001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 /*
019 * $Id: IdKeyPattern.java 1225842 2011-12-30 15:14:35Z mrglavas $
020 */
021
022 package org.apache.xalan.xsltc.compiler;
023
024 import org.apache.bcel.generic.ConstantPoolGen;
025 import org.apache.bcel.generic.GOTO;
026 import org.apache.bcel.generic.IFNE;
027 import org.apache.bcel.generic.INVOKEVIRTUAL;
028 import org.apache.bcel.generic.InstructionList;
029 import org.apache.bcel.generic.PUSH;
030 import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
031 import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
032 import org.apache.xalan.xsltc.compiler.util.Type;
033 import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
034
035 /**
036 * @author Jacek Ambroziak
037 * @author Santiago Pericas-Geertsen
038 */
039 abstract class IdKeyPattern extends LocationPathPattern {
040
041 protected RelativePathPattern _left = null;;
042 private String _index = null;
043 private String _value = null;;
044
045 public IdKeyPattern(String index, String value) {
046 _index = index;
047 _value = value;
048 }
049
050 public String getIndexName() {
051 return(_index);
052 }
053
054 public Type typeCheck(SymbolTable stable) throws TypeCheckError {
055 return Type.NodeSet;
056 }
057
058 public boolean isWildcard() {
059 return false;
060 }
061
062 public void setLeft(RelativePathPattern left) {
063 _left = left;
064 }
065
066 public StepPattern getKernelPattern() {
067 return(null);
068 }
069
070 public void reduceKernelPattern() { }
071
072 public String toString() {
073 return "id/keyPattern(" + _index + ", " + _value + ')';
074 }
075
076 /**
077 * This method is called when the constructor is compiled in
078 * Stylesheet.compileConstructor() and not as the syntax tree is traversed.
079 */
080 public void translate(ClassGenerator classGen,
081 MethodGenerator methodGen) {
082
083 final ConstantPoolGen cpg = classGen.getConstantPool();
084 final InstructionList il = methodGen.getInstructionList();
085
086 // Returns the KeyIndex object of a given name
087 final int getKeyIndex = cpg.addMethodref(TRANSLET_CLASS,
088 "getKeyIndex",
089 "(Ljava/lang/String;)"+
090 KEY_INDEX_SIG);
091
092 // Initialises a KeyIndex to return nodes with specific values
093 final int lookupId = cpg.addMethodref(KEY_INDEX_CLASS,
094 "containsID",
095 "(ILjava/lang/Object;)I");
096 final int lookupKey = cpg.addMethodref(KEY_INDEX_CLASS,
097 "containsKey",
098 "(ILjava/lang/Object;)I");
099 final int getNodeIdent = cpg.addInterfaceMethodref(DOM_INTF,
100 "getNodeIdent",
101 "(I)"+NODE_SIG);
102
103 // Call getKeyIndex in AbstractTranslet with the name of the key
104 // to get the index for this key (which is also a node iterator).
105 il.append(classGen.loadTranslet());
106 il.append(new PUSH(cpg,_index));
107 il.append(new INVOKEVIRTUAL(getKeyIndex));
108
109 // Now use the value in the second argument to determine what nodes
110 // the iterator should return.
111 il.append(SWAP);
112 il.append(new PUSH(cpg,_value));
113 if (this instanceof IdPattern)
114 {
115 il.append(new INVOKEVIRTUAL(lookupId));
116 }
117 else
118 {
119 il.append(new INVOKEVIRTUAL(lookupKey));
120 }
121
122 _trueList.add(il.append(new IFNE(null)));
123 _falseList.add(il.append(new GOTO(null)));
124 }
125
126 }
127