xdocs/sources/xalan/whatsnew.xml - xalan-j - Git at Google

 <?xml version="1.0" standalone="no"?>
 <!DOCTYPE s1 SYSTEM "../../style/dtd/document.dtd">
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  * 3. The end-user documentation included with the redistribution,
  *    if any, must include the following acknowledgment:
  *       "This product includes software developed by the
  *        Apache Software Foundation (http://www.apache.org/)."
  *    Alternately, this acknowledgment may appear in the software itself,
  *    if and wherever such third-party acknowledgments normally appear.
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  *    not be used to endorse or promote products derived from this
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  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  * ====================================================================
  *
  * This software consists of voluntary contributions made by many
  * individuals on behalf of the Apache Software Foundation and was
  * originally based on software copyright (c) 1999, Lotus
  * Development Corporation., http://www.lotus.com.  For more
  * information on the Apache Software Foundation, please see
  * <http://www.apache.org/>.
  -->
 <s1 title="What's new in &xslt4j2;">
 <p>&xslt4j; 2.5 contains the following new features:</p>
 <ul>
   <li><link anchor="XSLTC-DTM">Integration of DTM into the Xalan Compiled processor (XSLTC)</link></li>
   <li><link anchor="common_serializer">Integration of Xalan Interpretive and Xalan Compiled Serializers</link></li>
 </ul>

 <p>These new features have been driven by the need to have a closer integration
 and better code reuse between the Xalan Interpretive and the Xalan Compiled (XSLTC)
 processors. Prior to this release, the processors did not share much code and they
 had different underlying models for the input xml document. Xalan Interpretive used
 the <link idref="dtm">Document Table Model (DTM)</link> to model the input xml, while
 XSLTC used its own DOMImpl implementation. The serializers used by the processors were
 also different.  As the project matures sharing more components between the processors
 becomes increasingly important. This makes the code more maintainable in the future and
 also eliminates some subtle behavioral differences between the Interpretive and the
 Compiled processors.</p>

 <p>In addition to these design benefits, the integration of DTM with XSLTC and the common
 serializer provide conformance and performance improvements to our users. In a practical
 environment, the performance improvement for most stylesheets in XSLTC is likely to be
 in the range of 10-20%. Stylesheets that use a lot of small result tree fragments (RTF) can
 be a few times faster because of the new light-weight RTF model. Although the performance
 improvement work focused mainly on the XSLTC side, the enhancements introduced also
 contributed to performance benefits for the Xalan Interpretive processor.  As a result, the
 Interpretive processor is roughly 5-10% faster in this release.</p>

 <anchor name="XSLTC-DTM"/>
 <s2 title="Integration of DTM into the Xalan Compiled processor (XSLTC)">
 <p>As of the &xslt4j; 2.5 release, both the Xalan Interpretive and Xalan Compiled (XSLTC)
 processors use the same <link idref="dtm">Document Table Model (DTM)</link>.  XSLTC's
 underlying document model, DOMImpl, was replaced with DTM and the original DTM was extended
 so that it could be used more efficiently with XSLTC.  Many of the DOM-related classes in
 XSLTC were adapted to work with the new DTM model and only a few changes were made in the
 compiler-related classes. However, because of the changes in the core component, the
 translets generated by the XSLTC in this release are not binary compatible with the
 translets generated by previous releases of XSLTC (up to and including Xalan Java 2.5.D1).
 You'll need to recompile your stylesheets when you switch to this new release.</p>
 </s2>

 <anchor name="common_serializer"/>
 <s2 title="Integration of Xalan Interpretive and Xalan Compiled Serializers">
 <p>As of the &xslt4j; 2.5 release, a common serializer is shared between the
 Xalan Interpretive and Xalan Compiled (XSLTC) processors. The common serializer
 code resides in the org.apache.xml.serializer package. The new serializer is
 designed to take the benefits of the old serialization mechanisms from both sides.
 By using the common serializer, many of the output differences between the
 Interpretive and the Compiled processor go away, and maintenance effort is
 reduced.</p>
 <p>During the merge of the Xalan Interpretive and XSLTC serializers, an
 effort was made to use the best performing features from each serializer.
 The new class hierarchy is similar to the one used by XSLTC.  At the highest
 level the serializer classes split based on whether the output handler type
 ("Stream" or "SAX"). At the next level, the hierarchy branches based on
 the output type (XML, HTML or TEXT).  This allows each flavor of serializer
 to do optimizations based on the output type and whether that output is going
 to a "Stream" or a "SAX" handler.</p>
 <p>From a functional point of view, the new serializer's output matches the
 behavior of the Interpretive processor's old serializer, such as the choice of
 which HTML entities to write out, and how to escape attribute values in
 documents written to a stream. </p>
 </s2>
 </s1>
	<?xml version="1.0" standalone="no"?>
	<!DOCTYPE s1 SYSTEM "../../style/dtd/document.dtd">
	<!--
	* The Apache Software License, Version 1.1
	*
	*
	* Copyright (c) 1999-2003 The Apache Software Foundation. All rights
	* reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	*
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	*
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in
	* the documentation and/or other materials provided with the
	* distribution.
	*
	* 3. The end-user documentation included with the redistribution,
	* if any, must include the following acknowledgment:
	* "This product includes software developed by the
	* Apache Software Foundation (http://www.apache.org/)."
	* Alternately, this acknowledgment may appear in the software itself,
	* if and wherever such third-party acknowledgments normally appear.
	*
	* 4. The names "Xalan" and "Apache Software Foundation" must
	* not be used to endorse or promote products derived from this
	* software without prior written permission. For written
	* permission, please contact apache@apache.org.
	*
	* 5. Products derived from this software may not be called "Apache",
	* nor may "Apache" appear in their name, without prior written
	* permission of the Apache Software Foundation.
	*
	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
	* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
	* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	* ====================================================================
	*
	* This software consists of voluntary contributions made by many
	* individuals on behalf of the Apache Software Foundation and was
	* originally based on software copyright (c) 1999, Lotus
	* Development Corporation., http://www.lotus.com. For more
	* information on the Apache Software Foundation, please see
	* <http://www.apache.org/>.
	-->
	<s1 title="What's new in &xslt4j2;">
	<p>&xslt4j; 2.5 contains the following new features:</p>
	<ul>
	<li><link anchor="XSLTC-DTM">Integration of DTM into the Xalan Compiled processor (XSLTC)</link></li>
	<li><link anchor="common_serializer">Integration of Xalan Interpretive and Xalan Compiled Serializers</link></li>
	</ul>

	<p>These new features have been driven by the need to have a closer integration
	and better code reuse between the Xalan Interpretive and the Xalan Compiled (XSLTC)
	processors. Prior to this release, the processors did not share much code and they
	had different underlying models for the input xml document. Xalan Interpretive used
	the <link idref="dtm">Document Table Model (DTM)</link> to model the input xml, while
	XSLTC used its own DOMImpl implementation. The serializers used by the processors were
	also different. As the project matures sharing more components between the processors
	becomes increasingly important. This makes the code more maintainable in the future and
	also eliminates some subtle behavioral differences between the Interpretive and the
	Compiled processors.</p>

	<p>In addition to these design benefits, the integration of DTM with XSLTC and the common
	serializer provide conformance and performance improvements to our users. In a practical
	environment, the performance improvement for most stylesheets in XSLTC is likely to be
	in the range of 10-20%. Stylesheets that use a lot of small result tree fragments (RTF) can
	be a few times faster because of the new light-weight RTF model. Although the performance
	improvement work focused mainly on the XSLTC side, the enhancements introduced also
	contributed to performance benefits for the Xalan Interpretive processor. As a result, the
	Interpretive processor is roughly 5-10% faster in this release.</p>

	<anchor name="XSLTC-DTM"/>
	<s2 title="Integration of DTM into the Xalan Compiled processor (XSLTC)">
	<p>As of the &xslt4j; 2.5 release, both the Xalan Interpretive and Xalan Compiled (XSLTC)
	processors use the same <link idref="dtm">Document Table Model (DTM)</link>. XSLTC's
	underlying document model, DOMImpl, was replaced with DTM and the original DTM was extended
	so that it could be used more efficiently with XSLTC. Many of the DOM-related classes in
	XSLTC were adapted to work with the new DTM model and only a few changes were made in the
	compiler-related classes. However, because of the changes in the core component, the
	translets generated by the XSLTC in this release are not binary compatible with the
	translets generated by previous releases of XSLTC (up to and including Xalan Java 2.5.D1).
	You'll need to recompile your stylesheets when you switch to this new release.</p>
	</s2>

	<anchor name="common_serializer"/>
	<s2 title="Integration of Xalan Interpretive and Xalan Compiled Serializers">
	<p>As of the &xslt4j; 2.5 release, a common serializer is shared between the
	Xalan Interpretive and Xalan Compiled (XSLTC) processors. The common serializer
	code resides in the org.apache.xml.serializer package. The new serializer is
	designed to take the benefits of the old serialization mechanisms from both sides.
	By using the common serializer, many of the output differences between the
	Interpretive and the Compiled processor go away, and maintenance effort is
	reduced.</p>
	<p>During the merge of the Xalan Interpretive and XSLTC serializers, an
	effort was made to use the best performing features from each serializer.
	The new class hierarchy is similar to the one used by XSLTC. At the highest
	level the serializer classes split based on whether the output handler type
	("Stream" or "SAX"). At the next level, the hierarchy branches based on
	the output type (XML, HTML or TEXT). This allows each flavor of serializer
	to do optimizations based on the output type and whether that output is going
	to a "Stream" or a "SAX" handler.</p>
	<p>From a functional point of view, the new serializer's output matches the
	behavior of the Interpretive processor's old serializer, such as the choice of
	which HTML entities to write out, and how to escape attribute values in
	documents written to a stream. </p>
	</s2>
	</s1>