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.KeyValueIterator;
  import org.apache.kafka.streams.state.TimestampedKeyValueStore;
  import org.apache.kafka.streams.state.ValueAndTimestamp;
  
  import java.util.Optional;
  
  /**
   * Interactive query for issuing range queries and scans over {@link TimestampedKeyValueStore}
   * <p>
   *  A range query retrieves a set of records, specified using an upper and/or lower bound on the keys.
   * <p>
   *  A scan query retrieves all records contained in the store.
   * <p>
   *  Keys' order is based on the serialized byte[] of the keys, not the 'logical' key order.
   * @param <K> Type of keys
   * @param <V> Type of values
   */
  @Evolving
  public final class TimestampedRangeQuery<K, V> implements Query<KeyValueIterator<K, ValueAndTimestamp<V>>> {
  
  
      private final Optional<K> lower;
      private final Optional<K> upper;
      private final ResultOrder order;
  
      private TimestampedRangeQuery(final Optional<K> lower, final Optional<K> upper, final ResultOrder order) {
          this.lower = lower;
          this.upper = upper;
          this.order = order;
      }
  
      /**
       * Interactive range query using a lower and upper bound to filter the keys returned.
       * @param lower The key that specifies the lower bound of the range
       * @param upper The key that specifies the upper bound of the range
       * @param <K> The key type
       * @param <V> The value type
       */
      public static <K, V> TimestampedRangeQuery<K, V> withRange(final K lower, final K upper) {
          return new TimestampedRangeQuery<>(Optional.ofNullable(lower), Optional.ofNullable(upper), ResultOrder.ANY);
      }
  
      /**
       * Interactive range query using an upper bound to filter the keys returned.
       * If both {@code <K,V>} are null, RangQuery returns a full range scan.
       * @param upper The key that specifies the upper bound of the range
       * @param <K> The key type
       * @param <V> The value type
       */
      public static <K, V> TimestampedRangeQuery<K, V> withUpperBound(final K upper) {
          return new TimestampedRangeQuery<>(Optional.empty(), Optional.of(upper), ResultOrder.ANY);
      }
  
      /**
       * Interactive range query using a lower bound to filter the keys returned.
       * @param lower The key that specifies the lower bound of the range
       * @param <K> The key type
       * @param <V> The value type
       */
      public static <K, V> TimestampedRangeQuery<K, V> withLowerBound(final K lower) {
          return new TimestampedRangeQuery<>(Optional.of(lower), Optional.empty(), ResultOrder.ANY);
      }
  
      /**
       * Determines if the serialized byte[] of the keys in ascending or descending or unordered order.
       * Order is based on the serialized byte[] of the keys, not the 'logical' key order.
       * @return return the order of return records base on the serialized byte[] of the keys (can be unordered, or in ascending, or in descending order).
       */
      public ResultOrder resultOrder() {
          return order;
      }
  
      /**
       * Set the query to return the serialized byte[] of the keys in descending order.
       * Order is based on the serialized byte[] of the keys, not the 'logical' key order.
       * @return a new RangeQuery instance with descending flag set.
       */
      public TimestampedRangeQuery<K, V> withDescendingKeys() {
          return new TimestampedRangeQuery<>(this.lower, this.upper, ResultOrder.DESCENDING);
      }
  
      /**
       * Set the query to return the serialized byte[] of the keys in ascending order.
       * Order is based on the serialized byte[] of the keys, not the 'logical' key order.
       * @return a new RangeQuery instance with ascending flag set.
       */
      public TimestampedRangeQuery<K, V> withAscendingKeys() {
          return new TimestampedRangeQuery<>(this.lower, this.upper, ResultOrder.ASCENDING);
      }
  
      /**
       * Interactive scan query that returns all records in the store.
       * @param <K> The key type
       * @param <V> The value type
       */
      public static <K, V> TimestampedRangeQuery<K, V> withNoBounds() {
          return new TimestampedRangeQuery<>(Optional.empty(), Optional.empty(), ResultOrder.ANY);
      }
  
  
      /**
       * The lower bound of the query, if specified.
       */
      public Optional<K> lowerBound() {
          return lower;
      }
  
      /**
       * The upper bound of the query, if specified
       */
      public Optional<K> upperBound() {
          return upper;
      }
  }