sort.java

java1.6众多例子参考

        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.translateLang(classGen, methodGen);
              il.append(AASTORE);
        }
        il.append(new ASTORE(sortLangTemp.getIndex()));

        LocalVariableGen sortCaseOrderTemp
                 = methodGen.addLocalVariable("sort_case_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.translateCaseOrder(classGen, methodGen);
            il.append(AASTORE);
        }
        il.append(new ASTORE(sortCaseOrderTemp.getIndex()));
	
	il.append(new NEW(cpg.addClass(sortRecordFactoryClass)));
	il.append(DUP);
	il.append(methodGen.loadDOM());
	il.append(new PUSH(cpg, sortRecordClass));
	il.append(classGen.loadTranslet());

        il.append(new ALOAD(sortOrderTemp.getIndex()));
        il.append(new ALOAD(sortTypeTemp.getIndex()));
        il.append(new ALOAD(sortLangTemp.getIndex()));
        il.append(new ALOAD(sortCaseOrderTemp.getIndex()));

	il.append(new INVOKESPECIAL(
	    cpg.addMethodref(sortRecordFactoryClass, "<init>", 
		"(" + DOM_INTF_SIG 
		    + STRING_SIG
		    + TRANSLET_INTF_SIG
		    + "[" + STRING_SIG
                    + "[" + STRING_SIG
                    + "[" + STRING_SIG
		    + "[" + STRING_SIG + ")V")));

	// Initialize closure variables in sortRecordFactory
	final ArrayList dups = new ArrayList();

	for (int j = 0; j < nsorts; j++) {
	    final Sort sort = (Sort) sortObjects.get(j);
	    final int length = (sort._closureVars == null) ? 0 : 
		sort._closureVars.size();

	    for (int i = 0; i < length; i++) {
		VariableRefBase varRef = (VariableRefBase) sort._closureVars.get(i);

		// Discard duplicate variable references
		if (dups.contains(varRef)) continue;

		final VariableBase var = varRef.getVariable();

		// Store variable in new closure
		il.append(DUP);
		il.append(var.loadInstruction());
		il.append(new PUTFIELD(
			cpg.addFieldref(sortRecordFactoryClass, var.getEscapedName(), 
			    var.getType().toSignature())));
		dups.add(varRef);
	    }
	}
    }

    public static String compileSortRecordFactory(Vector sortObjects,
	ClassGenerator classGen, MethodGenerator methodGen, 
	String sortRecordClass)
    {
	final XSLTC  xsltc = ((Sort)sortObjects.firstElement()).getXSLTC();
	final String className = xsltc.getHelperClassName();

	final NodeSortRecordFactGenerator sortRecordFactory =
	    new NodeSortRecordFactGenerator(className,
					NODE_SORT_FACTORY,
					className + ".java",
					ACC_PUBLIC | ACC_SUPER | ACC_FINAL,
					new String[] {},
					classGen.getStylesheet());

	ConstantPoolGen cpg = sortRecordFactory.getConstantPool();

	// Add a new instance variable for each var in closure
	final int nsorts = sortObjects.size();
	final ArrayList dups = new ArrayList();

	for (int j = 0; j < nsorts; j++) {
	    final Sort sort = (Sort) sortObjects.get(j);
	    final int length = (sort._closureVars == null) ? 0 : 
		sort._closureVars.size();

	    for (int i = 0; i < length; i++) {
		final VariableRefBase varRef = (VariableRefBase) sort._closureVars.get(i);

		// Discard duplicate variable references
		if (dups.contains(varRef)) continue;

		final VariableBase var = varRef.getVariable();
		sortRecordFactory.addField(new Field(ACC_PUBLIC, 
					   cpg.addUtf8(var.getEscapedName()),
					   cpg.addUtf8(var.getType().toSignature()),
					   null, cpg.getConstantPool()));
		dups.add(varRef);
	    }
	}

	// Define a constructor for this class
	final com.sun.org.apache.bcel.internal.generic.Type[] argTypes = 
	    new com.sun.org.apache.bcel.internal.generic.Type[7];
	argTypes[0] = Util.getJCRefType(DOM_INTF_SIG);
	argTypes[1] = Util.getJCRefType(STRING_SIG);
	argTypes[2] = Util.getJCRefType(TRANSLET_INTF_SIG);
	argTypes[3] = Util.getJCRefType("[" + STRING_SIG);
	argTypes[4] = Util.getJCRefType("[" + STRING_SIG);
  argTypes[5] = Util.getJCRefType("[" + STRING_SIG);
  argTypes[6] = Util.getJCRefType("[" + STRING_SIG);

	final String[] argNames = new String[7];
	argNames[0] = DOCUMENT_PNAME;
	argNames[1] = "className";
	argNames[2] = TRANSLET_PNAME;
	argNames[3] = "order";
	argNames[4] = "type";
  argNames[5] = "lang";
  argNames[6] = "case_order";
  

	InstructionList il = new InstructionList();
	final MethodGenerator constructor =
	    new MethodGenerator(ACC_PUBLIC,
				com.sun.org.apache.bcel.internal.generic.Type.VOID, 
				argTypes, argNames, "<init>", 
				className, il, cpg);

	// Push all parameters onto the stack and called super.<init>()
	il.append(ALOAD_0);
	il.append(ALOAD_1);
	il.append(ALOAD_2);
	il.append(new ALOAD(3));
	il.append(new ALOAD(4));
	il.append(new ALOAD(5));
  il.append(new ALOAD(6));
  il.append(new ALOAD(7));
	il.append(new INVOKESPECIAL(cpg.addMethodref(NODE_SORT_FACTORY,
	    "<init>", 
	    "(" + DOM_INTF_SIG 
		+ STRING_SIG 
		+ TRANSLET_INTF_SIG 
		+ "[" + STRING_SIG
    + "[" + STRING_SIG
    + "[" + STRING_SIG
		+ "[" + STRING_SIG + ")V")));
	il.append(RETURN);

	// Override the definition of makeNodeSortRecord()
	il = new InstructionList(); 
	final MethodGenerator makeNodeSortRecord =
	    new MethodGenerator(ACC_PUBLIC,
		Util.getJCRefType(NODE_SORT_RECORD_SIG), 
		new com.sun.org.apache.bcel.internal.generic.Type[] { 
		    com.sun.org.apache.bcel.internal.generic.Type.INT,
		    com.sun.org.apache.bcel.internal.generic.Type.INT },
		new String[] { "node", "last" }, "makeNodeSortRecord",
		className, il, cpg);

	il.append(ALOAD_0);
	il.append(ILOAD_1);
	il.append(ILOAD_2);
	il.append(new INVOKESPECIAL(cpg.addMethodref(NODE_SORT_FACTORY,
	    "makeNodeSortRecord", "(II)" + NODE_SORT_RECORD_SIG)));
	il.append(DUP);
	il.append(new CHECKCAST(cpg.addClass(sortRecordClass)));

	// Initialize closure in record class
	final int ndups = dups.size();
	for (int i = 0; i < ndups; i++) {
	    final VariableRefBase varRef = (VariableRefBase) dups.get(i);
	    final VariableBase var = varRef.getVariable();
	    final Type varType = var.getType();
	    
	    il.append(DUP);

	    // Get field from factory class
	    il.append(ALOAD_0);
	    il.append(new GETFIELD(
		cpg.addFieldref(className,
		    var.getEscapedName(), varType.toSignature())));

	    // Put field in record class
	    il.append(new PUTFIELD(
		cpg.addFieldref(sortRecordClass,
		    var.getEscapedName(), varType.toSignature())));
	}
	il.append(POP);
	il.append(ARETURN);

	constructor.setMaxLocals();
	constructor.setMaxStack();
	sortRecordFactory.addMethod(constructor.getMethod());
	makeNodeSortRecord.setMaxLocals();
	makeNodeSortRecord.setMaxStack();
	sortRecordFactory.addMethod(makeNodeSortRecord.getMethod());
	xsltc.dumpClass(sortRecordFactory.getJavaClass());

	return className;
    }

    /**
     * Create a new auxillary class extending NodeSortRecord.
     */
    private static String compileSortRecord(Vector sortObjects,
					    ClassGenerator classGen,
					    MethodGenerator methodGen) {
	final XSLTC  xsltc = ((Sort)sortObjects.firstElement()).getXSLTC();
	final String className = xsltc.getHelperClassName();

	// This generates a new class for handling this specific sort
	final NodeSortRecordGenerator sortRecord =
	    new NodeSortRecordGenerator(className,
					NODE_SORT_RECORD,
					"sort$0.java",
					ACC_PUBLIC | ACC_SUPER | ACC_FINAL,
					new String[] {},
					classGen.getStylesheet());
	
	final ConstantPoolGen cpg = sortRecord.getConstantPool();	

	// Add a new instance variable for each var in closure
	final int nsorts = sortObjects.size();
	final ArrayList dups = new ArrayList();

	for (int j = 0; j < nsorts; j++) {
	    final Sort sort = (Sort) sortObjects.get(j);

	    // Set the name of the inner class in this sort object
	    sort.setInnerClassName(className);	

	    final int length = (sort._closureVars == null) ? 0 : 
		sort._closureVars.size();
	    for (int i = 0; i < length; i++) {
		final VariableRefBase varRef = (VariableRefBase) sort._closureVars.get(i);

		// Discard duplicate variable references
		if (dups.contains(varRef)) continue;

		final VariableBase var = varRef.getVariable();
		sortRecord.addField(new Field(ACC_PUBLIC, 
				    cpg.addUtf8(var.getEscapedName()),
				    cpg.addUtf8(var.getType().toSignature()),
				    null, cpg.getConstantPool()));
		dups.add(varRef);
	    }
	}

	Method init = compileInit(sortObjects, sortRecord,
					 cpg, className);
	Method extract = compileExtract(sortObjects, sortRecord,
					cpg, className);
	sortRecord.addMethod(init);
	sortRecord.addMethod(extract);

	xsltc.dumpClass(sortRecord.getJavaClass());
	return className;
    }

    /**
     * Create a constructor for the new class. Updates the reference to the 
     * collator in the super calls only when the stylesheet specifies a new
     * language in xsl:sort.
     */
    private static Method compileInit(Vector sortObjects,
					   NodeSortRecordGenerator sortRecord,
					   ConstantPoolGen cpg,
					   String className) 
    {
	final InstructionList il = new InstructionList();
	final MethodGenerator init = 
	    new MethodGenerator(ACC_PUBLIC, 
				com.sun.org.apache.bcel.internal.generic.Type.VOID, 
				null, null, "<init>", className, 
				il, cpg);

	// Call the constructor in the NodeSortRecord superclass
	il.append(ALOAD_0);
	il.append(new INVOKESPECIAL(cpg.addMethodref(NODE_SORT_RECORD,
						     "<init>", "()V")));

	

	il.append(RETURN);

	init.stripAttributes(true);
	init.setMaxLocals();
	init.setMaxStack();

	return init.getMethod();
    }


    /**
     * Compiles a method that overloads NodeSortRecord.extractValueFromDOM()
     */
    private static Method compileExtract(Vector sortObjects,
					 NodeSortRecordGenerator sortRecord,
					 ConstantPoolGen cpg,
					 String className) {
	final InstructionList il = new InstructionList();
	
	// String NodeSortRecord.extractValueFromDOM(dom,node,level);
	final CompareGenerator extractMethod =
	    new CompareGenerator(ACC_PUBLIC | ACC_FINAL,
				 com.sun.org.apache.bcel.internal.generic.Type.STRING, 
				 new com.sun.org.apache.bcel.internal.generic.Type[] {
		                     Util.getJCRefType(DOM_INTF_SIG),
				     com.sun.org.apache.bcel.internal.generic.Type.INT,
				     com.sun.org.apache.bcel.internal.generic.Type.INT,
				     Util.getJCRefType(TRANSLET_SIG),
				     com.sun.org.apache.bcel.internal.generic.Type.INT
				 },
				 new String[] { "dom",
						"current",
						"level",
						"translet",
						"last"
				 },
				 "extractValueFromDOM", className, il, cpg);

	// Values needed for the switch statement
	final int levels = sortObjects.size();
	final int match[] = new int[levels];
	final InstructionHandle target[] = new InstructionHandle[levels];
	InstructionHandle tblswitch = null;

	// Compile switch statement only if the key has multiple levels
	if (levels > 1) {
	    // Put the parameter to the swtich statement on the stack
	    il.append(new ILOAD(extractMethod.getLocalIndex("level")));
	    // Append the switch statement here later on
	    tblswitch = il.append(new NOP());
	}

	// Append all the cases for the switch statment
	for (int level = 0; level < levels; level++) {
	    match[level] = level;
	    final Sort sort = (Sort)sortObjects.elementAt(level);
	    target[level] = il.append(NOP);
	    sort.translateSelect(sortRecord, extractMethod);
	    il.append(ARETURN);
	}
	
	// Compile def. target for switch statement if key has multiple levels
	if (levels > 1) {
	    // Append the default target - it will _NEVER_ be reached
	    InstructionHandle defaultTarget =
		il.append(new PUSH(cpg, EMPTYSTRING));
	    il.insert(tblswitch,new TABLESWITCH(match, target, defaultTarget));
	    il.append(ARETURN);
	}

	extractMethod.stripAttributes(true);
	extractMethod.setMaxLocals();
	extractMethod.setMaxStack();
	extractMethod.removeNOPs();

	return extractMethod.getMethod();
    }
}