/*
    * 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:
    *
    *   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.jboss.netty.buffer;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.ByteBuffer;
  import java.nio.ByteOrder;
  import java.nio.ReadOnlyBufferException;
  import java.nio.channels.GatheringByteChannel;
  import java.nio.channels.ScatteringByteChannel;
  
  /**
   * A derived buffer which forbids any write requests to its parent.  It is
   * recommended to use {@link ChannelBuffers#unmodifiableBuffer(ChannelBuffer)}
   * instead of calling the constructor explicitly.
   */
  public class ReadOnlyChannelBuffer extends AbstractChannelBuffer implements WrappedChannelBuffer {
  
      private final ChannelBuffer buffer;
  
      public ReadOnlyChannelBuffer(ChannelBuffer buffer) {
          if (buffer == null) {
              throw new NullPointerException("buffer");
          }
          this.buffer = buffer;
          setIndex(buffer.readerIndex(), buffer.writerIndex());
      }
  
      private ReadOnlyChannelBuffer(ReadOnlyChannelBuffer buffer) {
          this.buffer = buffer.buffer;
          setIndex(buffer.readerIndex(), buffer.writerIndex());
      }
  
      public ChannelBuffer unwrap() {
          return buffer;
      }
  
      public ChannelBufferFactory factory() {
          return buffer.factory();
      }
  
      public ByteOrder order() {
          return buffer.order();
      }
  
      public boolean isDirect() {
          return buffer.isDirect();
      }
  
      public boolean hasArray() {
          return false;
      }
  
      public byte[] array() {
          throw new ReadOnlyBufferException();
      }
  
      public int arrayOffset() {
          throw new ReadOnlyBufferException();
      }
  
      @Override
      public void discardReadBytes() {
          throw new ReadOnlyBufferException();
      }
  
      public void setByte(int index, int value) {
          throw new ReadOnlyBufferException();
      }
  
      public void setBytes(int index, ChannelBuffer src, int srcIndex, int length) {
          throw new ReadOnlyBufferException();
      }
  
      public void setBytes(int index, byte[] src, int srcIndex, int length) {
          throw new ReadOnlyBufferException();
      }
  
      public void setBytes(int index, ByteBuffer src) {
          throw new ReadOnlyBufferException();
      }
  
      public void setShort(int index, int value) {
          throw new ReadOnlyBufferException();
     }
 
     public void setMedium(int index, int value) {
         throw new ReadOnlyBufferException();
     }
 
     public void setInt(int index, int value) {
         throw new ReadOnlyBufferException();
     }
 
     public void setLong(int index, long value) {
         throw new ReadOnlyBufferException();
     }
 
     public int setBytes(int index, InputStream in, int length)
             throws IOException {
         throw new ReadOnlyBufferException();
     }
 
     public int setBytes(int index, ScatteringByteChannel in, int length)
             throws IOException {
         throw new ReadOnlyBufferException();
     }
 
     public int getBytes(int index, GatheringByteChannel out, int length)
             throws IOException {
         return buffer.getBytes(index, out, length);
     }
 
     public void getBytes(int index, OutputStream out, int length)
             throws IOException {
         buffer.getBytes(index, out, length);
     }
 
     public void getBytes(int index, byte[] dst, int dstIndex, int length) {
         buffer.getBytes(index, dst, dstIndex, length);
     }
 
     public void getBytes(int index, ChannelBuffer dst, int dstIndex, int length) {
         buffer.getBytes(index, dst, dstIndex, length);
     }
 
     public void getBytes(int index, ByteBuffer dst) {
         buffer.getBytes(index, dst);
     }
 
     public ChannelBuffer duplicate() {
         return new ReadOnlyChannelBuffer(this);
     }
 
     public ChannelBuffer copy(int index, int length) {
         return buffer.copy(index, length);
     }
 
     public ChannelBuffer slice(int index, int length) {
         return new ReadOnlyChannelBuffer(buffer.slice(index, length));
     }
 
     public byte getByte(int index) {
         return buffer.getByte(index);
     }
 
     public short getShort(int index) {
         return buffer.getShort(index);
     }
 
     public int getUnsignedMedium(int index) {
         return buffer.getUnsignedMedium(index);
     }
 
     public int getInt(int index) {
         return buffer.getInt(index);
     }
 
     public long getLong(int index) {
         return buffer.getLong(index);
     }
 
     public ByteBuffer toByteBuffer(int index, int length) {
         return buffer.toByteBuffer(index, length).asReadOnlyBuffer();
     }
 
     @Override
     public ByteBuffer[] toByteBuffers(int index, int length) {
         ByteBuffer[] bufs = buffer.toByteBuffers(index, length);
         for (int i = 0; i < bufs.length; i ++) {
             bufs[i] = bufs[i].asReadOnlyBuffer();
         }
         return bufs;
     }
 
     public int capacity() {
         return buffer.capacity();
     }
 }