时间轮算法

public class TimeHashWheel {
    // 任务存储
    private Map<Integer, List<Task>> taskMap;
    // 每轮时长
    private int                      duration;
    // 单期耗时
    private int                      tick;
    private volatile boolean start;
    public static void main(String[] args) {
        TimeHashWheel wheel = new TimeHashWheel(6000, 100);
        wheel.start();
        for (int i = 0; i < 100; i++) {
            String date = "task_no_" + i;
            int delay = (int) (Math.random() * 3 * 6000);
            wheel.addTask(date, delay);
            System.out.println("insert task : " + date + ", delay by : " + delay);
        }
    }
    public TimeHashWheel(int duration, int tick) {
        this.taskMap = new HashMap<>(duration / tick);
        this.duration = duration;
        this.tick = tick;
        this.start = true;
    }
    public void addTask(String data, int delay) {
        int bucket = (delay % duration) / tick;
        int round = delay / duration;
        taskMap.computeIfAbsent(bucket, k -> new ArrayList<>());
        taskMap.get(bucket).add(new Task(data, round));
    }
    public void start() {
        Executors.newSingleThreadExecutor().execute(() -> {
            try {
                int begin = 0;
                while (start) {
                    if ((begin == (duration / tick))) {
                        System.out.println("tick to next round ---- ");
                        begin = 0;
                    }
                    System.out.println("tick to :" + (begin));
                    List<Task> list = taskMap.get(begin++);
                    System.out.println("found bucket has " + (list == null ? 0 : list.size())
                            + " task");
                    if (!CollectionUtils.isEmpty(list)) {
                        Iterator<Task> it = list.iterator();
                        while (it.hasNext()) {
                            Task task = it.next();
                            if (task.round > 0) {
                                task.round--;
                            } else {
                                System.out.println("=============  execute task : " + task.data);
                                it.remove();
                            }
                        }
                    }
                    TimeUnit.MILLISECONDS.sleep(tick);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        });
    }
    class Task {
        private String data;
        private int    round;
        public Task(String data, int round) {
            this.data = data;
            this.round = round;
        }
    }
}