Scala example source code file (ParallelHashTries.scala)

This example Scala source code file (ParallelHashTries.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, int, int, iterablebench, iterablebenchcompanion, list, map2, reduce2, string, v, v

The Scala ParallelHashTries.scala source code

package scala.collection.parallel.benchmarks.hashtries




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.immutable.ParHashMap





trait ParHashTrieBenches[K, V] extends StandardParIterableBenches[(K, V), ParHashMap[K, V]] {
  
  def nameOfCollection = "immutable.ParHashMap"
  def comparisonMap = collection.Map()
  val forkJoinPool = new scala.concurrent.forkjoin.ForkJoinPool
  
  object Map2 extends IterableBenchCompanion {
    override def defaultSize = 5000
    override def comparisons = List("jhashtable", "hashtable")
    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 _, "hashtable" -> runhashtable _)
    def runseq = {
      val r = this.seqcoll.asInstanceOf[collection.immutable.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
      while (it.hasNext) {
        val p = it.next
        jumap.put(p._1, p._2)
      }
      result = jumap.size
    }
    def runhashtable = {
      val smap = collection.mutable.HashMap[K, V]()
      val it = this.seqcoll.iterator
      while (it.hasNext) {
        val p = it.next
        smap.put(p._1, p._2)
      }
      result = smap.size
    }
    override def reset = runWhat match {
      case "jhashtable" => this.seqcoll = createSequential(size, parallelism)
      case "hashtable" => 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 Reduce2 extends IterableBenchCompanion {
    override def defaultSize = 50000
    override def comparisons = List("hashtable")
    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 {
    private var ht: collection.mutable.HashMap[K, V] = _
    def comparisonMap = collection.Map("hashtable" -> runhashtable _)
    def runseq = this.seqcoll.reduceLeft(operators.reducer)
    def runpar = this.parcoll.reduce(operators.reducer)
    def runhashtable = ht.reduceLeft(operators.reducer)
    override def reset = runWhat match {
      case "hashtable" => ht = createHashTable(size)
      case _ => super.reset
    }
    def companion = Reduce2
  }
  
  def createHashTable(sz: Int): collection.mutable.HashMap[K, V]
  
}





object RefParHashTrieBenches extends ParHashTrieBenches[Dummy, Dummy] {
  
  type DPair = (Dummy, Dummy)
  
  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) => {
      List(p, p, p, p, 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) => {
      val a = p._1
      var i = -100
      while (i < 0) {
        if (a.in < i) a.num += 1
        i += 1
      }
      (a, p._2)
    }
    val taker = (p: DPair) => true
    val eachFun: DPair => Unit = { dp =>
      dp._1.dummy
    }
  }
  
  def createSequential(sz: Int, p: Int) = {
    var ht = new collection.immutable.HashMap[Dummy, Dummy]
    for (i <- 0 until sz) ht += ((new Dummy(i), new Dummy(i)))
    ht
  }
  
  def createParallel(sz: Int, p: Int) = {
    var pht = new ParHashMap[Dummy, Dummy]
    for (i <- 0 until sz) pht += ((new Dummy(i), new Dummy(i)))
    forkJoinPool.setParallelism(p)
    collection.parallel.tasksupport.environment = forkJoinPool
    pht
  }
  
  def createHashTable(sz: Int) = {
    val hm = collection.mutable.HashMap[Dummy, Dummy]()
    for (i <- 0 until sz) hm.put(new Dummy(i), new Dummy(i))
    hm
  }
  
}