code: /*
   * Copyright (c) 2019 the Eclipse Milo Authors
   *
   * This program and the accompanying materials are made
   * available under the terms of the Eclipse Public License 2.0
   * which is available at https://www.eclipse.org/legal/epl-2.0/
   *
   * SPDX-License-Identifier: EPL-2.0
   */
  
  package org.eclipse.milo.opcua.stack.core.channel.headers;
  
  import com.google.common.base.MoreObjects;
  import io.netty.buffer.ByteBuf;
  import org.eclipse.milo.opcua.stack.core.util.annotations.UInt32Primitive;
  
  public class SymmetricSecurityHeader {
  
      public static final int SYMMETRIC_SECURITY_HEADER_SIZE = 4;
  
      @UInt32Primitive
      private final long tokenId;
  
      /**
       * @param tokenId A unique identifier for the SecureChannel SecurityToken used to secure the Message.
       */
      public SymmetricSecurityHeader(long tokenId) {
          this.tokenId = tokenId;
      }
  
      public long getTokenId() {
          return tokenId;
      }
  
      @Override
      public boolean equals(Object o) {
          if (this == o) return true;
          if (o == null || getClass() != o.getClass()) return false;
  
          SymmetricSecurityHeader that = (SymmetricSecurityHeader) o;
  
          return tokenId == that.tokenId;
      }
  
      @Override
      public int hashCode() {
          return (int) (tokenId ^ (tokenId >>> 32));
      }
  
      @Override
      public String toString() {
          return MoreObjects.toStringHelper(this)
              .add("tokenId", tokenId)
              .toString();
      }
  
      public static ByteBuf encode(SymmetricSecurityHeader header, ByteBuf buffer) {
          buffer.writeIntLE((int) header.getTokenId());
  
          return buffer;
      }
  
      public static SymmetricSecurityHeader decode(ByteBuf buffer) {
          return new SymmetricSecurityHeader(buffer.readUnsignedIntLE());
      }
  
  }
  