Control.Distributed.Fork.Backend

You only need this module if you want to create a new backend for distributed-fork.

See LocalProcessBackend for a minimal example.

Writing a Backend.

newtype Backend

Backend is responsible for running your functions in a remote environment.

See:

• localProcessBackend
• distributed-fork-aws-lambda

Constructors

Backend

Fields

• bExecute :: ByteString -> BackendM ByteString

  Should run the current binary in the target environment, put the given string as standard input and return the executables answer on the standard output.

data BackendM a

BackendM is essentially IO, but also has the ability to report the status of the executor.

Instances

Monad BackendM

Methods

(>>=) :: BackendM a -> (a -> BackendM b) -> BackendM b

(>>) :: BackendM a -> BackendM b -> BackendM b

return :: a -> BackendM a

fail :: String -> BackendM a

Functor BackendM

Methods

fmap :: (a -> b) -> BackendM a -> BackendM b

(<$) :: a -> BackendM b -> BackendM a

Applicative BackendM

Methods

pure :: a -> BackendM a

(<*>) :: BackendM (a -> b) -> BackendM a -> BackendM b

liftA2 :: (a -> b -> c) -> BackendM a -> BackendM b -> BackendM c

(*>) :: BackendM a -> BackendM b -> BackendM b

(<*) :: BackendM a -> BackendM b -> BackendM a

MonadIO BackendM

Methods

liftIO :: IO a -> BackendM a

MonadThrow BackendM

Methods

throwM :: Exception e => e -> BackendM a

MonadCatch BackendM

Methods

catch :: Exception e => BackendM a -> (e -> BackendM a) -> BackendM a

argExecutorMode :: String

We switch to executor mode only when argv[1] == argExecutorMode.

Reporting status

data ExecutorFinalStatus a

Constructors

ExecutorFailed Text

ExecutorSucceeded a

Instances

Generic (ExecutorFinalStatus a)

Associated Types

type Rep (ExecutorFinalStatus a) :: * -> *

Methods

from :: ExecutorFinalStatus a -> Rep (ExecutorFinalStatus a) x

to :: Rep (ExecutorFinalStatus a) x -> ExecutorFinalStatus a

Binary a => Binary (ExecutorFinalStatus a)

Methods

put :: ExecutorFinalStatus a -> Put

get :: Get (ExecutorFinalStatus a)

putList :: [ExecutorFinalStatus a] -> Put

type Rep (ExecutorFinalStatus a)

type Rep (ExecutorFinalStatus a) = D1 * (MetaData "ExecutorFinalStatus" "Control.Distributed.Fork.Internal" "distributed-fork-0.0.1.1-9aGU6IWjuUf565jaocBNN1" False) ((:+:) * (C1 * (MetaCons "ExecutorFailed" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * Text))) (C1 * (MetaCons "ExecutorSucceeded" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * a))))

data ExecutorStatus a

Constructors

ExecutorPending ExecutorPendingStatus

ExecutorFinished (ExecutorFinalStatus a)

data ExecutorPendingStatus

Constructors

ExecutorWaiting (Maybe Text)

ExecutorSubmitted (Maybe Text)

ExecutorStarted (Maybe Text)

waiting :: BackendM ()

waitingDesc :: Text -> BackendM ()

submitted :: BackendM ()

submittedDesc :: Text -> BackendM ()

started :: BackendM ()

startedDesc :: Text -> BackendM ()

Re-exports

liftIO :: MonadIO m => forall a. IO a -> m a

Lift a computation from the IO monad.

getExecutablePath :: IO FilePath

Returns the absolute pathname of the current executable.

Note that for scripts and interactive sessions, this is the path to the interpreter (e.g. ghci.)

Since: 4.6.0.0