Rocket – diplomacy – TransferSizes

https://mp.weixin.qq.com/s/Sf0owQxWzxacVvykJZ5oTQ 介绍TransferSizes的实现。 ​​ 1. 基本定义 从min到max的闭合区间：[min, max] 判断条件：a. min和max为2的幂；b. min <= max;c. min和max为非负整数；d. min和max必须同时为0； ​​ 2. none 因为min和max必须同时为0，所以只需要判断min是否为0即可：​​ 3. contains 判断this是否包含x，即x落在this的范围内：​​ 4. containsLg 判断this是否包含2^x。 5. intersect 计算this和x的交集。 6. 伴生对象 ​​a. 构造方法：min = max = x;b. none对象：min = max = 0;c. asBool：x是否为空； 7. 附录 TransferSizes：// An potentially empty inclusive range of 2-powers [min, max] (in bytes)case class TransferSizes(min: Int, max: Int){ def this(x: Int) = this(x, x)  require (min <= max, s”Min transfer $min > max transfer $max”) require (min >= 0 && max >= 0, s”TransferSizes must be positive, got: ($min, $max)”) require (max == 0 || isPow2(max), s”TransferSizes must be a power of 2, got: $max”) require (min == 0 || isPow2(min), s”TransferSizes must be a power of 2, got: $min”) require (max == 0 || min != 0, s”TransferSize 0 is forbidden unless (0,0), got: ($min, $max)”)  def none = min == 0 def contains(x: Int) = isPow2(x) && min <= x && x <= max def containsLg(x: Int) = contains(1 << x) def containsLg(x: UInt) = if (none) Bool(false) else if (min == max) { UInt(log2Ceil(min)) === x } else { UInt(log2Ceil(min)) <= x && x <= UInt(log2Ceil(max)) }  def contains(x: TransferSizes) = x.none || (min <= x.min && x.max <= max)  def intersect(x: TransferSizes) = if (x.max < min || max < x.min) TransferSizes.none else TransferSizes(scala.math.max(min, x.min), scala.math.min(max, x.max))  override def toString() = “TransferSizes[%d, %d]”.format(min, max) } object TransferSizes { def apply(x: Int) = new TransferSizes(x) val none = new TransferSizes(0)  implicit def asBool(x: TransferSizes) = !x.none}