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package com.sun.org.apache.xerces.internal.impl.xpath.regex;

import java.text.CharacterIterator;

Boyer-Moore searcher.
@xerces.internal
/** * Boyer-Moore searcher. * * @xerces.internal * */
public class BMPattern { final char[] pattern; final int[] shiftTable; final boolean ignoreCase; public BMPattern(String pat, boolean ignoreCase) { this(pat, 256, ignoreCase); } public BMPattern(String pat, int tableSize, boolean ignoreCase) { this.pattern = pat.toCharArray(); this.shiftTable = new int[tableSize]; this.ignoreCase = ignoreCase; int length = pattern.length; for (int i = 0; i < this.shiftTable.length; i ++) this.shiftTable[i] = length; for (int i = 0; i < length; i ++) { char ch = this.pattern[i]; int diff = length-i-1; int index = ch % this.shiftTable.length; if (diff < this.shiftTable[index]) this.shiftTable[index] = diff; if (this.ignoreCase) { ch = Character.toUpperCase(ch); index = ch % this.shiftTable.length; if (diff < this.shiftTable[index]) this.shiftTable[index] = diff; ch = Character.toLowerCase(ch); index = ch % this.shiftTable.length; if (diff < this.shiftTable[index]) this.shiftTable[index] = diff; } } }
Returns:-1 if iterator does not contain this pattern.
/** * * @return -1 if <var>iterator</var> does not contain this pattern. */
public int matches(CharacterIterator iterator, int start, int limit) { if (this.ignoreCase) return this.matchesIgnoreCase(iterator, start, limit); int plength = this.pattern.length; if (plength == 0) return start; int index = start+plength; while (index <= limit) { int pindex = plength; int nindex = index+1; char ch; do { if ((ch = iterator.setIndex(--index)) != this.pattern[--pindex]) break; if (pindex == 0) return index; } while (pindex > 0); index += this.shiftTable[ch % this.shiftTable.length]+1; if (index < nindex) index = nindex; } return -1; }
Returns:-1 if str does not contain this pattern.
/** * * @return -1 if <var>str</var> does not contain this pattern. */
public int matches(String str, int start, int limit) { if (this.ignoreCase) return this.matchesIgnoreCase(str, start, limit); int plength = this.pattern.length; if (plength == 0) return start; int index = start+plength; while (index <= limit) { //System.err.println("Starts at "+index); int pindex = plength; int nindex = index+1; char ch; do { if ((ch = str.charAt(--index)) != this.pattern[--pindex]) break; if (pindex == 0) return index; } while (pindex > 0); index += this.shiftTable[ch % this.shiftTable.length]+1; if (index < nindex) index = nindex; } return -1; }
Returns:-1 if chars does not contain this pattern.
/** * * @return -1 if <var>chars</char> does not contain this pattern. */
public int matches(char[] chars, int start, int limit) { if (this.ignoreCase) return this.matchesIgnoreCase(chars, start, limit); int plength = this.pattern.length; if (plength == 0) return start; int index = start+plength; while (index <= limit) { //System.err.println("Starts at "+index); int pindex = plength; int nindex = index+1; char ch; do { if ((ch = chars[--index]) != this.pattern[--pindex]) break; if (pindex == 0) return index; } while (pindex > 0); index += this.shiftTable[ch % this.shiftTable.length]+1; if (index < nindex) index = nindex; } return -1; } int matchesIgnoreCase(CharacterIterator iterator, int start, int limit) { int plength = this.pattern.length; if (plength == 0) return start; int index = start+plength; while (index <= limit) { int pindex = plength; int nindex = index+1; char ch; do { char ch1 = ch = iterator.setIndex(--index); char ch2 = this.pattern[--pindex]; if (ch1 != ch2) { ch1 = Character.toUpperCase(ch1); ch2 = Character.toUpperCase(ch2); if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2)) break; } if (pindex == 0) return index; } while (pindex > 0); index += this.shiftTable[ch % this.shiftTable.length]+1; if (index < nindex) index = nindex; } return -1; } int matchesIgnoreCase(String text, int start, int limit) { int plength = this.pattern.length; if (plength == 0) return start; int index = start+plength; while (index <= limit) { int pindex = plength; int nindex = index+1; char ch; do { char ch1 = ch = text.charAt(--index); char ch2 = this.pattern[--pindex]; if (ch1 != ch2) { ch1 = Character.toUpperCase(ch1); ch2 = Character.toUpperCase(ch2); if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2)) break; } if (pindex == 0) return index; } while (pindex > 0); index += this.shiftTable[ch % this.shiftTable.length]+1; if (index < nindex) index = nindex; } return -1; } int matchesIgnoreCase(char[] chars, int start, int limit) { int plength = this.pattern.length; if (plength == 0) return start; int index = start+plength; while (index <= limit) { int pindex = plength; int nindex = index+1; char ch; do { char ch1 = ch = chars[--index]; char ch2 = this.pattern[--pindex]; if (ch1 != ch2) { ch1 = Character.toUpperCase(ch1); ch2 = Character.toUpperCase(ch2); if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2)) break; } if (pindex == 0) return index; } while (pindex > 0); index += this.shiftTable[ch % this.shiftTable.length]+1; if (index < nindex) index = nindex; } return -1; } /* public static void main(String[] argv) { try { int[] shiftTable = new int[256]; initializeBoyerMoore(argv[0], shiftTable, true); int o = -1; CharacterIterator ite = new java.text.StringCharacterIterator(argv[1]); long start = System.currentTimeMillis(); //for (int i = 0; i < 10000; i ++) o = searchIgnoreCasesWithBoyerMoore(ite, 0, argv[0], shiftTable); start = System.currentTimeMillis()-start; System.out.println("Result: "+o+", Elapsed: "+start); } catch (Exception ex) { ex.printStackTrace(); } }*/ }