ohair | 6c32066 | 2012-03-04 11:55:34 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * reserved comment block |
| 3 | * DO NOT REMOVE OR ALTER! |
| 4 | */ |
| 5 | /* |
| 6 | * Copyright 1999-2002,2004 The Apache Software Foundation. |
| 7 | * |
| 8 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 9 | * you may not use this file except in compliance with the License. |
| 10 | * You may obtain a copy of the License at |
| 11 | * |
| 12 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 13 | * |
| 14 | * Unless required by applicable law or agreed to in writing, software |
| 15 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 16 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 17 | * See the License for the specific language governing permissions and |
| 18 | * limitations under the License. |
| 19 | */ |
| 20 | |
| 21 | package com.sun.org.apache.xerces.internal.impl.xpath.regex; |
| 22 | |
| 23 | import java.text.CharacterIterator; |
| 24 | |
| 25 | /** |
| 26 | * Boyer-Moore searcher. |
| 27 | * |
| 28 | * @xerces.internal |
| 29 | * |
| 30 | */ |
| 31 | public class BMPattern { |
| 32 | char[] pattern; |
| 33 | int[] shiftTable; |
| 34 | boolean ignoreCase; |
| 35 | |
| 36 | public BMPattern(String pat, boolean ignoreCase) { |
| 37 | this(pat, 256, ignoreCase); |
| 38 | } |
| 39 | |
| 40 | public BMPattern(String pat, int tableSize, boolean ignoreCase) { |
| 41 | this.pattern = pat.toCharArray(); |
| 42 | this.shiftTable = new int[tableSize]; |
| 43 | this.ignoreCase = ignoreCase; |
| 44 | |
| 45 | int length = pattern.length; |
| 46 | for (int i = 0; i < this.shiftTable.length; i ++) |
| 47 | this.shiftTable[i] = length; |
| 48 | |
| 49 | for (int i = 0; i < length; i ++) { |
| 50 | char ch = this.pattern[i]; |
| 51 | int diff = length-i-1; |
| 52 | int index = ch % this.shiftTable.length; |
| 53 | if (diff < this.shiftTable[index]) |
| 54 | this.shiftTable[index] = diff; |
| 55 | if (this.ignoreCase) { |
| 56 | ch = Character.toUpperCase(ch); |
| 57 | index = ch % this.shiftTable.length; |
| 58 | if (diff < this.shiftTable[index]) |
| 59 | this.shiftTable[index] = diff; |
| 60 | ch = Character.toLowerCase(ch); |
| 61 | index = ch % this.shiftTable.length; |
| 62 | if (diff < this.shiftTable[index]) |
| 63 | this.shiftTable[index] = diff; |
| 64 | } |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | /** |
| 69 | * |
| 70 | * @return -1 if <var>iterator</var> does not contain this pattern. |
| 71 | */ |
| 72 | public int matches(CharacterIterator iterator, int start, int limit) { |
| 73 | if (this.ignoreCase) return this.matchesIgnoreCase(iterator, start, limit); |
| 74 | int plength = this.pattern.length; |
| 75 | if (plength == 0) return start; |
| 76 | int index = start+plength; |
| 77 | while (index <= limit) { |
| 78 | int pindex = plength; |
| 79 | int nindex = index+1; |
| 80 | char ch; |
| 81 | do { |
| 82 | if ((ch = iterator.setIndex(--index)) != this.pattern[--pindex]) |
| 83 | break; |
| 84 | if (pindex == 0) |
| 85 | return index; |
| 86 | } while (pindex > 0); |
| 87 | index += this.shiftTable[ch % this.shiftTable.length]+1; |
| 88 | if (index < nindex) index = nindex; |
| 89 | } |
| 90 | return -1; |
| 91 | } |
| 92 | |
| 93 | /** |
| 94 | * |
| 95 | * @return -1 if <var>str</var> does not contain this pattern. |
| 96 | */ |
| 97 | public int matches(String str, int start, int limit) { |
| 98 | if (this.ignoreCase) return this.matchesIgnoreCase(str, start, limit); |
| 99 | int plength = this.pattern.length; |
| 100 | if (plength == 0) return start; |
| 101 | int index = start+plength; |
| 102 | while (index <= limit) { |
| 103 | //System.err.println("Starts at "+index); |
| 104 | int pindex = plength; |
| 105 | int nindex = index+1; |
| 106 | char ch; |
| 107 | do { |
| 108 | if ((ch = str.charAt(--index)) != this.pattern[--pindex]) |
| 109 | break; |
| 110 | if (pindex == 0) |
| 111 | return index; |
| 112 | } while (pindex > 0); |
| 113 | index += this.shiftTable[ch % this.shiftTable.length]+1; |
| 114 | if (index < nindex) index = nindex; |
| 115 | } |
| 116 | return -1; |
| 117 | } |
| 118 | /** |
| 119 | * |
| 120 | * @return -1 if <var>chars</char> does not contain this pattern. |
| 121 | */ |
| 122 | public int matches(char[] chars, int start, int limit) { |
| 123 | if (this.ignoreCase) return this.matchesIgnoreCase(chars, start, limit); |
| 124 | int plength = this.pattern.length; |
| 125 | if (plength == 0) return start; |
| 126 | int index = start+plength; |
| 127 | while (index <= limit) { |
| 128 | //System.err.println("Starts at "+index); |
| 129 | int pindex = plength; |
| 130 | int nindex = index+1; |
| 131 | char ch; |
| 132 | do { |
| 133 | if ((ch = chars[--index]) != this.pattern[--pindex]) |
| 134 | break; |
| 135 | if (pindex == 0) |
| 136 | return index; |
| 137 | } while (pindex > 0); |
| 138 | index += this.shiftTable[ch % this.shiftTable.length]+1; |
| 139 | if (index < nindex) index = nindex; |
| 140 | } |
| 141 | return -1; |
| 142 | } |
| 143 | |
| 144 | int matchesIgnoreCase(CharacterIterator iterator, int start, int limit) { |
| 145 | int plength = this.pattern.length; |
| 146 | if (plength == 0) return start; |
| 147 | int index = start+plength; |
| 148 | while (index <= limit) { |
| 149 | int pindex = plength; |
| 150 | int nindex = index+1; |
| 151 | char ch; |
| 152 | do { |
| 153 | char ch1 = ch = iterator.setIndex(--index); |
| 154 | char ch2 = this.pattern[--pindex]; |
| 155 | if (ch1 != ch2) { |
| 156 | ch1 = Character.toUpperCase(ch1); |
| 157 | ch2 = Character.toUpperCase(ch2); |
| 158 | if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2)) |
| 159 | break; |
| 160 | } |
| 161 | if (pindex == 0) |
| 162 | return index; |
| 163 | } while (pindex > 0); |
| 164 | index += this.shiftTable[ch % this.shiftTable.length]+1; |
| 165 | if (index < nindex) index = nindex; |
| 166 | } |
| 167 | return -1; |
| 168 | } |
| 169 | |
| 170 | int matchesIgnoreCase(String text, int start, int limit) { |
| 171 | int plength = this.pattern.length; |
| 172 | if (plength == 0) return start; |
| 173 | int index = start+plength; |
| 174 | while (index <= limit) { |
| 175 | int pindex = plength; |
| 176 | int nindex = index+1; |
| 177 | char ch; |
| 178 | do { |
| 179 | char ch1 = ch = text.charAt(--index); |
| 180 | char ch2 = this.pattern[--pindex]; |
| 181 | if (ch1 != ch2) { |
| 182 | ch1 = Character.toUpperCase(ch1); |
| 183 | ch2 = Character.toUpperCase(ch2); |
| 184 | if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2)) |
| 185 | break; |
| 186 | } |
| 187 | if (pindex == 0) |
| 188 | return index; |
| 189 | } while (pindex > 0); |
| 190 | index += this.shiftTable[ch % this.shiftTable.length]+1; |
| 191 | if (index < nindex) index = nindex; |
| 192 | } |
| 193 | return -1; |
| 194 | } |
| 195 | int matchesIgnoreCase(char[] chars, int start, int limit) { |
| 196 | int plength = this.pattern.length; |
| 197 | if (plength == 0) return start; |
| 198 | int index = start+plength; |
| 199 | while (index <= limit) { |
| 200 | int pindex = plength; |
| 201 | int nindex = index+1; |
| 202 | char ch; |
| 203 | do { |
| 204 | char ch1 = ch = chars[--index]; |
| 205 | char ch2 = this.pattern[--pindex]; |
| 206 | if (ch1 != ch2) { |
| 207 | ch1 = Character.toUpperCase(ch1); |
| 208 | ch2 = Character.toUpperCase(ch2); |
| 209 | if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2)) |
| 210 | break; |
| 211 | } |
| 212 | if (pindex == 0) |
| 213 | return index; |
| 214 | } while (pindex > 0); |
| 215 | index += this.shiftTable[ch % this.shiftTable.length]+1; |
| 216 | if (index < nindex) index = nindex; |
| 217 | } |
| 218 | return -1; |
| 219 | } |
| 220 | |
| 221 | /* |
| 222 | public static void main(String[] argv) { |
| 223 | try { |
| 224 | int[] shiftTable = new int[256]; |
| 225 | initializeBoyerMoore(argv[0], shiftTable, true); |
| 226 | int o = -1; |
| 227 | CharacterIterator ite = new java.text.StringCharacterIterator(argv[1]); |
| 228 | long start = System.currentTimeMillis(); |
| 229 | //for (int i = 0; i < 10000; i ++) |
| 230 | o = searchIgnoreCasesWithBoyerMoore(ite, 0, argv[0], shiftTable); |
| 231 | start = System.currentTimeMillis()-start; |
| 232 | System.out.println("Result: "+o+", Elapsed: "+start); |
| 233 | } catch (Exception ex) { |
| 234 | ex.printStackTrace(); |
| 235 | } |
| 236 | }*/ |
| 237 | } |