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	/*
	* reserved comment block
	* DO NOT REMOVE OR ALTER!
	*/
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF 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 com.sun.org.apache.xml.internal.serializer;

	import java.io.IOException;
	import java.io.OutputStream;
	import java.io.Writer;

	/**
	* This class wraps the real writer, it only purpose is to send
	* CHARACTERTOSTREAM events to the trace listener.
	* Each method immediately sends the call to the wrapped writer unchanged, but
	* in addition it collects characters to be issued to a trace listener.
	*
	* In this way the trace
	* listener knows what characters have been written to the output Writer.
	*
	* There may still be differences in what the trace events say is going to the
	* output writer and what is really going there. These differences will be due
	* to the fact that this class is UTF-8 encoding before emiting the trace event
	* and the underlying writer may not be UTF-8 encoding. There may also be
	* encoding differences. So the main pupose of this class is to provide a
	* resonable facsimile of the true output.
	*
	* @xsl.usage internal
	*/
	final class SerializerTraceWriter extends Writer implements WriterChain
	{

	/** The real writer to immediately write to.
	* This reference may be null, in which case nothing is written out, but
	* only the trace events are fired for output.
	*/
	private final java.io.Writer m_writer;

	/** The tracer to send events to */
	private final SerializerTrace m_tracer;

	/** The size of the internal buffer, just to keep too many
	* events from being sent to the tracer
	*/
	private int buf_length;

	/**
	* Internal buffer to collect the characters to go to the trace listener.
	*
	*/
	private byte buf[];

	/**
	* How many bytes have been collected and still need to go to trace
	* listener.
	*/
	private int count;

	/**
	* Creates or replaces the internal buffer, and makes sure it has a few
	* extra bytes slight overflow of the last UTF8 encoded character.
	* @param size
	*/
	private void setBufferSize(int size)
	{
	buf = new byte[size + 3];
	buf_length = size;
	count = 0;
	}

	/**
	* Constructor.
	* If the writer passed in is null, then this SerializerTraceWriter will
	* only signal trace events of what would have been written to that writer.
	* If the writer passed in is not null then the trace events will mirror
	* what is going to that writer. In this way tools, such as a debugger, can
	* gather information on what is being written out.
	*
	* @param out the Writer to write to (possibly null)
	* @param tracer the tracer to inform that characters are being written
	*/
	public SerializerTraceWriter(Writer out, SerializerTrace tracer)
	{
	m_writer = out;
	m_tracer = tracer;
	setBufferSize(1024);
	}

	/**
	* Flush out the collected characters by sending them to the trace
	* listener. These characters are never written to the real writer
	* (m_writer) because that has already happened with every method
	* call. This method simple informs the listener of what has already
	* happened.
	* @throws IOException
	*/
	private void flushBuffer() throws IOException
	{

	// Just for tracing purposes
	if (count > 0)
	{
	char[] chars = new char[count];
	for(int i=0; i<count; i++)
	chars[i] = (char) buf[i];

	if (m_tracer != null)
	m_tracer.fireGenerateEvent(
	SerializerTrace.EVENTTYPE_OUTPUT_CHARACTERS,
	chars,
	0,
	chars.length);

	count = 0;
	}
	}

	/**
	* Flush the internal buffer and flush the Writer
	* @see java.io.Writer#flush()
	*/
	public void flush() throws java.io.IOException
	{
	// send to the real writer
	if (m_writer != null)
	m_writer.flush();

	// from here on just for tracing purposes
	flushBuffer();
	}

	/**
	* Flush the internal buffer and close the Writer
	* @see java.io.Writer#close()
	*/
	public void close() throws java.io.IOException
	{
	// send to the real writer
	if (m_writer != null)
	m_writer.close();

	// from here on just for tracing purposes
	flushBuffer();
	}


	/**
	* Write a single character. The character to be written is contained in
	* the 16 low-order bits of the given integer value; the 16 high-order bits
	* are ignored.
	*
	* <p> Subclasses that intend to support efficient single-character output
	* should override this method.
	*
	* @param c int specifying a character to be written.
	* @exception IOException If an I/O error occurs
	*/
	public void write(final int c) throws IOException
	{
	// send to the real writer
	if (m_writer != null)
	m_writer.write(c);

	// ---------- from here on just collect for tracing purposes

	/* If we are close to the end of the buffer then flush it.
	* Remember the buffer can hold a few more characters than buf_length
	*/
	if (count >= buf_length)
	flushBuffer();

	if (c < 0x80)
	{
	buf[count++] = (byte) (c);
	}
	else if (c < 0x800)
	{
	buf[count++] = (byte) (0xc0 + (c >> 6));
	buf[count++] = (byte) (0x80 + (c & 0x3f));
	}
	else
	{
	buf[count++] = (byte) (0xe0 + (c >> 12));
	buf[count++] = (byte) (0x80 + ((c >> 6) & 0x3f));
	buf[count++] = (byte) (0x80 + (c & 0x3f));
	}
	}

	/**
	* Write a portion of an array of characters.
	*
	* @param chars Array of characters
	* @param start Offset from which to start writing characters
	* @param length Number of characters to write
	*
	* @exception IOException If an I/O error occurs
	*
	* @throws java.io.IOException
	*/
	public void write(final char chars[], final int start, final int length)
	throws java.io.IOException
	{
	// send to the real writer
	if (m_writer != null)
	m_writer.write(chars, start, length);

	// from here on just collect for tracing purposes
	int lengthx3 = (length << 1) + length;

	if (lengthx3 >= buf_length)
	{

	/* If the request length exceeds the size of the output buffer,
	* flush the output buffer and make the buffer bigger to handle.
	*/

	flushBuffer();
	setBufferSize(2 * lengthx3);

	}

	if (lengthx3 > buf_length - count)
	{
	flushBuffer();
	}

	final int n = length + start;
	for (int i = start; i < n; i++)
	{
	final char c = chars[i];

	if (c < 0x80)
	buf[count++] = (byte) (c);
	else if (c < 0x800)
	{
	buf[count++] = (byte) (0xc0 + (c >> 6));
	buf[count++] = (byte) (0x80 + (c & 0x3f));
	}
	else
	{
	buf[count++] = (byte) (0xe0 + (c >> 12));
	buf[count++] = (byte) (0x80 + ((c >> 6) & 0x3f));
	buf[count++] = (byte) (0x80 + (c & 0x3f));
	}
	}

	}

	/**
	* Write a string.
	*
	* @param s String to be written
	*
	* @exception IOException If an I/O error occurs
	*/
	public void write(final String s) throws IOException
	{
	// send to the real writer
	if (m_writer != null)
	m_writer.write(s);

	// from here on just collect for tracing purposes
	final int length = s.length();

	// We multiply the length by three since this is the maximum length
	// of the characters that we can put into the buffer. It is possible
	// for each Unicode character to expand to three bytes.

	int lengthx3 = (length << 1) + length;

	if (lengthx3 >= buf_length)
	{

	/* If the request length exceeds the size of the output buffer,
	* flush the output buffer and make the buffer bigger to handle.
	*/

	flushBuffer();
	setBufferSize(2 * lengthx3);
	}

	if (lengthx3 > buf_length - count)
	{
	flushBuffer();
	}

	for (int i = 0; i < length; i++)
	{
	final char c = s.charAt(i);

	if (c < 0x80)
	buf[count++] = (byte) (c);
	else if (c < 0x800)
	{
	buf[count++] = (byte) (0xc0 + (c >> 6));
	buf[count++] = (byte) (0x80 + (c & 0x3f));
	}
	else
	{
	buf[count++] = (byte) (0xe0 + (c >> 12));
	buf[count++] = (byte) (0x80 + ((c >> 6) & 0x3f));
	buf[count++] = (byte) (0x80 + (c & 0x3f));
	}
	}
	}

	/**
	* Get the writer that this one directly wraps.
	*/
	public Writer getWriter()
	{
	return m_writer;
	}

	/**
	* Get the OutputStream that is the at the end of the
	* chain of writers.
	*/
	public OutputStream getOutputStream()
	{
	OutputStream retval = null;
	if (m_writer instanceof WriterChain)
	retval = ((WriterChain) m_writer).getOutputStream();
	return retval;
	}
	}

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