阿克卡演员计算足球联赛排名

Question

我对Scala / Akka很陌生，这是我第一次尝试写一个演员。

我想要完成的任务是:给定一个足球比赛序列，根据足球的一般规则生成一个排名(胜利者得到3分，输家得到0分，平局时每个人得到1分)。

以下是我目前的角色演员：

package soccerLeague.akka

import akka.actor.Actor
import soccerLeague.common.{LeagueRules, MatchResult, TeamWithPoints}

// Stateful Ranker actor that maintains a rank.
// The rank gets updated every time a MatchResult message is received.
class RankerActor(rules: LeagueRules) extends Actor {

  private var rank: Seq[TeamWithPoints] = List()
  private var rankMap = Map[String, Int]()

  def receive = {
    case MatchResult(team1, score1, team2, score2) => {
      updateRank(MatchResult(team1, score1, team2, score2))
      sender ! rank
    }
    case Message("getRank") => {
      sender ! rank
    }
  }

  private def updateRank(matchRes: MatchResult): Unit = {

    def calcDeltaPoints(score1: Int, score2: Int): Int = {
      if(score1 == score2) rules.drawScore
      else if(score1 > score2) rules.winScore
      else rules.lossScore
    }

    val newPoints1 = rankMap.getOrElse(matchRes.team1, 0) + calcDeltaPoints(matchRes.score1, matchRes.score2)
    val newPoints2 = rankMap.getOrElse(matchRes.team2, 0) + calcDeltaPoints(matchRes.score2, matchRes.score1)

    rankMap += (matchRes.team1 -> newPoints1, matchRes.team2 -> newPoints2)

    // Sort by score, in reverse order (i.e. the team with most points is first).
    // Teams that have the same score are sorted in alphabetical order.
    // TODO: this *can* be improved by only moving around the two teams that are changing.
    rank = rankMap.toSeq
      .map { case (t, s) => new TeamWithPoints(t, s) }
      .sortBy { case TeamWithPoints(team, points) => (-points, team) }
  }

}

我有几门辅助性案例课：

case class MatchResult(team1: String, score1: Int, team2: String, score2: Int)
case class LeagueRules(winScore: Int, drawScore: Int, lossScore: Int)
case class TeamWithPoints(team: String, points: Int)

• 有什么方法可以使这段代码更好、更地道呢？
• 我如何避免解构MatchResult (在receive方法中)，然后当我想将它传递给updateRank方法时，再重新构造它？

Answer 1

首先，您可以尝试向Actor发送命令，而不是名词(源: Actor模型的反应性消息传递模式)。

1. 将命令放入Actor的伴生对象中。
2. 用过去式命名命令。
3. 删除“文字匹配”getRank(消息)并创建一个命令(类型-safet)来处理该方法。

有关命名命令的信息，请参阅此线程。https://stackoverflow.com/questions/12510535/naming-convention-for-commands-events