mbuslite 0.1.0

A small, in-process message bus implementation.

mbuslite provides a message bus implementation embedded within the application’s process.

With it, you can loosely couple your application components. It implements the publish-subscribe pattern.

Motivation

Having worked with crossbar and autobahn, as well as DBus, I like the message bus pattern. I’ve wanted to use it in some projects to achieve the same loose coupling between internal components.

Having also worked wih sqlite, I like the simplicity of a library instead of a remote service.

Thus, mbuslite.

Installation

pip install mbuslite

Usage

To get started, import mbuslite.Bus and start calling .subscribe() and .publish().

from mbuslite import Bus

class Producer:
    def announce( self ):
        Bus.publish( 'topic.name', 'Hello, consumers!' )

class Consumer:
    def __init__( self ):
        Bus.subscribe( 'topic.name', self.on_message )
    def on_message( self, msg ):
        print( msg )

consumer1 = Consumer()
consumer2 = Consumer()
consumer3 = Consumer()
producer = Producer()
producer.announce()

Hello, consumers!
Hello, consumers!
Hello, consumers!

Publishers and subscribers must agree upon a call signature as the arguments are passed as-is by mbuslite.

def handler( one, two, three, four ):
    pass
Bus.subscribe( 'foo', handler )
Bus.publish( 'foo', 1, 2, three = 3, four = 4 )

See more in examples/.

Logging

mbuslite makes use of the python logging module. To manipulate mbuslite’s logging behavior, use logging.getLogger('mbuslite') or import mbuslite and manipulate mbuslite.logger. For example, you can set that logger’s level to info or debug to get additional information about what mbuslite is doing.

Note that mbuslite does not configure the logging module, so unless your application does, logs from mbuslite will not be written anywhere, even those that match the default level of WARNING. You are encouraged to at least call logging.basicConfig() to ensure you see warning messages from mbuslite. For example, unhandled exceptions from handlers you subscribe to topics are logged as warnings and will not be available if you never configure logging.

Links

• PyPI: https://pypi.org/project/mbuslite

• Source: https://gitlab.com/francisferrell/mbuslite

• API Docs: https://francisferrell.gitlab.io/mbuslite