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.processor;
  
  import java.util.Objects;
  
  /**
   * This class is used to provide the optional parameters when sending output records to downstream processor
   * using {@link ProcessorContext#forward(Object, Object, To)}.
   */
  public class To {
      protected String childName;
      protected long timestamp;
  
      private To(final String childName,
                 final long timestamp) {
          this.childName = childName;
          this.timestamp = timestamp;
      }
  
      protected To(final To to) {
          this(to.childName, to.timestamp);
      }
  
      protected void update(final To to) {
          childName = to.childName;
          timestamp = to.timestamp;
      }
  
      /**
       * Forward the key/value pair to one of the downstream processors designated by the downstream processor name.
       * @param childName name of downstream processor
       * @return a new {@link To} instance configured with {@code childName}
       */
      public static To child(final String childName) {
          return new To(childName, -1);
      }
  
      /**
       * Forward the key/value pair to all downstream processors
       * @return a new {@link To} instance configured for all downstream processor
       */
      public static To all() {
          return new To(null, -1);
      }
  
      /**
       * Set the timestamp of the output record.
       * @param timestamp the output record timestamp
       * @return itself (i.e., {@code this})
       */
      public To withTimestamp(final long timestamp) {
          this.timestamp = timestamp;
          return this;
      }
  
      @Override
      public boolean equals(final Object o) {
          if (this == o) {
              return true;
          }
          if (o == null || getClass() != o.getClass()) {
              return false;
          }
          final To to = (To) o;
          return timestamp == to.timestamp &&
              Objects.equals(childName, to.childName);
      }
  
      /**
       * Equality is implemented in support of tests, *not* for use in Hash collections, since this class is mutable.
       */
      @Override
      public int hashCode() {
          throw new UnsupportedOperationException("To is unsafe for use in Hash collections");
      }
  
      @Override
      public String toString() {
          return "To{" +
                 "childName='" + childName + '\'' +
                 ", timestamp=" + timestamp +
                 '}';
      }
  }
  