- /*
- * Copyright 2003-2004 The Apache Software Foundation.
- *
- * Licensed 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.
- */
- /*
- * $Id: SerializerTraceWriter.java,v 1.2 2004/02/17 04:18:18 minchau Exp $
- */
- package com.sun.org.apache.xml.internal.serializer;
-
- import java.io.IOException;
- 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.
- *
- */
- public class SerializerTraceWriter extends Writer
- {
-
- /** 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));
- }
- }
- }
-
- }