/*
* Copyright (c) 2001-2007 Sun Microsystems, Inc. All rights reserved.
*
* The Sun Project JXTA(TM) Software License
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The end-user documentation included with the redistribution, if any, must
* include the following acknowledgment: "This product includes software
* developed by Sun Microsystems, Inc. for JXTA(TM) technology."
* Alternately, this acknowledgment may appear in the software itself, if
* and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
* not be used to endorse or promote products derived from this software
* without prior written permission. For written permission, please contact
* Project JXTA at http://www.jxta.org.
*
* 5. Products derived from this software may not be called "JXTA", nor may
* "JXTA" appear in their name, without prior written permission of Sun.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SUN
* MICROSYSTEMS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* JXTA is a registered trademark of Sun Microsystems, Inc. in the United
* States and other countries.
*
* Please see the license information page at :
* <http://www.jxta.org/project/www/license.html> for instructions on use of
* the license in source files.
*
* ====================================================================
*
* This software consists of voluntary contributions made by many individuals
* on behalf of Project JXTA. For more information on Project JXTA, please see
* http://www.jxta.org.
*
* This license is based on the BSD license adopted by the Apache Foundation.
*/
package net.jxta.impl.cm;
import java.math.BigInteger;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import net.jxta.impl.util.JxtaHash;
/**
* A SrdiGetReplica unit test
*/
public class SrdiReplicaTest extends TestCase {
private JxtaHash jxtaHash = new JxtaHash();
private static final int OFFBY = 30;
private static final int ITERATIONS = 10;
private static final int SIZE = 100;
private static final String TSTSTR = "This is only a Test, nothing else";
/**
* Constructor for the SrdiIndexTest object
*
* @param testName test name
*/
public SrdiReplicaTest(String testName) {
super(testName);
}
/**
* A unit test suite for JUnit
*
* @return The test suite
*/
public static Test suite() {
return new TestSuite(SrdiReplicaTest.class);
}
/**
* The JUnit setup method
*/
@Override
protected void setUp() {
}
@Override
public void tearDown() {
System.gc();
}
/**
* The main program to test CmCache
*
* @param argv The command line arguments
* @throws Exception Description of Exception
*/
public static void main(String[] argv) throws Exception {
junit.textui.TestRunner.run(suite());
System.err.flush();
System.out.flush();
}
public void testOffBy() {
for (int i = 0; i < OFFBY; i++) {
offBy(i);
}
}
private void offBy(int size) {
System.out.println("Test Off By : " + size);
System.out.println("---------------");
for (int i = 0; i < ITERATIONS; i++) {
int rp1 = getReplica1(TSTSTR + i, SIZE);
int rp2 = getReplica2(TSTSTR + i, SIZE);
int rp11 = getReplica1(TSTSTR + i, SIZE + size);
int rp21 = getReplica2(TSTSTR + i, SIZE + size);
System.out.print("Get replica 1 actual pos: " + rp1 + " RPV Off by " + size + " : " + rp11 + " skew :" + (rp1 - rp11));
System.out.println(
" ---- Get replica 2 actual pos: " + rp2 + " Off by " + size + " : " + rp21 + " skew :" + (rp2 - rp21));
}
}
/* 2.0 Replica Function */
private int getReplica1(String expression, int size) {
jxtaHash.update(expression);
return jxtaHash.mod(size);
}
/* Replica Function contributed by Shinya*/
private int getReplica2(String expression, int size) {
jxtaHash.update(expression);
BigInteger sizeOfPeerView = java.math.BigInteger.valueOf(size);
BigInteger digest = jxtaHash.getDigestInteger().abs();
BigInteger sizeOfHashSpace = BigInteger.ONE.shiftLeft(8 * digest.toByteArray().length);
return (digest.multiply(sizeOfPeerView)).divide(sizeOfHashSpace).intValue();
}
}