1/* 2 * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25/* 26 * Copyright (C) 2004-2011 27 * 28 * Permission is hereby granted, free of charge, to any person obtaining a copy 29 * of this software and associated documentation files (the "Software"), to deal 30 * in the Software without restriction, including without limitation the rights 31 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 32 * copies of the Software, and to permit persons to whom the Software is 33 * furnished to do so, subject to the following conditions: 34 * 35 * The above copyright notice and this permission notice shall be included in 36 * all copies or substantial portions of the Software. 37 * 38 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 39 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 40 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 41 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 42 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 43 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 44 * THE SOFTWARE. 45 */ 46package com.sun.xml.internal.rngom.binary; 47 48final class PatternInterner { 49 private static final int INIT_SIZE = 256; 50 private static final float LOAD_FACTOR = 0.3f; 51 private Pattern[] table; 52 private int used; 53 private int usedLimit; 54 55 PatternInterner() { 56 table = null; 57 used = 0; 58 usedLimit = 0; 59 } 60 61 PatternInterner(PatternInterner parent) { 62 table = parent.table; 63 if (table != null) 64 table = (Pattern[]) table.clone(); 65 used = parent.used; 66 usedLimit = parent.usedLimit; 67 } 68 69 @SuppressWarnings("empty-statement") 70 Pattern intern(Pattern p) { 71 int h; 72 73 if (table == null) { 74 table = new Pattern[INIT_SIZE]; 75 usedLimit = (int) (INIT_SIZE * LOAD_FACTOR); 76 h = firstIndex(p); 77 } else { 78 for (h = firstIndex(p); table[h] != null; h = nextIndex(h)) { 79 if (p.samePattern(table[h])) 80 return table[h]; 81 } 82 } 83 if (used >= usedLimit) { 84 // rehash 85 Pattern[] oldTable = table; 86 table = new Pattern[table.length << 1]; 87 for (int i = oldTable.length; i > 0;) { 88 --i; 89 if (oldTable[i] != null) { 90 int j; 91 for (j = firstIndex(oldTable[i]); 92 table[j] != null; 93 j = nextIndex(j)); 94 table[j] = oldTable[i]; 95 } 96 } 97 for (h = firstIndex(p); table[h] != null; h = nextIndex(h)); 98 usedLimit = (int) (table.length * LOAD_FACTOR); 99 } 100 used++; 101 table[h] = p; 102 return p; 103 } 104 105 private int firstIndex(Pattern p) { 106 return p.patternHashCode() & (table.length - 1); 107 } 108 109 private int nextIndex(int i) { 110 return i == 0 ? table.length - 1 : i - 1; 111 } 112} 113