content: /*
   * 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;
  
  /**
   * Retrieves embedded metadata timestamps from Kafka messages.
   * If a record has a negative (invalid) timestamp value, an error handler method is called.
   * <p>
   * Embedded metadata timestamp was introduced in "KIP-32: Add timestamps to Kafka message" for the new
   * 0.10+ Kafka message format.
   * <p>
   * Here, "embedded metadata" refers to the fact that compatible Kafka producer clients automatically and
   * transparently embed such timestamps into message metadata they send to Kafka, which can then be retrieved
   * via this timestamp extractor.
   * <p>
   * If the embedded metadata timestamp represents <i>CreateTime</i> (cf. Kafka broker setting
   * {@code message.timestamp.type} and Kafka topic setting {@code log.message.timestamp.type}),
   * this extractor effectively provides <i>event-time</i> semantics.
   * If <i>LogAppendTime</i> is used as broker/topic setting to define the embedded metadata timestamps,
   * using this extractor effectively provides <i>ingestion-time</i> semantics.
   * <p>
   * If you need <i>processing-time</i> semantics, use {@link WallclockTimestampExtractor}.
   *
   * @see FailOnInvalidTimestamp
   * @see LogAndSkipOnInvalidTimestamp
   * @see UsePartitionTimeOnInvalidTimestamp
   * @see WallclockTimestampExtractor
   */
  abstract class ExtractRecordMetadataTimestamp implements TimestampExtractor {
  
      /**
       * Extracts the embedded metadata timestamp from the given {@link ConsumerRecord}.
       *
       * @param record a data record
       * @param partitionTime the highest extracted valid timestamp of the current record's partition˙ (could be -1 if unknown)
       * @return the embedded metadata timestamp of the given {@link ConsumerRecord}
       */
      @Override
      public long extract(final ConsumerRecord<Object, Object> record, final long partitionTime) {
          final long timestamp = record.timestamp();
  
          if (timestamp < 0) {
              return onInvalidTimestamp(record, timestamp, partitionTime);
          }
  
          return timestamp;
      }
  
      /**
       * Called if no valid timestamp is embedded in the record meta data.
       *
       * @param record a data record
       * @param recordTimestamp the timestamp extractor from the record
       * @param partitionTime the highest extracted valid timestamp of the current record's partition˙ (could be -1 if unknown)
       * @return a new timestamp for the record (if negative, record will not be processed but dropped silently)
       */
      public abstract long onInvalidTimestamp(final ConsumerRecord<Object, Object> record,
                                              final long recordTimestamp,
                                              final long partitionTime);
  }
  