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.query;
  
  import org.apache.kafka.common.annotation.InterfaceStability.Evolving;
  import org.apache.kafka.streams.state.TimestampedKeyValueStore;
  import org.apache.kafka.streams.state.ValueAndTimestamp;
  
  import java.util.Objects;
  
  /**
   * Interactive query for retrieving a single record based on its key from {@link TimestampedKeyValueStore}
   * @param <K> Type of keys
   * @param <V> Type of values
   */
  @Evolving
  public final class TimestampedKeyQuery<K, V> implements Query<ValueAndTimestamp<V>> {
  
      private final K key;
      private final boolean skipCache;
  
      private TimestampedKeyQuery(final K key, final boolean skipCache) {
          this.key = key;
          this.skipCache = skipCache;
      }
  
      /**
       * Creates a query that will retrieve the record identified by {@code key} if it exists
       * (or {@code null} otherwise).
       * @param key The key to retrieve
       * @param <K> The type of the key
       * @param <V> The type of the value that will be retrieved
       */
      public static <K, V> TimestampedKeyQuery<K, V> withKey(final K key) {
          Objects.requireNonNull(key, "the key should not be null");
          return new TimestampedKeyQuery<>(key, false);
      }
  
      /**
       * Specifies that the cache should be skipped during query evaluation. This means, that the query will always
       * get forwarded to the underlying store.
       */
      public TimestampedKeyQuery<K, V> skipCache() {
          return new TimestampedKeyQuery<>(key, true);
      }
  
      /**
       * Return the key that was specified for this query.
       *
       * @return The key that was specified for this query.
       */
      public K key() {
          return key;
      }
  
      /**
       * The flag whether to skip the cache or not during query evaluation.
       */
      public boolean isSkipCache() {
          return skipCache;
      }
  }
  