Message(message, ack_id, delivery_attempt, request_queue)A representation of a single Pub/Sub message.
The common way to interact with
.pubsub_v1.subscriber.message.Message objects is to receive
them in callbacks on subscriptions; most users should never have a need
to instantiate them by hand. (The exception to this is if you are
implementing a custom subclass to
.pubsub_v1.subscriber._consumer.Consumer.)
Attributes
| Name | Description |
| message_id |
str
The message ID. In general, you should not need to use this directly. |
| data |
bytes
The data in the message. Note that this will be a `bytes`, not a text string. |
| attributes |
.ScalarMapContainer
The attributes sent along with the message. See `attributes` for more information on this type. |
| publish_time |
datetime
The time that this message was originally published. |
Inheritance
builtins.object > MessageProperties
ack_id
str: the ID used to ack the message.
attributes
Return the attributes of the underlying Pub/Sub Message.
.. warning::
A ``ScalarMapContainer`` behaves slightly differently than a
``dict``. For a Pub / Sub message this is a ``string->string`` map.
When trying to access a value via ``map['key']``, if the key is
not in the map, then the default value for the string type will
be returned, which is an empty string. It may be more intuitive
to just cast the map to a ``dict`` or to one use ``map.get``.
| Type | Description |
| .ScalarMapContainer | The message's attributes. This is a ``dict``-like object provided by ``google.protobuf``. |
data
Return the data for the underlying Pub/Sub Message.
| Type | Description |
| bytes | The message data. This is always a bytestring; if you want a text string, call `bytes.decode`. |
delivery_attempt
The delivery attempt counter is 1 + (the sum of number of NACKs and number of ack_deadline exceeds) for this message. It is set to None if a DeadLetterPolicy is not set on the subscription.
A NACK is any call to ModifyAckDeadline with a 0 deadline. An ack_deadline exceeds event is whenever a message is not acknowledged within ack_deadline. Note that ack_deadline is initially Subscription.ackDeadlineSeconds, but may get extended automatically by the client library.
The first delivery of a given message will have this value as 1. The value is calculated at best effort and is approximate.
EXPERIMENTAL: This feature is part of a closed alpha release. This API might be changed in backward-incompatible ways and is not recommended for production use. It is not subject to any SLA or deprecation policy.
| Type | Description |
| Optional[int] | The delivery attempt counter or None. |
ordering_key
str: the ordering key used to publish the message.
publish_time
Return the time that the message was originally published.
| Type | Description |
| datetime | The date and time that the message was published. |
size
Return the size of the underlying message, in bytes.
Methods
Message
Message(message, ack_id, delivery_attempt, request_queue)Construct the Message.
.. note::
This class should not be constructed directly; it is the
responsibility of `BasePolicy` subclasses to do so.
| Name | Description |
| message |
`.pubsub_v1.types.PubsubMessage`
The message received from Pub/Sub. |
| ack_id |
str
The ack_id received from Pub/Sub. |
| delivery_attempt |
int
The delivery attempt counter received from Pub/Sub if a DeadLetterPolicy is set on the subscription, and zero otherwise. |
| request_queue |
queue.Queue
A queue provided by the policy that can accept requests; the policy is responsible for handling those requests. |
ack
ack()Acknowledge the given message.
Acknowledging a message in Pub/Sub means that you are done with it, and it will not be delivered to this subscription again. You should avoid acknowledging messages until you have finished processing them, so that in the event of a failure, you receive the message again.
.. warning:: Acks in Pub/Sub are best effort. You should always ensure that your processing code is idempotent, as you may receive any given message more than once.
drop
drop()Release the message from lease management.
This informs the policy to no longer hold on to the lease for this message. Pub/Sub will re-deliver the message if it is not acknowledged before the existing lease expires.
.. warning::
For most use cases, the only reason to drop a message from
lease management is on ack or nack; this library
automatically drop()s the message on ack or nack. You probably
do not want to call this method directly.
modify_ack_deadline
modify_ack_deadline(seconds)Resets the deadline for acknowledgement.
New deadline will be the given value of seconds from now.
The default implementation handles this for you; you should not need
to manually deal with setting ack deadlines. The exception case is
if you are implementing your own custom subclass of
.pubsub_v1.subcriber._consumer.Consumer.
| Name | Description |
| seconds |
int
The number of seconds to set the lease deadline to. This should be between 0 and 600. Due to network latency, values below 10 are advised against. |
nack
nack()Decline to acknowldge the given message.
This will cause the message to be re-delivered to the subscription.