Messages#
-
class
google.cloud.pubsub_v1.subscriber.message.
Message
(message, ack_id, request_queue)[source]# A representation of a single Pub/Sub message.
The common way to interact with
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 toConsumer
.)-
attributes
# The attributes sent along with the message. See
attributes
for more information on this type.- Type
ScalarMapContainer
-
publish_time
# The time that this message was originally published.
- Type
datetime
Construct the Message.
Note
This class should not be constructed directly; it is the responsibility of
BasePolicy
subclasses to do so.- Parameters
message (PubsubMessage) – The message received from Pub/Sub.
ack_id (str) – The ack_id received from Pub/Sub.
request_queue (queue.Queue) – A queue provided by the policy that can accept requests; the policy is responsible for handling those requests.
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ack
()[source]# 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.
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property
attributes
Return the attributes of the underlying Pub/Sub Message.
Warning
A
ScalarMapContainer
behaves slightly differently than adict
. For a Pub / Sub message this is astring->string
map. When trying to access a value viamap['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 adict
or to one usemap.get
.- Returns
The message’s attributes. This is a
dict
-like object provided bygoogle.protobuf
.- Return type
ScalarMapContainer
-
property
data
Return the data for the underlying Pub/Sub Message.
- Returns
- The message data. This is always a bytestring; if you
want a text string, call
bytes.decode()
.
- Return type
-
drop
()[source]# 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.
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modify_ack_deadline
(seconds)[source]# 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
Consumer
.- Parameters
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.
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nack
()[source]# Decline to acknowldge the given message.
This will cause the message to be re-delivered to the subscription.
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property
publish_time
Return the time that the message was originally published.
- Returns
The date and time that the message was published.
- Return type
datetime
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property
size
# Return the size of the underlying message, in bytes.
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