package org.jboss.resteasy.client.jaxrs.engines;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.jboss.resteasy.resteasy_jaxrs.i18n.Messages;

Extension of BufferedInputStream enforcing the contract where reset() always returns to the beginning of the stream, and the internal buffer expands automatically to the total length of content read from the underlying stream. 
Author:
ul8b/**
 * Extension of {@link BufferedInputStream} enforcing the contract where reset()
 * always returns to the beginning of the stream, and the internal buffer
 * expands automatically to the total length of content read from the underlying
 * stream.
 *
 * @author ul8b
 */
public class SelfExpandingBufferredInputStream extends BufferedInputStream
{
   private static int defaultBufferSize = 8192;

   public SelfExpandingBufferredInputStream(final InputStream in)
   {
      super(in);
      super.mark(defaultBufferSize);
   }

   public SelfExpandingBufferredInputStream(final InputStream in, final int size)
   {
      super(in, size);
      super.mark(size);
   }

   
Not supported. Mark position is always zero.
/**
    * Not supported. Mark position is always zero.
    */
   @Override
   public synchronized void mark(int readlimit)
   {
      throw new UnsupportedOperationException(Messages.MESSAGES.alwaysMarkedAtIndex0());
   }

   @Override
   public synchronized int read() throws IOException
   {
      if (pos == marklimit)
      {
         expand();
      }
      return super.read();
   }

   @Override
   public synchronized int read(byte[] b, int off, int len) throws IOException
   {
      while (pos + len > marklimit)
      {
         expand();
      }
      return super.read(b, off, len);
   }

   @Override
   public synchronized int read(byte[] b) throws IOException
   {
      while (pos + b.length > marklimit)
      {
         expand();
      }
      return super.read(b);
   }

   
Double the current buffer size limit. Reset to zero, then double the
buffer size and restore last position in the buffer.
Throws:
IOException – /**
    * Double the current buffer size limit. Reset to zero, then double the
    * buffer size and restore last position in the buffer.
    *
    * @throws IOException
    */
   private void expand() throws IOException
   {
      int lastPos = pos;
      super.reset();
      super.mark((marklimit < (Integer.MAX_VALUE - 8) / 2) ? (marklimit * 2) : (Integer.MAX_VALUE - 8));
      pos = lastPos;
   }

   
Return the current maximum size of the internal buffer. This is
independent of how much data is actually contained within the buffer.
Returns:
internal buffer size/**
    * Return the current maximum size of the internal buffer. This is
    * independent of how much data is actually contained within the buffer.
    * @return internal buffer size
    */
   public int getBufSize()
   {
      return buf.length;
   }

   public int getCount()
   {
      return count;
   }

   public int getPos()
   {
      return pos;
   }

   public int getMarkLimit()
   {
      return marklimit;
   }

   public int getMarkPos()
   {
      return markpos;
   }
}