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.state;
  
  import org.apache.kafka.streams.KeyValue;
  import org.apache.kafka.streams.processor.StateStore;
  import org.apache.kafka.streams.processor.StateStoreContext;
  import org.apache.kafka.streams.query.Position;
  
  import java.time.Instant;
  import java.util.NoSuchElementException;
  
  public class NoOpWindowStore implements ReadOnlyWindowStore, StateStore {
  
      private static class EmptyWindowStoreIterator implements WindowStoreIterator<KeyValue> {
  
          @Override
          public void close() {
          }
  
          @Override
          public Long peekNextKey() {
              throw new NoSuchElementException();
          }
  
          @Override
          public boolean hasNext() {
              return false;
          }
  
          @Override
          public KeyValue<Long, KeyValue> next() {
              throw new NoSuchElementException();
          }
      }
  
      private static final WindowStoreIterator<KeyValue> EMPTY_WINDOW_STORE_ITERATOR = new EmptyWindowStoreIterator();
  
      @Override
      public String name() {
          return "";
      }
  
      @Override
      public void init(final StateStoreContext stateStoreContext, final StateStore root) {}
  
      @Override
      public void flush() {
  
      }
  
      @Override
      public void close() {
  
      }
  
      @Override
      public boolean persistent() {
          return false;
      }
  
      @Override
      public boolean isOpen() {
          return false;
      }
  
      @Override
      public Position getPosition() {
          throw new UnsupportedOperationException("Position handling not implemented");
      }
  
      @Override
      public Object fetch(final Object key, final long time) {
          return null;
      }
  
      @Override
      public WindowStoreIterator fetch(final Object key, final Instant timeFrom, final Instant timeTo) throws IllegalArgumentException {
          return EMPTY_WINDOW_STORE_ITERATOR;
      }
  
      @Override
      public WindowStoreIterator backwardFetch(final  Object key,
                                               final Instant timeFrom,
                                               final Instant timeTo) throws IllegalArgumentException {
          return EMPTY_WINDOW_STORE_ITERATOR;
      }
  
      @Override
      public KeyValueIterator fetch(final Object keyFrom,
                                    final Object keyTo,
                                    final Instant timeFrom,
                                    final Instant timeTo) throws IllegalArgumentException {
          return EMPTY_WINDOW_STORE_ITERATOR;
      }
  
      @Override
      public KeyValueIterator backwardFetch(final Object from,
                                            final Object keyTo,
                                            final Instant timeFrom,
                                            final Instant timeTo) throws IllegalArgumentException {
          return EMPTY_WINDOW_STORE_ITERATOR;
      }
  
      @Override
      public WindowStoreIterator<KeyValue> all() {
          return EMPTY_WINDOW_STORE_ITERATOR;
      }
  
      @Override
      public WindowStoreIterator<KeyValue> backwardAll() {
          return EMPTY_WINDOW_STORE_ITERATOR;
      }
  
      @Override
      public KeyValueIterator fetchAll(final Instant timeFrom, final Instant timeTo) throws IllegalArgumentException {
          return EMPTY_WINDOW_STORE_ITERATOR;
      }
  
      @Override
      public KeyValueIterator backwardFetchAll(final Instant timeFrom,
                                               final Instant timeTo) throws IllegalArgumentException {
          return EMPTY_WINDOW_STORE_ITERATOR;
      }
  }
  