@hackage network-transport0.3.0

Network abstraction layer

Network.Transport is a Network Abstraction Layer which provides the following high-level concepts:

  • Nodes in the network are represented by EndPoints. These are heavyweight stateful objects.

  • Each EndPoint has an EndPointAddress.

  • Connections can be established from one EndPoint to another using the EndPointAddress of the remote end.

  • The EndPointAddress can be serialised and sent over the network, where as EndPoints and connections cannot.

  • Connections between EndPoints are unidirectional and lightweight.

  • Outgoing messages are sent via a Connection object that represents the sending end of the connection.

  • Incoming messages for all of the incoming connections on an EndPoint are collected via a shared receive queue.

  • In addition to incoming messages, EndPoints are notified of other Events such as new connections or broken connections.

This design was heavily influenced by the design of the Common Communication Interface (http://www.olcf.ornl.gov/center-projects/common-communication-interface). Important design goals are:

  • Connections should be lightweight: it should be no problem to create thousands of connections between endpoints.

  • Error handling is explicit: every function declares as part of its type which errors it can return (no exceptions are thrown)

  • Error handling is "abstract": errors that originate from implementation specific problems (such as "no more sockets" in the TCP implementation) get mapped to generic errors ("insufficient resources") at the Transport level.

This package provides the generic interface only; you will probably also want to install at least one transport implementation (network-transport-*).