Network.WebSockets.Connection

This module exposes connection internals and should only be used if you really know what you are doing.

Documentation

data PendingConnection

A new client connected to the server. We haven't accepted the connection yet, though.

Constructors

PendingConnection

Fields

• pendingOptions :: !ConnectionOptions

  Options, passed as-is to the Connection

• pendingRequest :: !RequestHead

  Useful for e.g. inspecting the request path.

• pendingOnAccept :: !(Connection -> IO ())

  One-shot callback fired when a connection is accepted, i.e., *after* the accepting response is sent to the client.

• pendingStream :: !Stream

  Input/output stream

acceptRequest :: PendingConnection -> IO Connection

Accept a pending connection, turning it into a Connection.

data AcceptRequest

This datatype allows you to set options for acceptRequestWith. It is strongly recommended to use defaultAcceptRequest and then modify the various fields, that way new fields introduced in the library do not break your code.

Constructors

AcceptRequest

Fields

• acceptSubprotocol :: !(Maybe ByteString)

  The subprotocol to speak with the client. If pendingSubprotcols is non-empty, acceptSubprotocol must be one of the subprotocols from the list.

• acceptHeaders :: !Headers

  Extra headers to send with the response.

defaultAcceptRequest :: AcceptRequest

acceptRequestWith :: PendingConnection -> AcceptRequest -> IO Connection

This function is like acceptRequest but allows you to set custom options using the AcceptRequest datatype.

rejectRequest :: PendingConnection -> ByteString -> IO ()

data Connection

Constructors

Connection

Fields

• connectionOptions :: !ConnectionOptions
• connectionType :: !ConnectionType
• connectionProtocol :: !Protocol
• connectionParse :: !(IO (Maybe Message))
• connectionWrite :: !([Message] -> IO ())
• connectionSentClose :: !(IORef Bool)

  According to the RFC, both the client and the server MUST send a close control message to each other. Either party can initiate the first close message but then the other party must respond. Finally, the server is in charge of closing the TCP connection. This IORef tracks if we have sent a close message and are waiting for the peer to respond.

data ConnectionOptions

Set options for a Connection.

Constructors

ConnectionOptions

Fields

• connectionOnPong :: !(IO ())

  Whenever a pong is received, this IO action is executed. It can be used to tickle connections or fire missiles.

defaultConnectionOptions :: ConnectionOptions

receive :: Connection -> IO Message

receiveDataMessage :: Connection -> IO DataMessage

Receive an application message. Automatically respond to control messages.

When the peer sends a close control message, an exception of type CloseRequest is thrown. The peer can send a close control message either to initiate a close or in response to a close message we have sent to the peer. In either case the CloseRequest exception will be thrown. The RFC specifies that the server is responsible for closing the TCP connection, which should happen after receiving the CloseRequest exception from this function.

This will throw ConnectionClosed if the TCP connection dies unexpectedly.

receiveData :: WebSocketsData a => Connection -> IO a

Receive a message, converting it to whatever format is needed.

send :: Connection -> Message -> IO ()

sendDataMessage :: Connection -> DataMessage -> IO ()

Send a DataMessage

sendDataMessages :: Connection -> [DataMessage] -> IO ()

Send a collection of DataMessages

sendTextData :: WebSocketsData a => Connection -> a -> IO ()

Send a message as text

sendTextDatas :: WebSocketsData a => Connection -> [a] -> IO ()

Send a collection of messages as text

sendBinaryData :: WebSocketsData a => Connection -> a -> IO ()

Send a message as binary data

sendBinaryDatas :: WebSocketsData a => Connection -> [a] -> IO ()

Send a collection of messages as binary data

sendClose :: WebSocketsData a => Connection -> a -> IO ()

Send a friendly close message. Note that after sending this message, you should still continue calling receiveDataMessage to process any in-flight messages. The peer will eventually respond with a close control message of its own which will cause receiveDataMessage to throw the CloseRequest exception. This exception is when you can finally consider the connection closed.

sendCloseCode :: WebSocketsData a => Connection -> Word16 -> a -> IO ()

Send a friendly close message and close code. Similar to sendClose, you should continue calling receiveDataMessage until you receive a CloseRequest exception.

See http://tools.ietf.org/html/rfc6455#section-7.4 for a list of close codes.

sendPing :: WebSocketsData a => Connection -> a -> IO ()

Send a ping

forkPingThread :: Connection -> Int -> IO ()

Forks a ping thread, sending a ping message every n seconds over the connection. The thread dies silently if the connection crashes or is closed.