Source code for google.pubsub.v1.subscriber_api

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"""Accesses the google.pubsub.v1 Subscriber API."""

import json
import os
import pkg_resources
import platform

from google.gax import api_callable
from google.gax import config
from google.gax import path_template
import google.gax

from google.pubsub.v1 import pubsub_pb2

_PageDesc = google.gax.PageDescriptor


[docs]class SubscriberApi(object): """ The service that an application uses to manipulate subscriptions and to consume messages from a subscription via the ``Pull`` method. """ SERVICE_ADDRESS = 'pubsub.googleapis.com' """The default address of the service.""" DEFAULT_SERVICE_PORT = 443 """The default port of the service.""" _CODE_GEN_NAME_VERSION = 'gapic/0.1.0' _GAX_VERSION = pkg_resources.get_distribution('google-gax').version _DEFAULT_TIMEOUT = 30 _PAGE_DESCRIPTORS = { 'list_subscriptions': _PageDesc('page_token', 'next_page_token', 'subscriptions') } # The scopes needed to make gRPC calls to all of the methods defined in # this service _ALL_SCOPES = ('https://www.googleapis.com/auth/pubsub', 'https://www.googleapis.com/auth/cloud-platform', ) _PROJECT_PATH_TEMPLATE = path_template.PathTemplate('projects/{project}') _SUBSCRIPTION_PATH_TEMPLATE = path_template.PathTemplate( 'projects/{project}/subscriptions/{subscription}') _TOPIC_PATH_TEMPLATE = path_template.PathTemplate( 'projects/{project}/topics/{topic}') @classmethod
[docs] def project_path(cls, project): """Returns a fully-qualified project resource name string.""" return cls._PROJECT_PATH_TEMPLATE.render({'project': project, })
@classmethod
[docs] def subscription_path(cls, project, subscription): """Returns a fully-qualified subscription resource name string.""" return cls._SUBSCRIPTION_PATH_TEMPLATE.render({ 'project': project, 'subscription': subscription, })
@classmethod
[docs] def topic_path(cls, project, topic): """Returns a fully-qualified topic resource name string.""" return cls._TOPIC_PATH_TEMPLATE.render({ 'project': project, 'topic': topic, })
@classmethod
[docs] def match_project_from_project_name(cls, project_name): """Parses the project from a project resource. Args: project_name (string): A fully-qualified path representing a project resource. Returns: A string representing the project. """ return cls._PROJECT_PATH_TEMPLATE.match(project_name).get('project')
@classmethod
[docs] def match_project_from_subscription_name(cls, subscription_name): """Parses the project from a subscription resource. Args: subscription_name (string): A fully-qualified path representing a subscription resource. Returns: A string representing the project. """ return cls._SUBSCRIPTION_PATH_TEMPLATE.match(subscription_name).get( 'project')
@classmethod
[docs] def match_subscription_from_subscription_name(cls, subscription_name): """Parses the subscription from a subscription resource. Args: subscription_name (string): A fully-qualified path representing a subscription resource. Returns: A string representing the subscription. """ return cls._SUBSCRIPTION_PATH_TEMPLATE.match(subscription_name).get( 'subscription')
@classmethod
[docs] def match_project_from_topic_name(cls, topic_name): """Parses the project from a topic resource. Args: topic_name (string): A fully-qualified path representing a topic resource. Returns: A string representing the project. """ return cls._TOPIC_PATH_TEMPLATE.match(topic_name).get('project')
@classmethod
[docs] def match_topic_from_topic_name(cls, topic_name): """Parses the topic from a topic resource. Args: topic_name (string): A fully-qualified path representing a topic resource. Returns: A string representing the topic. """ return cls._TOPIC_PATH_TEMPLATE.match(topic_name).get('topic')
def __init__(self, service_path=SERVICE_ADDRESS, port=DEFAULT_SERVICE_PORT, channel=None, metadata_transformer=None, ssl_creds=None, scopes=None, client_config=None, timeout=_DEFAULT_TIMEOUT, app_name='gax', app_version=_GAX_VERSION): """Constructor. Args: service_path (string): The domain name of the API remote host. port (int): The port on which to connect to the remote host. channel (:class:`grpc.beta.implementations.Channel`): A ``Channel`` object through which to make calls. ssl_creds (:class:`grpc.beta.implementations.ClientCredentials`): A `ClientCredentials` for use with an SSL-enabled channel. client_config (dict): A dictionary for call options for each method. See :func:`google.gax.construct_settings` for the structure of this data. Falls back to the default config if not specified or the specified config is missing data points. metadata_transformer (Callable[[], list]): A function that creates the metadata for requests. timeout (int): The default timeout, in seconds, for calls made through this client app_name (string): The codename of the calling service. app_version (string): The version of the calling service. Returns: A SubscriberApi object. """ if scopes is None: scopes = self._ALL_SCOPES if client_config is None: client_config = {} goog_api_client = '{}/{} {} gax/{} python/{}'.format( app_name, app_version, self._CODE_GEN_NAME_VERSION, self._GAX_VERSION, platform.python_version()) metadata = [('x-goog-api-client', goog_api_client)] default_client_config = json.loads(pkg_resources.resource_string( __name__, 'subscriber_client_config.json')) defaults = api_callable.construct_settings( 'google.pubsub.v1.Subscriber', default_client_config, client_config, config.STATUS_CODE_NAMES, timeout, kwargs={'metadata': metadata}, page_descriptors=self._PAGE_DESCRIPTORS) self.stub = config.create_stub( pubsub_pb2.beta_create_Subscriber_stub, service_path, port, ssl_creds=ssl_creds, channel=channel, metadata_transformer=metadata_transformer, scopes=scopes) self._create_subscription = api_callable.create_api_call( self.stub.CreateSubscription, settings=defaults['create_subscription']) self._get_subscription = api_callable.create_api_call( self.stub.GetSubscription, settings=defaults['get_subscription']) self._list_subscriptions = api_callable.create_api_call( self.stub.ListSubscriptions, settings=defaults['list_subscriptions']) self._delete_subscription = api_callable.create_api_call( self.stub.DeleteSubscription, settings=defaults['delete_subscription']) self._modify_ack_deadline = api_callable.create_api_call( self.stub.ModifyAckDeadline, settings=defaults['modify_ack_deadline']) self._acknowledge = api_callable.create_api_call( self.stub.Acknowledge, settings=defaults['acknowledge']) self._pull = api_callable.create_api_call(self.stub.Pull, settings=defaults['pull']) self._modify_push_config = api_callable.create_api_call( self.stub.ModifyPushConfig, settings=defaults['modify_push_config']) # Service calls
[docs] def create_subscription(self, name, topic, push_config=None, ack_deadline_seconds=0, options=None): """ Creates a subscription to a given topic for a given subscriber. If the subscription already exists, returns ``ALREADY_EXISTS``. If the corresponding topic doesn't exist, returns ``NOT_FOUND``. If the name is not provided in the request, the server will assign a random name for this subscription on the same project as the topic. Example: >>> from google.pubsub.v1.subscriber_api import SubscriberApi >>> api = SubscriberApi() >>> name = api.subscription_path('[PROJECT]', '[SUBSCRIPTION]') >>> topic = api.topic_path('[PROJECT]', '[TOPIC]') >>> response = api.create_subscription(name, topic) Args: name (string): The name of the subscription. It must have the format ``"projects/{project}/subscriptions/{subscription}"``. ``{subscription}`` must start with a letter, and contain only letters (``[A-Za-z]``), numbers (``[0-9]``), dashes (``-``), underscores (``_``), periods (``.``), tildes (``~``), plus (``+``) or percent signs (``%``). It must be between 3 and 255 characters in length, and it must not start with ``"goog"``. topic (string): The name of the topic from which this subscription is receiving messages. The value of this field will be ``_deleted-topic_`` if the topic has been deleted. push_config (:class:`google.pubsub.v1.pubsub_pb2.PushConfig`): If push delivery is used with this subscription, this field is used to configure it. An empty ``pushConfig`` signifies that the subscriber will pull and ack messages using API methods. ack_deadline_seconds (int): This value is the maximum time after a subscriber receives a message before the subscriber should acknowledge the message. After message delivery but before the ack deadline expires and before the message is acknowledged, it is an outstanding message and will not be delivered again during that time (on a best-effort basis). For pull subscriptions, this value is used as the initial value for the ack deadline. To override this value for a given message, call ``ModifyAckDeadline`` with the corresponding ``ack_id`` if using pull. For push delivery, this value is also used to set the request timeout for the call to the push endpoint. If the subscriber never acknowledges the message, the Pub/Sub system will eventually redeliver the message. If this parameter is not set, the default value of 10 seconds is used. options (:class:`google.gax.CallOptions`): Overrides the default settings for this call, e.g, timeout, retries etc. Returns: A :class:`google.pubsub.v1.pubsub_pb2.Subscription` instance. Raises: :exc:`google.gax.errors.GaxError` if the RPC is aborted. """ if push_config is None: push_config = pubsub_pb2.PushConfig() request = pubsub_pb2.Subscription( name=name, topic=topic, push_config=push_config, ack_deadline_seconds=ack_deadline_seconds) return self._create_subscription(request, options)
[docs] def get_subscription(self, subscription, options=None): """ Gets the configuration details of a subscription. Example: >>> from google.pubsub.v1.subscriber_api import SubscriberApi >>> api = SubscriberApi() >>> subscription = api.subscription_path('[PROJECT]', '[SUBSCRIPTION]') >>> response = api.get_subscription(subscription) Args: subscription (string): The name of the subscription to get. options (:class:`google.gax.CallOptions`): Overrides the default settings for this call, e.g, timeout, retries etc. Returns: A :class:`google.pubsub.v1.pubsub_pb2.Subscription` instance. Raises: :exc:`google.gax.errors.GaxError` if the RPC is aborted. """ request = pubsub_pb2.GetSubscriptionRequest(subscription=subscription) return self._get_subscription(request, options)
[docs] def list_subscriptions(self, project, page_size=0, options=None): """ Lists matching subscriptions. Example: >>> from google.pubsub.v1.subscriber_api import SubscriberApi >>> from google.gax import CallOptions, INITIAL_PAGE >>> api = SubscriberApi() >>> project = api.project_path('[PROJECT]') >>> >>> # Iterate over all results >>> for element in api.list_subscriptions(project): >>> # process element >>> pass >>> >>> # Or iterate over results one page at a time >>> for page in api.list_subscriptions(project, options=CallOptions(page_token=INITIAL_PAGE)): >>> for element in page: >>> # process element >>> pass Args: project (string): The name of the cloud project that subscriptions belong to. page_size (int): Maximum number of subscriptions to return. options (:class:`google.gax.CallOptions`): Overrides the default settings for this call, e.g, timeout, retries etc. Returns: A :class:`google.gax.PageIterator` instance. By default, this is an iterable of :class:`google.pubsub.v1.pubsub_pb2.Subscription` instances. This object can also be configured to iterate over the pages of the response through the `CallOptions` parameter. Raises: :exc:`google.gax.errors.GaxError` if the RPC is aborted. """ request = pubsub_pb2.ListSubscriptionsRequest(project=project, page_size=page_size) return self._list_subscriptions(request, options)
[docs] def delete_subscription(self, subscription, options=None): """ Deletes an existing subscription. All pending messages in the subscription are immediately dropped. Calls to ``Pull`` after deletion will return ``NOT_FOUND``. After a subscription is deleted, a new one may be created with the same name, but the new one has no association with the old subscription, or its topic unless the same topic is specified. Example: >>> from google.pubsub.v1.subscriber_api import SubscriberApi >>> api = SubscriberApi() >>> subscription = api.subscription_path('[PROJECT]', '[SUBSCRIPTION]') >>> api.delete_subscription(subscription) Args: subscription (string): The subscription to delete. options (:class:`google.gax.CallOptions`): Overrides the default settings for this call, e.g, timeout, retries etc. Raises: :exc:`google.gax.errors.GaxError` if the RPC is aborted. """ request = pubsub_pb2.DeleteSubscriptionRequest( subscription=subscription) self._delete_subscription(request, options)
[docs] def modify_ack_deadline(self, subscription, ack_ids, ack_deadline_seconds, options=None): """ Modifies the ack deadline for a specific message. This method is useful to indicate that more time is needed to process a message by the subscriber, or to make the message available for redelivery if the processing was interrupted. Example: >>> from google.pubsub.v1.subscriber_api import SubscriberApi >>> api = SubscriberApi() >>> subscription = api.subscription_path('[PROJECT]', '[SUBSCRIPTION]') >>> ack_ids = [] >>> ack_deadline_seconds = 0 >>> api.modify_ack_deadline(subscription, ack_ids, ack_deadline_seconds) Args: subscription (string): The name of the subscription. ack_ids (list[string]): List of acknowledgment IDs. ack_deadline_seconds (int): The new ack deadline with respect to the time this request was sent to the Pub/Sub system. Must be >= 0. For example, if the value is 10, the new ack deadline will expire 10 seconds after the ``ModifyAckDeadline`` call was made. Specifying zero may immediately make the message available for another pull request. options (:class:`google.gax.CallOptions`): Overrides the default settings for this call, e.g, timeout, retries etc. Raises: :exc:`google.gax.errors.GaxError` if the RPC is aborted. """ request = pubsub_pb2.ModifyAckDeadlineRequest( subscription=subscription, ack_ids=ack_ids, ack_deadline_seconds=ack_deadline_seconds) self._modify_ack_deadline(request, options)
[docs] def acknowledge(self, subscription, ack_ids, options=None): """ Acknowledges the messages associated with the ``ack_ids`` in the ``AcknowledgeRequest``. The Pub/Sub system can remove the relevant messages from the subscription. Acknowledging a message whose ack deadline has expired may succeed, but such a message may be redelivered later. Acknowledging a message more than once will not result in an error. Example: >>> from google.pubsub.v1.subscriber_api import SubscriberApi >>> api = SubscriberApi() >>> subscription = api.subscription_path('[PROJECT]', '[SUBSCRIPTION]') >>> ack_ids = [] >>> api.acknowledge(subscription, ack_ids) Args: subscription (string): The subscription whose message is being acknowledged. ack_ids (list[string]): The acknowledgment ID for the messages being acknowledged that was returned by the Pub/Sub system in the ``Pull`` response. Must not be empty. options (:class:`google.gax.CallOptions`): Overrides the default settings for this call, e.g, timeout, retries etc. Raises: :exc:`google.gax.errors.GaxError` if the RPC is aborted. """ request = pubsub_pb2.AcknowledgeRequest(subscription=subscription, ack_ids=ack_ids) self._acknowledge(request, options)
[docs] def pull(self, subscription, max_messages, return_immediately=False, options=None): """ Pulls messages from the server. Returns an empty list if there are no messages available in the backlog. The server may return ``UNAVAILABLE`` if there are too many concurrent pull requests pending for the given subscription. Example: >>> from google.pubsub.v1.subscriber_api import SubscriberApi >>> api = SubscriberApi() >>> subscription = api.subscription_path('[PROJECT]', '[SUBSCRIPTION]') >>> max_messages = 0 >>> response = api.pull(subscription, max_messages) Args: subscription (string): The subscription from which messages should be pulled. return_immediately (bool): If this is specified as true the system will respond immediately even if it is not able to return a message in the ``Pull`` response. Otherwise the system is allowed to wait until at least one message is available rather than returning no messages. The client may cancel the request if it does not wish to wait any longer for the response. max_messages (int): The maximum number of messages returned for this request. The Pub/Sub system may return fewer than the number specified. options (:class:`google.gax.CallOptions`): Overrides the default settings for this call, e.g, timeout, retries etc. Returns: A :class:`google.pubsub.v1.pubsub_pb2.PullResponse` instance. Raises: :exc:`google.gax.errors.GaxError` if the RPC is aborted. """ request = pubsub_pb2.PullRequest(subscription=subscription, max_messages=max_messages, return_immediately=return_immediately) return self._pull(request, options)
[docs] def modify_push_config(self, subscription, push_config, options=None): """ Modifies the ``PushConfig`` for a specified subscription. This may be used to change a push subscription to a pull one (signified by an empty ``PushConfig``) or vice versa, or change the endpoint URL and other attributes of a push subscription. Messages will accumulate for delivery continuously through the call regardless of changes to the ``PushConfig``. Example: >>> from google.pubsub.v1.subscriber_api import SubscriberApi >>> from google.pubsub.v1 import pubsub_pb2 >>> api = SubscriberApi() >>> subscription = api.subscription_path('[PROJECT]', '[SUBSCRIPTION]') >>> push_config = pubsub_pb2.PushConfig() >>> api.modify_push_config(subscription, push_config) Args: subscription (string): The name of the subscription. push_config (:class:`google.pubsub.v1.pubsub_pb2.PushConfig`): The push configuration for future deliveries. An empty ``pushConfig`` indicates that the Pub/Sub system should stop pushing messages from the given subscription and allow messages to be pulled and acknowledged - effectively pausing the subscription if ``Pull`` is not called. options (:class:`google.gax.CallOptions`): Overrides the default settings for this call, e.g, timeout, retries etc. Raises: :exc:`google.gax.errors.GaxError` if the RPC is aborted. """ request = pubsub_pb2.ModifyPushConfigRequest(subscription=subscription, push_config=push_config) self._modify_push_config(request, options)