Akka/Scala example source code file (VectorClockSpec.scala)

This example Akka source code file (VectorClockSpec.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

a, akka, akkaspec, cluster, node, test, testing, testkit, vectorclock, vectorclockspec

The VectorClockSpec.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */

package akka.cluster

import akka.testkit.AkkaSpec

class VectorClockSpec extends AkkaSpec {
  import VectorClock._

  "A VectorClock" must {

    "have zero versions when created" in {
      val clock = VectorClock()
      clock.versions should be(Map())
    }

    "not happen before itself" in {
      val clock1 = VectorClock()
      val clock2 = VectorClock()

      clock1 <> clock2 should be(false)
    }

    "pass misc comparison test 1" in {
      val clock1_1 = VectorClock()
      val clock2_1 = clock1_1 :+ Node("1")
      val clock3_1 = clock2_1 :+ Node("2")
      val clock4_1 = clock3_1 :+ Node("1")

      val clock1_2 = VectorClock()
      val clock2_2 = clock1_2 :+ Node("1")
      val clock3_2 = clock2_2 :+ Node("2")
      val clock4_2 = clock3_2 :+ Node("1")

      clock4_1 <> clock4_2 should be(false)
    }

    "pass misc comparison test 2" in {
      val clock1_1 = VectorClock()
      val clock2_1 = clock1_1 :+ Node("1")
      val clock3_1 = clock2_1 :+ Node("2")
      val clock4_1 = clock3_1 :+ Node("1")

      val clock1_2 = VectorClock()
      val clock2_2 = clock1_2 :+ Node("1")
      val clock3_2 = clock2_2 :+ Node("2")
      val clock4_2 = clock3_2 :+ Node("1")
      val clock5_2 = clock4_2 :+ Node("3")

      clock4_1 < clock5_2 should be(true)
    }

    "pass misc comparison test 3" in {
      var clock1_1 = VectorClock()
      val clock2_1 = clock1_1 :+ Node("1")

      val clock1_2 = VectorClock()
      val clock2_2 = clock1_2 :+ Node("2")

      clock2_1 <> clock2_2 should be(true)
    }

    "pass misc comparison test 4" in {
      val clock1_3 = VectorClock()
      val clock2_3 = clock1_3 :+ Node("1")
      val clock3_3 = clock2_3 :+ Node("2")
      val clock4_3 = clock3_3 :+ Node("1")

      val clock1_4 = VectorClock()
      val clock2_4 = clock1_4 :+ Node("1")
      val clock3_4 = clock2_4 :+ Node("1")
      val clock4_4 = clock3_4 :+ Node("3")

      clock4_3 <> clock4_4 should be(true)
    }

    "pass misc comparison test 5" in {
      val clock1_1 = VectorClock()
      val clock2_1 = clock1_1 :+ Node("2")
      val clock3_1 = clock2_1 :+ Node("2")

      val clock1_2 = VectorClock()
      val clock2_2 = clock1_2 :+ Node("1")
      val clock3_2 = clock2_2 :+ Node("2")
      val clock4_2 = clock3_2 :+ Node("2")
      val clock5_2 = clock4_2 :+ Node("3")

      clock3_1 < clock5_2 should be(true)
      clock5_2 > clock3_1 should be(true)
    }

    "pass misc comparison test 6" in {
      val clock1_1 = VectorClock()
      val clock2_1 = clock1_1 :+ Node("1")
      val clock3_1 = clock2_1 :+ Node("2")

      val clock1_2 = VectorClock()
      val clock2_2 = clock1_2 :+ Node("1")
      val clock3_2 = clock2_2 :+ Node("1")

      clock3_1 <> clock3_2 should be(true)
      clock3_2 <> clock3_1 should be(true)
    }

    "pass misc comparison test 7" in {
      val clock1_1 = VectorClock()
      val clock2_1 = clock1_1 :+ Node("1")
      val clock3_1 = clock2_1 :+ Node("2")
      val clock4_1 = clock3_1 :+ Node("2")
      val clock5_1 = clock4_1 :+ Node("3")

      val clock1_2 = clock4_1
      val clock2_2 = clock1_2 :+ Node("2")
      val clock3_2 = clock2_2 :+ Node("2")

      clock5_1 <> clock3_2 should be(true)
      clock3_2 <> clock5_1 should be(true)
    }

    "pass misc comparison test 8" in {
      val clock1_1 = VectorClock()
      val clock2_1 = clock1_1 :+ Node.fromHash("1")
      val clock3_1 = clock2_1 :+ Node.fromHash("3")

      val clock1_2 = clock3_1 :+ Node.fromHash("2")

      val clock4_1 = clock3_1 :+ Node.fromHash("3")

      clock4_1 <> clock1_2 should be(true)
      clock1_2 <> clock4_1 should be(true)
    }

    "correctly merge two clocks" in {
      val node1 = Node("1")
      val node2 = Node("2")
      val node3 = Node("3")

      val clock1_1 = VectorClock()
      val clock2_1 = clock1_1 :+ node1
      val clock3_1 = clock2_1 :+ node2
      val clock4_1 = clock3_1 :+ node2
      val clock5_1 = clock4_1 :+ node3

      val clock1_2 = clock4_1
      val clock2_2 = clock1_2 :+ node2
      val clock3_2 = clock2_2 :+ node2

      val merged1 = clock3_2 merge clock5_1
      merged1.versions.size should be(3)
      merged1.versions.contains(node1) should be(true)
      merged1.versions.contains(node2) should be(true)
      merged1.versions.contains(node3) should be(true)

      val merged2 = clock5_1 merge clock3_2
      merged2.versions.size should be(3)
      merged2.versions.contains(node1) should be(true)
      merged2.versions.contains(node2) should be(true)
      merged2.versions.contains(node3) should be(true)

      clock3_2 < merged1 should be(true)
      clock5_1 < merged1 should be(true)

      clock3_2 < merged2 should be(true)
      clock5_1 < merged2 should be(true)

      merged1 == merged2 should be(true)
    }

    "correctly merge two disjoint vector clocks" in {
      val node1 = Node("1")
      val node2 = Node("2")
      val node3 = Node("3")
      val node4 = Node("4")

      val clock1_1 = VectorClock()
      val clock2_1 = clock1_1 :+ node1
      val clock3_1 = clock2_1 :+ node2
      val clock4_1 = clock3_1 :+ node2
      val clock5_1 = clock4_1 :+ node3

      val clock1_2 = VectorClock()
      val clock2_2 = clock1_2 :+ node4
      val clock3_2 = clock2_2 :+ node4

      val merged1 = clock3_2 merge clock5_1
      merged1.versions.size should be(4)
      merged1.versions.contains(node1) should be(true)
      merged1.versions.contains(node2) should be(true)
      merged1.versions.contains(node3) should be(true)
      merged1.versions.contains(node4) should be(true)

      val merged2 = clock5_1 merge clock3_2
      merged2.versions.size should be(4)
      merged2.versions.contains(node1) should be(true)
      merged2.versions.contains(node2) should be(true)
      merged2.versions.contains(node3) should be(true)
      merged2.versions.contains(node4) should be(true)

      clock3_2 < merged1 should be(true)
      clock5_1 < merged1 should be(true)

      clock3_2 < merged2 should be(true)
      clock5_1 < merged2 should be(true)

      merged1 == merged2 should be(true)
    }

    "pass blank clock incrementing" in {
      val node1 = Node("1")
      val node2 = Node("2")

      val v1 = VectorClock()
      val v2 = VectorClock()

      val vv1 = v1 :+ node1
      val vv2 = v2 :+ node2

      (vv1 > v1) should be(true)
      (vv2 > v2) should be(true)

      (vv1 > v2) should be(true)
      (vv2 > v1) should be(true)

      (vv2 > vv1) should be(false)
      (vv1 > vv2) should be(false)
    }

    "pass merging behavior" in {
      val node1 = Node("1")
      val node2 = Node("2")
      val node3 = Node("3")

      val a = VectorClock()
      val b = VectorClock()

      val a1 = a :+ node1
      val b1 = b :+ node2

      var a2 = a1 :+ node1
      var c = a2.merge(b1)
      var c1 = c :+ node3

      (c1 > a2) should be(true)
      (c1 > b1) should be(true)
    }
  }
}