aliehsaeedii commented on code in PR #21409: URL: https://github.com/apache/kafka/pull/21409#discussion_r2773280579
########## streams/src/main/java/org/apache/kafka/streams/state/HeadersBytesStore.java: ########## @@ -0,0 +1,63 @@ +/* + * 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.state; + +import java.nio.ByteBuffer; + +/** + * Marker interface to indicate that a bytes store understands the value-with-headers format + * and can convert legacy timestamped value entries (ValueAndTimestamp format) to the new format. + * <p> + * This is analogous to {@link TimestampedBytesStore} but for header-aware stores. + * <p> + * Per KIP-1271, the value format is: [headersSize(varint)][headersBytes][payloadBytes] + * where payloadBytes is the existing serialized value (e.g., [timestamp(8)][value] for timestamped stores). + */ +public interface HeadersBytesStore { + + /** + * Converts a legacy timestamped value (ValueAndTimestamp format, without headers) to the header-embedded format. + * <p> + * For timestamped stores, the legacy format is: [timestamp(8)][value] + * The new format is: [headersSize(varint)][headersBytes][timestamp(8)][value] + * <p> + * This method adds empty headers to the existing timestamped value format. + * <p> + * The headersBytes format per KIP-1271 is: [count(varint)][header1][header2]... + * For empty headers, this is simply a single varint encoding 0. + * + * @param valueAndTimestamp the legacy timestamped value bytes (ValueAndTimestamp format: [timestamp(8)][value]) + * @return the value in header-embedded format with empty headers + */ + static byte[] convertToHeaderFormat(final byte[] valueAndTimestamp) { + if (valueAndTimestamp == null) { + return null; + } + + // Format: [headersSize(varint)][headersBytes][payload] + // For empty headers: + // headersSize = varint(1) = [0x02] (ZigZag varint) + // headersBytes = [count(varint) = 0] = [0x00] + // Result: [0x02][0x00][payload] + return ByteBuffer + .allocate(2 + valueAndTimestamp.length) Review Comment: Considering zero bytes for empty headers, this mustbe changed I assume. ########## streams/src/main/java/org/apache/kafka/streams/state/HeadersBytesStore.java: ########## @@ -0,0 +1,63 @@ +/* + * 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.state; + +import java.nio.ByteBuffer; + +/** + * Marker interface to indicate that a bytes store understands the value-with-headers format + * and can convert legacy timestamped value entries (ValueAndTimestamp format) to the new format. + * <p> + * This is analogous to {@link TimestampedBytesStore} but for header-aware stores. + * <p> + * Per KIP-1271, the value format is: [headersSize(varint)][headersBytes][payloadBytes] + * where payloadBytes is the existing serialized value (e.g., [timestamp(8)][value] for timestamped stores). + */ +public interface HeadersBytesStore { + + /** + * Converts a legacy timestamped value (ValueAndTimestamp format, without headers) to the header-embedded format. + * <p> + * For timestamped stores, the legacy format is: [timestamp(8)][value] + * The new format is: [headersSize(varint)][headersBytes][timestamp(8)][value] + * <p> + * This method adds empty headers to the existing timestamped value format. + * <p> + * The headersBytes format per KIP-1271 is: [count(varint)][header1][header2]... + * For empty headers, this is simply a single varint encoding 0. + * + * @param valueAndTimestamp the legacy timestamped value bytes (ValueAndTimestamp format: [timestamp(8)][value]) + * @return the value in header-embedded format with empty headers + */ + static byte[] convertToHeaderFormat(final byte[] valueAndTimestamp) { Review Comment: is it always `valueAndTimestamp`? What about the record of `VersionedStore`? Could it be renamed to `plainValue`? -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
