rsb.eventprocessing

Contains code mediating between the user interface and the transport layer.

Code author: jwienke

Code author: jmoringe

Classes

BroadcastProcessor([handlers])	Implements synchronous broadcast dispatch to a list of handlers.
Configurator([connectors])	Superclass for in- and out-direction Configurator classes.
DirectEventSendingStrategy()
EventReceivingStrategy	Superclass for event receiving strategies.
EventSendingStrategy
FullyParallelEventReceivingStrategy()	Dispatches events to multiple handlers that can be called in parallel.
InRouteConfigurator([connectors, …])	Manages event receiving using a push strategy.
NonQueuingParallelEventReceivingStrategy()	Dispatches events to handlers using a single thread and no queues.
OutRouteConfigurator([connectors, …])	Manages send events using one or more connectors and a sending strategy.
ParallelEventReceivingStrategy([num_threads])	Dispatches events to multiple handlers in parallel.
ScopeDispatcher()	Maintains a map of Scopes to sink objects.

class rsb.eventprocessing.BroadcastProcessor(handlers=None)

Bases: object

Implements synchronous broadcast dispatch to a list of handlers.

Code author: jmoringe

add_handler(handler)

dispatch(event)

handle(event)

remove_handler(handler)

property handlers

class rsb.eventprocessing.Configurator(connectors=None)

Bases: object

Superclass for in- and out-direction Configurator classes.

Manages the basic aspects like the connector list and (de)activation that are not direction-specific.

Code author: jwienke

Code author: jmoringe

activate()

deactivate()

set_quality_of_service_spec(qos)

property active

property connectors

property scope

property transport_urls

Return the transport URLs of all used connectors.

Returns

List of transport URLs.

Rtype

list

class rsb.eventprocessing.DirectEventSendingStrategy

Bases: rsb.eventprocessing.EventSendingStrategy

add_connector(connector)

handle(event)

remove_connector(connector)

property connectors

class rsb.eventprocessing.EventReceivingStrategy

Bases: object

Superclass for event receiving strategies.

Code author: jwienke

abstract add_filter(the_filter)

abstract add_handler(handler, wait)

abstract handle(event)

abstract remove_filter(the_filter)

abstract remove_handler(handler, wait)

class rsb.eventprocessing.EventSendingStrategy

Bases: object

abstract add_connector(connector)

abstract handle(event)

abstract remove_connector(connector)

abstract property connectors

class rsb.eventprocessing.FullyParallelEventReceivingStrategy

Bases: rsb.eventprocessing.EventReceivingStrategy

Dispatches events to multiple handlers that can be called in parallel.

An EventReceivingStrategy that dispatches events to multiple handlers in individual threads in parallel. Each handler can be called in parallel for different requests.

Code author: jwienke

class Worker(handler, event, filters)

Bases: threading.Thread

getName()

isAlive()

Return whether the thread is alive.

This method returns True just before the run() method starts until just after the run() method terminates. The module function enumerate() returns a list of all alive threads.

isDaemon()

is_alive()

Return whether the thread is alive.

This method returns True just before the run() method starts until just after the run() method terminates. The module function enumerate() returns a list of all alive threads.

join(timeout=None)

Wait until the thread terminates.

This blocks the calling thread until the thread whose join() method is called terminates – either normally or through an unhandled exception or until the optional timeout occurs.

When the timeout argument is present and not None, it should be a floating point number specifying a timeout for the operation in seconds (or fractions thereof). As join() always returns None, you must call isAlive() after join() to decide whether a timeout happened – if the thread is still alive, the join() call timed out.

When the timeout argument is not present or None, the operation will block until the thread terminates.

A thread can be join()ed many times.

join() raises a RuntimeError if an attempt is made to join the current thread as that would cause a deadlock. It is also an error to join() a thread before it has been started and attempts to do so raises the same exception.

run()

Method representing the thread’s activity.

You may override this method in a subclass. The standard run() method invokes the callable object passed to the object’s constructor as the target argument, if any, with sequential and keyword arguments taken from the args and kwargs arguments, respectively.

setDaemon(daemonic)

setName(name)

start()

Start the thread’s activity.

It must be called at most once per thread object. It arranges for the object’s run() method to be invoked in a separate thread of control.

This method will raise a RuntimeError if called more than once on the same thread object.

property daemon

A boolean value indicating whether this thread is a daemon thread.

This must be set before start() is called, otherwise RuntimeError is raised. Its initial value is inherited from the creating thread; the main thread is not a daemon thread and therefore all threads created in the main thread default to daemon = False.

The entire Python program exits when no alive non-daemon threads are left.

property ident

Thread identifier of this thread or None if it has not been started.

This is a nonzero integer. See the thread.get_ident() function. Thread identifiers may be recycled when a thread exits and another thread is created. The identifier is available even after the thread has exited.

property name

A string used for identification purposes only.

It has no semantics. Multiple threads may be given the same name. The initial name is set by the constructor.

add_filter(f)

add_handler(handler, wait)

deactivate()

handle(event)

Dispatch the event to all registered listeners.

Parameters

event – event to dispatch

remove_filter(the_filter)

remove_handler(handler, wait)

class rsb.eventprocessing.InRouteConfigurator(connectors=None, receiving_strategy=None)

Bases: rsb.eventprocessing.Configurator

Manages event receiving using a push strategy.

Instances of this class manage the receiving, filtering and dispatching of events via one or more rsb.transport.Connector s and an EventReceivingStrategy.

Code author: jwienke

Code author: jmoringe

Create a new configurator.

Parameters

• connectors – Connectors through which events are received.

• receiving_strategy – The event receiving strategy according to which the filtering and dispatching of incoming events should be performed.

activate()

deactivate()

filter_added(the_filter)

filter_removed(the_filter)

handler_added(handler, wait)

handler_removed(handler, wait)

set_quality_of_service_spec(qos)

property active

property connectors

property scope

property transport_urls

Return the transport URLs of all used connectors.

Returns

List of transport URLs.

Rtype

list

class rsb.eventprocessing.NonQueuingParallelEventReceivingStrategy

Bases: rsb.eventprocessing.EventReceivingStrategy

Dispatches events to handlers using a single thread and no queues.

An EventReceivingStrategy that dispatches events to multiple handlers using a single thread and without queuing. Only a single buffer is used to decouple the transport from the registered handlers. In case the handler processing is slower than the transport, the transport will block on inserting events into this strategy. Callers must ensure that they are in no active call for #handle when deactivating this instance.

Code author: jwienke

add_filter(f)

add_handler(handler, wait)

deactivate()

handle(event)

remove_filter(the_filter)

remove_handler(handler, wait)

class rsb.eventprocessing.OutRouteConfigurator(connectors=None, sending_strategy=None)

Bases: rsb.eventprocessing.Configurator

Manages send events using one or more connectors and a sending strategy.

Instances of this class manage the sending of events via one or more rsb.transport.Connector s and an EventSendingStrategy.

Code author: jmoringe

activate()

deactivate()

handle(event)

set_quality_of_service_spec(qos)

property active

property connectors

property scope

property transport_urls

Return the transport URLs of all used connectors.

Returns

List of transport URLs.

Rtype

list

class rsb.eventprocessing.ParallelEventReceivingStrategy(num_threads=5)

Bases: rsb.eventprocessing.EventReceivingStrategy

Dispatches events to multiple handlers in parallel.

An EventReceivingStrategy that dispatches events to multiple handlers in individual threads in parallel. Each handler is called only sequentially but potentially from different threads.

Code author: jwienke

add_filter(the_filter)

add_handler(handler, wait)

deactivate()

handle(event)

Dispatch the event to all registered listeners.

Parameters

event – event to dispatch

remove_filter(the_filter)

remove_handler(handler, wait)

class rsb.eventprocessing.ScopeDispatcher

Bases: object

Maintains a map of Scopes to sink objects.

Code author: jmoringe

add_sink(scope, sink)

Associate sink to scope.

Parameters

• scope – The scope to which sink should be associated.

• sink – The arbitrary object that should be associated to scope.

Type scope

Scope

Type sink

object

matching_sinks(scope)

Return a generator yielding sinks matching scope.

A sink matches scope if it was previously associated to scope or one of its super-scopes.

Yields

sinks – A generator yielding all matching sinks in an unspecified order.

remove_sink(scope, sink)

Disassociate sink from scope.

Parameters

• scope – The scope from which sink should be disassociated.

• sink – The arbitrary object that should be disassociated from scope.

Type scope

Scope

Type sink

object

property sinks

Return a generator yielding all sinks.

Yields

sinks – A generator yielding all known sinks in an unspecified order.