001/** 002 * 003 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved. 004 * 005 * This library is free software; you can redistribute it and/or 006 * modify it under the terms of the GNU Lesser General Public 007 * License as published by the Free Software Foundation; either 008 * version 2.1 of the License, or (at your option) any later version. 009 * 010 * This library is distributed in the hope that it will be useful, 011 * but WITHOUT ANY WARRANTY; without even the implied warranty of 012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 013 * Lesser General Public License for more details. 014 * 015 * You should have received a copy of the GNU Lesser General Public 016 * License along with this library. If not, see <http://www.gnu.org/licenses/>. 017 * 018 **/ 019package lucee.commons.digest; 020 021public class HashUtil { 022 private static final long[] byteTable = createLookupTable(); 023 private static final long HSTART = 0xBB40E64DA205B064L; 024 private static final long HMULT = 7664345821815920749L; 025 026 public static long create64BitHash(CharSequence cs) { 027 long h = HSTART; 028 final long hmult = HMULT; 029 final long[] ht = byteTable; 030 final int len = cs.length(); 031 for (int i = 0; i < len; i++) { 032 char ch = cs.charAt(i); 033 h = (h * hmult) ^ ht[ch & 0xff]; 034 h = (h * hmult) ^ ht[(ch >>> 8) & 0xff]; 035 } 036 if(h<0) 037 return 0-h; 038 return h; 039 } 040 041 public static String create64BitHashAsString(CharSequence cs, int radix) { 042 return Long.toString(create64BitHash(cs), radix); 043 } 044 045 private static final long[] createLookupTable() { 046 long[] _byteTable = new long[256]; 047 long h = 0x544B2FBACAAF1684L; 048 for (int i = 0; i < 256; i++) { 049 for (int j = 0; j < 31; j++) { 050 h = (h >>> 7) ^ h; 051 h = (h << 11) ^ h; 052 h = (h >>> 10) ^ h; 053 } 054 _byteTable[i] = h; 055 } 056 return _byteTable; 057 } 058}