| /* |
| * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Sun designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Sun in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| */ |
| |
| package com.sun.xml.internal.rngom.binary; |
| |
| final class PatternInterner { |
| private static final int INIT_SIZE = 256; |
| private static final float LOAD_FACTOR = 0.3f; |
| private Pattern[] table; |
| private int used; |
| private int usedLimit; |
| |
| PatternInterner() { |
| table = null; |
| used = 0; |
| usedLimit = 0; |
| } |
| |
| PatternInterner(PatternInterner parent) { |
| table = parent.table; |
| if (table != null) |
| table = (Pattern[]) table.clone(); |
| used = parent.used; |
| usedLimit = parent.usedLimit; |
| } |
| |
| Pattern intern(Pattern p) { |
| int h; |
| |
| if (table == null) { |
| table = new Pattern[INIT_SIZE]; |
| usedLimit = (int) (INIT_SIZE * LOAD_FACTOR); |
| h = firstIndex(p); |
| } else { |
| for (h = firstIndex(p); table[h] != null; h = nextIndex(h)) { |
| if (p.samePattern(table[h])) |
| return table[h]; |
| } |
| } |
| if (used >= usedLimit) { |
| // rehash |
| Pattern[] oldTable = table; |
| table = new Pattern[table.length << 1]; |
| for (int i = oldTable.length; i > 0;) { |
| --i; |
| if (oldTable[i] != null) { |
| int j; |
| for (j = firstIndex(oldTable[i]); |
| table[j] != null; |
| j = nextIndex(j)); |
| table[j] = oldTable[i]; |
| } |
| } |
| for (h = firstIndex(p); table[h] != null; h = nextIndex(h)); |
| usedLimit = (int) (table.length * LOAD_FACTOR); |
| } |
| used++; |
| table[h] = p; |
| return p; |
| } |
| |
| private int firstIndex(Pattern p) { |
| return p.patternHashCode() & (table.length - 1); |
| } |
| |
| private int nextIndex(int i) { |
| return i == 0 ? table.length - 1 : i - 1; |
| } |
| } |