[fix][broker] Fix uncompleted future when getting the topic policies of a deleted topic

[liangyepianzhou]

Motivation

Fix the uncompleted future when getting the topic policies of a deleted topic.

pulsar/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/SystemTopicBasedTopicPoliciesService.java

Lines 513 to 535 in 30b52a1

	reader.readNextAsync().whenComplete((msg, e) -> {
	if (e != null) {
	future.completeExceptionally(e);
	}
	if (msg.getValue() != null
	&& EventType.TOPIC_POLICY.equals(msg.getValue().getEventType())) {
	TopicPoliciesEvent topicPoliciesEvent = msg.getValue().getTopicPoliciesEvent();
	if (topicName.equals(TopicName.get(
	topicPoliciesEvent.getDomain(),
	topicPoliciesEvent.getTenant(),
	topicPoliciesEvent.getNamespace(),
	topicPoliciesEvent.getTopic()))
	) {
	fetchTopicPoliciesAsyncAndCloseReader(reader, topicName,
	topicPoliciesEvent.getPolicies(), future);
	} else {
	fetchTopicPoliciesAsyncAndCloseReader(reader, topicName, policies, future);
	}
	}
	});
	} else {
	future.complete(policies);
	reader.closeAsync().whenComplete((v, e) -> {

Modification

future.complete(null); when msg.getValue() == null.

Verifying this change

• Make sure that the change passes the CI checks.

(Please pick either of the following options)

This change is a trivial rework / code cleanup without any test coverage.

(or)

This change is already covered by existing tests, such as (please describe tests).

(or)

This change added tests and can be verified as follows:

(example:)

• Added integration tests for end-to-end deployment with large payloads (10MB)
• Extended integration test for recovery after broker failure

Does this pull request potentially affect one of the following parts:

If the box was checked, please highlight the changes

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• Anything that affects deployment

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository: liangyepianzhou#17

[AnonHxy]

LGTM. It seems that this method will only be called from UT test case now

[codecov-commenter]

Codecov Report

Merging #18824 (3b54a05) into master (cd85a67) will increase coverage by 0.72%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master   #18824      +/-   ##
============================================
+ Coverage     47.39%   48.12%   +0.72%     
- Complexity    10479    10730     +251     
============================================
  Files           698      703       +5     
  Lines         68070    68819     +749     
  Branches       7279     7376      +97     
============================================
+ Hits          32264    33118     +854     
+ Misses        32228    32003     -225     
- Partials       3578     3698     +120     

Flag	Coverage Δ
unittests	48.12% <100.00%> (+0.72%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
.../service/SystemTopicBasedTopicPoliciesService.java	72.25% <100.00%> (+7.53%)	⬆️
.../transaction/buffer/metadata/AbortTxnMetadata.java	28.57% <0.00%> (-57.15%)	⬇️
...ker/service/schema/exceptions/SchemaException.java	60.00% <0.00%> (-40.00%)	⬇️
...ar/broker/loadbalance/impl/BundleSplitterTask.java	60.00% <0.00%> (-20.00%)	⬇️
...oker/service/nonpersistent/NonPersistentTopic.java	42.19% <0.00%> (-15.44%)	⬇️
.../apache/pulsar/broker/admin/impl/PackagesBase.java	54.12% <0.00%> (-13.77%)	⬇️
...lsar/broker/loadbalance/impl/ThresholdShedder.java	30.32% <0.00%> (-12.81%)	⬇️
.../org/apache/pulsar/broker/service/PulsarStats.java	72.56% <0.00%> (-7.97%)	⬇️
...er/loadbalance/impl/ModularLoadManagerWrapper.java	78.04% <0.00%> (-7.32%)	⬇️
...apache/pulsar/client/impl/AutoClusterFailover.java	70.00% <0.00%> (-6.12%)	⬇️
... and 114 more