Kamaelia.Internet.ConnectedSocketAdapter

• component ConnectedSocketAdapter

• Talking to network sockets
  • Example Usage
  • See also
  • How does it work?

Talking to network sockets

A Connected Socket Adapter (CSA) component talks to a network server socket. Data is sent to and received from the socket via this component's inboxes and outboxes. A CSA is effectively a wrapper for a socket.

Most components should not need to create CSAs themselves. Instead, use components such as TCPClient to make an outgoing connection, or TCPServer or SimpleServer to be a server that responds to incoming connections.

Example Usage

See source code for TCPClient to see how Connected Socket Adapters can be used.

See also

• TCPClient -- for making a connection to a server
• TCPServer --
• SimpleServer -- a prefab chassis for building a server

How does it work?

A CSA is usually created either by a component such as TCPClient that wants to establish a connection to a server; or by a primary listener socket - a component acting as a server - listening for incoming connections from clients.

The socket should be set up and passed to the constructor to make the CSA.

Incoming data, read by the CSA, is sent out of its "outbox" outbox as strings containing the received binary data. Send data by sending it, as strings, to the "inbox" outbox.

The CSA expects to be wired to a component that will notify it when new data has arrived at its socket (by sending an Axon.Ipc.status message to its "ReadReady" inbox. This is to allow the CSA to sleep rather than busy-wait or blocking when waiting for new data to arrive. Typically this is the Selector component.

This component will terminate (and close its socket) if it receives a producerFinished or shutdownMicroprocess message on its "control" inbox.

When this component terminates, it sends a socketShutdown(socket) message out of its "CreatorFeedback" outbox and a shutdownCSA((selfCSA,self.socket)) message out of its "signal" outbox.

The message sent to "CreatorFeedback" is to notify the original creator that the socket is now closed and that this component should be unwired.

The message sent to the "signal" outbox serves to notify any other component involved - such as the one feeding notifications to the "ReadReady" inbox (eg. the Selector component).

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Kamaelia.Internet.ConnectedSocketAdapter.ConnectedSocketAdapter

class ConnectedSocketAdapter(Axon.Component.component)

ConnectedSocketAdapter(socket) -> new CSA component wrapping specified socket

Component for communicating with a socket. Send to its "inbox" inbox to send data, and receive data from its "outbox" outbox.

"ReadReady" inbox must be wired to something that will notify it when new data has arrived at the socket.

Inboxes

• control : Shutdown on producerFinished message (incoming & outgoing data is flushed first)
• ReadReady : Notify this CSA that there is incoming data ready on the socket
• makessl : Notify this CSA that the socket should be wrapped into SSL
• inbox : Data for this CSA to send through the socket (Axon.Ipc.status message)
• SendReady : Notify this CSA that the socket is ready to send

Outboxes

• outbox : Data received from the socket
• CreatorFeedback : Expected to be connected to some form of signal input on the CSA's creator. Signals socketShutdown (this socket has closed)
• sslready : Notifies components that the socket is now wrapped into SSL
• signal : Signals shutdownCSA (this CSA is shutting down)
• _selectorSignal : For communication to the selector

Methods defined here

__init__(self, listensocket, selectorService[, crashOnBadDataToSend][, noisyErrors])

x.__init__(...) initializes x; see x.__class__.__doc__ for signature

_saferecv(self, sock[, size])

Internal only function, used for recieving data, and handling EAGAIN style retry scenarios gracefully

_safesend(self, sock, data)

Internal only function, used for sending data, and handling EAGAIN style retry scenarios gracefully

canDoSomething(self)

checkSocketStatus(self)

flushSendQueue(self)

handleControl(self)

Check for producerFinished message and shutdown in response

handleReceive(self)

main(self)

passOnShutdown(self)

stop(self)