kafka ConsumerRecords 源码

kafka ConsumerRecords 代码

文件路径：/clients/src/main/java/org/apache/kafka/clients/consumer/ConsumerRecords.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.clients.consumer;

import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.utils.AbstractIterator;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * A container that holds the list {@link ConsumerRecord} per partition for a
 * particular topic. There is one {@link ConsumerRecord} list for every topic
 * partition returned by a {@link Consumer#poll(java.time.Duration)} operation.
 */
public class ConsumerRecords<K, V> implements Iterable<ConsumerRecord<K, V>> {
    public static final ConsumerRecords<Object, Object> EMPTY = new ConsumerRecords<>(Collections.emptyMap());

    private final Map<TopicPartition, List<ConsumerRecord<K, V>>> records;

    public ConsumerRecords(Map<TopicPartition, List<ConsumerRecord<K, V>>> records) {
        this.records = records;
    }

    /**
     * Get just the records for the given partition
     * 
     * @param partition The partition to get records for
     */
    public List<ConsumerRecord<K, V>> records(TopicPartition partition) {
        List<ConsumerRecord<K, V>> recs = this.records.get(partition);
        if (recs == null)
            return Collections.emptyList();
        else
            return Collections.unmodifiableList(recs);
    }

    /**
     * Get just the records for the given topic
     */
    public Iterable<ConsumerRecord<K, V>> records(String topic) {
        if (topic == null)
            throw new IllegalArgumentException("Topic must be non-null.");
        List<List<ConsumerRecord<K, V>>> recs = new ArrayList<>();
        for (Map.Entry<TopicPartition, List<ConsumerRecord<K, V>>> entry : records.entrySet()) {
            if (entry.getKey().topic().equals(topic))
                recs.add(entry.getValue());
        }
        return new ConcatenatedIterable<>(recs);
    }

    /**
     * Get the partitions which have records contained in this record set.
     * @return the set of partitions with data in this record set (may be empty if no data was returned)
     */
    public Set<TopicPartition> partitions() {
        return Collections.unmodifiableSet(records.keySet());
    }

    @Override
    public Iterator<ConsumerRecord<K, V>> iterator() {
        return new ConcatenatedIterable<>(records.values()).iterator();
    }

    /**
     * The number of records for all topics
     */
    public int count() {
        int count = 0;
        for (List<ConsumerRecord<K, V>> recs: this.records.values())
            count += recs.size();
        return count;
    }

    private static class ConcatenatedIterable<K, V> implements Iterable<ConsumerRecord<K, V>> {

        private final Iterable<? extends Iterable<ConsumerRecord<K, V>>> iterables;

        public ConcatenatedIterable(Iterable<? extends Iterable<ConsumerRecord<K, V>>> iterables) {
            this.iterables = iterables;
        }

        @Override
        public Iterator<ConsumerRecord<K, V>> iterator() {
            return new AbstractIterator<ConsumerRecord<K, V>>() {
                Iterator<? extends Iterable<ConsumerRecord<K, V>>> iters = iterables.iterator();
                Iterator<ConsumerRecord<K, V>> current;

                public ConsumerRecord<K, V> makeNext() {
                    while (current == null || !current.hasNext()) {
                        if (iters.hasNext())
                            current = iters.next().iterator();
                        else
                            return allDone();
                    }
                    return current.next();
                }
            };
        }
    }

    public boolean isEmpty() {
        return records.isEmpty();
    }

    @SuppressWarnings("unchecked")
    public static <K, V> ConsumerRecords<K, V> empty() {
        return (ConsumerRecords<K, V>) EMPTY;
    }

}

相关信息

kafka 源码目录

相关文章

kafka CommitFailedException 源码

kafka Consumer 源码

kafka ConsumerConfig 源码

kafka ConsumerGroupMetadata 源码

kafka ConsumerInterceptor 源码

kafka ConsumerPartitionAssignor 源码

kafka ConsumerRebalanceListener 源码

kafka ConsumerRecord 源码

kafka CooperativeStickyAssignor 源码

kafka InvalidOffsetException 源码