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   /*
    * Copyright 2016 The Netty Project
    *
    * The Netty Project 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:
    *
    *   https://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 io.netty.handler.codec.dns;
  
  import io.netty.channel.socket.InternetProtocolFamily;
  import io.netty.util.internal.UnstableApi;
  
  import java.net.InetAddress;
  import java.util.Arrays;
  
  /**
   * Default {@link DnsOptEcsRecord} implementation.
   */
  @UnstableApi
  public final class DefaultDnsOptEcsRecord extends AbstractDnsOptPseudoRrRecord implements DnsOptEcsRecord {
      private final int srcPrefixLength;
      private final byte[] address;
  
      /**
       * Creates a new instance.
       *
       * @param maxPayloadSize the suggested max payload size in bytes
       * @param extendedRcode the extended rcode
       * @param version the version
       * @param srcPrefixLength the prefix length
       * @param address the bytes of the {@link InetAddress} to use
       */
      public DefaultDnsOptEcsRecord(int maxPayloadSize, int extendedRcode, int version,
                                    int srcPrefixLength, byte[] address) {
          super(maxPayloadSize, extendedRcode, version);
          this.srcPrefixLength = srcPrefixLength;
          this.address = verifyAddress(address).clone();
      }
  
      /**
       * Creates a new instance.
       *
       * @param maxPayloadSize the suggested max payload size in bytes
       * @param srcPrefixLength the prefix length
       * @param address the bytes of the {@link InetAddress} to use
       */
      public DefaultDnsOptEcsRecord(int maxPayloadSize, int srcPrefixLength, byte[] address) {
          this(maxPayloadSize, 0, 0, srcPrefixLength, address);
      }
  
      /**
       * Creates a new instance.
       *
       * @param maxPayloadSize the suggested max payload size in bytes
       * @param protocolFamily the {@link InternetProtocolFamily} to use. This should be the same as the one used to
       *                       send the query.
       */
      public DefaultDnsOptEcsRecord(int maxPayloadSize, InternetProtocolFamily protocolFamily) {
          this(maxPayloadSize, 0, 0, 0, protocolFamily.localhost().getAddress());
      }
  
      private static byte[] verifyAddress(byte[] bytes) {
          if (bytes.length == 4 || bytes.length == 16) {
              return bytes;
          }
          throw new IllegalArgumentException("bytes.length must either 4 or 16");
      }
  
      @Override
      public int sourcePrefixLength() {
          return srcPrefixLength;
      }
  
      @Override
      public int scopePrefixLength() {
          return 0;
      }
  
      @Override
      public byte[] address() {
          return address.clone();
      }
  
      @Override
      public String toString() {
          StringBuilder sb = toStringBuilder();
          sb.setLength(sb.length() - 1);
          return sb.append(" address:")
            .append(Arrays.toString(address))
            .append(" sourcePrefixLength:")
            .append(sourcePrefixLength())
           .append(" scopePrefixLength:")
           .append(scopePrefixLength())
           .append(')').toString();
     }
 }