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.beam.runners.samza.state;
  
  import java.util.Iterator;
  import org.apache.beam.sdk.state.ReadableState;
  import org.apache.beam.sdk.state.SetState;
  
  /** Samza's extended SetState, allowing extra access methods to the state. */
  public interface SamzaSetState<T> extends SetState<T> {
  
    /**
     * Returns an iterator from the current set state. Note this is different from the iterable
     * implementation in {@link SetState#read()}, where we load the entries into memory and return
     * iterable from that. To handle large state that doesn't fit in memory, we also need this method
     * so it's possible to iterate on large data set and close the iterator when not needed.
     *
     * @return a {@link ReadableState} of an iterator
     */
    ReadableState<Iterator<T>> readIterator();
  
    /** Closes the iterator returned from {@link SamzaSetState#readIterator()}. */
    void closeIterators();
  }
  