mode.java

java1.6众多例子参考

/*
 * Copyright 2001-2004 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: Mode.java,v 1.2.4.1 2005/09/19 05:18:11 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Vector;

import com.sun.org.apache.bcel.internal.generic.Instruction;
import com.sun.org.apache.bcel.internal.generic.BranchHandle;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.DUP;
import com.sun.org.apache.bcel.internal.generic.GOTO_W;
import com.sun.org.apache.bcel.internal.generic.IFLT;
import com.sun.org.apache.bcel.internal.generic.ILOAD;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.ISTORE;
import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
import com.sun.org.apache.bcel.internal.generic.SWITCH;
import com.sun.org.apache.bcel.internal.generic.TargetLostException;
import com.sun.org.apache.bcel.internal.util.InstructionFinder;
import com.sun.org.apache.xalan.internal.xsltc.DOM;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NamedMethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
import com.sun.org.apache.xml.internal.dtm.Axis;
import com.sun.org.apache.xml.internal.dtm.DTM;

/**
 * Mode gathers all the templates belonging to a given mode; 
 * it is responsible for generating an appropriate 
 * applyTemplates + (mode name) method in the translet.
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 * @author Erwin Bolwidt <[e-mail]>
 * @author G. Todd Miller
 */
final class Mode implements Constants {

    /**
     * The name of this mode as defined in the stylesheet.
     */
    private final QName _name;

    /**
     * A reference to the stylesheet object that owns this mode.
     */
    private final Stylesheet _stylesheet; 

    /**
     * The name of the method in which this mode is compiled.
     */
    private final String _methodName;

    /**
     * A vector of all the templates in this mode.
     */
    private Vector _templates; 

    /**
     * Group for patterns with node()-type kernel and child axis.
     */
    private Vector _childNodeGroup = null;

    /**
     * Test sequence for patterns with node()-type kernel and child axis.
     */
    private TestSeq _childNodeTestSeq = null;

    /**
     * Group for patterns with node()-type kernel and attribute axis.
     */
    private Vector _attribNodeGroup = null;

    /**
     * Test sequence for patterns with node()-type kernel and attribute axis.
     */
    private TestSeq _attribNodeTestSeq = null;
    
    /**
     * Group for patterns with id() or key()-type kernel.
     */
    private Vector _idxGroup = null;

    /**
     * Test sequence for patterns with id() or key()-type kernel.
     */
    private TestSeq _idxTestSeq = null;

    /**
     * Group for patterns with any other kernel type.
     */
    private Vector[] _patternGroups;

    /**
     * Test sequence for patterns with any other kernel type.
     */
    private TestSeq[] _testSeq;

    
    /**
     * A mapping between templates and test sequences.
     */
    private Hashtable _neededTemplates = new Hashtable();

    /**
     * A mapping between named templates and Mode objects.
     */
    private Hashtable _namedTemplates = new Hashtable();

    /**
     * A mapping between templates and instruction handles.
     */
    private Hashtable _templateIHs = new Hashtable();

    /**
     * A mapping between templates and instruction lists.
     */
    private Hashtable _templateILs = new Hashtable();

    /**
     * A reference to the pattern matching the root node.
     */
    private LocationPathPattern _rootPattern = null;

    /**
     * Stores ranges of template precendences for the compilation 
     * of apply-imports (a Hashtable for historical reasons).
     */
    private Hashtable _importLevels = null;

    /**
     * A mapping between key names and keys.
     */
    private Hashtable _keys = null;

    /**
     * Variable index for the current node used in code generation.
     */
    private int _currentIndex;

    /**
     * Creates a new Mode.
     *
     * @param name A textual representation of the mode's QName
     * @param stylesheet The Stylesheet in which the mode occured
     * @param suffix A suffix to append to the method name for this mode
     *               (normally a sequence number - still in a String).
     */
    public Mode(QName name, Stylesheet stylesheet, String suffix) {
	_name = name;
	_stylesheet = stylesheet;
	_methodName = APPLY_TEMPLATES + suffix;
	_templates = new Vector();
	_patternGroups = new Vector[32];
    }

    /**
     * Returns the name of the method (_not_ function) that will be 
     * compiled for this mode. Normally takes the form 'applyTemplates()' 
     * or * 'applyTemplates2()'.
     *
     * @return Method name for this mode
     */
    public String functionName() {
	return _methodName;
    }

    public String functionName(int min, int max) {
	if (_importLevels == null) {
	    _importLevels = new Hashtable();
	}
	_importLevels.put(new Integer(max), new Integer(min));
	return _methodName + '_' + max;
    }

    /**
     * Shortcut to get the class compiled for this mode (will be inlined).
     */
    private String getClassName() {
	return _stylesheet.getClassName();
    }

    public Stylesheet getStylesheet() {
	return _stylesheet;
    }

    public void addTemplate(Template template) {
	_templates.addElement(template);
    }

    private Vector quicksort(Vector templates, int p, int r) {
	if (p < r) {
	    final int q = partition(templates, p, r);
	    quicksort(templates, p, q);
	    quicksort(templates, q + 1, r);
	}
	return templates;
    }
    
    private int partition(Vector templates, int p, int r) {
	final Template x = (Template)templates.elementAt(p);
	int i = p - 1;
	int j = r + 1;
	while (true) {
	    while (x.compareTo((Template)templates.elementAt(--j)) > 0);
	    while (x.compareTo((Template)templates.elementAt(++i)) < 0);
	    if (i < j) {
		templates.set(j, templates.set(i, templates.elementAt(j)));
	    }
	    else {
		return j;
	    }
	}
    }

    /**
     * Process all the test patterns in this mode
     */
    public void processPatterns(Hashtable keys) {
	_keys = keys;

/*
System.out.println("Before Sort " + _name);
for (int i = 0; i < _templates.size(); i++) {
    System.out.println("name = " + ((Template)_templates.elementAt(i)).getName());
    System.out.println("pattern = " + ((Template)_templates.elementAt(i)).getPattern());
    System.out.println("priority = " + ((Template)_templates.elementAt(i)).getPriority());
    System.out.println("position = " + ((Template)_templates.elementAt(i)).getPosition());
}
*/

	_templates = quicksort(_templates, 0, _templates.size() - 1);

/*
System.out.println("\n After Sort " + _name);
for (int i = 0; i < _templates.size(); i++) {
    System.out.println("name = " + ((Template)_templates.elementAt(i)).getName());
    System.out.println("pattern = " + ((Template)_templates.elementAt(i)).getPattern());
    System.out.println("priority = " + ((Template)_templates.elementAt(i)).getPriority());
    System.out.println("position = " + ((Template)_templates.elementAt(i)).getPosition());
}
*/

	// Traverse all templates
	final Enumeration templates = _templates.elements();
	while (templates.hasMoreElements()) {
	    // Get the next template
	    final Template template = (Template)templates.nextElement();

	    /* 
	     * Add this template to a table of named templates if it has a name.
	     * If there are multiple templates with the same name, all but one
	     * (the one with highest priority) will be disabled.
	     */
	    if (template.isNamed() && !template.disabled()) {
		_namedTemplates.put(template, this);
	    }

	    // Add this template to a test sequence if it has a pattern
	    final Pattern pattern = template.getPattern();
	    if (pattern != null) {
		flattenAlternative(pattern, template, keys);
	    }
	}
	prepareTestSequences();
    }

    /**
     * This method will break up alternative patterns (ie. unions of patterns,
     * such as match="A/B | C/B") and add the basic patterns to their
     * respective pattern groups.
     */
    private void flattenAlternative(Pattern pattern,
				    Template template,
				    Hashtable keys) {
	// Patterns on type id() and key() are special since they do not have
	// any kernel node type (it can be anything as long as the node is in
	// the id's or key's index).
	if (pattern instanceof IdKeyPattern) {
	    final IdKeyPattern idkey = (IdKeyPattern)pattern;
	    idkey.setTemplate(template);
	    if (_idxGroup == null) _idxGroup = new Vector();
	    _idxGroup.add(pattern);
	}
	// Alternative patterns are broken up and re-processed recursively
	else if (pattern instanceof AlternativePattern) {
	    final AlternativePattern alt = (AlternativePattern)pattern;
	    flattenAlternative(alt.getLeft(), template, keys);
	    flattenAlternative(alt.getRight(), template, keys);
	}
	// Finally we have a pattern that can be added to a test sequence!
	else if (pattern instanceof LocationPathPattern) {
	    final LocationPathPattern lpp = (LocationPathPattern)pattern;
	    lpp.setTemplate(template);
	    addPatternToGroup(lpp);
	}
    }

    /**
     * Group patterns by NodeTests of their last Step
     * Keep them sorted by priority within group
     */
    private void addPatternToGroup(final LocationPathPattern lpp) {
	// id() and key()-type patterns do not have a kernel type
	if (lpp instanceof IdKeyPattern) {
	    addPattern(-1, lpp);
	}
	// Otherwise get the kernel pattern from the LPP
	else {
	    // kernel pattern is the last (maybe only) Step
	    final StepPattern kernel = lpp.getKernelPattern();
	    if (kernel != null) {
		addPattern(kernel.getNodeType(), lpp);
	    }
	    else if (_rootPattern == null ||
		     lpp.noSmallerThan(_rootPattern)) {
		_rootPattern = lpp;
	    }
	}
    }

    /**
     * Adds a pattern to a pattern group
     */
    private void addPattern(int kernelType, LocationPathPattern pattern) {
	// Make sure the array of pattern groups is long enough
	final int oldLength = _patternGroups.length;
	if (kernelType >= oldLength) {
	    Vector[] newGroups = new Vector[kernelType * 2];
	    System.arraycopy(_patternGroups, 0, newGroups, 0, oldLength);
	    _patternGroups = newGroups;
	}
	
	// Find the vector to put this pattern into
	Vector patterns;

	if (kernelType == DOM.NO_TYPE) {
	    if (pattern.getAxis() == Axis.ATTRIBUTE) {
		patterns = (_attribNodeGroup == null) ?
		    (_attribNodeGroup = new Vector(2)) : _attribNodeGroup;
	    }
	    else {
		patterns = (_childNodeGroup == null) ?
		    (_childNodeGroup = new Vector(2)) : _childNodeGroup;
	    }
	}
	else {
	    patterns = (_patternGroups[kernelType] == null) ?
		(_patternGroups[kernelType] = new Vector(2)) : 
		_patternGroups[kernelType];
	}

	if (patterns.size() == 0) {
	    patterns.addElement(pattern);
	}
	else {
	    boolean inserted = false;