com.torodb.torod.mongodb.repl.ObjectIdFactory.java Source code

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Here is the source code for com.torodb.torod.mongodb.repl.ObjectIdFactory.java

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/*
 * This file is part of ToroDB.
 *
 * ToroDB is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * ToroDB 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with mongodb-layer. If not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright (C) 2016 8Kdata.
 * 
 */

package com.torodb.torod.mongodb.repl;

import com.eightkdata.mongowp.bson.BsonObjectId;
import com.eightkdata.mongowp.bson.impl.IntBasedBsonObjectId;
import com.google.common.hash.Hasher;
import com.google.common.hash.Hashing;
import com.google.common.primitives.UnsignedInteger;
import java.lang.management.ManagementFactory;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.security.SecureRandom;
import java.util.Enumeration;
import java.util.concurrent.atomic.AtomicInteger;
import javax.inject.Singleton;
import org.slf4j.LoggerFactory;

/**
 *
 */
@Singleton
public class ObjectIdFactory {
    private static final org.slf4j.Logger LOGGER = LoggerFactory.getLogger(ObjectIdFactory.class);

    private static final int MACHINE_ID = createMachineId();
    private static final int PROCESS_ID = createProcessId();
    private static final AtomicInteger COUNTER = new AtomicInteger(new SecureRandom().nextInt());

    public BsonObjectId consumeObjectId() {
        long secs = System.currentTimeMillis() / 1000;
        return new IntBasedBsonObjectId(UnsignedInteger.valueOf(secs).intValue(), MACHINE_ID, PROCESS_ID,
                COUNTER.getAndIncrement() & 0xFFFFFF);
    }

    private static int createMachineId() {
        int machineId;
        try {
            Hasher hasher = Hashing.crc32c().newHasher();
            Enumeration<NetworkInterface> nics = NetworkInterface.getNetworkInterfaces();
            boolean atLeastOne = false;
            while (nics.hasMoreElements()) {
                NetworkInterface ni = nics.nextElement();
                if (ni != null) {
                    byte[] macAddress = ni.getHardwareAddress();
                    if (macAddress != null) {
                        for (byte _byte : macAddress) {
                            atLeastOne = true;
                            hasher.putByte(_byte);
                        }
                    }
                }
            }
            if (!atLeastOne) {
                LOGGER.warn("Failed to calculate the machine id. A random number is used");
                machineId = new SecureRandom().nextInt();
            } else {
                machineId = hasher.hash().asInt();
            }
        } catch (SocketException ex) {
            LOGGER.warn("Failed to calculate the machine id. A random number is used");
            machineId = new SecureRandom().nextInt();
        }

        return machineId & 0xFFFFFF;
    }

    private static int createProcessId() {
        int pid;
        String name = ManagementFactory.getRuntimeMXBean().getName();
        try {
            pid = Integer.parseInt(name.substring(0, name.indexOf("@")));
        } catch (Throwable ex) {
            LOGGER.warn("Failed to calculate the process id. A random number is used");
            pid = new SecureRandom().nextInt();
        }
        return pid & 0xFFFF;
    }

}