kafka PunctuationSchedule 源码

kafka PunctuationSchedule 代码

文件路径：/streams/src/main/java/org/apache/kafka/streams/processor/internals/PunctuationSchedule.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.streams.processor.internals;

import org.apache.kafka.streams.processor.Cancellable;
import org.apache.kafka.streams.processor.Punctuator;

public class PunctuationSchedule extends Stamped<ProcessorNode> {

    private final long interval;
    private final Punctuator punctuator;
    private boolean isCancelled = false;
    // this Cancellable will be re-pointed at the successor schedule in next()
    private final RepointableCancellable cancellable;

    PunctuationSchedule(final ProcessorNode node,
                        final long time,
                        final long interval,
                        final Punctuator punctuator) {
        this(node, time, interval, punctuator, new RepointableCancellable());
        cancellable.setSchedule(this);
    }

    private PunctuationSchedule(final ProcessorNode node,
                                final long time,
                                final long interval,
                                final Punctuator punctuator,
                                final RepointableCancellable cancellable) {
        super(node, time);
        this.interval = interval;
        this.punctuator = punctuator;
        this.cancellable = cancellable;
    }

    public ProcessorNode node() {
        return value;
    }

    public Punctuator punctuator() {
        return punctuator;
    }

    public Cancellable cancellable() {
        return cancellable;
    }

    void markCancelled() {
        isCancelled = true;
    }

    boolean isCancelled() {
        return isCancelled;
    }

    public PunctuationSchedule next(final long currTimestamp) {
        long nextPunctuationTime = timestamp + interval;
        if (currTimestamp >= nextPunctuationTime) {
            // we missed one ore more punctuations
            // avoid scheduling a new punctuations immediately, this can happen:
            // - when using STREAM_TIME punctuation and there was a gap i.e., no data was
            //   received for at least 2*interval
            // - when using WALL_CLOCK_TIME and there was a gap i.e., punctuation was delayed for at least 2*interval (GC pause, overload, ...)
            final long intervalsMissed = (currTimestamp - timestamp) / interval;
            nextPunctuationTime = timestamp + (intervalsMissed + 1) * interval;
        }

        final PunctuationSchedule nextSchedule = new PunctuationSchedule(value, nextPunctuationTime, interval, punctuator, cancellable);

        cancellable.setSchedule(nextSchedule);

        return nextSchedule;
    }

    @Override
    public boolean equals(final Object other) {
        return super.equals(other);
    }

    @Override
    public int hashCode() {
        return super.hashCode();
    }

    private static class RepointableCancellable implements Cancellable {
        private PunctuationSchedule schedule;

        synchronized void setSchedule(final PunctuationSchedule schedule) {
            this.schedule = schedule;
        }

        @Override
        synchronized public void cancel() {
            schedule.markCancelled();
        }
    }
}

相关信息

kafka 源码目录

相关文章

kafka AbstractProcessorContext 源码

kafka AbstractReadOnlyDecorator 源码

kafka AbstractReadWriteDecorator 源码

kafka AbstractTask 源码

kafka ActiveTaskCreator 源码

kafka ChangelogReader 源码

kafka ChangelogRecordDeserializationHelper 源码

kafka ChangelogRegister 源码

kafka ChangelogTopics 源码

kafka ClientUtils 源码