Github user pnowojski commented on a diff in the pull request:
https://github.com/apache/flink/pull/4955#discussion_r149315173
--- Diff:
flink-connectors/flink-connector-kafka-0.11/src/test/java/org/apache/flink/streaming/connectors/kafka/internal/TransactionalIdsGeneratorTest.java
---
@@ -0,0 +1,79 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.streaming.connectors.kafka.internal;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Tests for {@link TransactionalIdsGenerator}.
+ */
+public class TransactionalIdsGeneratorTest {
+ private static final int POOL_SIZE = 3;
+ private static final int SAFE_SCALE_DOWN_FACTOR = 3;
+ private static final int SUBTASKS_COUNT = 5;
+
+ @Test
+ public void testGenerateIdsToUse() {
+ TransactionalIdsGenerator generator = new
TransactionalIdsGenerator("test", 2, SUBTASKS_COUNT, POOL_SIZE,
SAFE_SCALE_DOWN_FACTOR);
+
+ assertEquals(
+ new HashSet<>(Arrays.asList("test-42", "test-43",
"test-44")),
+ generator.generateIdsToUse(36));
+ }
+
+ /**
+ * Ids to abort and to use should never clash between subtasks.
+ */
+ @Test
+ public void testGeneratedIdsDoNotClash() {
+ List<Set<String>> idsToAbort = new ArrayList<>();
+ List<Set<String>> idsToUse = new ArrayList<>();
+
+ for (int subtask = 0; subtask < SUBTASKS_COUNT; subtask++) {
+ TransactionalIdsGenerator generator = new
TransactionalIdsGenerator("test", subtask, SUBTASKS_COUNT, POOL_SIZE,
SAFE_SCALE_DOWN_FACTOR);
+ idsToUse.add(generator.generateIdsToUse(0));
+ idsToAbort.add(generator.generateIdsToAbort());
+ }
+
+ for (int subtask1 = 0; subtask1 < SUBTASKS_COUNT; subtask1++) {
+ for (int subtask2 = 0; subtask2 < SUBTASKS_COUNT;
subtask2++) {
+ if (subtask2 == subtask1) {
+ continue;
+ }
+
assertIntersectionIsEmpty(idsToAbort.get(subtask2), idsToAbort.get(subtask1));
+
assertIntersectionIsEmpty(idsToUse.get(subtask2), idsToUse.get(subtask1));
+
assertIntersectionIsEmpty(idsToAbort.get(subtask2), idsToUse.get(subtask1));
--- End diff --
that will be covered by second half of looping (everytime I start from
index 0). It would be necessary if the loop would look like:
```
for (int subtask1 = 0; subtask1 < SUBTASKS_COUNT; subtask1++) {
for (int subtask2 = subtask1; subtask2 < SUBTASKS_COUNT; subtask2++) {
```
instead of as it is now:
```
for (int subtask1 = 0; subtask1 < SUBTASKS_COUNT; subtask1++) {
for (int subtask2 = 0; subtask2 < SUBTASKS_COUNT; subtask2++) {
```
---
