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.internals;
  
  public interface CachedStateStore<K, V> {
      /**
       * Set the {@link CacheFlushListener} to be notified when entries are flushed from the
       * cache to the underlying {@link org.apache.kafka.streams.processor.StateStore}
       * @param listener
       * @param sendOldValues
       */
      boolean setFlushListener(final CacheFlushListener<K, V> listener,
                               final boolean sendOldValues);
  
      /**
       * Flush only the cache but not the underlying state stores
       *
       * TODO: this is a hacky workaround for now, should be removed when we decouple caching with emitting
       */
      void flushCache();
  
      /**
       * Clear the cache; this is used if the underlying store could be updated directly
       * and hence making the cache out of date.
       * Please note this call does not try to flush the cache, instead if assumes the cache
       * itself has been flushed completely
       *
       * TODO: this is a hacky workaround for now, should be removed when we decouple caching with emitting
       */
      void clearCache();
  }
  