chia7712 commented on code in PR #20456: URL: https://github.com/apache/kafka/pull/20456#discussion_r2638650908
########## transaction-coordinator/src/main/java/org/apache/kafka/coordinator/transaction/TransactionLog.java: ########## @@ -0,0 +1,166 @@ +/* + * 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.coordinator.transaction; + +import org.apache.kafka.common.TopicPartition; +import org.apache.kafka.common.compress.Compression; +import org.apache.kafka.common.protocol.ByteBufferAccessor; +import org.apache.kafka.common.protocol.MessageUtil; +import org.apache.kafka.common.record.RecordBatch; +import org.apache.kafka.coordinator.transaction.generated.CoordinatorRecordType; +import org.apache.kafka.coordinator.transaction.generated.TransactionLogKey; +import org.apache.kafka.coordinator.transaction.generated.TransactionLogValue; +import org.apache.kafka.server.common.TransactionVersion; + +import java.nio.ByteBuffer; +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.stream.Collectors; + +/** + * Messages stored for the transaction topic represent the producer id and transactional status of the corresponding + * transactional id, which have versions for both the key and value fields. Key and value + * versions are used to evolve the message formats: + * + * key version 0: [transactionalId] + * -> value version 0: [producer_id, producer_epoch, expire_timestamp, status, [topic, [partition] ], timestamp] + */ +public class TransactionLog { + + // enforce always using + // 1. cleanup policy = compact + // 2. compression = none + // 3. unclean leader election = disabled + // 4. required acks = -1 when writing + public static final Compression ENFORCED_COMPRESSION = Compression.NONE; + public static final short ENFORCED_REQUIRED_ACKS = (short) -1; + + /** + * Generates the bytes for transaction log message key + * + * @return key bytes + */ + public static byte[] keyToBytes(String transactionalId) { + return MessageUtil.toCoordinatorTypePrefixedBytes( + new TransactionLogKey().setTransactionalId(transactionalId) + ); + } + + /** + * Generates the payload bytes for transaction log message value + * + * @return value payload bytes + */ + public static byte[] valueToBytes(TxnTransitMetadata txnMetadata, + TransactionVersion transactionVersionLevel) { + if (txnMetadata.txnState() == TransactionState.EMPTY && !txnMetadata.topicPartitions().isEmpty()) { + throw new IllegalStateException("Transaction is not expected to have any partitions since its state is " + + txnMetadata.txnState() + ": " + txnMetadata); + } + + List<TransactionLogValue.PartitionsSchema> transactionPartitions = null; + + if (txnMetadata.txnState() != TransactionState.EMPTY) { + transactionPartitions = txnMetadata.topicPartitions().stream() + .collect(Collectors.groupingBy(TopicPartition::topic)) + .entrySet().stream() + .map(entry -> { + TransactionLogValue.PartitionsSchema schema = new TransactionLogValue.PartitionsSchema(); + schema.setTopic(entry.getKey()); + schema.setPartitionIds( + entry.getValue().stream() + .map(TopicPartition::partition) + .toList() + ); + return schema; + }).toList(); + } + + return MessageUtil.toVersionPrefixedBytes( + transactionVersionLevel.transactionLogValueVersion(), + new TransactionLogValue() + .setProducerId(txnMetadata.producerId()) + .setProducerEpoch(txnMetadata.producerEpoch()) + .setTransactionTimeoutMs(txnMetadata.txnTimeoutMs()) + .setTransactionStatus(txnMetadata.txnState().id()) + .setTransactionLastUpdateTimestampMs(txnMetadata.txnLastUpdateTimestamp()) + .setTransactionStartTimestampMs(txnMetadata.txnStartTimestamp()) + .setTransactionPartitions(transactionPartitions) + .setClientTransactionVersion(txnMetadata.clientTransactionVersion().featureLevel()) + ); + } + + /** + * Decodes the transaction log messages' key + * + * @return Either: left with the version if the key is not a transaction log key, right with the transactional id otherwise + */ + public static Object readTxnRecordKey(ByteBuffer buffer) { + short version = buffer.getShort(); + if (version == CoordinatorRecordType.TRANSACTION_LOG.id()) { + return new TransactionLogKey(new ByteBufferAccessor(buffer), (short) 0).transactionalId(); + } else { + return version; // like Scala Left(version) + } + } + + /** + * Decodes the transaction log messages' payload and retrieves the transaction metadata from it + * + * @return a transaction metadata object from the message, or null if tombstone + */ + public static TransactionMetadata readTxnRecordValue(String transactionalId, ByteBuffer buffer) { + if (buffer == null) { + return null; // tombstone + } else { + short version = buffer.getShort(); + if (version >= TransactionLogValue.LOWEST_SUPPORTED_VERSION + && version <= TransactionLogValue.HIGHEST_SUPPORTED_VERSION) { + + TransactionLogValue value = new TransactionLogValue(new ByteBufferAccessor(buffer), version); + TransactionState state = TransactionState.fromId(value.transactionStatus()); + + Set<TopicPartition> tps = new HashSet<>(); + if (!state.equals(TransactionState.EMPTY)) { Review Comment: ``` state != TransactionState.EMPTY ``` -- 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]
