/*
|
* CDDL HEADER START
|
*
|
* The contents of this file are subject to the terms of the
|
* Common Development and Distribution License, Version 1.0 only
|
* (the "License"). You may not use this file except in compliance
|
* with the License.
|
*
|
* You can obtain a copy of the license at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
|
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
|
* See the License for the specific language governing permissions
|
* and limitations under the License.
|
*
|
* When distributing Covered Code, include this CDDL HEADER in each
|
* file and include the License file at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
|
* add the following below this CDDL HEADER, with the fields enclosed
|
* by brackets "[]" replaced with your own identifying information:
|
* Portions Copyright [yyyy] [name of copyright owner]
|
*
|
* CDDL HEADER END
|
*
|
*
|
* Copyright 2008 Sun Microsystems, Inc.
|
*/
|
package org.opends.server.replication.plugin;
|
|
import java.util.zip.Checksum;
|
|
/**
|
* This class computes the generation id used for a replication domain.
|
* It is a checksum based on some special entries/attributes of the domain.
|
* The written stream to this class is the LDIF representation of the entries
|
* we are interested in for computing the generation id. The current
|
* implementation simply does the sum of each written byte and stores the value
|
* in a long. We do not care about the cycling long as the probability of 2
|
* data sets having the same checksum is very low.
|
*/
|
public class GenerationIdChecksum implements Checksum
|
{
|
// Checksum to be returned.
|
private long checksum = 0L;
|
|
/**
|
* Update the checksum with one added byte.
|
*/
|
private void updateWithOneByte(byte b)
|
{
|
checksum += (long) b;
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
public void update(int b)
|
{
|
updateWithOneByte((byte) b);
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
public void update(byte[] b, int off, int len)
|
{
|
for (int i = off; i < (off + len); i++)
|
{
|
updateWithOneByte(b[i]);
|
}
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
public long getValue()
|
{
|
return checksum;
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
public void reset()
|
{
|
checksum = 0L;
|
}
|
}
|
