예제 #1
0
  /**
   * Compile transform() into the output class. This method is used to initialize global variables
   * and global parameters. The current node is set to be the document's root node.
   */
  private void compileTransform(ClassGenerator classGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();

    /*
     * Define the the method transform with the following signature:
     * void transform(DOM, NodeIterator, HandlerBase)
     */
    final com.sun.org.apache.bcel.internal.generic.Type[] argTypes =
        new com.sun.org.apache.bcel.internal.generic.Type[3];
    argTypes[0] = Util.getJCRefType(DOM_INTF_SIG);
    argTypes[1] = Util.getJCRefType(NODE_ITERATOR_SIG);
    argTypes[2] = Util.getJCRefType(TRANSLET_OUTPUT_SIG);

    final String[] argNames = new String[3];
    argNames[0] = DOCUMENT_PNAME;
    argNames[1] = ITERATOR_PNAME;
    argNames[2] = TRANSLET_OUTPUT_PNAME;

    final InstructionList il = new InstructionList();
    final MethodGenerator transf =
        new MethodGenerator(
            ACC_PUBLIC,
            com.sun.org.apache.bcel.internal.generic.Type.VOID,
            argTypes,
            argNames,
            "transform",
            _className,
            il,
            classGen.getConstantPool());
    transf.addException("com.sun.org.apache.xalan.internal.xsltc.TransletException");

    // Define and initialize current with the root node
    final LocalVariableGen current =
        transf.addLocalVariable(
            "current", com.sun.org.apache.bcel.internal.generic.Type.INT, null, null);
    final String applyTemplatesSig = classGen.getApplyTemplatesSig();
    final int applyTemplates =
        cpg.addMethodref(getClassName(), "applyTemplates", applyTemplatesSig);
    final int domField = cpg.addFieldref(getClassName(), DOM_FIELD, DOM_INTF_SIG);

    // push translet for PUTFIELD
    il.append(classGen.loadTranslet());
    // prepare appropriate DOM implementation

    if (isMultiDocument()) {
      il.append(new NEW(cpg.addClass(MULTI_DOM_CLASS)));
      il.append(DUP);
    }

    il.append(classGen.loadTranslet());
    il.append(transf.loadDOM());
    il.append(
        new INVOKEVIRTUAL(
            cpg.addMethodref(
                TRANSLET_CLASS, "makeDOMAdapter", "(" + DOM_INTF_SIG + ")" + DOM_ADAPTER_SIG)));
    // DOMAdapter is on the stack

    if (isMultiDocument()) {
      final int init = cpg.addMethodref(MULTI_DOM_CLASS, "<init>", "(" + DOM_INTF_SIG + ")V");
      il.append(new INVOKESPECIAL(init));
      // MultiDOM is on the stack
    }

    // store to _dom variable
    il.append(new PUTFIELD(domField));

    // continue with globals initialization
    final int gitr = cpg.addInterfaceMethodref(DOM_INTF, "getIterator", "()" + NODE_ITERATOR_SIG);
    il.append(transf.loadDOM());
    il.append(new INVOKEINTERFACE(gitr, 1));
    il.append(transf.nextNode());
    current.setStart(il.append(new ISTORE(current.getIndex())));

    // Transfer the output settings to the output post-processor
    il.append(classGen.loadTranslet());
    il.append(transf.loadHandler());
    final int index =
        cpg.addMethodref(TRANSLET_CLASS, "transferOutputSettings", "(" + OUTPUT_HANDLER_SIG + ")V");
    il.append(new INVOKEVIRTUAL(index));

    /*
     * Compile buildKeys() method. Note that this method is not
     * invoked here as keys for the input document are now created
     * in topLevel(). However, this method is still needed by the
     * LoadDocument class.
     */
    final String keySig = compileBuildKeys(classGen);
    final int keyIdx = cpg.addMethodref(getClassName(), "buildKeys", keySig);

    // Look for top-level elements that need handling
    final Enumeration toplevel = elements();
    if (_globals.size() > 0 || toplevel.hasMoreElements()) {
      // Compile method for handling top-level elements
      final String topLevelSig = compileTopLevel(classGen);
      // Get a reference to that method
      final int topLevelIdx = cpg.addMethodref(getClassName(), "topLevel", topLevelSig);
      // Push all parameters on the stack and call topLevel()
      il.append(classGen.loadTranslet()); // The 'this' pointer
      il.append(classGen.loadTranslet());
      il.append(new GETFIELD(domField)); // The DOM reference
      il.append(transf.loadIterator());
      il.append(transf.loadHandler()); // The output handler
      il.append(new INVOKEVIRTUAL(topLevelIdx));
    }

    // start document
    il.append(transf.loadHandler());
    il.append(transf.startDocument());

    // push first arg for applyTemplates
    il.append(classGen.loadTranslet());
    // push translet for GETFIELD to get DOM arg
    il.append(classGen.loadTranslet());
    il.append(new GETFIELD(domField));
    // push remaining 2 args
    il.append(transf.loadIterator());
    il.append(transf.loadHandler());
    il.append(new INVOKEVIRTUAL(applyTemplates));
    // endDocument
    il.append(transf.loadHandler());
    il.append(transf.endDocument());

    il.append(RETURN);

    // Compute max locals + stack and add method to class
    classGen.addMethod(transf);
  }