The gemstone.event module

Event transports

class gemstone.event.BaseEventTransport

Base class for defining event transports.

The basic workflow would be the following:

• the handlers are registered with the BaseEventTransport.register_event_handler() method
• the BaseEventTransport.start_accepting_events() is invoked
• for each incoming event, call BaseEventTransport.on_event_received() whose responsibility is to invoke the proper handler function (recommended to use the run_on_main_thread method)

emit_event(event_name, event_body)

Emits an event of type event_name with the event_body content using the current event transport.

Parameters:

• event_name –
• event_body –

Returns:

on_event_received(event_name, event_body)

Handles generic event. This function should treat every event that is received with the designated handler function.

Parameters:

• event_name – the name of the event to be handled
• event_body – the body of the event to be handled

Returns:

register_event_handler(handler_func, handled_event_name)

Registers a function to handle all events of type handled_event_name

Parameters:

• handler_func – the handler function
• handled_event_name – the handled event type

run_on_main_thread(func, args=None, kwargs=None)

Runs the func callable on the main thread, by using the provided microservice instance’s IOLoop.

Parameters:

• func – callable to run on the main thread
• args – tuple or list with the positional arguments.
• kwargs – dict with the keyword arguments.

Returns:

set_microservice(microservice)

Used by the microservice instance to send reference to itself. Do not override this.

start_accepting_events()

Starts accepting and handling events.

class gemstone.event.RedisEventTransport(redis_url)

Event transport that uses a Redis server as message transport by using the PUBSUB mechanism.

Parameters:redis_url – A string that specifies the network location of the redis server: - redis://[:password@]hostaddr:port/dbnumber (plaintext) - rediss://[:password@]hostaddr:port/dbnumber (over TLS) - unix://[:password@]/path/to/socket?db=dbnumber (Unix socket)

class gemstone.event.RabbitMqEventTransport(host='127.0.0.1', port=5672, username='', password='', **connection_options)

Event transport via RabbitMQ server.

Parameters:

• host – ipv4 or hostname
• port – the port where the server listens
• username – username used for authentication
• password – password used for authentication
• connection_options – extra arguments that will be used in pika.BlockingConnection initialization.