kafka Window 源码

kafka Window 代码

文件路径：/streams/src/main/java/org/apache/kafka/streams/kstream/Window.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.kstream;

import org.apache.kafka.streams.processor.TimestampExtractor;

import java.time.Instant;

/**
 * A single window instance, defined by its start and end timestamp.
 * {@code Window} is agnostic if start/end boundaries are inclusive or exclusive; this is defined by concrete
 * window implementations.
 * <p>
 * To specify how {@code Window} boundaries are defined use {@link Windows}.
 * For time semantics, see {@link TimestampExtractor}.
 *
 * @see Windows
 * @see org.apache.kafka.streams.kstream.internals.TimeWindow
 * @see org.apache.kafka.streams.kstream.internals.SessionWindow
 * @see org.apache.kafka.streams.kstream.internals.UnlimitedWindow
 * @see TimestampExtractor
 */
public abstract class Window {

    protected final long startMs;
    protected final long endMs;
    private final Instant startTime;
    private final Instant endTime;


    /**
     * Create a new window for the given start and end time.
     *
     * @param startMs the start timestamp of the window
     * @param endMs   the end timestamp of the window
     * @throws IllegalArgumentException if {@code startMs} is negative or if {@code endMs} is smaller than {@code startMs}
     */
    public Window(final long startMs, final long endMs) throws IllegalArgumentException {
        if (startMs < 0) {
            throw new IllegalArgumentException("Window startMs time cannot be negative.");
        }
        if (endMs < startMs) {
            throw new IllegalArgumentException("Window endMs time cannot be smaller than window startMs time.");
        }
        this.startMs = startMs;
        this.endMs = endMs;

        this.startTime = Instant.ofEpochMilli(startMs);
        this.endTime = Instant.ofEpochMilli(endMs);
    }

    /**
     * Return the start timestamp of this window.
     *
     * @return The start timestamp of this window.
     */
    public long start() {
        return startMs;
    }

    /**
     * Return the end timestamp of this window.
     *
     * @return The end timestamp of this window.
     */
    public long end() {
        return endMs;
    }

    /**
     * Return the start time of this window.
     *
     * @return The start time of this window.
     */
    public Instant startTime() {
        return startTime;
    }

    /**
     * Return the end time of this window.
     *
     * @return The end time of this window.
     */
    public Instant endTime() {
        return endTime;
    }

    /**
     * Check if the given window overlaps with this window.
     * Should throw an {@link IllegalArgumentException} if the {@code other} window has a different type than {@code
     * this} window.
     *
     * @param other another window of the same type
     * @return {@code true} if {@code other} overlaps with this window&mdash;{@code false} otherwise
     */
    public abstract boolean overlap(final Window other);

    @Override
    public boolean equals(final Object obj) {
        if (obj == this) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }

        final Window other = (Window) obj;
        return startMs == other.startMs && endMs == other.endMs;
    }

    @Override
    public int hashCode() {
        return (int) (((startMs << 32) | endMs) % 0xFFFFFFFFL);
    }

    @Override
    public String toString() {
        return "Window{" +
            "startMs=" + startMs +
            ", endMs=" + endMs +
            '}';
    }
}

相关信息

kafka 源码目录

相关文章

kafka Aggregator 源码

kafka Branched 源码

kafka BranchedKStream 源码

kafka CogroupedKStream 源码

kafka Consumed 源码

kafka EmitStrategy 源码

kafka ForeachAction 源码

kafka ForeachProcessor 源码

kafka GlobalKTable 源码

kafka Grouped 源码