/*
    * Copyright 2012 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.http;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.Unpooled;
  import io.netty.handler.codec.DecoderResult;
  
  /**
   * The last {@link HttpContent} which has trailing headers.
   */
  public interface LastHttpContent extends HttpContent {
  
      /**
       * The 'end of content' marker in chunked encoding.
       */
      LastHttpContent EMPTY_LAST_CONTENT = new LastHttpContent() {
  
          @Override
          public ByteBuf content() {
              return Unpooled.EMPTY_BUFFER;
          }
  
          @Override
          public LastHttpContent copy() {
              return EMPTY_LAST_CONTENT;
          }
  
          @Override
          public LastHttpContent duplicate() {
              return this;
          }
  
          @Override
          public LastHttpContent replace(ByteBuf content) {
              return new DefaultLastHttpContent(content);
          }
  
          @Override
          public LastHttpContent retainedDuplicate() {
              return this;
          }
  
          @Override
          public HttpHeaders trailingHeaders() {
              return EmptyHttpHeaders.INSTANCE;
          }
  
          @Override
          public DecoderResult decoderResult() {
              return DecoderResult.SUCCESS;
          }
  
          @Override
          @Deprecated
          public DecoderResult getDecoderResult() {
              return decoderResult();
          }
  
          @Override
          public void setDecoderResult(DecoderResult result) {
              throw new UnsupportedOperationException("read only");
          }
  
          @Override
          public int refCnt() {
              return 1;
          }
  
          @Override
          public LastHttpContent retain() {
              return this;
          }
  
          @Override
          public LastHttpContent retain(int increment) {
              return this;
          }
  
          @Override
          public LastHttpContent touch() {
              return this;
          }
  
          @Override
          public LastHttpContent touch(Object hint) {
             return this;
         }
 
         @Override
         public boolean release() {
             return false;
         }
 
         @Override
         public boolean release(int decrement) {
             return false;
         }
 
         @Override
         public String toString() {
             return "EmptyLastHttpContent";
         }
     };
 
     HttpHeaders trailingHeaders();
 
     @Override
     LastHttpContent copy();
 
     @Override
     LastHttpContent duplicate();
 
     @Override
     LastHttpContent retainedDuplicate();
 
     @Override
     LastHttpContent replace(ByteBuf content);
 
     @Override
     LastHttpContent retain(int increment);
 
     @Override
     LastHttpContent retain();
 
     @Override
     LastHttpContent touch();
 
     @Override
     LastHttpContent touch(Object hint);
 }