Add Bagel test suite

Note: This test suite currently fails for the same reason that the
Spark Core test suite fails: Spark currently seems to have a bug where
any test after the first one fails.

bagel/src/main/scala/bagel/Pregel.scala

@@ -75,6 +75,14 @@ object Pregel extends Logging {
       run(sc, newVerts, newMsgs, createCombiner, mergeMsg, mergeCombiners, numSplits, superstep + 1)(compute)
     }
   }
+
+  def defaultCreateCombiner[M <: Message](msg: M): ArrayBuffer[M] = ArrayBuffer(msg)
+  def defaultMergeMsg[M <: Message](combiner: ArrayBuffer[M], msg: M): ArrayBuffer[M] =
+    combiner += msg
+  def defaultMergeCombiners[M <: Message](a: ArrayBuffer[M], b: ArrayBuffer[M]): ArrayBuffer[M] =
+    a ++= b
+  def defaultCompute[V <: Vertex, M <: Message](self: V, msgs: Option[ArrayBuffer[M]], superstep: Int): (V, Iterable[M]) =
+    (self, List())
 }
 
 /**

bagel/src/test/scala/bagel/BagelSuite.scala

+package bagel
+
+import org.scalatest.{FunSuite, Assertions}
+import org.scalatest.prop.Checkers
+import org.scalacheck.Arbitrary._
+import org.scalacheck.Gen
+import org.scalacheck.Prop._
+
+import scala.collection.mutable.ArrayBuffer
+
+import spark._
+
+@serializable class TestVertex(val id: String, val active: Boolean, val age: Int) extends Vertex
+@serializable class TestMessage(val targetId: String) extends Message
+
+class BagelSuite extends FunSuite with Assertions {
+  test("halting by voting") {
+    val sc = new SparkContext("local", "test")
+    val verts = sc.parallelize(Array("a", "b", "c", "d").map(id => (id, new TestVertex(id, true, 0))))
+    val msgs = sc.parallelize(Array[(String, TestMessage)]())
+    val numSupersteps = 5
+    val result =
+      Pregel.run(sc, verts, msgs,
+                 Pregel.defaultCreateCombiner[TestMessage],
+                 Pregel.defaultMergeMsg[TestMessage],
+                 Pregel.defaultMergeCombiners[TestMessage], 1) {
+      (self: TestVertex, msgs: Option[ArrayBuffer[TestMessage]], superstep: Int) =>
+        (new TestVertex(self.id, superstep < numSupersteps - 1, self.age + 1), Array[TestMessage]())
+    }
+    for (vert <- result.collect)
+      assert(vert.age === numSupersteps)
+  }
+
+  test("halting by message silence") {
+    val sc = new SparkContext("local", "test")
+    val verts = sc.parallelize(Array("a", "b", "c", "d").map(id => (id, new TestVertex(id, false, 0))))
+    val msgs = sc.parallelize(Array("a" -> new TestMessage("a")))
+    val numSupersteps = 5
+    val result =
+      Pregel.run(sc, verts, msgs,
+                 Pregel.defaultCreateCombiner[TestMessage],
+                 Pregel.defaultMergeMsg[TestMessage],
+                 Pregel.defaultMergeCombiners[TestMessage], 1) {
+      (self: TestVertex, msgs: Option[ArrayBuffer[TestMessage]], superstep: Int) =>
+        val msgsOut =
+          msgs match {
+            case Some(ms) if (superstep < numSupersteps - 1) =>
+              ms
+            case _ =>
+              new ArrayBuffer[TestMessage]()
+          }
+        (new TestVertex(self.id, self.active, self.age + 1), msgsOut)
+    }
+    for (vert <- result.collect)
+      assert(vert.age === numSupersteps)
+  }
+}

project/build/SparkProject.scala

@@ -14,7 +14,7 @@ extends ParentProject(info) with IdeaProject
   lazy val examples =
     project("examples", "Spark Examples", new ExamplesProject(_), core)
 
-  lazy val bagel = project("bagel", "Bagel", core)
+  lazy val bagel = project("bagel", "Bagel", new BagelProject(_), core)
 
   class CoreProject(info: ProjectInfo)
   extends DefaultProject(info) with Eclipsify with IdeaProject with DepJar with XmlTestReport
@@ -23,6 +23,10 @@ extends ParentProject(info) with IdeaProject
   class ExamplesProject(info: ProjectInfo)
   extends DefaultProject(info) with Eclipsify with IdeaProject
   {}
+
+  class BagelProject(info: ProjectInfo)
+  extends DefaultProject(info) with DepJar with XmlTestReport
+  {}
 }