org.apache.xmlbeans.impl.regex.BMPattern Maven / Gradle / Ivy
/* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.xmlbeans.impl.regex;
import java.text.CharacterIterator;
/**
* Boyer-Moore searcher.
*/
public class BMPattern {
char[] pattern;
int[] shiftTable;
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;
}
}
}
/**
*
* @return -1 if iterator 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;
}
/**
*
* @return -1 if str 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;
}
/**
*
* @return -1 if chars 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();
}
}*/
}
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