[GitHub] [kafka] patrickstuedi commented on a change in pull request #11513: feat: Write and restore position to/from changelog

[GitBox <gi...@apache.org>]

patrickstuedi commented on a change in pull request #11513:
URL: https://github.com/apache/kafka/pull/11513#discussion_r763810277



##########
File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/ChangelogRecordDeserializationHelper.java
##########
@@ -0,0 +1,75 @@
+/*
+ * 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.kafka.streams.processor.internals;
+
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+import org.apache.kafka.common.header.Header;
+import org.apache.kafka.common.header.internals.RecordHeader;
+import org.apache.kafka.streams.errors.StreamsException;
+import org.apache.kafka.streams.query.Position;
+import org.apache.kafka.streams.state.internals.PositionSerde;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Changelog records without any headers are considered old format.
+ * New format changelog records will have a version in their headers.
+ * Version 0: This indicates that the changelog records have consistency information.
+ */
+public class ChangelogRecordDeserializationHelper {
+    public static final Logger log = LoggerFactory.getLogger(ChangelogRecordDeserializationHelper.class);
+    private static final byte[] V_0_CHANGELOG_VERSION_HEADER_VALUE = {(byte) 0};
+    public static final String CHANGELOG_VERSION_HEADER_KEY = "v";
+    public static final String CHANGELOG_POSITION_HEADER_KEY = "c";
+    public static final RecordHeader CHANGELOG_VERSION_HEADER_RECORD_CONSISTENCY = new RecordHeader(
+            CHANGELOG_VERSION_HEADER_KEY, V_0_CHANGELOG_VERSION_HEADER_VALUE);
+
+    public static Position applyChecksAndUpdatePosition(
+            final ConsumerRecord<byte[], byte[]> record,
+            final boolean consistencyEnabled,
+            final Position position
+    ) {
+        Position restoredPosition = Position.emptyPosition();
+        if (!consistencyEnabled) {

Review comment:
       nit: creating restoredPosition is not required if !constinceyEnabled




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: jira-unsubscribe@kafka.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org