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1: /* UID.java -- 2: Copyright (c) 1996, 1997, 1998, 1999, 2004 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package java.rmi.server; 40: 41: import java.io.DataInput; 42: import java.io.DataOutput; 43: import java.io.IOException; 44: import java.io.Serializable; 45: 46: public final class UID implements Serializable 47: { 48: private static final long serialVersionUID = 1086053664494604050L; 49: 50: private static final Object lock = UID.class; 51: private static long baseTime = System.currentTimeMillis(); 52: private static short nextCount = Short.MIN_VALUE; 53: // This is sun's algorithm - don't ask me why ... 54: private static final int uniqueNr = (new Object()).hashCode(); 55: 56: private int unique; 57: private long time; 58: private short count; 59: 60: /** 61: * This is sun's algorithm - don't ask me why ... 62: */ 63: public UID() { 64: synchronized (lock) { 65: if (nextCount == Short.MAX_VALUE) { 66: long newtime; 67: for (;;) { 68: newtime = System.currentTimeMillis(); 69: if (newtime - baseTime > 1000) { 70: break; 71: } 72: try { 73: Thread.sleep(1000); 74: } 75: catch (InterruptedException _) { 76: } 77: } 78: baseTime = newtime; 79: nextCount = Short.MIN_VALUE; 80: } 81: count = nextCount++; 82: unique = uniqueNr; 83: time = baseTime; 84: } 85: } 86: 87: public UID(short num) { 88: unique = (int)num; 89: time = 0; 90: count = 0; 91: } 92: 93: public int hashCode() { 94: return (unique); 95: } 96: 97: public boolean equals(Object obj) { 98: if (obj instanceof UID) { 99: UID uid = (UID)obj; 100: if (this.unique == uid.unique && 101: this.time == uid.time && 102: this.count == uid.count) { 103: return (true); 104: } 105: } 106: return (false); 107: } 108: 109: public String toString() { 110: return ("[UID: " + unique + "," + time + "," + count + "]"); 111: } 112: 113: public void write(DataOutput out) throws IOException { 114: out.writeInt(unique); 115: out.writeLong(time); 116: out.writeShort(count); 117: } 118: 119: public static UID read(DataInput in) throws IOException { 120: UID id = new UID(); 121: id.unique = in.readInt(); 122: id.time = in.readLong(); 123: id.count = in.readShort(); 124: return (id); 125: } 126: 127: }
GNU Classpath (0.20) |