RecordedEvent' from an 'EventRecord'. newRecordedEvent :: EventRecord -> RecordedEvent newRecordedEvent er = re where evt_id = getField $ eventRecordId er evt_uuid = fromJust $ fromByteString $ fromStrict evt_id data_type = getField $ eventRecordDataType er epoch = getField $ eventRecordCreatedEpoch er utc_created = fmap toUTC epoch re = RecordedEvent { recordedEventStreamId = getField $ eventRecordStreamId er , recordedEventNumber = getField $ eventRecordNumber er , recordedEventId = evt_uuid , recordedEventType = getField $ eventRecordType er , recordedEventData = getField $ eventRecordData er , recordedEventMetadata = getField $ eventRecordMetadata er , recordedEventIsJson = data_type == 1 , recordedEventCreated = utc_created } -------------------------------------------------------------------------------- -- | A structure representing a single event or an resolved link event. data ResolvedEvent = ResolvedEvent { resolvedEventRecord :: !(Maybe RecordedEvent) -- ^ The event, or the resolved link event if this 'ResolvedEvent' is a -- link event. , resolvedEventLink :: !(Maybe RecordedEvent) -- ^ The link event if this 'ResolvedEvent' is a link event. , resolvedEventPosition :: !(Maybe Position) -- ^ Possible 'Position' of that event. } deriving Show -------------------------------------------------------------------------------- -- | Constructs a 'ResolvedEvent' from a 'ResolvedIndexedEvent'. newResolvedEvent :: ResolvedIndexedEvent -> ResolvedEvent newResolvedEvent rie = re where record = getField $ resolvedIndexedRecord rie link = getField $ resolvedIndexedLink rie re = ResolvedEvent { resolvedEventRecord = fmap newRecordedEvent record , resolvedEventLink = fmap newRecordedEvent link , resolvedEventPosition = Nothing } -------------------------------------------------------------------------------- -- | Constructs a 'ResolvedEvent' from a 'ResolvedEventBuf'. newResolvedEventFromBuf :: ResolvedEventBuf -> ResolvedEvent newResolvedEventFromBuf reb = re where record = Just $ newRecordedEvent $ getField $ resolvedEventBufEvent reb link = getField $ resolvedEventBufLink reb com = getField $ resolvedEventBufCommitPosition reb pre = getField $ resolvedEventBufPreparePosition reb pos = Position com pre re = ResolvedEvent { resolvedEventRecord = record , resolvedEventLink = fmap newRecordedEvent link , resolvedEventPosition = Just pos } -------------------------------------------------------------------------------- -- | Returns the event that was read or which triggered the subscription. -- -- If this 'ResolvedEvent' represents a link event, the link will be the -- original event, otherwise it will be the event. resolvedEventOriginal :: ResolvedEvent -> RecordedEvent resolvedEventOriginal (ResolvedEvent record link _) = let Just evt = link <|> record in evt -------------------------------------------------------------------------------- -- | Tries to desarialize 'resolvedEventOriginal' data as JSON. resolvedEventDataAsJson :: A.FromJSON a => ResolvedEvent -> Maybe a resolvedEventDataAsJson = recordedEventDataAsJson . resolvedEventOriginal -------------------------------------------------------------------------------- -- | Indicates whether this 'ResolvedEvent' is a resolved link event. isEventResolvedLink :: ResolvedEvent -> Bool isEventResolvedLink = isJust . resolvedEventLink -------------------------------------------------------------------------------- -- | The stream name of the original event. resolvedEventOriginalStreamId :: ResolvedEvent -> Text resolvedEventOriginalStreamId = recordedEventStreamId . resolvedEventOriginal -------------------------------------------------------------------------------- -- | The ID of the original event. resolvedEventOriginalId :: ResolvedEvent -> UUID resolvedEventOriginalId = recordedEventId . resolvedEventOriginal -------------------------------------------------------------------------------- -- | Represents the direction of read operation (both from $all an usual -- streams). data ReadDirection = Forward -- ^ From beginning to end | Backward -- ^ From end to beginning deriving (Eq, Show) -------------------------------------------------------------------------------- -- Flag -------------------------------------------------------------------------------- -- | Indicates either a 'Package' contains 'Credentials' data or not. data Flag = None | Authenticated deriving Show -------------------------------------------------------------------------------- -- | Maps a 'Flag' into a 'Word8' understandable by the server. flagWord8 :: Flag -> Word8 flagWord8 None = 0x00 flagWord8 Authenticated = 0x01 -------------------------------------------------------------------------------- -- Credentials -------------------------------------------------------------------------------- -- | Holds login and password information. data Credentials = Credentials { credLogin :: !ByteString , credPassword :: !ByteString } deriving (Eq, Show) -------------------------------------------------------------------------------- -- | Creates a 'Credentials' given a login and a password. credentials :: ByteString -- ^ Login -> ByteString -- ^ Password -> Credentials credentials = Credentials -------------------------------------------------------------------------------- -- Package -------------------------------------------------------------------------------- -- | Represents a package exchanged between the client and the server. data Package = Package { packageCmd :: !Command , packageCorrelation :: !UUID , packageData :: !ByteString , packageCred :: !(Maybe Credentials) } deriving Show -------------------------------------------------------------------------------- -- | Constructs a heartbeat response given the 'UUID' of heartbeat request. heartbeatResponsePackage :: UUID -> Package heartbeatResponsePackage uuid = Package { packageCmd = 0x02 , packageCorrelation = uuid , packageData = "" , packageCred = Nothing } -------------------------------------------------------------------------------- -- Settings -------------------------------------------------------------------------------- -- | Represents reconnection strategy. data Retry = AtMost Int | KeepRetrying -------------------------------------------------------------------------------- -- | Indicates how many times we should try to reconnect to the server. A value -- less than or equal to 0 means no retry. atMost :: Int -> Retry atMost = AtMost -------------------------------------------------------------------------------- -- | Indicates we should try to reconnect to the server until the end of the -- Universe. keepRetrying :: Retry keepRetrying = KeepRetrying -------------------------------------------------------------------------------- -- | Global 'Connection' settings data Settings = Settings { s_heartbeatInterval :: NominalDiffTime , s_heartbeatTimeout :: NominalDiffTime , s_requireMaster :: Bool , s_credentials :: Maybe Credentials , s_retry :: Retry , s_reconnect_delay_secs :: Int -- ^ In seconds , s_logger :: Maybe (Log -> IO ()) , s_ssl :: Maybe TLSSettings } -------------------------------------------------------------------------------- -- | Default global settings. -- s_heartbeatInterval = 750 ms -- s_heartbeatTimeout = 1500 ms -- s_requireMaster = True -- s_credentials = Nothing -- s_retry = 'atMost' 3 -- s_reconnect_delay_secs = 3 -- s_logger = Nothing defaultSettings :: Settings defaultSettings = Settings { s_heartbeatInterval = msDiffTime 750 -- 750ms , s_heartbeatTimeout = msDiffTime 1500 -- 1500ms , s_requireMaster = True , s_credentials = Nothing , s_retry = atMost 3 , s_reconnect_delay_secs = 3 , s_logger = Nothing , s_ssl = Nothing } -------------------------------------------------------------------------------- -- | Default SSLÂ settings based on 'defaultSettings'. defaultSSLSettings :: TLSSettings -> Settings defaultSSLSettings tls = defaultSettings { s_ssl = Just tls } -------------------------------------------------------------------------------- -- | Triggers the logger callback if it has been set. _settingsLog :: Settings -> Log -> IO () _settingsLog Settings{..} l = case s_logger of Just k -> k l _ -> return () -------------------------------------------------------------------------------- -- | Millisecond timespan msDiffTime :: Float -> NominalDiffTime msDiffTime i = fromRational $ toRational (i / 1000) -------------------------------------------------------------------------------- -- | Represents an access control list for a stream. data StreamACL = StreamACL { streamACLReadRoles :: ![Text] -- ^ Roles and users permitted to read the stream. , streamACLWriteRoles :: ![Text] -- ^ Roles and users permitted to write to the stream. , streamACLDeleteRoles :: ![Text] -- ^ Roles and users permitted to delete to the stream. , streamACLMetaReadRoles :: ![Text] -- ^ Roles and users permitted to read stream metadata. , streamACLMetaWriteRoles :: ![Text] -- ^ Roles and users permitted to write stream metadata. } deriving Show ------------------------------------------------------------------------------- instance A.FromJSON StreamACL where parseJSON = parseStreamACL ------------------------------------------------------------------------------- instance A.ToJSON StreamACL where toJSON = streamACLJSON -------------------------------------------------------------------------------- -- | 'StreamACL' with no role or users whatsoever. emptyStreamACL :: StreamACL emptyStreamACL = StreamACL { streamACLReadRoles = [] , streamACLWriteRoles = [] , streamACLDeleteRoles = [] , streamACLMetaReadRoles = [] , streamACLMetaWriteRoles = [] } -------------------------------------------------------------------------------- -- | Represents stream metadata with strongly typed properties for system values -- and a dictionary-like interface for custom values. data StreamMetadata = StreamMetadata { streamMetadataMaxCount :: !(Maybe Int32) -- ^ The maximum number of events allowed in the stream. , streamMetadataMaxAge :: !(Maybe TimeSpan) -- ^ The maximum age of events allowed in the stream. , streamMetadataTruncateBefore :: !(Maybe Int32) -- ^ The event number from which previous events can be scavenged. This -- is used to implement soft-deletion of streams. , streamMetadataCacheControl :: !(Maybe TimeSpan) -- ^ The amount of time for which the stream head is cachable. , streamMetadataACL :: !StreamACL -- ^ The access control list for the stream. , streamMetadataCustom :: !Object -- ^ An enumerable of key-value pairs of keys to JSON text for -- user-provider metadata. } deriving Show -------------------------------------------------------------------------------- -- | Gets a custom property value from metadata. getCustomPropertyValue :: StreamMetadata -> Text -> Maybe A.Value getCustomPropertyValue s k = lookup k obj where obj = streamMetadataCustom s -------------------------------------------------------------------------------- -- | Get a custom property value from metadata. getCustomProperty :: A.FromJSON a => StreamMetadata -> Text -> Maybe a getCustomProperty s k = do v <- getCustomPropertyValue s k case A.fromJSON v of A.Error _ -> Nothing A.Success a -> return a ------------------------------------------------------------------------------- instance A.FromJSON StreamMetadata where parseJSON = parseStreamMetadata ------------------------------------------------------------------------------- instance A.ToJSON StreamMetadata where toJSON = streamMetadataJSON -------------------------------------------------------------------------------- -- | 'StreamMetadata' with everything set to 'Nothing', using 'emptyStreamACL' -- and an empty 'Object'. emptyStreamMetadata :: StreamMetadata emptyStreamMetadata = StreamMetadata { streamMetadataMaxCount = Nothing , streamMetadataMaxAge = Nothing , streamMetadataTruncateBefore = Nothing , streamMetadataCacheControl = Nothing , streamMetadataACL = emptyStreamACL , streamMetadataCustom = mempty } -------------------------------------------------------------------------------- -- | Maps an 'Object' to a list of 'Pair' to ease the 'StreamMetadata'. customMetaToPairs :: Object -> [Pair] customMetaToPairs = fmap go . mapToList where go (k,v) = k .= v -------------------------------------------------------------------------------- -- | Serialized a 'StreamACL' to 'Value' for serialization purpose. streamACLJSON :: StreamACL -> A.Value streamACLJSON StreamACL{..} = A.object [ p_readRoles .= streamACLReadRoles , p_writeRoles .= streamACLWriteRoles , p_deleteRoles .= streamACLDeleteRoles , p_metaReadRoles .= streamACLMetaReadRoles , p_metaWriteRoles .= streamACLMetaWriteRoles ] -------------------------------------------------------------------------------- -- | Serialized a 'StreamMetadata' to 'Value' for serialization purpose. streamMetadataJSON :: StreamMetadata -> A.Value streamMetadataJSON StreamMetadata{..} = A.object $ [ p_maxAge .= fmap toInt64 streamMetadataMaxAge , p_maxCount .= streamMetadataMaxCount , p_truncateBefore .= streamMetadataTruncateBefore , p_cacheControl .= fmap toInt64 streamMetadataCacheControl , p_acl .= streamACLJSON streamMetadataACL ] ++ custPairs where custPairs = customMetaToPairs streamMetadataCustom toInt64 :: TimeSpan -> Int64 toInt64 = truncate . totalSeconds -------------------------------------------------------------------------------- -- Stream ACL Properties -------------------------------------------------------------------------------- -- | Read ACL property. p_readRoles :: Text p_readRoles = "$r" -------------------------------------------------------------------------------- -- | Write ACL property. p_writeRoles :: Text p_writeRoles = "$w" -------------------------------------------------------------------------------- -- | Delete ACL property. p_deleteRoles :: Text p_deleteRoles = "$d" -------------------------------------------------------------------------------- -- | Metadata read ACL property. p_metaReadRoles :: Text p_metaReadRoles = "$mr" -------------------------------------------------------------------------------- -- | Metadata write ACL property. p_metaWriteRoles :: Text p_metaWriteRoles = "$mw" -------------------------------------------------------------------------------- -- Internal MetaData Properties -------------------------------------------------------------------------------- -- | Max age metadata property. p_maxAge :: Text p_maxAge = "$maxAge" -------------------------------------------------------------------------------- -- | Max count metadata property. p_maxCount :: Text p_maxCount = "$maxCount" -------------------------------------------------------------------------------- -- | truncated before metadata property. p_truncateBefore :: Text p_truncateBefore = "$tb" -------------------------------------------------------------------------------- -- | Cache control metadata property. p_cacheControl :: Text p_cacheControl = "$cacheControl" -------------------------------------------------------------------------------- -- | ACL metadata property. p_acl :: Text p_acl = "$acl" -------------------------------------------------------------------------------- -- | Gathers every internal metadata properties into a 'Set'. It used to safely -- 'StreamMetadata' in JSON. internalMetaProperties :: Set Text internalMetaProperties = setFromList [ p_maxAge , p_maxCount , p_truncateBefore , p_cacheControl , p_acl ] -------------------------------------------------------------------------------- -- | Only keeps the properties the users has set. keepUserProperties :: Object -> Object keepUserProperties = filterWithKey go where go k _ = notMember k internalMetaProperties -------------------------------------------------------------------------------- -- | Parses a 'NominalDiffTime' from an 'Object' given a JSON property. parseNominalDiffTime :: Text -> Object -> Parser (Maybe NominalDiffTime) parseNominalDiffTime k m = fmap (fmap go) (m A..: k) where go i = (realToFrac $ CTime i) -------------------------------------------------------------------------------- -- | Parses 'StreamACL'. parseStreamACL :: A.Value -> Parser StreamACL parseStreamACL (A.Object m) = StreamACL <$> m A..: p_readRoles <*> m A..: p_writeRoles <*> m A..: p_deleteRoles <*> m A..: p_metaReadRoles <*> m A..: p_metaWriteRoles parseStreamACL _ = mzero -------------------------------------------------------------------------------- -- | Parses 'StreamMetadata'. parseStreamMetadata :: A.Value -> Parser StreamMetadata parseStreamMetadata (A.Object m) = StreamMetadata <$> m A..: p_maxCount <*> parseTimeSpan p_maxAge <*> m A..: p_truncateBefore <*> parseTimeSpan p_cacheControl <*> (m A..: p_acl >>= parseStreamACL) <*> pure (keepUserProperties m) where parseTimeSpan :: Text -> Parser (Maybe TimeSpan) parseTimeSpan prop = do (secs :: Maybe Int64) <- m A..: prop return $ fmap (fromSeconds . realToFrac) secs parseStreamMetadata _ = mzero -------------------------------------------------------------------------------- -- Builder -------------------------------------------------------------------------------- -- | Allows to build a structure using 'Monoid' functions. type Builder a = Endo a -------------------------------------------------------------------------------- -- | Build a structure given a 'Builder' and an initial value. build :: a -> Builder a -> a build a (Endo k) = k a -------------------------------------------------------------------------------- -- | A 'Builder' applies to 'StreamACL'. type StreamACLBuilder = Builder StreamACL -------------------------------------------------------------------------------- -- | Sets role names with read permission for the stream. setReadRoles :: [Text] -> StreamACLBuilder setReadRoles xs = Endo $ \s -> s { streamACLReadRoles = xs } -------------------------------------------------------------------------------- -- | Sets a single role name with read permission for the stream. setReadRole :: Text -> StreamACLBuilder setReadRole x = setReadRoles [x] -------------------------------------------------------------------------------- -- | Sets role names with write permission for the stream. setWriteRoles :: [Text] -> StreamACLBuilder setWriteRoles xs = Endo $ \s -> s { streamACLWriteRoles = xs } -------------------------------------------------------------------------------- -- | Sets a single role name with write permission for the stream. setWriteRole :: Text -> StreamACLBuilder setWriteRole x = setWriteRoles [x] -------------------------------------------------------------------------------- -- | Sets role names with delete permission for the stream. setDeleteRoles :: [Text] -> StreamACLBuilder setDeleteRoles xs = Endo $ \s -> s { streamACLDeleteRoles = xs } -------------------------------------------------------------------------------- -- | Sets a single role name with delete permission for the stream. setDeleteRole :: Text -> StreamACLBuilder setDeleteRole x = setDeleteRoles [x] -------------------------------------------------------------------------------- -- | Sets role names with metadata read permission for the stream. setMetaReadRoles :: [Text] -> StreamACLBuilder setMetaReadRoles xs = Endo $ \s -> s { streamACLMetaReadRoles = xs } -------------------------------------------------------------------------------- -- | Sets a single role name with metadata read permission for the stream. setMetaReadRole :: Text -> StreamACLBuilder setMetaReadRole x = setMetaReadRoles [x] -------------------------------------------------------------------------------- -- | Sets role names with metadata write permission for the stream. setMetaWriteRoles :: [Text] -> StreamACLBuilder setMetaWriteRoles xs = Endo $ \s -> s { streamACLMetaWriteRoles = xs } -------------------------------------------------------------------------------- -- | Sets a single role name with metadata write permission for the stream. setMetaWriteRole :: Text -> StreamACLBuilder setMetaWriteRole x = setMetaWriteRoles [x] -------------------------------------------------------------------------------- -- | Builds a 'StreamACL' from a 'StreamACLBuilder'. buildStreamACL :: StreamACLBuilder -> StreamACL buildStreamACL b = modifyStreamACL b emptyStreamACL -------------------------------------------------------------------------------- -- | Modifies a 'StreamACL' using a 'StreamACLBuilder'. modifyStreamACL :: StreamACLBuilder -> StreamACL -> StreamACL modifyStreamACL b acl = build acl b -------------------------------------------------------------------------------- -- | A 'Builder' applies to 'StreamMetadata'. type StreamMetadataBuilder = Builder StreamMetadata -------------------------------------------------------------------------------- -- | Sets the maximum number of events allowed in the stream. setMaxCount :: Int32 -> StreamMetadataBuilder setMaxCount i = Endo $ \s -> s { streamMetadataMaxCount = Just i } -------------------------------------------------------------------------------- -- | Sets the maximum age of events allowed in the stream. setMaxAge :: TimeSpan -> StreamMetadataBuilder setMaxAge d = Endo $ \s -> s { streamMetadataMaxAge = Just d } -------------------------------------------------------------------------------- -- | Sets the event number from which previous events can be scavenged. setTruncateBefore :: Int32 -> StreamMetadataBuilder setTruncateBefore i = Endo $ \s -> s { streamMetadataTruncateBefore = Just i } -------------------------------------------------------------------------------- -- | Sets the amount of time for which the stream head is cachable. setCacheControl :: TimeSpan -> StreamMetadataBuilder setCacheControl d = Endo $ \s -> s { streamMetadataCacheControl = Just d } -------------------------------------------------------------------------------- -- | Overwrites any previous 'StreamACL' by the given one in a -- 'StreamMetadataBuilder'. setACL :: StreamACL -> StreamMetadataBuilder setACL a = Endo $ \s -> s { streamMetadataACL = a } -------------------------------------------------------------------------------- -- | Updates a 'StreamMetadata''s 'StreamACL' given a 'StreamACLBuilder'. modifyACL :: StreamACLBuilder -> StreamMetadataBuilder modifyACL b = Endo $ \s -> let old = streamMetadataACL s in s { streamMetadataACL = modifyStreamACL b old } -------------------------------------------------------------------------------- -- | Sets a custom metadata property. setCustomProperty :: ToJSON a => Text -> a -> StreamMetadataBuilder setCustomProperty k v = Endo $ \s -> let m = streamMetadataCustom s m' = insertMap k (toJSON v) m in s { streamMetadataCustom = m' } -------------------------------------------------------------------------------- -- | Builds a 'StreamMetadata' from a 'StreamMetadataBuilder'. buildStreamMetadata :: StreamMetadataBuilder -> StreamMetadata buildStreamMetadata b = modifyStreamMetadata b emptyStreamMetadata -------------------------------------------------------------------------------- -- | Modifies a 'StreamMetadata' using a 'StreamMetadataBuilder' modifyStreamMetadata :: StreamMetadataBuilder -> StreamMetadata -> StreamMetadata modifyStreamMetadata b meta = build meta b -------------------------------------------------------------------------------- -- | Represents stream metadata as a series of properties for system data and a -- 'StreamMetadata' object for user metadata. data StreamMetadataResult = StreamMetadataResult { streamMetaResultStream :: !Text -- ^ The name of the stream. , streamMetaResultVersion :: !Int32 -- ^ The version of the metadata format. , streamMetaResultData :: !StreamMetadata -- ^ A 'StreamMetadata' containing user-specified metadata. } | NotFoundStreamMetadataResult { streamMetaResultStream :: !Text } -- ^ When the stream is either not found or 'no stream'. | DeletedStreamMetadataResult { streamMetaResultStream :: !Text } -- ^ When the stream is soft-deleted. deriving Show -------------------------------------------------------------------------------- -- | System supported consumer strategies for use with persistent subscriptions. data SystemConsumerStrategy = DispatchToSingle -- ^ Distributes events to a single client until it is full. Then round -- robin to the next client. | RoundRobin -- ^ Distributes events to each client in a round robin fashion. deriving (Show, Eq) -------------------------------------------------------------------------------- -- | Maps a 'SystemConsumerStrategy' to a 'Text' understandable by the server. strategyText :: SystemConsumerStrategy -> Text strategyText DispatchToSingle = "DispatchToSingle" strategyText RoundRobin = "RoundRobin" -------------------------------------------------------------------------------- -- | Tries to parse a 'SystemConsumerStrategy' given a raw 'Text'. strategyFromText :: Text -> Maybe SystemConsumerStrategy strategyFromText "DispatchToSingle" = Just DispatchToSingle strategyFromText "RoundRobin" = Just RoundRobin strategyFromText _ = Nothing -------------------------------------------------------------------------------- -- | Gathers every persistent subscription property. data PersistentSubscriptionSettings = PersistentSubscriptionSettings { psSettingsResolveLinkTos :: !Bool -- ^ Whether or not the persistent subscription should resolve linkTo -- events to their linked events. , psSettingsStartFrom :: !Int32 -- ^ Where the subscription should start from (position). , psSettingsExtraStats :: !Bool -- ^ Whether or not in depth latency statistics should be tracked on this -- subscription. , psSettingsMsgTimeout :: !TimeSpan -- ^ The amount of time after which a message should be considered to be -- timeout and retried. , psSettingsMaxRetryCount :: !Int32 -- ^ The maximum number of retries (due to timeout) before a message get -- considered to be parked. , psSettingsLiveBufSize :: !Int32 -- ^ The size of the buffer listening to live messages as they happen. , psSettingsReadBatchSize :: !Int32 -- ^ The number of events read at a time when paging in history. , psSettingsHistoryBufSize :: !Int32 -- ^ The number of events to cache when paging through history. , psSettingsCheckPointAfter :: !TimeSpan -- ^ The amount of time to try checkpoint after. , psSettingsMinCheckPointCount :: !Int32 -- ^ The minimum number of messages to checkpoint. , psSettingsMaxCheckPointCount :: !Int32 -- ^ The maximum number of message to checkpoint. If this number is -- reached, a checkpoint will be forced. , psSettingsMaxSubsCount :: !Int32 -- ^ The maximum number of subscribers allowed. , psSettingsNamedConsumerStrategy :: !SystemConsumerStrategy -- ^ The strategy to use for distributing events to client consumers. } deriving (Show, Eq) -------------------------------------------------------------------------------- -- | System default persistent subscription settings. defaultPersistentSubscriptionSettings :: PersistentSubscriptionSettings defaultPersistentSubscriptionSettings = PersistentSubscriptionSettings { psSettingsResolveLinkTos = False , psSettingsStartFrom = (-1) , psSettingsExtraStats = False , psSettingsMsgTimeout = fromSeconds 30 , psSettingsMaxRetryCount = 500 , psSettingsLiveBufSize = 500 , psSettingsReadBatchSize = 10 , psSettingsHistoryBufSize = 20 , psSettingsCheckPointAfter = fromSeconds 2 , psSettingsMinCheckPointCount = 10 , psSettingsMaxCheckPointCount = 1000 , psSettingsMaxSubsCount = 0 , psSettingsNamedConsumerStrategy = RoundRobin }