junrao commented on a change in pull request #10271: URL: https://github.com/apache/kafka/pull/10271#discussion_r616081872
########## File path: storage/src/main/java/org/apache/kafka/server/log/remote/metadata/storage/serialization/RemoteLogMetadataSerdes.java ########## @@ -0,0 +1,54 @@ +/* + * 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.server.log.remote.metadata.storage.serialization; + +import java.nio.ByteBuffer; + +/** + * The default implementation of {@link org.apache.kafka.server.log.remote.storage.RemoteLogMetadataManager} stores all + * the remote log metadata in an internal topic. Those messages can be {@link org.apache.kafka.server.log.remote.storage.RemoteLogSegmentMetadata}, + * {@link org.apache.kafka.server.log.remote.storage.RemoteLogSegmentMetadataUpdate}, or {@link org.apache.kafka.server.log.remote.storage.RemotePartitionDeleteMetadata}. + * These messages are written in Kafka's protocol message format as mentioned in + * <a href="https://cwiki.apache.org/confluence/display/KAFKA/KIP-405%3A+Kafka+Tiered+Storage#KIP405:KafkaTieredStorage-MessageFormat";>KIP-405</a> + * <p> + * This interface is about serializing and deserializing these messages that are stored in remote log metadata internal + * topic. There are respective implementations for the mentioned message types. + * <p> + * @param <T> metadata type to be serialized/deserialized. + * + * @see RemoteLogSegmentMetadataSerdes + * @see RemoteLogSegmentMetadataUpdateSerdes + * @see RemotePartitionDeleteMetadataSerdes + */ +public interface RemoteLogMetadataSerdes<T> { + + /** + * Returns the message serialized for the given {@code metadata} object. Review comment: We are no longer returning message. ########## File path: storage/src/main/java/org/apache/kafka/server/log/remote/metadata/storage/serialization/RemoteLogMetadataContextSerdes.java ########## @@ -0,0 +1,123 @@ +/* + * 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.server.log.remote.metadata.storage.serialization; + +import org.apache.kafka.common.serialization.Deserializer; +import org.apache.kafka.common.serialization.Serde; +import org.apache.kafka.common.serialization.Serializer; +import org.apache.kafka.server.log.remote.metadata.storage.RemoteLogMetadataContext; +import org.apache.kafka.server.log.remote.metadata.storage.generated.RemoteLogSegmentMetadataRecord; +import org.apache.kafka.server.log.remote.metadata.storage.generated.RemoteLogSegmentMetadataUpdateRecord; +import org.apache.kafka.server.log.remote.metadata.storage.generated.RemotePartitionDeleteMetadataRecord; + +import java.nio.ByteBuffer; +import java.util.HashMap; +import java.util.Map; + +/** + * This class provides serialization and deserialization for {@link RemoteLogMetadataContext}. This is the root serdes + * for the messages that are stored in internal remote log metadata topic. + */ +public class RemoteLogMetadataContextSerdes implements Serde<RemoteLogMetadataContext> { + + public static final byte REMOTE_LOG_SEGMENT_METADATA_API_KEY = (byte) new RemoteLogSegmentMetadataRecord().apiKey(); + public static final byte REMOTE_LOG_SEGMENT_METADATA_UPDATE_API_KEY = (byte) new RemoteLogSegmentMetadataUpdateRecord().apiKey(); + public static final byte REMOTE_PARTITION_DELETE_API_KEY = (byte) new RemotePartitionDeleteMetadataRecord().apiKey(); + + private static final Map<Byte, RemoteLogMetadataSerdes> KEY_TO_SERDES = createInternalSerde(); + + private final Deserializer<RemoteLogMetadataContext> rootDeserializer; + private final Serializer<RemoteLogMetadataContext> rootSerializer; + + public RemoteLogMetadataContextSerdes() { + rootSerializer = (topic, data) -> serialize(data); + rootDeserializer = (topic, data) -> deserialize(data); + } + + private static Map<Byte, RemoteLogMetadataSerdes> createInternalSerde() { + Map<Byte, RemoteLogMetadataSerdes> map = new HashMap<>(); + map.put(REMOTE_LOG_SEGMENT_METADATA_API_KEY, new RemoteLogSegmentMetadataSerdes()); + map.put(REMOTE_LOG_SEGMENT_METADATA_UPDATE_API_KEY, new RemoteLogSegmentMetadataUpdateSerdes()); + map.put(REMOTE_PARTITION_DELETE_API_KEY, new RemotePartitionDeleteMetadataSerdes()); + return map; + } + + private byte[] serialize(RemoteLogMetadataContext remoteLogMetadataContext) { + RemoteLogMetadataSerdes serdes = KEY_TO_SERDES.get(remoteLogMetadataContext.apiKey()); + if (serdes == null) { + throw new IllegalArgumentException("Serializer for apiKey: " + remoteLogMetadataContext.apiKey() + + " does not exist."); + } + + @SuppressWarnings("unchecked") + ByteBuffer message = serdes.serialize(remoteLogMetadataContext.version(), remoteLogMetadataContext.payload()); + + return toBytes(message, remoteLogMetadataContext.apiKey(), remoteLogMetadataContext.version()); + } + + private RemoteLogMetadataContext deserialize(byte[] data) { + ByteBuffer byteBuffer = ByteBuffer.wrap(data); + byte apiKey = byteBuffer.get(); + byte version = byteBuffer.get(); + RemoteLogMetadataSerdes serdes = KEY_TO_SERDES.get(apiKey); + if (serdes == null) { + throw new IllegalArgumentException("Deserializer for apikey: " + apiKey + " does not exist."); + } + + Object deserializedObj = serdes.deserialize(version, byteBuffer); + return new RemoteLogMetadataContext(apiKey, version, deserializedObj); + } + + private byte[] toBytes(ByteBuffer message, byte apiKey, byte apiVersion) { + // Add header containing apiKey and apiVersion, + // headerSize is 1 byte for apiKey and 1 byte for apiVersion + int headerSize = 1 + 1; + int messageSize = message.capacity(); + ByteBuffer byteBuffer = ByteBuffer.allocate(headerSize + messageSize); + + // Write apiKey and apiVersion + byteBuffer.put(apiKey); + byteBuffer.put(apiVersion); + + // Write the message + byteBuffer.put(message); Review comment: Hmm, this copies the payload. Could we have a standardized ApiMessage serializer that writes apiKey, apiVersion and the payload in one pass? ########## File path: storage/src/main/java/org/apache/kafka/server/log/remote/metadata/storage/serialization/RemoteLogMetadataContextSerdes.java ########## @@ -0,0 +1,123 @@ +/* + * 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.server.log.remote.metadata.storage.serialization; + +import org.apache.kafka.common.serialization.Deserializer; +import org.apache.kafka.common.serialization.Serde; +import org.apache.kafka.common.serialization.Serializer; +import org.apache.kafka.server.log.remote.metadata.storage.RemoteLogMetadataContext; +import org.apache.kafka.server.log.remote.metadata.storage.generated.RemoteLogSegmentMetadataRecord; +import org.apache.kafka.server.log.remote.metadata.storage.generated.RemoteLogSegmentMetadataUpdateRecord; +import org.apache.kafka.server.log.remote.metadata.storage.generated.RemotePartitionDeleteMetadataRecord; + +import java.nio.ByteBuffer; +import java.util.HashMap; +import java.util.Map; + +/** + * This class provides serialization and deserialization for {@link RemoteLogMetadataContext}. This is the root serdes + * for the messages that are stored in internal remote log metadata topic. + */ +public class RemoteLogMetadataContextSerdes implements Serde<RemoteLogMetadataContext> { + + public static final byte REMOTE_LOG_SEGMENT_METADATA_API_KEY = (byte) new RemoteLogSegmentMetadataRecord().apiKey(); + public static final byte REMOTE_LOG_SEGMENT_METADATA_UPDATE_API_KEY = (byte) new RemoteLogSegmentMetadataUpdateRecord().apiKey(); + public static final byte REMOTE_PARTITION_DELETE_API_KEY = (byte) new RemotePartitionDeleteMetadataRecord().apiKey(); + + private static final Map<Byte, RemoteLogMetadataSerdes> KEY_TO_SERDES = createInternalSerde(); + + private final Deserializer<RemoteLogMetadataContext> rootDeserializer; + private final Serializer<RemoteLogMetadataContext> rootSerializer; + + public RemoteLogMetadataContextSerdes() { + rootSerializer = (topic, data) -> serialize(data); Review comment: Overall, this seems to be a convoluted way of doing serialization. (1) The logic is kind of hard to follow due to the indirections. (2) The Serde api is really designed for clients. So things like topic, configure() and close() don't really apply here. I am wondering if we could do the following. (a) Have a generic ApiMessageSerde that converts between a generic ApiMessageContext (with ApiMessage and version) and bytes. The serializer will write apiKey, version, payload in that order. (b) Have a remote storage specific RemoteStorageSerde that wraps ApiMessageSerde and converts ApiMessageContext from/to RemoteStroageContext (with remote stroage specific objects). This way, if we have other usage of serializing ApiMessage into a log, we could reuse (a). -- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
