TypesWriter.java :  » Net » Ganymed-SSH-2 » ch » ethz » ssh2 » packets » Java Open Source

package ch.ethz.ssh2.packets;

import java.io.UnsupportedEncodingException;
import java.math.BigInteger;

/**
 * TypesWriter.
 * 
 * @author Christian Plattner, plattner@inf.ethz.ch
 * @version $Id: TypesWriter.java,v 1.6 2006/08/31 20:04:29 cplattne Exp $
 */
public class TypesWriter
{
  byte arr[];
  int pos;

  public TypesWriter()
  {
    arr = new byte[256];
    pos = 0;
  }

  private void resize(int len)
  {
    byte new_arr[] = new byte[len];
    System.arraycopy(arr, 0, new_arr, 0, arr.length);
    arr = new_arr;
  }

  public int length()
  {
    return pos;
  }

  public byte[] getBytes()
  {
    byte[] dst = new byte[pos];
    System.arraycopy(arr, 0, dst, 0, pos);
    return dst;
  }
  
  public void getBytes(byte dst[])
  {
    System.arraycopy(arr, 0, dst, 0, pos);
  }

  public void writeUINT32(int val, int off)
  {
    if ((off + 4) > arr.length)
      resize(off + 32);

    arr[off++] = (byte) (val >> 24);
    arr[off++] = (byte) (val >> 16);
    arr[off++] = (byte) (val >> 8);
    arr[off++] = (byte) val;
  }

  public void writeUINT32(int val)
  {
    writeUINT32(val, pos);
    pos += 4;
  }

  public void writeUINT64(long val)
  {
    if ((pos + 8) > arr.length)
      resize(arr.length + 32);

    arr[pos++] = (byte) (val >> 56);
    arr[pos++] = (byte) (val >> 48);
    arr[pos++] = (byte) (val >> 40);
    arr[pos++] = (byte) (val >> 32);
    arr[pos++] = (byte) (val >> 24);
    arr[pos++] = (byte) (val >> 16);
    arr[pos++] = (byte) (val >> 8);
    arr[pos++] = (byte) val;
  }

  public void writeBoolean(boolean v)
  {
    if ((pos + 1) > arr.length)
      resize(arr.length + 32);

    arr[pos++] = v ? (byte) 1 : (byte) 0;
  }

  public void writeByte(int v, int off)
  {
    if ((off + 1) > arr.length)
      resize(off + 32);

    arr[off] = (byte) v;
  }

  public void writeByte(int v)
  {
    writeByte(v, pos);
    pos++;
  }

  public void writeMPInt(BigInteger b)
  {
    byte raw[] = b.toByteArray();

    if ((raw.length == 1) && (raw[0] == 0))
      writeUINT32(0); /* String with zero bytes of data */
    else
      writeString(raw, 0, raw.length);
  }

  public void writeBytes(byte[] buff)
  {
    writeBytes(buff, 0, buff.length);
  }
  
  public void writeBytes(byte[] buff, int off, int len)
  {
    if ((pos + len) > arr.length)
      resize(arr.length + len + 32);

    System.arraycopy(buff, off, arr, pos, len);
    pos += len;
  }

  public void writeString(byte[] buff, int off, int len)
  {
    writeUINT32(len);
    writeBytes(buff, off, len);
  }

  public void writeString(String v)
  {
    byte[] b = v.getBytes();

    writeUINT32(b.length);
    writeBytes(b, 0, b.length);
  }
  
  public void writeString(String v, String charsetName) throws UnsupportedEncodingException
  {
    byte[] b = (charsetName == null) ? v.getBytes() : v.getBytes(charsetName);
    
    writeUINT32(b.length);
    writeBytes(b, 0, b.length);
  }

  public void writeNameList(String v[])
  {
    StringBuffer sb = new StringBuffer();
    for (int i = 0; i < v.length; i++)
    {
      if (i > 0)
        sb.append(',');
      sb.append(v[i]);
    }
    writeString(sb.toString());
  }
}