/*
 *  Copyright 1999-2018 Alibaba Group Holding Ltd.
 *
 *  Licensed 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 com.alibaba.fescar.server;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.atomic.AtomicLong;

import com.alibaba.fescar.common.exception.ShouldNeverHappenException;

/**
 * The type Uuid generator.
 */
public class UUIDGenerator {

    private static AtomicLong UUID = new AtomicLong(1000);
    private static int serverNodeId = 1;
    private static final long UUID_INTERNAL = 2000000000;

    /**
     * Generate uuid long.
     *
     * @return the long
     */
    public static long generateUUID() {
        long id = UUID.incrementAndGet();
        if (id > UUID_INTERNAL * serverNodeId) {
            synchronized (UUID) {
                if (UUID.get() >= id) {
                    id -= UUID_INTERNAL;
                    UUID.set(id);
                }
            }
        }
        return id;
    }

    /**
     * Init.
     *
     * @param serverNodeId the server node id
     */
    public static void init(int serverNodeId) {
        try {
            UUIDGenerator.serverNodeId = serverNodeId;
            UUID.set(UUID_INTERNAL * serverNodeId);
            SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
            Calendar cal = Calendar.getInstance();
            Date date = format.parse("2019-01-01");
            cal.setTime(date);
            long base = cal.getTimeInMillis();
            long current = System.currentTimeMillis();
            UUID.addAndGet((current - base) / 1000);
        } catch (ParseException e) {
            throw new ShouldNeverHappenException(e);
        }
    }
}

@@ -979,16 +979,22 @@
  static 
+final 
 AtomicLo
@@ -1297,16 +1297,17 @@
 if (id %3E
+=
  UUID_IN
@@ -1307,32 +1307,33 @@
 UUID_INTERNAL * 
+(
 serverNodeId) %7B%0A
@@ -1320,32 +1320,37 @@
  * (serverNodeId
+ + 1)
 ) %7B%0A            

fix #415 transId needs to recycle (#436)