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.

Creates a snapshot from the requested subscription. Snapshots are used in [Seek](https://cloud.google.com/pubsub/docs/replay-overview) operations, which allow you to manage message acknowledgments in bulk. That is, you can set the acknowledgment state of messages in an existing subscription to the state captured by a snapshot. If the snapshot already exists, returns ALREADY_EXISTS. If the requested subscription doesn't exist, returns NOT_FOUND. If the backlog in the subscription is too old -- and the resulting snapshot would expire in less than 1 hour -- then FAILED_PRECONDITION is returned. See also the Snapshot.expire_time field. If the name is not provided in the request, the server will assign a random name for this snapshot on the same project as the subscription, conforming to the [resource name format] (https://cloud.google.com/pubsub/docs/pubsub-basics#resource_names). The generated name is populated in the returned Snapshot object. Note that for REST API requests, you must specify a name in the request.

Creates a subscription to a given topic. See the [resource name rules] (https://cloud.google.com/pubsub/docs/pubsub-basics#resource_names). 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, conforming to the [resource name format] (https://cloud.google.com/pubsub/docs/pubsub-basics#resource_names). The generated name is populated in the returned Subscription object. Note that for REST API requests, you must specify a name in the request.

Removes an existing snapshot. Snapshots are used in [Seek] (https://cloud.google.com/pubsub/docs/replay-overview) operations, which allow you to manage message acknowledgments in bulk. That is, you can set the acknowledgment state of messages in an existing subscription to the state captured by a snapshot. When the snapshot is deleted, all messages retained in the snapshot are immediately dropped. After a snapshot is deleted, a new one may be created with the same name, but the new one has no association with the old snapshot or its subscription, unless the same subscription is specified.

Deletes an existing subscription. All messages retained 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.

Gets the configuration details of a snapshot. Snapshots are used in [Seek](https://cloud.google.com/pubsub/docs/replay-overview) operations, which allow you to manage message acknowledgments in bulk. That is, you can set the acknowledgment state of messages in an existing subscription to the state captured by a snapshot.

Lists the existing snapshots. Snapshots are used in [Seek]( https://cloud.google.com/pubsub/docs/replay-overview) operations, which allow you to manage message acknowledgments in bulk. That is, you can set the acknowledgment state of messages in an existing subscription to the state captured by a snapshot.

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. Note that this does not modify the subscription-level ackDeadlineSeconds used for subsequent messages.

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.

Seeks an existing subscription to a point in time or to a given snapshot, whichever is provided in the request. Snapshots are used in [Seek] (https://cloud.google.com/pubsub/docs/replay-overview) operations, which allow you to manage message acknowledgments in bulk. That is, you can set the acknowledgment state of messages in an existing subscription to the state captured by a snapshot. Note that both the subscription and the snapshot must be on the same topic.

Establishes a stream with the server, which sends messages down to the client. The client streams acknowledgements and ack deadline modifications back to the server. The server will close the stream and return the status on any error. The server may close the stream with status UNAVAILABLE to reassign server-side resources, in which case, the client should re-establish the stream. Flow control can be achieved by configuring the underlying RPC channel.

Updates an existing snapshot by updating the fields specified in the update mask. Snapshots are used in [Seek](https://cloud.google.com/pubsub/docs/replay-overview) operations, which allow you to manage message acknowledgments in bulk. That is, you can set the acknowledgment state of messages in an existing subscription to the state captured by a snapshot.

Updates an existing subscription by updating the fields specified in the update mask. Note that certain properties of a subscription, such as its topic, are not modifiable.