Source code for google.cloud.pubsub.message

# Copyright 2015 Google 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
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# 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.

"""Define API Topics."""

import base64

from google.cloud._helpers import _rfc3339_to_datetime


[docs]class Message(object): """Messages can be published to a topic and received by subscribers. See: https://cloud.google.com/pubsub/docs/reference/rest/v1/PubsubMessage :type data: bytes :param data: the payload of the message. :type message_id: string :param message_id: An ID assigned to the message by the API. :type attributes: dict or None :param attributes: Extra metadata associated by the publisher with the message. """ _service_timestamp = None def __init__(self, data, message_id, attributes=None): self.data = data self.message_id = message_id self._attributes = attributes @property def attributes(self): """Lazily-constructed attribute dictionary.""" if self._attributes is None: self._attributes = {} return self._attributes @property def timestamp(self): """Return sortable timestamp from attributes, if passed. Allows sorting messages in publication order (assuming consistent clocks across all publishers). :rtype: :class:`datetime.datetime` :returns: timestamp (in UTC timezone) parsed from RFC 3339 timestamp :raises: ValueError if timestamp not in ``attributes``, or if it does not match the RFC 3339 format. """ stamp = self.attributes.get('timestamp') if stamp is None: raise ValueError('No timestamp') return _rfc3339_to_datetime(stamp) @property def service_timestamp(self): """Return server-set timestamp. :rtype: string :returns: timestamp (in UTC timezone) in RFC 3339 format """ return self._service_timestamp @classmethod
[docs] def from_api_repr(cls, api_repr): """Factory: construct message from API representation. :type api_repr: dict or None :param api_repr: The API representation of the message :rtype: :class:`Message` :returns: The message created from the response. """ data = base64.b64decode(api_repr.get('data', b'')) instance = cls( data=data, message_id=api_repr['messageId'], attributes=api_repr.get('attributes')) instance._service_timestamp = api_repr.get('publishTimestamp') return instance