// CharArrayWriter.java - Character array output stream.

/* Copyright (C) 1998, 1999, 2001  Free Software Foundation

   This file is part of libgcj.

This software is copyrighted work licensed under the terms of the
Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
details.  */

package java.io;

/**
 * @author Tom Tromey <tromey@cygnus.com>
 * @date September 25, 1998 
 */

/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
 * "The Java Language Specification", ISBN 0-201-63451-1
 * Status:  Complete to 1.1.
 */

public class CharArrayWriter extends Writer
{
  public CharArrayWriter ()
  {
    this (32);
  }

  public CharArrayWriter (int size)
  {
    super ();
    buf = new char[size];
  }

  public void close ()
  {
    closed = true;
  }

  public void flush () throws IOException
  {
    synchronized (lock)
      {
	if (closed)
	  throw new IOException ("Stream closed");
      }
  }

  public void reset ()
  {
    synchronized (lock)
      {
	count = 0;
	// Allow this to reopen the stream.
	// FIXME - what does the JDK do?
	closed = false;
      }
  }

  public int size ()
  {
    return count;
  }

  public char[] toCharArray ()
  {
    synchronized (lock)
      {      
	char[] nc = new char[count];
	System.arraycopy(buf, 0, nc, 0, count);
	return nc;
      }
  }

  public String toString ()
  {
    synchronized (lock)
      {
	return new String (buf, 0, count);
      }
  }

  public void write (int oneChar) throws IOException
  {
    synchronized (lock)
      {
	if (closed)
	  throw new IOException ("Stream closed");

	resize (1);
	buf[count++] = (char) oneChar;
      }
  }

  public void write (char[] buffer, int offset, int len) throws IOException
  {
    synchronized (lock)
      {
	if (closed)
	  throw new IOException ("Stream closed");

	if (len >= 0)
	  resize (len);
	System.arraycopy(buffer, offset, buf, count, len);
	count += len;
      }
  }

  public void write (String str, int offset, int len) throws IOException
  {
    synchronized (lock)
      {
	if (closed)
	  throw new IOException ("Stream closed");

	if (len >= 0)
	  resize (len);
	str.getChars(offset, offset + len, buf, count);
	count += len;
      }
  }

  public void writeTo (Writer out) throws IOException
  {
    synchronized (lock)
      {
	out.write(buf, 0, count);
      }
  }

  private final void resize (int len)
  {
    if (count + len >= buf.length)
      {
	int newlen = buf.length * 2;
	if (count + len > newlen)
	  newlen = count + len;
	char[] newbuf = new char[newlen];
	System.arraycopy(buf, 0, newbuf, 0, count);
	buf = newbuf;
      }
  }

  // The character buffer.
  protected char[] buf;
  // Number of valid characters in buffer.
  protected int count;
  // True if stream is closed.
  private boolean closed;
}