68 lines
2.8 KiB
Python
68 lines
2.8 KiB
Python
|
|
# Copyright 2013 Red Hat, Inc.
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
|
|
class Target(object):
|
|
|
|
"""Identifies the destination of messages.
|
|
|
|
A Target encapsulates all the information to identify where a message
|
|
should be sent or what messages a server is listening for.
|
|
|
|
Its attributes are:
|
|
|
|
:param exchange: A scope for topics. Leave unspecified to default to the
|
|
control_exchange configuration option.
|
|
:type exchange: str
|
|
:param topic: A name which identifies the set of interfaces exposed by a
|
|
server. Multiple servers may listen on a topic and messages will be
|
|
dispatched to one of the servers in a round-robin fashion.
|
|
:type topic: str
|
|
:param namespace: Identifies a particular interface (i.e. set of methods)
|
|
exposed by a server. The default interface has no namespace identifier
|
|
and is referred to as the null namespace.
|
|
:type topic: str
|
|
:param version: Interfaces have a major.minor version number associated
|
|
with them. A minor number increment indicates a backwards compatible
|
|
change and an incompatible change is indicated by a major number bump.
|
|
Servers may implement multiple major versions and clients may require
|
|
indicate that their message requires a particular minimum minor version.
|
|
:type topic: str
|
|
:param server: Clients can request that a message be directed to a specific
|
|
server, rather than just one of a pool of servers listening on the topic.
|
|
:type topic: str
|
|
:param fanout: Clients may request that a message be directed to all
|
|
servers listening on a topic by setting fanout to ``True``, rather than
|
|
just one of them.
|
|
:type topic: bool
|
|
"""
|
|
|
|
def __init__(self, exchange=None, topic=None, namespace=None,
|
|
version=None, server=None, fanout=None):
|
|
self.exchange = exchange
|
|
self.topic = topic
|
|
self.namespace = namespace
|
|
self.version = version
|
|
self.server = server
|
|
self.fanout = fanout
|
|
|
|
def __call__(self, **kwargs):
|
|
kwargs.setdefault('exchange', self.exchange)
|
|
kwargs.setdefault('topic', self.topic)
|
|
kwargs.setdefault('namespace', self.version)
|
|
kwargs.setdefault('server', self.server)
|
|
kwargs.setdefault('fanout', self.fanout)
|
|
return Target(**kwargs)
|