org.sakaiproject.nakamura.cluster.IDTest.java Source code

Introduction

Here is the source code for org.sakaiproject.nakamura.cluster.IDTest.java

Source

/*
 * Licensed to the Sakai Foundation (SF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The SF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */
package org.sakaiproject.nakamura.cluster;

import static org.junit.Assert.assertFalse;

import org.apache.commons.codec.binary.Base64;
import org.junit.BeforeClass;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.math.BigInteger;
import java.util.GregorianCalendar;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;

/**
 *
 */
public class IDTest {

    private static final Logger LOGGER = LoggerFactory.getLogger(IDTest.class);
    private static long tstart;
    private static long epoch;
    private Map<BigInteger, BigInteger> hash = new ConcurrentHashMap<BigInteger, BigInteger>();
    private long prev = 0;
    private long next = 0;
    private Object lockObject = new Object();
    private int nrunning = 0;

    @BeforeClass
    public static void beforeClass() {
        GregorianCalendar calendar = new GregorianCalendar(2009, 8, 21);
        epoch = calendar.getTimeInMillis();
        tstart = 99;
    }

    @Test
    public void testId() {

        for (int i = 0; i < 10; i++) {
            Thread t = new Thread(new Runnable() {

                public void run() {
                    nrunning++;
                    try {
                        for (int j = 0; j < 100; j++) {
                            BigInteger id = getId();
                            assertFalse("Failed for " + id + " after " + j, hash.containsKey(id));
                            hash.put(id, id);
                        }
                    } finally {
                        nrunning--;
                    }

                }

            });
            t.start();
        }

        do {
            LOGGER.info("Running " + nrunning + " Hash Size is " + hash.size());
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                LOGGER.info(e.getMessage(), e);
            }
        } while (nrunning > 0);

        Base64 b64 = new Base64();
        for (Entry<BigInteger, BigInteger> e : hash.entrySet()) {
            LOGGER.info(" Entry is " + e.getValue() + " " + b64.encodeToString(e.getValue().toByteArray()).trim());

        }

    }

    private BigInteger getId() {
        synchronized (lockObject) {
            do {
                next = System.currentTimeMillis() - epoch;
            } while (next == prev);
            BigInteger ret = new BigInteger(String.valueOf(tstart) + String.valueOf(next));
            prev = next;
            return ret;
        }
    }

}