1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 /* 19 * $Id: Counter.java 468645 2006-10-28 06:57:24Z minchau $ 20 */ 21 package org.apache.xalan.transformer; 22 23 import javax.xml.transform.TransformerException; 24 25 import org.apache.xalan.templates.ElemNumber; 26 import org.apache.xml.dtm.DTM; 27 import org.apache.xpath.NodeSetDTM; 28 import org.apache.xpath.XPathContext; 29 30 /** 31 * A class that does incremental counting for support of xsl:number. 32 * This class stores a cache of counted nodes (m_countNodes). 33 * It tries to cache the counted nodes in document order... 34 * the node count is based on its position in the cache list 35 * @xsl.usage internal 36 */ 37 public class Counter 38 { 39 40 /** 41 * Set the maximum ammount the m_countNodes list can 42 * grow to. 43 */ 44 static final int MAXCOUNTNODES = 500; 45 46 /** 47 * The start count from where m_countNodes counts 48 * from. In other words, the count of a given node 49 * in the m_countNodes vector is node position + 50 * m_countNodesStartCount. 51 */ 52 int m_countNodesStartCount = 0; 53 54 /** 55 * A vector of all nodes counted so far. 56 */ 57 NodeSetDTM m_countNodes; 58 59 /** 60 * The node from where the counting starts. This is needed to 61 * find a counter if the node being counted is not immediatly 62 * found in the m_countNodes vector. 63 */ 64 int m_fromNode = DTM.NULL; 65 66 /** 67 * The owning xsl:number element. 68 */ 69 ElemNumber m_numberElem; 70 71 /** 72 * Value to store result of last getCount call, for benifit 73 * of returning val from CountersTable.getCounterByCounted, 74 * who calls getCount. 75 */ 76 int m_countResult; 77 78 /** 79 * Construct a counter object. 80 * 81 * @param numberElem The owning xsl:number element. 82 * @param countNodes A vector of all nodes counted so far. 83 * 84 * @throws TransformerException 85 */ Counter(ElemNumber numberElem, NodeSetDTM countNodes)86 Counter(ElemNumber numberElem, NodeSetDTM countNodes) throws TransformerException 87 { 88 m_countNodes = countNodes; 89 m_numberElem = numberElem; 90 } 91 92 /** 93 * Construct a counter object. 94 * 95 * @param numberElem The owning xsl:number element. 96 * 97 * @throws TransformerException 98 * 99 Counter(ElemNumber numberElem) throws TransformerException 100 { 101 m_numberElem = numberElem; 102 }*/ 103 104 /** 105 * Try and find a node that was previously counted. If found, 106 * return a positive integer that corresponds to the count. 107 * 108 * @param support The XPath context to use 109 * @param node The node to be counted. 110 * 111 * @return The count of the node, or -1 if not found. 112 */ getPreviouslyCounted(XPathContext support, int node)113 int getPreviouslyCounted(XPathContext support, int node) 114 { 115 116 int n = m_countNodes.size(); 117 118 m_countResult = 0; 119 120 for (int i = n - 1; i >= 0; i--) 121 { 122 int countedNode = m_countNodes.elementAt(i); 123 124 if (node == countedNode) 125 { 126 127 // Since the list is in backwards order, the count is 128 // how many are in the rest of the list. 129 m_countResult = i + 1 + m_countNodesStartCount; 130 131 break; 132 } 133 134 DTM dtm = support.getDTM(countedNode); 135 136 // Try to see if the given node falls after the counted node... 137 // if it does, don't keep searching backwards. 138 if (dtm.isNodeAfter(countedNode, node)) 139 break; 140 } 141 142 return m_countResult; 143 } 144 145 /** 146 * Get the last node in the list. 147 * 148 * @return the last node in the list. 149 */ getLast()150 int getLast() 151 { 152 153 int size = m_countNodes.size(); 154 155 return (size > 0) ? m_countNodes.elementAt(size - 1) : DTM.NULL; 156 } 157 } 158