(kafka) branch trunk updated: MINOR: remove redundant stream round-trip in MirrorSourceConnector (#23403)

[mi...@apache.org]

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mimaison pushed a commit to branch trunk
in repository https://gitbox.apache.org/repos/asf/kafka.git


The following commit(s) were added to refs/heads/trunk by this push:
     new 6bafed66563 MINOR: remove redundant stream round-trip in MirrorSourceConnector (#23403)
6bafed66563 is described below

commit 6bafed6656303c7cd23c0eb7695b674306824fa4
Author: OuO <ma...@outlook.com>
AuthorDate: Wed Sep 9 19:58:21 2026 +0800

    MINOR: remove redundant stream round-trip in MirrorSourceConnector (#23403)
    
    `computeAndCreateTopicPartitions` collected the partition counts with
    `Collectors.groupingBy(..., counting())` and then immediately streamed
    the resulting entry set back into `Collectors.toMap(Entry::getKey,
    Entry::getValue)`. That second pass rebuilds an identical map, so it is
    pure overhead.
    
    This removes the redundant round-trip for both
    `sourceTopicToPartitionCounts` and `targetTopicToPartitionCounts`.
    
    Reviewers: Mickael Maison <mi...@gmail.com>
---
 .../java/org/apache/kafka/connect/mirror/MirrorSourceConnector.java | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/connect/mirror/src/main/java/org/apache/kafka/connect/mirror/MirrorSourceConnector.java b/connect/mirror/src/main/java/org/apache/kafka/connect/mirror/MirrorSourceConnector.java
index 8eb5a929440..b0ef2834820 100644
--- a/connect/mirror/src/main/java/org/apache/kafka/connect/mirror/MirrorSourceConnector.java
+++ b/connect/mirror/src/main/java/org/apache/kafka/connect/mirror/MirrorSourceConnector.java
@@ -455,11 +455,9 @@ public class MirrorSourceConnector extends SourceConnector {
     void computeAndCreateTopicPartitions() throws ExecutionException, InterruptedException {
         // get source and target topics with respective partition counts
         Map<String, Long> sourceTopicToPartitionCounts = knownSourceTopicPartitions.stream()
-                .collect(Collectors.groupingBy(TopicPartition::topic, Collectors.counting())).entrySet().stream()
-                .collect(Collectors.toMap(Entry::getKey, Entry::getValue));
+                .collect(Collectors.groupingBy(TopicPartition::topic, Collectors.counting()));
         Map<String, Long> targetTopicToPartitionCounts = knownTargetTopicPartitions.stream()
-                .collect(Collectors.groupingBy(TopicPartition::topic, Collectors.counting())).entrySet().stream()
-                .collect(Collectors.toMap(Entry::getKey, Entry::getValue));
+                .collect(Collectors.groupingBy(TopicPartition::topic, Collectors.counting()));
 
         Set<String> knownSourceTopics = sourceTopicToPartitionCounts.keySet();
         Set<String> knownTargetTopics = targetTopicToPartitionCounts.keySet();