nanonext: NNG (Nanomsg Next Gen) Lightweight Messaging Library

R binding for NNG (Nanomsg Next Gen), a successor to ZeroMQ. NNG is a socket library implementing ‘Scalability Protocols’, a reliable, high-performance standard for common communications patterns including publish/subscribe, request/reply and service discovery, over in-process, IPC, TCP, WebSocket and secure TLS transports. As its own threaded concurrency framework, provides a toolkit for asynchronous programming and distributed computing, with intuitive ‘aio’ objects which resolve automatically upon completion of asynchronous operations, and synchronisation primitives allowing R to wait upon events signalled by concurrent threads.

Usage notes

nanonext offers 2 equivalent interfaces: a functional interface, and an object-oriented interface.

The primary object in the functional interface is the Socket. Use socket to create a socket and dial or listen at an address. The socket is then passed as the first argument of subsequent actions such as send() or recv().

The primary object in the object-oriented interface is the nano object. Use nano to create a nano object which encapsulates a Socket and Dialer/Listener. Methods such as $send() or $recv() can then be accessed directly from the object.

Documentation

Guide to the implemented protocols for sockets: protocols

Guide to the supported transports for dialers and listeners: transports

Guide to the options that can be inspected and set using: opt / opt<-

Reference Manual

vignette("nanonext", package = "nanonext")

Conceptual overview

NNG presents a socket view of networking. A socket implements precisely one protocol, such as ‘bus’, etc.

Each socket can be used to send and receive messages (if the protocol supports it, and implements the appropriate protocol semantics). For example, the ‘sub’ protocol automatically filters incoming messages to discard topics that have not been subscribed.

NNG sockets are message-oriented, and messages are either delivered wholly, or not at all. Partial delivery is not possible. Furthermore, NNG does not provide any other delivery or ordering guarantees: messages may be dropped or reordered (some protocols, such as ‘req’ may offer stronger guarantees by performing their own retry and validation schemes).

Each socket can have zero, one, or many endpoints, which are either listeners or dialers (a given socket may use listeners, dialers, or both). These endpoints provide access to underlying transports, such as TCP, etc.

Each endpoint is associated with a URL, which is a service address. For dialers, this is the service address that is contacted, whereas for listeners this is where new connections will be accepted.

Links

NNG: https://nng.nanomsg.org/
Mbed TLS: https://www.trustedfirmware.org/projects/mbed-tls/

Author

Charlie Gao charlie.gao@shikokuchuo.net (ORCID)