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.coordinator.group;
  
  import java.util.function.Function;
  
  public class OffsetExpirationConditionImpl implements OffsetExpirationCondition {
  
      /**
       * Given an offset and metadata, obtain the base timestamp that should be used
       * as the start of the offsets retention period.
       */
      private final Function<OffsetAndMetadata, Long> baseTimestamp;
  
      public OffsetExpirationConditionImpl(Function<OffsetAndMetadata, Long> baseTimestamp) {
          this.baseTimestamp = baseTimestamp;
      }
  
      /**
       * Determine whether an offset is expired. Older versions have an expire timestamp per partition. If this
       * exists, compare against the current timestamp. Otherwise, use the base timestamp (either commit timestamp
       * or current state timestamp if group is empty for classic groups) and check whether the offset has
       * exceeded the offset retention.
       *
       * @param offset              The offset and metadata.
       * @param currentTimestampMs  The current timestamp.
       * @param offsetsRetentionMs  The offsets retention in milliseconds.
       *
       * @return Whether the given offset is expired or not.
       */
      @Override
      public boolean isOffsetExpired(OffsetAndMetadata offset, long currentTimestampMs, long offsetsRetentionMs) {
          if (offset.expireTimestampMs.isPresent()) {
              // Older versions with explicit expire_timestamp field => old expiration semantics is used
              return currentTimestampMs >= offset.expireTimestampMs.getAsLong();
          } else {
              // Current version with no per partition retention
              return currentTimestampMs - baseTimestamp.apply(offset) >= offsetsRetentionMs;
          }
      }
  
      /**
       * @return The base timestamp.
       */
      public Function<OffsetAndMetadata, Long> baseTimestamp() {
          return this.baseTimestamp;
      }
  }
  