HAppS.State

HAppS-State-0.9.3: Event-based distributed state.

HAppS.State

Contents

ACID monad
Types
Misc utilities
Random numbers
TH helpers
Serialization
Unsafe things

Synopsis

data Ev m t

type AnyEv a = forall t. (Monad (t STM), MonadTrans t) => Ev (t STM) a

query :: (MonadIO m, QueryEvent ev res) => ev -> m res

update :: (MonadIO m, UpdateEvent ev res) => ev -> m res

type Update state = Ev (StateT state STM)

type Query state = Ev (ReaderT state STM)

type TxId = Int64

type EpochMilli = Int64

data TxConfig = TxConfig {

txcCheckpointSeconds :: Seconds

txcOperationMode :: OperationMode

txcClusterSize :: Int

txcClusterPort :: Int

txcCommitFrequency :: Int

}

nullTxConfig :: TxConfig

data Saver

| FileSaver String

| Memory (MVar Store)

setUpdateType :: Proxy t -> Update t ()

setQueryType :: Proxy t -> Query t ()

asUpdate :: Update t a -> Proxy t -> Update t a

asQuery :: Query t a -> Proxy t -> Query t a

askState :: Query st st

getState :: Update st st

putState :: st -> Update st ()

liftSTM :: STM a -> AnyEv a

class CatchEv m where

catchEv :: Ev m a -> (SomeException -> a) -> Ev m a

sel :: (Env -> b) -> AnyEv b

localState :: (outer -> inner) -> (inner -> outer -> outer) -> Ev (StateT inner STM) a -> Ev (StateT outer STM) a

localStateReader :: (outer -> inner) -> Ev (ReaderT inner STM) a -> Ev (ReaderT outer STM) a

runQuery :: Query st a -> Update st a

getEventId :: Integral txId => AnyEv txId

getTime :: Integral epochTime => AnyEv epochTime

getEventClockTime :: AnyEv ClockTime

getEventStream :: IO (IO EventItem)

data EventItem = EventItem {

eventContext :: TxContext

eventData :: Dynamic

}

getRandom :: Random a => AnyEv a

getRandomR :: Random a => (a, a) -> AnyEv a

inferRecordUpdaters :: Name -> Q [Dec]

module HAppS.Data.Serialize

module HAppS.Data.SerializeTH

module HAppS.State.Control

runTxSystem :: (Methods st, Component st) => Saver -> Proxy st -> IO (MVar TxControl)

runTxSystem' :: (Methods st, Component st) => Bool -> Saver -> Proxy st -> IO (MVar TxControl)

shutdownSystem :: MVar TxControl -> IO ()

module HAppS.State.ComponentTH

module HAppS.State.ComponentSystem

closeTxControl :: MVar TxControl -> IO ()

createCheckpoint :: MVar TxControl -> IO ()

unsafeIOToEv :: IO a -> AnyEv a

data Ev m t

Monad for ACID event handlers.

show/hide

Instances

MonadReader st (Update st)

MonadReader st (Query st)

MonadState st (Update st)

Monad m => Monad (Ev m)

Monad m => Functor (Ev m)

MonadPlus m => MonadPlus (Ev m)

(Typeable state, Typeable t) => Typeable (Ev (StateT state STM) t)

(Typeable state, Typeable t) => Typeable (Ev (ReaderT state STM) t)

type AnyEv a = forall t. (Monad (t STM), MonadTrans t) => Ev (t STM) a

ACID computations that work with any state and event types.

data TxControl

query :: (MonadIO m, QueryEvent ev res) => ev -> m res

Emit a state query and wait for the result.

update :: (MonadIO m, UpdateEvent ev res) => ev -> m res

Schedule an update and wait for it to complete. When this function returns, you're guaranteed the update will be persistent.

type Update state = Ev (StateT state STM)

type Query state = Ev (ReaderT state STM)

type TxId = Int64

type EpochMilli = Int64

data TxConfig

Constructors

TxConfig

txcCheckpointSeconds :: Seconds	Perform checkpoint at least every N seconds.
txcOperationMode :: OperationMode
txcClusterSize :: Int	Number of active nodes in the cluster (not counting this node).
txcClusterPort :: Int
txcCommitFrequency :: Int	Commits per second. Only applies to cluster mode.

nullTxConfig :: TxConfig

data Saver

Constructors

NullSaver	A saver that discards all output
FileSaver String	A saver that operates on files. The parameter is the prefix for the files. Creates the prefix directory.
Queue Saver	Enable queueing.
Memory (MVar Store)

setUpdateType :: Proxy t -> Update t ()

Use a proxy to force the type of an update action.

setQueryType :: Proxy t -> Query t ()

Use a proxy to force the type of a query action.

asUpdate :: Update t a -> Proxy t -> Update t a

Currying version of setUpdateType.

asQuery :: Query t a -> Proxy t -> Query t a

Currying version of setQueryType.

askState :: Query st st

Specialized version of ask

getState :: Update st st

Specialized version of get

putState :: st -> Update st ()

Specialized version of put.

liftSTM :: STM a -> AnyEv a

Lift an STM action into Ev.

class CatchEv m where

Methods

catchEv :: Ev m a -> (SomeException -> a) -> Ev m a

show/hide

Instances

CatchEv (StateT st STM)

CatchEv (ReaderT st STM)

sel :: (Env -> b) -> AnyEv b

Select a part of the environment.

localState :: (outer -> inner) -> (inner -> outer -> outer) -> Ev (StateT inner STM) a -> Ev (StateT outer STM) a

Run a computation with a local environment.

Run a computation with local state. Changes to state will be visible to outside.

localStateReader :: (outer -> inner) -> Ev (ReaderT inner STM) a -> Ev (ReaderT outer STM) a

Run a computation with local state.

runQuery :: Query st a -> Update st a

Execute a Query action in the Update monad.

getEventId :: Integral txId => AnyEv txId

getTime :: Integral epochTime => AnyEv epochTime

getEventClockTime :: AnyEv ClockTime

getEventStream :: IO (IO EventItem)

data EventItem

Constructors

EventItem

eventContext :: TxContext
eventData :: Dynamic

getRandom :: Random a => AnyEv a

Get a random number.

getRandomR :: Random a => (a, a) -> AnyEv a

Get a random number inside the range.

inferRecordUpdaters :: Name -> Q [Dec]

Infer updating functions for a record a_foo :: component -> record -> record and withFoo = localState foo a_foo.

module HAppS.Data.Serialize

module HAppS.Data.SerializeTH

module HAppS.State.Control

runTxSystem :: (Methods st, Component st) => Saver -> Proxy st -> IO (MVar TxControl)

Run a transaction system

runTxSystem' :: (Methods st, Component st) => Bool -> Saver -> Proxy st -> IO (MVar TxControl)

shutdownSystem :: MVar TxControl -> IO ()

module HAppS.State.ComponentTH

module HAppS.State.ComponentSystem

closeTxControl :: MVar TxControl -> IO ()

createCheckpoint :: MVar TxControl -> IO ()

unsafeIOToEv :: IO a -> AnyEv a

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