sort.java

java1.6众多例子参考

/*
 * Copyright 2001-2005 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: Sort.java,v 1.2.4.1 2005/09/12 11:08:12 pvedula Exp $
 */

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

import java.text.Collator;
import java.util.ArrayList;
import java.util.NoSuchElementException;
import java.util.StringTokenizer;
import java.util.Vector;

import com.sun.org.apache.bcel.internal.classfile.Field;
import com.sun.org.apache.bcel.internal.classfile.Method;
import com.sun.org.apache.bcel.internal.generic.ALOAD;
import com.sun.org.apache.bcel.internal.generic.ANEWARRAY;
import com.sun.org.apache.bcel.internal.generic.ASTORE;
import com.sun.org.apache.bcel.internal.generic.CHECKCAST;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.GETFIELD;
import com.sun.org.apache.bcel.internal.generic.ICONST;
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.INVOKESPECIAL;
import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
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.NEW;
import com.sun.org.apache.bcel.internal.generic.NOP;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.bcel.internal.generic.PUTFIELD;
import com.sun.org.apache.bcel.internal.generic.TABLESWITCH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.CompareGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.IntType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeSortRecordFactGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeSortRecordGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.StringType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
import com.sun.org.apache.xml.internal.dtm.Axis;


/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
final class Sort extends Instruction implements Closure {

    private Expression     _select;
    private AttributeValue _order;
    private AttributeValue _caseOrder;
    private AttributeValue _dataType;
    private String  _lang; // bug! see 26869

    private String         _data = null;


    private String _className = null;
    private ArrayList _closureVars = null;
    private boolean _needsSortRecordFactory = false;

    // -- Begin Closure interface --------------------

    /**
     * Returns true if this closure is compiled in an inner class (i.e.
     * if this is a real closure).
     */
    public boolean inInnerClass() {
	return (_className != null);
    }

    /**
     * Returns a reference to its parent closure or null if outermost.
     */
    public Closure getParentClosure() {
	return null;
    }

    /**
     * Returns the name of the auxiliary class or null if this predicate 
     * is compiled inside the Translet.
     */
    public String getInnerClassName() {
	return _className;
    }

    /**
     * Add new variable to the closure.
     */
    public void addVariable(VariableRefBase variableRef) {
	if (_closureVars == null) {
	    _closureVars = new ArrayList();
	}

	// Only one reference per variable
	if (!_closureVars.contains(variableRef)) {
	    _closureVars.add(variableRef);
	    _needsSortRecordFactory = true;
	}
    }

    // -- End Closure interface ----------------------

    private void setInnerClassName(String className) {
	_className = className;
    }

    /**
     * Parse the attributes of the xsl:sort element
     */
    public void parseContents(Parser parser) {

	final SyntaxTreeNode parent = getParent();
	if (!(parent instanceof ApplyTemplates) &&
	    !(parent instanceof ForEach)) {
	    reportError(this, parser, ErrorMsg.STRAY_SORT_ERR, null);
	    return;
	}

	// Parse the select expression (node string value if no expression)
	_select = parser.parseExpression(this, "select", "string(.)");

	// Get the sort order; default is 'ascending'
	String val = getAttribute("order");
	if (val.length() == 0) val = "ascending";
	_order = AttributeValue.create(this, val, parser);

	// Get the sort data type; default is text
	val = getAttribute("data-type");
	if (val.length() == 0) {
	    try {
		final Type type = _select.typeCheck(parser.getSymbolTable());
		if (type instanceof IntType)
		    val = "number";
		else
		    val = "text";
	    }
	    catch (TypeCheckError e) {
		val = "text";
	    }
	}
	_dataType = AttributeValue.create(this, val, parser);

	 _lang =  getAttribute("lang"); // bug! see 26869
  // val =  getAttribute("lang"); 
  // _lang = AttributeValue.create(this, val, parser);
        // Get the case order; default is language dependant
    val = getAttribute("case-order");
    _caseOrder = AttributeValue.create(this, val, parser);
	
    }
    
    /**
     * Run type checks on the attributes; expression must return a string
     * which we will use as a sort key
     */
    public Type typeCheck(SymbolTable stable) throws TypeCheckError {
	final Type tselect = _select.typeCheck(stable);

	// If the sort data-type is not set we use the natural data-type
	// of the data we will sort
	if (!(tselect instanceof StringType)) {
	    _select = new CastExpr(_select, Type.String);
	}

	_order.typeCheck(stable);
	_caseOrder.typeCheck(stable);
	_dataType.typeCheck(stable);
	return Type.Void;
    }

    /**
     * These two methods are needed in the static methods that compile the
     * overloaded NodeSortRecord.compareType() and NodeSortRecord.sortOrder()
     */
    public void translateSortType(ClassGenerator classGen,
				  MethodGenerator methodGen) {
	_dataType.translate(classGen, methodGen);
    }
    
    public void translateSortOrder(ClassGenerator classGen,
				   MethodGenerator methodGen) {
	_order.translate(classGen, methodGen);
    }
    
     public void translateCaseOrder(ClassGenerator classGen,
                   MethodGenerator methodGen) {
    _caseOrder.translate(classGen, methodGen);
    }
    
    public void translateLang(ClassGenerator classGen,
                   MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    il.append(new PUSH(cpg, _lang)); // bug! see 26869
    }
    
    /**
     * This method compiles code for the select expression for this
     * xsl:sort element. The method is called from the static code-generating
     * methods in this class.
     */
    public void translateSelect(ClassGenerator classGen,
				MethodGenerator methodGen) {
	_select.translate(classGen,methodGen);
    }

    /**
     * This method should not produce any code
     */
    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
	// empty
    }

    /**
     * Compiles code that instantiates a SortingIterator object.
     * This object's constructor needs referencdes to the current iterator
     * and a node sort record producing objects as its parameters.
     */
    public static void translateSortIterator(ClassGenerator classGen,
				      MethodGenerator methodGen,
				      Expression nodeSet,
				      Vector sortObjects) 
    {
	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();

	// SortingIterator.SortingIterator(NodeIterator,NodeSortRecordFactory);
	final int init = cpg.addMethodref(SORT_ITERATOR, "<init>",
					  "("
					  + NODE_ITERATOR_SIG
					  + NODE_SORT_FACTORY_SIG
					  + ")V");	

        // Backwards branches are prohibited if an uninitialized object is
        // on the stack by section 4.9.4 of the JVM Specification, 2nd Ed.
        // We don't know whether this code might contain backwards branches
        // so we mustn't create the new object until after we've created
        // the suspect arguments to its constructor.  Instead we calculate
        // the values of the arguments to the constructor first, store them
        // in temporary variables, create the object and reload the
        // arguments from the temporaries to avoid the problem.

        LocalVariableGen nodesTemp =
            methodGen.addLocalVariable("sort_tmp1",
                                       Util.getJCRefType(NODE_ITERATOR_SIG),
                                       il.getEnd(), null);

        LocalVariableGen sortRecordFactoryTemp =
            methodGen.addLocalVariable("sort_tmp2",
                                      Util.getJCRefType(NODE_SORT_FACTORY_SIG),
                                      il.getEnd(), null);

	// Get the current node iterator
	if (nodeSet == null) {	// apply-templates default
	    final int children = cpg.addInterfaceMethodref(DOM_INTF,
							   "getAxisIterator",
							   "(I)"+
							   NODE_ITERATOR_SIG);
	    il.append(methodGen.loadDOM());
	    il.append(new PUSH(cpg, Axis.CHILD));
	    il.append(new INVOKEINTERFACE(children, 2));
	}
	else {
	    nodeSet.translate(classGen, methodGen);
	}

        il.append(new ASTORE(nodesTemp.getIndex()));
	
	// Compile the code for the NodeSortRecord producing class and pass
	// that as the last argument to the SortingIterator constructor.
	compileSortRecordFactory(sortObjects, classGen, methodGen);
        il.append(new ASTORE(sortRecordFactoryTemp.getIndex()));

	il.append(new NEW(cpg.addClass(SORT_ITERATOR)));
	il.append(DUP);
        il.append(new ALOAD(nodesTemp.getIndex()));
        il.append(new ALOAD(sortRecordFactoryTemp.getIndex()));
	il.append(new INVOKESPECIAL(init));
    }


    /**
     * Compiles code that instantiates a NodeSortRecordFactory object which
     * will produce NodeSortRecord objects of a specific type.
     */
    public static void compileSortRecordFactory(Vector sortObjects,
	ClassGenerator classGen, MethodGenerator methodGen) 
    {
	String sortRecordClass = 
	    compileSortRecord(sortObjects, classGen, methodGen);

	boolean needsSortRecordFactory = false;
	final int nsorts = sortObjects.size();
	for (int i = 0; i < nsorts; i++) {
	    final Sort sort = (Sort) sortObjects.elementAt(i);
	    needsSortRecordFactory |= sort._needsSortRecordFactory;
	}

	String sortRecordFactoryClass = NODE_SORT_FACTORY;
	if (needsSortRecordFactory) {
	    sortRecordFactoryClass = 
		compileSortRecordFactory(sortObjects, classGen, methodGen, 
		    sortRecordClass);
	}

	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();

        // Backwards branches are prohibited if an uninitialized object is
        // on the stack by section 4.9.4 of the JVM Specification, 2nd Ed.
        // We don't know whether this code might contain backwards branches
        // so we mustn't create the new object until after we've created
        // the suspect arguments to its constructor.  Instead we calculate
        // the values of the arguments to the constructor first, store them
        // in temporary variables, create the object and reload the
        // arguments from the temporaries to avoid the problem.

	// Compile code that initializes the static _sortOrder
        LocalVariableGen sortOrderTemp
                 = methodGen.addLocalVariable("sort_order_tmp",
                                      Util.getJCRefType("[" + STRING_SIG),
                                      il.getEnd(), null);
	il.append(new PUSH(cpg, nsorts));
	il.append(new ANEWARRAY(cpg.addClass(STRING)));
	for (int level = 0; level < nsorts; level++) {
	    final Sort sort = (Sort)sortObjects.elementAt(level);
	    il.append(DUP);
	    il.append(new PUSH(cpg, level));
	    sort.translateSortOrder(classGen, methodGen);
	    il.append(AASTORE);
	}
        il.append(new ASTORE(sortOrderTemp.getIndex()));

        LocalVariableGen sortTypeTemp
                 = methodGen.addLocalVariable("sort_type_tmp",
                                      Util.getJCRefType("[" + STRING_SIG),
                                      il.getEnd(), null);
	il.append(new PUSH(cpg, nsorts));
	il.append(new ANEWARRAY(cpg.addClass(STRING)));
	for (int level = 0; level < nsorts; level++) {
	    final Sort sort = (Sort)sortObjects.elementAt(level);
	    il.append(DUP);
	    il.append(new PUSH(cpg, level));
	    sort.translateSortType(classGen, methodGen);
	    il.append(AASTORE);
	}
        il.append(new ASTORE(sortTypeTemp.getIndex()));

        LocalVariableGen sortLangTemp
                 = methodGen.addLocalVariable("sort_lang_tmp",
                                      Util.getJCRefType("[" + STRING_SIG),
                                      il.getEnd(), null);
        il.append(new PUSH(cpg, nsorts));