1 /*
2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
3 * @LastModified: Oct 2017
4 */
5 /*
6 * Licensed to the Apache Software Foundation (ASF) under one or more
7 * contributor license agreements. See the NOTICE file distributed with
8 * this work for additional information regarding copyright ownership.
9 * The ASF licenses this file to You under the Apache License, Version 2.0
10 * (the "License"); you may not use this file except in compliance with
11 * the License. You may obtain a copy of the License at
12 *
13 * http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS,
17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
20 */
21
22 package com.sun.org.apache.xpath.internal.axes;
23
24 import com.sun.org.apache.xml.internal.dtm.DTM;
25 import com.sun.org.apache.xml.internal.utils.QName;
26 import com.sun.org.apache.xpath.internal.Expression;
27 import com.sun.org.apache.xpath.internal.ExpressionOwner;
28 import com.sun.org.apache.xpath.internal.XPathVisitor;
29 import com.sun.org.apache.xpath.internal.objects.XNodeSet;
30 import java.util.List;
31
32 public class FilterExprIterator extends BasicTestIterator
33 {
34 static final long serialVersionUID = 2552176105165737614L;
35 /** The contained expression. Should be non-null.
36 * @serial */
37 private Expression m_expr;
38
39 /** The result of executing m_expr. Needs to be deep cloned on clone op. */
40 transient private XNodeSet m_exprObj;
41
42 private boolean m_mustHardReset = false;
43 private boolean m_canDetachNodeset = true;
44
45 /**
46 * Create a FilterExprIterator object.
47 *
48 */
49 public FilterExprIterator()
50 {
51 super(null);
52 }
53
54 /**
55 * Create a FilterExprIterator object.
56 *
57 */
58 public FilterExprIterator(Expression expr)
59 {
60 super(null);
61 m_expr = expr;
62 }
63
64 /**
65 * Initialize the context values for this expression
66 * after it is cloned.
67 *
68 * @param context The XPath runtime context for this
69 * transformation.
70 */
71 public void setRoot(int context, Object environment)
72 {
73 super.setRoot(context, environment);
74
75 m_exprObj = FilterExprIteratorSimple.executeFilterExpr(context,
76 m_execContext, getPrefixResolver(),
77 getIsTopLevel(), m_stackFrame, m_expr);
78 }
79
80
81 /**
82 * Get the next node via getNextXXX. Bottlenecked for derived class override.
83 * @return The next node on the axis, or DTM.NULL.
84 */
85 protected int getNextNode()
86 {
87 if (null != m_exprObj)
88 {
89 m_lastFetched = m_exprObj.nextNode();
90 }
91 else
92 m_lastFetched = DTM.NULL;
93
94 return m_lastFetched;
95 }
96
97 /**
98 * Detaches the walker from the set which it iterated over, releasing
99 * any computational resources and placing the iterator in the INVALID
100 * state.
101 */
102 public void detach()
103 {
104 super.detach();
105 m_exprObj.detach();
106 m_exprObj = null;
107 }
108
109 /**
110 * This function is used to fixup variables from QNames to stack frame
111 * indexes at stylesheet build time.
112 * @param vars List of QNames that correspond to variables. This list
113 * should be searched backwards for the first qualified name that
114 * corresponds to the variable reference qname. The position of the
115 * QName in the vector from the start of the vector will be its position
116 * in the stack frame (but variables above the globalsTop value will need
117 * to be offset to the current stack frame).
118 */
119 public void fixupVariables(List<QName> vars, int globalsSize)
120 {
121 super.fixupVariables(vars, globalsSize);
122 m_expr.fixupVariables(vars, globalsSize);
123 }
124
125 /**
126 * Get the inner contained expression of this filter.
127 */
128 public Expression getInnerExpression()
129 {
130 return m_expr;
131 }
132
133 /**
134 * Set the inner contained expression of this filter.
135 */
136 public void setInnerExpression(Expression expr)
137 {
138 expr.exprSetParent(this);
139 m_expr = expr;
140 }
141
142 /**
143 * Get the analysis bits for this walker, as defined in the WalkerFactory.
144 * @return One of WalkerFactory#BIT_DESCENDANT, etc.
145 */
146 public int getAnalysisBits()
147 {
148 if (null != m_expr && m_expr instanceof PathComponent)
149 {
150 return ((PathComponent) m_expr).getAnalysisBits();
151 }
152 return WalkerFactory.BIT_FILTER;
153 }
154
155 /**
156 * Returns true if all the nodes in the iteration well be returned in document
157 * order.
158 * Warning: This can only be called after setRoot has been called!
159 *
160 * @return true as a default.
161 */
162 public boolean isDocOrdered()
163 {
164 return m_exprObj.isDocOrdered();
165 }
166
167 class filterExprOwner implements ExpressionOwner
168 {
169 /**
170 * @see ExpressionOwner#getExpression()
171 */
172 public Expression getExpression()
173 {
174 return m_expr;
175 }
176
177 /**
178 * @see ExpressionOwner#setExpression(Expression)
179 */
180 public void setExpression(Expression exp)
181 {
182 exp.exprSetParent(FilterExprIterator.this);
183 m_expr = exp;
184 }
185
186 }
187
188 /**
189 * This will traverse the heararchy, calling the visitor for
190 * each member. If the called visitor method returns
191 * false, the subtree should not be called.
192 *
193 * @param visitor The visitor whose appropriate method will be called.
194 */
195 public void callPredicateVisitors(XPathVisitor visitor)
196 {
197 m_expr.callVisitors(new filterExprOwner(), visitor);
198
199 super.callPredicateVisitors(visitor);
200 }
201
202 /**
203 * @see Expression#deepEquals(Expression)
204 */
205 public boolean deepEquals(Expression expr)
206 {
207 if (!super.deepEquals(expr))
208 return false;
209
210 FilterExprIterator fet = (FilterExprIterator) expr;
211 if (!m_expr.deepEquals(fet.m_expr))
212 return false;
213
214 return true;
215 }
216
217 }