streams/src/main/java/org/apache/kafka/streams/processor/TimestampExtractor.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;

import org.apache.kafka.clients.consumer.ConsumerRecord;

/**
 * An interface that allows the Kafka Streams framework to extract a timestamp from an instance of {@link ConsumerRecord}.
 * The extracted timestamp is defined as milliseconds.
 */
public interface TimestampExtractor {

    /**
     * Extracts a timestamp from a message
     *
     * @param record ConsumerRecord
     * @return timestamp
     */
    long extract(ConsumerRecord<Object, Object> record);
}