# Copyright 2016-2021 Doug Latornell, 43ravens
# 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.
"""NEMO_Nowcast framework message object.
"""
import attr
import yaml
[docs]@attr.s
class Message:
"""Construct a :py:class:`nemo_nowcast.message.Message` instance.
"""
#: Name of the worker or manager sending the message.
source = attr.ib()
#: Key of a message type that is defined for source in the message
#: registry section of the configuration data structure.
type = attr.ib()
#: Content of message; must be serializable by YAML such that it can be
#: deserialized by :py:func:`yaml.safe_load`.
payload = attr.ib(default=None)
[docs] def serialize(self):
"""Construct a message data structure and transform it into a string
suitable for sending.
:returns: Message data structure serialized using YAML.
"""
return yaml.dump(
{"source": self.source, "type": self.type, "payload": self.payload}
)
[docs] @classmethod
def deserialize(cls, message):
"""Transform received message from str to message data structure.
:arg str message: Message dict serialized using YAML.
:returns: :py:class:`nemo_nowcast.lib.Message` instance
"""
msg = yaml.safe_load(message)
return cls(source=msg["source"], type=msg["type"], payload=msg["payload"])