1/* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 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 22package com.sun.org.apache.xpath.internal.axes; 23 24import com.sun.org.apache.xml.internal.dtm.DTM; 25import com.sun.org.apache.xml.internal.dtm.DTMFilter; 26import com.sun.org.apache.xml.internal.dtm.DTMIterator; 27import com.sun.org.apache.xml.internal.utils.PrefixResolver; 28import com.sun.org.apache.xpath.internal.compiler.Compiler; 29import com.sun.org.apache.xpath.internal.compiler.OpMap; 30 31/** 32 * Base for iterators that handle predicates. Does the basic next 33 * node logic, so all the derived iterator has to do is get the 34 * next node. 35 */ 36public abstract class BasicTestIterator extends LocPathIterator 37{ 38 static final long serialVersionUID = 3505378079378096623L; 39 /** 40 * Create a LocPathIterator object. 41 * 42 * @param nscontext The namespace context for this iterator, 43 * should be OK if null. 44 */ 45 protected BasicTestIterator() 46 { 47 } 48 49 50 /** 51 * Create a LocPathIterator object. 52 * 53 * @param nscontext The namespace context for this iterator, 54 * should be OK if null. 55 */ 56 protected BasicTestIterator(PrefixResolver nscontext) 57 { 58 59 super(nscontext); 60 } 61 62 /** 63 * Create a LocPathIterator object, including creation 64 * of step walkers from the opcode list, and call back 65 * into the Compiler to create predicate expressions. 66 * 67 * @param compiler The Compiler which is creating 68 * this expression. 69 * @param opPos The position of this iterator in the 70 * opcode list from the compiler. 71 * 72 * @throws javax.xml.transform.TransformerException 73 */ 74 protected BasicTestIterator(Compiler compiler, int opPos, int analysis) 75 throws javax.xml.transform.TransformerException 76 { 77 super(compiler, opPos, analysis, false); 78 79 int firstStepPos = OpMap.getFirstChildPos(opPos); 80 int whatToShow = compiler.getWhatToShow(firstStepPos); 81 82 if ((0 == (whatToShow 83 & (DTMFilter.SHOW_ATTRIBUTE 84 | DTMFilter.SHOW_NAMESPACE 85 | DTMFilter.SHOW_ELEMENT 86 | DTMFilter.SHOW_PROCESSING_INSTRUCTION))) 87 || (whatToShow == DTMFilter.SHOW_ALL)) 88 initNodeTest(whatToShow); 89 else 90 { 91 initNodeTest(whatToShow, compiler.getStepNS(firstStepPos), 92 compiler.getStepLocalName(firstStepPos)); 93 } 94 initPredicateInfo(compiler, firstStepPos); 95 } 96 97 /** 98 * Create a LocPathIterator object, including creation 99 * of step walkers from the opcode list, and call back 100 * into the Compiler to create predicate expressions. 101 * 102 * @param compiler The Compiler which is creating 103 * this expression. 104 * @param opPos The position of this iterator in the 105 * opcode list from the compiler. 106 * @param shouldLoadWalkers True if walkers should be 107 * loaded, or false if this is a derived iterator and 108 * it doesn't wish to load child walkers. 109 * 110 * @throws javax.xml.transform.TransformerException 111 */ 112 protected BasicTestIterator( 113 Compiler compiler, int opPos, int analysis, boolean shouldLoadWalkers) 114 throws javax.xml.transform.TransformerException 115 { 116 super(compiler, opPos, analysis, shouldLoadWalkers); 117 } 118 119 120 /** 121 * Get the next node via getNextXXX. Bottlenecked for derived class override. 122 * @return The next node on the axis, or DTM.NULL. 123 */ 124 protected abstract int getNextNode(); 125 126 /** 127 * Returns the next node in the set and advances the position of the 128 * iterator in the set. After a NodeIterator is created, the first call 129 * to nextNode() returns the first node in the set. 130 * 131 * @return The next <code>Node</code> in the set being iterated over, or 132 * <code>null</code> if there are no more members in that set. 133 */ 134 public int nextNode() 135 { 136 if(m_foundLast) 137 { 138 m_lastFetched = DTM.NULL; 139 return DTM.NULL; 140 } 141 142 if(DTM.NULL == m_lastFetched) 143 { 144 resetProximityPositions(); 145 } 146 147 int next; 148 149 com.sun.org.apache.xpath.internal.VariableStack vars; 150 int savedStart; 151 if (-1 != m_stackFrame) 152 { 153 vars = m_execContext.getVarStack(); 154 155 // These three statements need to be combined into one operation. 156 savedStart = vars.getStackFrame(); 157 158 vars.setStackFrame(m_stackFrame); 159 } 160 else 161 { 162 // Yuck. Just to shut up the compiler! 163 vars = null; 164 savedStart = 0; 165 } 166 167 try 168 { 169 do 170 { 171 next = getNextNode(); 172 173 if (DTM.NULL != next) 174 { 175 if(DTMIterator.FILTER_ACCEPT == acceptNode(next)) 176 break; 177 else 178 continue; 179 } 180 else 181 break; 182 } 183 while (next != DTM.NULL); 184 185 if (DTM.NULL != next) 186 { 187 m_pos++; 188 return next; 189 } 190 else 191 { 192 m_foundLast = true; 193 194 return DTM.NULL; 195 } 196 } 197 finally 198 { 199 if (-1 != m_stackFrame) 200 { 201 // These two statements need to be combined into one operation. 202 vars.setStackFrame(savedStart); 203 } 204 } 205 } 206 207 /** 208 * Get a cloned Iterator that is reset to the beginning 209 * of the query. 210 * 211 * @return A cloned NodeIterator set of the start of the query. 212 * 213 * @throws CloneNotSupportedException 214 */ 215 public DTMIterator cloneWithReset() throws CloneNotSupportedException 216 { 217 218 ChildTestIterator clone = (ChildTestIterator) super.cloneWithReset(); 219 220 clone.resetProximityPositions(); 221 222 return clone; 223 } 224 225 226} 227