/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE
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* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
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* add the following below this CDDL HEADER, with the fields enclosed
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* by brackets "[]" replaced with your own identifying information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Copyright 2006-2009 Sun Microsystems, Inc.
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* Portions Copyright 2013 ForgeRock AS.
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*/
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package org.opends.server.replication.common;
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import java.io.Serializable;
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import java.util.Date;
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import org.opends.server.types.ByteSequence;
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import org.opends.server.types.ByteSequenceReader;
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import org.opends.server.types.ByteString;
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import org.opends.server.types.ByteStringBuilder;
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/**
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* Class used to represent Change Sequence Numbers.
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*/
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public class CSN implements Serializable, Comparable<CSN>
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{
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/**
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* The number of bytes used by the byte string representation of a change
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* number.
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*
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* @see #valueOf(ByteSequence)
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* @see #toByteString()
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* @see #toByteString(ByteStringBuilder)
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*/
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public static final int BYTE_ENCODING_LENGTH = 14;
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/**
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* The number of characters used by the string representation of a change
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* number.
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*
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* @see #valueOf(String)
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* @see #toString()
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*/
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public static final int STRING_ENCODING_LENGTH = 28;
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private static final long serialVersionUID = -8802722277749190740L;
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private final long timeStamp;
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private final int seqnum;
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private final int serverId;
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/**
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* Parses the provided {@link #toString()} representation of a CSN.
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*
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* @param s
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* The string to be parsed.
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* @return The parsed CSN.
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* @see #toString()
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*/
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public static CSN valueOf(String s)
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{
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return new CSN(s);
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}
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/**
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* Decodes the provided {@link #toByteString()} representation of a change
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* number.
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*
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* @param bs
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* The byte sequence to be parsed.
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* @return The decoded CSN.
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* @see #toByteString()
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*/
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public static CSN valueOf(ByteSequence bs)
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{
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ByteSequenceReader reader = bs.asReader();
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long timeStamp = reader.getLong();
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int serverId = reader.getShort() & 0xffff;
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int seqnum = reader.getInt();
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return new CSN(timeStamp, seqnum, serverId);
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}
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/**
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* Create a new {@link CSN} from a String.
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*
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* @param str the string from which to create a {@link CSN}
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*/
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public CSN(String str)
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{
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String temp = str.substring(0, 16);
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timeStamp = Long.parseLong(temp, 16);
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temp = str.substring(16, 20);
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serverId = Integer.parseInt(temp, 16);
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temp = str.substring(20, 28);
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seqnum = Integer.parseInt(temp, 16);
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}
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/**
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* Create a new {@link CSN}.
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*
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* @param timeStamp timeStamp for the {@link CSN}
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* @param seqNum sequence number
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* @param serverId identity of server
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*/
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public CSN(long timeStamp, int seqNum, int serverId)
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{
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this.serverId = serverId;
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this.timeStamp = timeStamp;
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this.seqnum = seqNum;
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}
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/**
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* Getter for the time.
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* @return the time
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*/
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public long getTime()
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{
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return timeStamp;
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}
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/**
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* Get the timestamp associated to this {@link CSN} in seconds.
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* @return timestamp associated to this {@link CSN} in seconds
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*/
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public long getTimeSec()
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{
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return timeStamp/1000;
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}
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/**
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* Getter for the sequence number.
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* @return the sequence number
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*/
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public int getSeqnum()
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{
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return seqnum;
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}
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/**
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* Getter for the server ID.
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* @return the server ID
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*/
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public int getServerId()
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{
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return serverId;
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}
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/**
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* {@inheritDoc}
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*/
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@Override
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public boolean equals(Object obj)
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{
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if (obj instanceof CSN)
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{
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CSN csn = (CSN) obj;
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return this.seqnum == csn.seqnum &&
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this.serverId == csn.serverId &&
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this.timeStamp == csn.timeStamp;
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}
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return false;
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}
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/**
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* {@inheritDoc}
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*/
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@Override
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public int hashCode()
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{
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return this.seqnum + this.serverId + Long.valueOf(timeStamp).hashCode();
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}
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/**
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* Encodes this CSN as a byte string.
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* <p>
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* NOTE: this representation must not be modified otherwise interop with
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* earlier protocol versions will be broken.
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*
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* @return The encoded representation of this CSN.
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* @see #valueOf(ByteSequence)
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*/
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public ByteString toByteString()
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{
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return toByteString(new ByteStringBuilder(BYTE_ENCODING_LENGTH))
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.toByteString();
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}
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/**
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* Encodes this CSN into the provided byte string builder.
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* <p>
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* NOTE: this representation must not be modified otherwise interop with
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* earlier protocol versions will be broken.
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*
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* @param builder
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* The byte string builder.
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* @return The byte string builder containing the encoded CSN.
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* @see #valueOf(ByteSequence)
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*/
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public ByteStringBuilder toByteString(ByteStringBuilder builder)
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{
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return builder.append(timeStamp).append((short) (serverId & 0xffff))
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.append(seqnum);
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}
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/**
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* Convert the {@link CSN} to a printable String.
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* <p>
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* NOTE: this representation must not be modified otherwise interop with
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* earlier protocol versions will be broken.
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*
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* @return the string
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*/
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@Override
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public String toString()
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{
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return String.format("%016x%04x%08x", timeStamp, serverId, seqnum);
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}
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/**
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* Convert the {@link CSN} to a printable String with a user friendly
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* format.
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*
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* @return the string
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*/
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public String toStringUI()
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{
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Date date = new Date(timeStamp);
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return String.format(
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"%016x%04x%08x (sid=%d,tsd=%s,ts=%d,seqnum=%d)",
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timeStamp, serverId, seqnum,
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serverId, date.toString(), timeStamp, seqnum);
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}
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/**
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* Compares 2 {@link CSN}.
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* @param csn1 the first {@link CSN} to compare
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* @param csn2 the second {@link CSN} to compare
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* @return value 0 if CSN matches, negative if first
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* CSN is smaller, positive otherwise
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*/
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public static int compare(CSN csn1, CSN csn2)
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{
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if (csn1 == null)
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{
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if (csn2 == null)
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return 0;
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return -1;
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}
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else if (csn2 == null)
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return 1;
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else if (csn1.timeStamp < csn2.timeStamp)
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return -1;
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else if (csn2.timeStamp < csn1.timeStamp)
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return 1;
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else
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{
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// timestamps are equals compare seqnums
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if (csn1.seqnum < csn2.seqnum)
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return -1;
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else if (csn2.seqnum < csn1.seqnum)
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return 1;
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else
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{
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// timestamp and seqnum are equals compare serverIds
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if (csn1.serverId < csn2.serverId)
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return -1;
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else if (csn2.serverId < csn1.serverId)
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return 1;
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// if we get here {@link CSN} are equals
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return 0;
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}
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}
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}
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/**
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* Computes the difference in number of changes between 2 CSNs. First one is
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* expected to be newer than second one. If this is not the case, 0 will be
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* returned.
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*
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* @param csn1
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* the first {@link CSN}
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* @param csn2
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* the second {@link CSN}
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* @return the difference
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*/
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public static int diffSeqNum(CSN csn1, CSN csn2)
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{
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if (csn1 == null)
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{
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return 0;
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}
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if (csn2 == null)
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{
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return csn1.getSeqnum();
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}
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if (csn2.newerOrEquals(csn1))
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{
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return 0;
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}
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int seqnum1 = csn1.getSeqnum();
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long time1 = csn1.getTime();
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int seqnum2 = csn2.getSeqnum();
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long time2 = csn2.getTime();
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if (time2 <= time1)
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{
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if (seqnum2 <= seqnum1)
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{
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return seqnum1 - seqnum2;
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}
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return Integer.MAX_VALUE - (seqnum2 - seqnum1) + 1;
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}
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return 0;
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}
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/**
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* check if the current Object is strictly older than {@link CSN}
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* given in parameter.
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* @param csn the {@link CSN} to compare with
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* @return true if strictly older, false if younger or same
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*/
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public boolean older(CSN csn)
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{
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return compare(this, csn) < 0;
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}
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/**
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* check if the current Object is older than {@link CSN}
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* given in parameter.
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* @param csn the {@link CSN} to compare with
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* @return true if older or equal, false if younger
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*/
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public boolean olderOrEqual(CSN csn)
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{
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return compare(this, csn) <= 0;
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}
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/**
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* Check if the current Object is newer than {@link CSN}.
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* @param csn the {@link CSN} to compare with
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* @return true if newer
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*/
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public boolean newerOrEquals(CSN csn)
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{
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return compare(this, csn) >= 0;
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}
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/**
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* Check if the current Object is strictly newer than {@link CSN}.
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* @param csn the {@link CSN} to compare with
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* @return true if strictly newer
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*/
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public boolean newer(CSN csn)
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{
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return compare(this, csn) > 0;
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}
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/**
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* Compares this object with the specified object for order.
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* @param csn the {@link CSN} to compare with.
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* @return a negative integer, zero, or a positive integer as this object
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* is less than, equal to, or greater than the specified object.
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*/
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@Override
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public int compareTo(CSN csn)
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{
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return compare(this, csn);
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}
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}
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