public abstract class LeapArray<T> {
 //毫秒时间周期，默认60*1000，例如计算QPS时，为1000
    protected int intervalInMs;
 //窗口数量，默认60
    protected int sampleCount;
//窗口时间长度，毫秒数，默认1000ms 该值 = intervalInMs / sampleCount
    protected int windowLengthInMs;
 
 // 存储时间窗口的数组
    protected final AtomicReferenceArray<WindowWrap<T>> array;
 
    public LeapArray(int sampleCount, int intervalInMs) {
        AssertUtil.isTrue(sampleCount > 0, "bucket count is invalid: " + sampleCount);
        AssertUtil.isTrue(intervalInMs > 0, "total time interval of the sliding window should be positive");
        AssertUtil.isTrue(intervalInMs % sampleCount == 0, "time span needs to be evenly divided");

        this.windowLengthInMs = intervalInMs / sampleCount;
        this.intervalInMs = intervalInMs;
        this.sampleCount = sampleCount;
  
        this.array = new AtomicReferenceArray<>(sampleCount);
    } 

}