[fix][broker][branch-4.0] Fix failed testFinishTakeSnapshotWhenTopicLoading due to topic future cache conflicts (#24947)

Author: BewareMyPower

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

@@ -1117,31 +1117,7 @@ public CompletableFuture<Optional<Topic>> getTopic(final TopicName topicName, bo
                     // The topic level policies are not needed now, but the meaning of calling
                     // "getTopicPoliciesBypassSystemTopic" will wait for system topic policies initialization.
                     getTopicPoliciesBypassSystemTopic(topicName, TopicPoliciesService.GetType.LOCAL_ONLY)
-                            .thenCompose(optionalTopicPolicies -> {
-                        if (topicName.isPartitioned()) {
-                            final TopicName topicNameEntity = TopicName.get(topicName.getPartitionedTopicName());
-                            return fetchPartitionedTopicMetadataAsync(topicNameEntity)
-                                    .thenCompose((metadata) -> {
-                                        // Allow creating non-partitioned persistent topic that name includes
-                                        // `partition`
-                                        if (metadata.partitions == 0
-                                                || topicName.getPartitionIndex() < metadata.partitions) {
-                                            return topics.computeIfAbsent(topicName.toString(), (tpName) ->
-                                                    loadOrCreatePersistentTopic(context));
-                                        } else {
-                                            final String errorMsg =
-                                                    String.format("Illegal topic partition name %s with max allowed "
-                                                            + "%d partitions", topicName, metadata.partitions);
-                                            log.warn(errorMsg);
-                                            return FutureUtil.failedFuture(
-                                                    new BrokerServiceException.NotAllowedException(errorMsg));
-                                        }
-                                    });
-                        } else {
-                            return topics.computeIfAbsent(topicName.toString(), (tpName) ->
-                                    loadOrCreatePersistentTopic(context));
-                        }
-                    }).thenRun(() -> {
+                            .thenRun(() -> {
                         final var inserted = new MutableBoolean(false);
                         final var cachedFuture = topics.computeIfAbsent(topicName.toString(), ___ -> {
                             inserted.setTrue();
@@ -1678,9 +1654,32 @@ public PulsarAdmin getClusterPulsarAdmin(String cluster, Optional<ClusterData> c
      * loading and puts them into queue once in-process topics are created.
      */
     protected CompletableFuture<Optional<Topic>> loadOrCreatePersistentTopic(TopicLoadingContext context) {
+        final var topicName = context.getTopicName();
         final var topic = context.getTopicName().toString();
+        final CompletableFuture<Void> ownedFuture;
+        if (topicName.isPartitioned()) {
+            final TopicName topicNameEntity = TopicName.get(topicName.getPartitionedTopicName());
+            ownedFuture = fetchPartitionedTopicMetadataAsync(topicNameEntity)
+                    .thenCompose((metadata) -> {
+                        // Allow creating non-partitioned persistent topic that name includes
+                        // `partition`
+                        if (metadata.partitions == 0
+                                || topicName.getPartitionIndex() < metadata.partitions) {
+                            return checkTopicNsOwnership(topic);
+                        } else {
+                            final String errorMsg =
+                                    String.format("Illegal topic partition name %s with max allowed "
+                                            + "%d partitions", topicName, metadata.partitions);
+                            log.warn(errorMsg);
+                            return FutureUtil.failedFuture(
+                                    new BrokerServiceException.NotAllowedException(errorMsg));
+                        }
+                    });
+        } else {
+            ownedFuture = checkTopicNsOwnership(topic);
+        }
         final var topicFuture = context.getTopicFuture();
-        checkTopicNsOwnership(topic)
+        ownedFuture
                 .thenRun(() -> {
                     final Semaphore topicLoadSemaphore = topicLoadRequestSemaphore.get();