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.snapshot;
  
  import org.apache.kafka.raft.Batch;
  import org.apache.kafka.server.common.OffsetAndEpoch;
  
  import java.util.Iterator;
  
  /**
   * A type for reading an immutable snapshot.
   *
   * A snapshot reader can be used to scan through all the objects T in a snapshot. It
   * is assumed that the content of the snapshot represents all the objects T for the topic
   * partition from offset 0 up to but not including the end offset in the snapshot id.
   *
   * The offsets ({@code baseOffset()} and {@code lastOffset()} stored in {@code Batch<T>}
   * objects returned by this iterator are independent of the offset of the records in the
   * log used to generate this batch.
   *
   * Use {@code lastContainedLogOffset()} and {@code lastContainedLogEpoch()} to query which
   * offsets and epoch from the log are included in this snapshot. Both of these values are
   * inclusive.
   */
  public interface SnapshotReader<T> extends AutoCloseable, Iterator<Batch<T>> {
      /**
       * Returns the end offset and epoch for the snapshot.
       */
      OffsetAndEpoch snapshotId();
  
      /**
       * Returns the last log offset which is represented in the snapshot.
       */
      long lastContainedLogOffset();
  
      /**
       * Returns the epoch of the last log offset which is represented in the snapshot.
       */
      int lastContainedLogEpoch();
  
      /**
       * Returns the timestamp of the last log offset which is represented in the snapshot.
       */
      long lastContainedLogTimestamp();
  
      /**
       * Closes the snapshot reader.
       */
      void close();
  }
  