Network.KRPC.Manager

Normally, you don't need to import this module.

Manager

class (MonadBaseControl IO m, MonadLogger m, MonadIO m) => MonadKRPC h m | m -> h where

A monad which can perform or handle queries.

Methods

getManager :: m (Manager h)

Ask for manager.

liftHandler :: h a -> m a

Can be used to add logging for instance.

Instances

(MonadBaseControl IO h, MonadLogger h, MonadIO h) => MonadKRPC h (ReaderT (Manager h) h)

data Options

RPC manager options.

Constructors

Options

Fields

optSeedTransaction :: !Int

Initial TransactionId incremented with each query;

optQueryTimeout :: !Int

Time to wait for response from remote node, in seconds.

optMaxMsgSize :: !Int

Maximum number of bytes to receive.

Instances

Eq Options

Show Options

Default Options

Permissive defaults.

data Manager h

Keep track pending queries made by this node and handle queries made by remote nodes.

Instances

(MonadBaseControl IO h, MonadLogger h, MonadIO h) => MonadKRPC h (ReaderT (Manager h) h)

newManager

Arguments

:: Options

various protocol options;

-> SockAddr

address to listen on;

-> [Handler h]

handlers to run on incoming queries.

-> IO (Manager h)

new rpc manager.

Bind socket to the specified address. To enable query handling run listen.

closeManager :: Manager m -> IO ()

Unblock all pending calls and close socket.

withManager :: Options -> SockAddr -> [Handler h] -> (Manager h -> IO a) -> IO a

Normally you should use Control.Monad.Trans.Resource.allocate function.

isActive :: Manager m -> IO Bool

Check if the manager is still active. Manager becomes active until closeManager called.

listen :: MonadKRPC h m => m ()

Should be run before any query, otherwise they will never succeed.

Queries

data QueryFailure

Used to signal query errors.

Constructors

SendFailed

unable to send query;

QueryFailed ErrorCode Text

remote node return error;

TimeoutExpired

remote node not responding.

Instances

Eq QueryFailure

Show QueryFailure

Typeable QueryFailure

Exception QueryFailure

query :: forall h m a b. (MonadKRPC h m, KRPC a b) => SockAddr -> a -> m b

Enqueue query to the given node.

This function should throw QueryFailure exception if quered node respond with error message or the query timeout expires.

getQueryCount :: MonadKRPC h m => m Int

How many times query call have been performed.

Handlers

data HandlerFailure

Used to signal protocol errors.

Constructors

BadAddress

for e.g.: node calls herself;

InvalidParameter Text

for e.g.: bad session token.

Instances

Eq HandlerFailure

Show HandlerFailure

Typeable HandlerFailure

Exception HandlerFailure

type Handler h = (MethodName, HandlerBody h)

Handler is a function which will be invoked then some remote node querying this node.

handler :: forall h a b. (KRPC a b, Monad h) => (SockAddr -> a -> h b) -> Handler h

Make handler from handler function. Any thrown exception will be supressed and send over the wire back to the querying node.

If the handler make some query normally it should handle corresponding QueryFailures.