kafka TopicDelta 源码

  • 2022-10-20
  • 浏览 (214)

kafka TopicDelta 代码

文件路径:/metadata/src/main/java/org/apache/kafka/image/TopicDelta.java

/*
 * 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.image;

import org.apache.kafka.common.Uuid;
import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.metadata.PartitionChangeRecord;
import org.apache.kafka.common.metadata.PartitionRecord;
import org.apache.kafka.metadata.PartitionRegistration;
import org.apache.kafka.metadata.Replicas;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map.Entry;
import java.util.Map;
import java.util.Set;

/**
 * Represents changes to a topic in the metadata image.
 */
public final class TopicDelta {
    private final TopicImage image;
    private final Map<Integer, PartitionRegistration> partitionChanges = new HashMap<>();

    public TopicDelta(TopicImage image) {
        this.image = image;
    }

    public TopicImage image() {
        return image;
    }

    public Map<Integer, PartitionRegistration> partitionChanges() {
        return partitionChanges;
    }

    public String name() {
        return image.name();
    }

    public Uuid id() {
        return image.id();
    }

    public void replay(PartitionRecord record) {
        partitionChanges.put(record.partitionId(), new PartitionRegistration(record));
    }

    public void replay(PartitionChangeRecord record) {
        PartitionRegistration partition = partitionChanges.get(record.partitionId());
        if (partition == null) {
            partition = image.partitions().get(record.partitionId());
            if (partition == null) {
                throw new RuntimeException("Unable to find partition " +
                    record.topicId() + ":" + record.partitionId());
            }
        }
        partitionChanges.put(record.partitionId(), partition.merge(record));
    }

    public TopicImage apply() {
        Map<Integer, PartitionRegistration> newPartitions = new HashMap<>();
        for (Entry<Integer, PartitionRegistration> entry : image.partitions().entrySet()) {
            int partitionId = entry.getKey();
            PartitionRegistration changedPartition = partitionChanges.get(partitionId);
            if (changedPartition == null) {
                newPartitions.put(partitionId, entry.getValue());
            } else {
                newPartitions.put(partitionId, changedPartition);
            }
        }
        for (Entry<Integer, PartitionRegistration> entry : partitionChanges.entrySet()) {
            if (!newPartitions.containsKey(entry.getKey())) {
                newPartitions.put(entry.getKey(), entry.getValue());
            }
        }
        return new TopicImage(image.name(), image.id(), newPartitions);
    }

    /**
     * Find the partitions that have change based on the replica given.
     *
     * The changes identified are:
     *   1. partitions for which the broker is not a replica anymore
     *   2. partitions for which the broker is now the leader
     *   3. partitions for which the broker is now a follower
     *
     * @param brokerId the broker id
     * @return the list of partitions which the broker should remove, become leader or become follower.
     */
    public LocalReplicaChanges localChanges(int brokerId) {
        Set<TopicPartition> deletes = new HashSet<>();
        Map<TopicPartition, LocalReplicaChanges.PartitionInfo> leaders = new HashMap<>();
        Map<TopicPartition, LocalReplicaChanges.PartitionInfo> followers = new HashMap<>();

        for (Entry<Integer, PartitionRegistration> entry : partitionChanges.entrySet()) {
            if (!Replicas.contains(entry.getValue().replicas, brokerId)) {
                PartitionRegistration prevPartition = image.partitions().get(entry.getKey());
                if (prevPartition != null && Replicas.contains(prevPartition.replicas, brokerId)) {
                    deletes.add(new TopicPartition(name(), entry.getKey()));
                }
            } else if (entry.getValue().leader == brokerId) {
                PartitionRegistration prevPartition = image.partitions().get(entry.getKey());
                if (prevPartition == null || prevPartition.partitionEpoch != entry.getValue().partitionEpoch) {
                    leaders.put(
                        new TopicPartition(name(), entry.getKey()),
                        new LocalReplicaChanges.PartitionInfo(id(), entry.getValue())
                    );
                }
            } else if (
                entry.getValue().leader != brokerId &&
                Replicas.contains(entry.getValue().replicas, brokerId)
            ) {
                PartitionRegistration prevPartition = image.partitions().get(entry.getKey());
                if (prevPartition == null || prevPartition.partitionEpoch != entry.getValue().partitionEpoch) {
                    followers.put(
                        new TopicPartition(name(), entry.getKey()),
                        new LocalReplicaChanges.PartitionInfo(id(), entry.getValue())
                    );
                }
            }
        }

        return new LocalReplicaChanges(deletes, leaders, followers);
    }

    @Override
    public String toString() {
        return "TopicDelta(" +
            "partitionChanges=" + partitionChanges +
            ')';
    }
}

相关信息

kafka 源码目录

相关文章

kafka AclsDelta 源码

kafka AclsImage 源码

kafka ClientQuotaDelta 源码

kafka ClientQuotaImage 源码

kafka ClientQuotasDelta 源码

kafka ClientQuotasImage 源码

kafka ClusterDelta 源码

kafka ClusterImage 源码

kafka ConfigurationDelta 源码

kafka ConfigurationImage 源码

0  赞