diff options
Diffstat (limited to 'libjava/classpath/java/rmi/server/UID.java')
-rw-r--r-- | libjava/classpath/java/rmi/server/UID.java | 225 |
1 files changed, 0 insertions, 225 deletions
diff --git a/libjava/classpath/java/rmi/server/UID.java b/libjava/classpath/java/rmi/server/UID.java deleted file mode 100644 index 464d3d8..0000000 --- a/libjava/classpath/java/rmi/server/UID.java +++ /dev/null @@ -1,225 +0,0 @@ -/* UID.java -- The unique object Id - Copyright (c) 2006 Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU Classpath 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 for more details. - -You should have received a copy of the GNU General Public License -along with GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - - -package java.rmi.server; - -import java.io.DataInput; -import java.io.DataOutput; -import java.io.IOException; -import java.io.Serializable; -import java.net.InetAddress; - -/** - * Represents the unique identifier over time for the host which has generated - * it. It contains time (when created), counter (the number of the UID - * creation order) and virtual machine id components. The UID can also be - * constructed specifying a "well known" identifier in the for of short: - * this identifier defines the UID uniqueness alone. - * - * @author Audrius Meskauskas (audriusa@bioinformatics.org) - */ -public final class UID - implements Serializable -{ - /** - * Use the serial version uid for interoperability. - */ - private static final long serialVersionUID = 1086053664494604050L; - - /** - * The UID counter (the ordinary number in the sequence of number of UID's, - * created during the recent millisecond). In the next millisecond, it - * starts from the minimal value again. In the unlikely case of creating - * more than 65536 uids per millisecond the process pauses till the next - * ms. - */ - private static short uidCounter = Short.MIN_VALUE; - - /** - * The time, when the last UID has been created. - */ - private static long last; - - /** - * This constant tries to be the unique identifier of the virtual machine. - */ - private static final int machineId = getMachineId(); - - /** - * The UID number in the UID creation sequence. - */ - private short count; - - /** - * Always gets the uniqueNr value. - */ - private int unique; - - /** - * The time stamp, when the UID was created. - */ - private long time; - - /** - * Create the new UID that would have the described features of the - * uniqueness. - */ - public UID() - { - synchronized (UID.class) - { - time = System.currentTimeMillis(); - unique = machineId; - if (time > last) - { - last = time; - count = uidCounter = Short.MIN_VALUE; - } - else - { - if (uidCounter == Short.MAX_VALUE) - { - // Make a 2 ms pause if the counter has reached the maximal - // value. This should seldom happen. - try - { - Thread.sleep(2); - } - catch (InterruptedException e) - { - } - uidCounter = Short.MIN_VALUE; - time = last = System.currentTimeMillis(); - } - count = ++uidCounter; - } - } - } - - /** - * Create the new UID with the well known id (number). All UIDs, creates - * with the this constructor having the same parameter are equal to each - * other (regardless to the host and time where they were created. - * - * @param wellKnownId the well known UID. - */ - public UID(short wellKnownId) - { - unique = wellKnownId; - } - - /** - * Get the hashCode of this UID. - */ - public int hashCode() - { - return (int) (unique ^ time ^ count); - } - - /** - * Compare this UID with another UID for equality (not equal to other types of - * objects). - */ - public boolean equals(Object other) - { - if (other instanceof UID) - { - UID ui = (UID) other; - return unique == ui.unique && time == ui.time && count == ui.count; - } - else - return false; - } - - public static UID read(DataInput in) throws IOException - { - UID uid = new UID(); - uid.unique = in.readInt(); - uid.time = in.readLong(); - uid.count = in.readShort(); - return (uid); - } - - public void write(DataOutput out) throws IOException - { - out.writeInt(unique); - out.writeLong(time); - out.writeShort(count); - } - - /** - * Do our best to get the Id of this virtual machine. - */ - static int getMachineId() - { - int hostIpHash; - - try - { - // Try to get the host IP. - String host = InetAddress.getLocalHost().toString(); - // This hash is content - based, not the address based. - hostIpHash = host.hashCode(); - } - catch (Exception e) - { - // Failed due some reason. - hostIpHash = 0; - } - - // Should be the unque address if hashcodes are addresses. - // Additionally, add the time when the RMI system was probably started - // (this class was first instantiated). - return new Object().hashCode() ^ (int) System.currentTimeMillis() - ^ hostIpHash; - } - - /** - * Get the string representation of this UID. - * - * @return a string, uniquely identifying this id. - */ - public String toString() - { - int max = Character.MAX_RADIX; - // Translate into object count, counting from 0. - long lc = (count - Short.MIN_VALUE) & 0xFFFF; - return Long.toString(unique, max) + ":" + Long.toString(time, max) + "." - + Long.toString(lc, max); - } -} |