Class: Google::Cloud::Pubsub::Snapshot

Inherits:
Object
  • Object
show all
Defined in:
lib/google/cloud/pubsub/snapshot.rb,
lib/google/cloud/pubsub/snapshot/list.rb

Overview

Snapshot

A named resource created from a subscription to retain a stream of messages from a topic. A snapshot is guaranteed to retain:

  • The existing backlog on the subscription. More precisely, this is defined as the messages in the subscription's backlog that are unacknowledged upon the successful completion of the create_snapshot operation; as well as:
  • Any messages published to the subscription's topic following the successful completion of the create_snapshot operation.

Examples:

require "google/cloud/pubsub"

pubsub = Google::Cloud::Pubsub.new
sub = pubsub.subscription "my-sub"

snapshot = sub.create_snapshot "my-snapshot"
snapshot.name #=> "projects/my-project/snapshots/my-snapshot"

Defined Under Namespace

Classes: List

Instance Method Summary collapse

Instance Method Details

#delete ⇒ Boolean

Removes an existing snapshot. 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.

Examples:

require "google/cloud/pubsub"

pubsub = Google::Cloud::Pubsub.new

pubsub.snapshots.each do |snapshot|
  snapshot.delete
end

Returns:

  • (Boolean) —

    Returns true if the snapshot was deleted.



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# File 'lib/google/cloud/pubsub/snapshot.rb', line 131

def delete
  ensure_service!
  service.delete_snapshot name
  true
end

#expiration_time ⇒ Time

The snapshot is guaranteed to exist up until this time. A newly-created snapshot expires no later than 7 days from the time of its creation. Its exact lifetime is determined at creation by the existing backlog in the source subscription. Specifically, the lifetime of the snapshot is 7 days - (age of oldest unacked message in the subscription). For example, consider a subscription whose oldest unacked message is 3 days old. If a snapshot is created from this subscription, the snapshot -- which will always capture this 3-day-old backlog as long as the snapshot exists -- will expire in 4 days.

Examples:

require "google/cloud/pubsub"

pubsub = Google::Cloud::Pubsub.new
sub = pubsub.subscription "my-sub"

snapshot = sub.create_snapshot "my-snapshot"
snapshot.topic.name #=> "projects/my-project/topics/my-topic"
snapshot.expiration_time

Returns:

  • (Time) —

    The time until which the snapshot is guaranteed to exist.



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# File 'lib/google/cloud/pubsub/snapshot.rb', line 109

def expiration_time
  self.class.timestamp_from_grpc @grpc.expire_time
end

#name ⇒ Object

The name of the snapshot. Format is projects/{project}/snapshots/{snap}.



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# File 'lib/google/cloud/pubsub/snapshot.rb', line 63

def name
  @grpc.name
end

#topic ⇒ Topic

The Topic from which this snapshot is retaining messages.

Examples:

require "google/cloud/pubsub"

pubsub = Google::Cloud::Pubsub.new
sub = pubsub.subscription "my-sub"

snapshot = sub.create_snapshot "my-snapshot"
snapshot.topic.name #=> "projects/my-project/topics/my-topic"

Returns:



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# File 'lib/google/cloud/pubsub/snapshot.rb', line 81

def topic
  Topic.new_lazy @grpc.topic, service
end