Scala example source code file (ParallelHashTables.scala)

This example Scala source code file (ParallelHashTables.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

dpair, dpair, dummy, dummy, foreach, foreachset, int, int, iterablebench, iterablebenchcompanion, list, reduce2, string, string

The Scala ParallelHashTables.scala source code

package scala.collection.parallel.benchmarks.hashtables




import scala.collection.parallel.benchmarks.generic.StandardParIterableBenches
import scala.collection.parallel.benchmarks.generic.Dummy
import scala.collection.parallel.benchmarks.generic.Operators
import scala.collection.parallel.mutable.ParHashMap





trait ParHashTableBenches[K, V] extends StandardParIterableBenches[(K, V), ParHashMap[K, V]] {
  
  def nameOfCollection = "mutable.ParHashMap"
  def comparisonMap = collection.mutable.Map()
  val forkJoinPool = new scala.concurrent.forkjoin.ForkJoinPool
  
  object Map2 extends IterableBenchCompanion {
    override def defaultSize = 40000
    override def comparisons = List("jhashtable")
    def benchName = "map2";
    def apply(sz: Int, p: Int, w: String) = new Map2(sz, p, w)
  }
  
  class Map2(val size: Int, val parallelism: Int, val runWhat: String)
  extends IterableBench {
    var result: Int = 0
    def comparisonMap = collection.Map("jhashtable" -> runjhashtable _)
    def runseq = {
      val r = this.seqcoll.asInstanceOf[collection.mutable.HashMap[K, V]].map(operators.mapper2)
      result = r.size
    }
    def runpar = {
      result = this.parcoll.map(operators.mapper2).size
    }
    def runjhashtable = {
      val jumap = new java.util.HashMap[K, V]()
      val it = this.seqcoll.iterator
      val f = operators.mapper2
      while (it.hasNext) {
        val p = f(it.next)
        jumap.put(p._1, p._2)
      }
      result = jumap.size
    }
    override def reset = runWhat match {
      case "jhashtable" => this.seqcoll = createSequential(size, parallelism)
      case _ => super.reset
    }
    def companion = Map2
    override def repetitionsPerRun = 50
    override def printResults {
      println("Size of last result: " + result)
    }
  }
  
  object FlatMap2 extends IterableBenchCompanion {
    override def defaultSize = 5000
    def benchName = "flatmap2";
    def apply(sz: Int, p: Int, w: String) = new FlatMap2(sz, p, w)
  }
  
  class FlatMap2(val size: Int, val parallelism: Int, val runWhat: String)
  extends IterableBench {
    def comparisonMap = collection.Map()
    override def repetitionsPerRun = 25
    def runseq = this.seqcoll.flatMap(operators.flatmapper)
    def runpar = this.parcoll.flatMap(operators.flatmapper)
    def companion = FlatMap2
  }  
    
  object HeavyMap extends IterableBenchCompanion {
    override def defaultSize = 5000
    override def comparisons = List()
    def benchName = "heavy-map";
    def apply(sz: Int, p: Int, w: String) = new HeavyMap(sz, p, w)
  }
  
  class HeavyMap(val size: Int, val parallelism: Int, val runWhat: String)
  extends IterableBench {
    var result: Int = 0
    def comparisonMap = collection.Map()
    def runseq = {
      val r = this.seqcoll.asInstanceOf[collection.mutable.HashMap[K, V]].map(operators.heavymapper)
      result = r.size
    }
    def runpar = {
      result = this.parcoll.map(operators.heavymapper).size
    }
    def companion = HeavyMap
    override def repetitionsPerRun = 50
  }
  
  object Reduce2 extends IterableBenchCompanion {
    override def defaultSize = 50000
    override def comparisons = List()
    def benchName = "reduce2";
    def apply(sz: Int, p: Int, w: String) = new Reduce2(sz, p, w)
  }
  
  class Reduce2(val size: Int, val parallelism: Int, val runWhat: String)
  extends IterableBench {
    def comparisonMap = collection.Map()
    def runseq = this.seqcoll.reduceLeft(operators.mediumreducer)
    def runpar = this.parcoll.reduce(operators.mediumreducer)
    def companion = Reduce2
  }
  
  object Foreach extends IterableBenchCompanion {
    override def defaultSize = 50000
    override def comparisons = List()
    def benchName = "foreach";
    def apply(sz: Int, p: Int, w: String) = new Foreach(sz, p, w)
  }
  
  class Foreach(val size: Int, val parallelism: Int, val runWhat: String)
  extends IterableBench {
    def comparisonMap = collection.Map()
    def runseq = this.seqcoll.foreach(operators.foreachFun)
    def runpar = this.parcoll.pforeach(operators.foreachFun)
    def companion = Foreach
  }
  
}





object RefParHashTableBenches extends ParHashTableBenches[Dummy, Dummy] {
  
  type DPair = (Dummy, Dummy);
  
  object ForeachSet extends IterableBenchCompanion {
    override def defaultSize = 50000
    override def comparisons = List()
    def benchName = "foreach-set";
    def apply(sz: Int, p: Int, w: String) = new ForeachSet(sz, p, w)
  }
  
  class ForeachSet(val size: Int, val parallelism: Int, val runWhat: String)
  extends IterableBench {
    val array = new Array[Int](size)
    def comparisonMap = collection.Map()
    def runseq = for (p <- this.seqcoll) array(p._1.in) += 1
    def runpar = this.parcoll.pforeach { p => array(p._1.in) += 1 }
    def companion = ForeachSet
    
    override def onEnd {
      for (i <- 0 until array.length) {
        assert(array(i) == repetitionsPerRun * runs)
      }
    }
  }
  
  object operators extends Operators[DPair] {
    def gcd(a: Int, b: Int): Int = {
      val result = if (b == 0) a else {
        gcd(b, a - b * (a / b))
      }
      result + 1000
    }
    def heavy(a: Int): Int = {
      var i = 0
      var sum = a
      while (i < 3000) {
        i += 1
        sum += a + i
      }
      sum
    }
    val foreachFun = (t: DPair) => {
      t
      ()
    }
    val reducer = (x: DPair, y: DPair) => {
      //y._2.num = x._2.in + y._2.in
      y
    }
    val mediumreducer = (x: DPair, y: DPair) => {
      y._2.num = gcd(x._2.in, y._2.in)
      y
    }
    val filterer = (p: DPair) => {
      p._1.num % 2 == 0
    }
    val mapper = (p: DPair) => {
      val a = p._1
      a.num = a.in % 2
      (a, p._2)
    }
    val flatmapper = (p: DPair) => {
      for (i <- 0 until 20) yield p
    }
    override val mapper2 = (p: DPair) => {
      val a = 1 //heavy(p._1.in)
      (new Dummy(p._1.in * -2 + a), p._2)
    }
    val heavymapper = (p: DPair) => {
      var i = -2000
      var t = p._1.in
      while (i < 0) {
        t += (p._2.num - p._1.num) / 500
        p._1.num += p._2.num + t
        i += 1
      }
      (p._1, new Dummy(0))
    }
    val taker = (p: DPair) => true
    val eachFun: DPair => Unit = { dp =>
      dp._1.dummy
    }
  }
  
  def createSequential(sz: Int, p: Int) = {
    val ht = new collection.mutable.HashMap[Dummy, Dummy]
    for (i <- 0 until sz) ht += ((new Dummy(i), new Dummy(i)))
    ht
  }
  
  def createParallel(sz: Int, p: Int) = {
    val phm = new ParHashMap[Dummy, Dummy]
    for (i <- 0 until sz) phm += ((new Dummy(i), new Dummy(i)))
    forkJoinPool.setParallelism(p)
    collection.parallel.tasksupport.environment = forkJoinPool
    phm
  }
  
}