Improved code style.

4 files changed, 19 insertions, 15 deletions

diff --git a/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala b/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
index d778692f45..322b519bd2 100644
--- a/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
@@ -219,7 +219,7 @@ class PairRDDFunctions[K: ClassManifest, V: ClassManifest](self: RDD[(K, V)])
   def countDistinctByKey(relativeSD: Double, partitioner: Partitioner): RDD[(K, Long)] = {
     val createHLL = (v: V) => {
       val hll = new SerializableHyperLogLog(new HyperLogLog(relativeSD))
-      val bres = hll.value.offer(v)
+      hll.value.offer(v)
       hll
     }
     val mergeValueHLL = (hll: SerializableHyperLogLog, v: V) => {
diff --git a/core/src/main/scala/org/apache/spark/rdd/RDD.scala b/core/src/main/scala/org/apache/spark/rdd/RDD.scala
index 38fa96fd6d..e23e7a63a1 100644
--- a/core/src/main/scala/org/apache/spark/rdd/RDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/RDD.scala
@@ -784,7 +784,7 @@ abstract class RDD[T: ClassManifest](
       }
       Iterator(hllCounter)
     }
-    def mergeCounters(c1: SerializableHyperLogLog, c2: SerializableHyperLogLog): SerializableHyperLogLog = c1.merge(c2)
+    def mergeCounters(c1: SerializableHyperLogLog, c2: SerializableHyperLogLog) = c1.merge(c2)
 
     mapPartitions(hllCountPartition).reduce(mergeCounters).value.cardinality()
   }
diff --git a/core/src/test/scala/org/apache/spark/rdd/PairRDDFunctionsSuite.scala b/core/src/test/scala/org/apache/spark/rdd/PairRDDFunctionsSuite.scala
index d81bc8cb4c..5683ada78a 100644
--- a/core/src/test/scala/org/apache/spark/rdd/PairRDDFunctionsSuite.scala
+++ b/core/src/test/scala/org/apache/spark/rdd/PairRDDFunctionsSuite.scala
@@ -19,6 +19,7 @@ package org.apache.spark.rdd
 
 import scala.collection.mutable.ArrayBuffer
 import scala.collection.mutable.HashSet
+import scala.util.Random
 
 import org.scalatest.FunSuite
 
@@ -110,15 +111,17 @@ class PairRDDFunctionsSuite extends FunSuite with SharedSparkContext {
   }
 
   test("countDistinctByKey") {
-    def error(est: Long, size: Long) = math.abs(est - size)/size.toDouble
+    def error(est: Long, size: Long) = math.abs(est - size) / size.toDouble
 
     /* Since HyperLogLog unique counting is approximate, and the relative standard deviation is
-    only a statistical bound, the tests can fail for large values of relativeSD. We will be using
-     relatively tight error bounds to check correctness of functionality rather than checking
-     whether the approximation conforms with the requested bound.
+     * only a statistical bound, the tests can fail for large values of relativeSD. We will be using
+     * relatively tight error bounds to check correctness of functionality rather than checking
+     * whether the approximation conforms with the requested bound.
      */
     val relativeSD = 0.001
 
+    // For each value i, there are i tuples with first element equal to i.
+    // Therefore, the expected count for key i would be i.
     val stacked = (1 to 100).flatMap(i => (1 to i).map(j => (i, j)))
     val rdd1 = sc.parallelize(stacked)
     val counted1 = rdd1.countDistinctByKey(relativeSD).collect()
@@ -126,10 +129,11 @@ class PairRDDFunctionsSuite extends FunSuite with SharedSparkContext {
       case(k, count) => assert(math.abs(error(count, k)) < relativeSD)
     }
 
-    import scala.util.Random
     val rnd = new Random()
-    val randStacked = (1 to 100).flatMap{i =>
-      val num = rnd.nextInt%500
+
+    // The expected count for key num would be num
+    val randStacked = (1 to 100).flatMap { i =>
+      val num = rnd.nextInt % 500
       (1 to num).map(j => (num, j))
     }
     val rdd2 = sc.parallelize(randStacked)
diff --git a/core/src/test/scala/org/apache/spark/rdd/RDDSuite.scala b/core/src/test/scala/org/apache/spark/rdd/RDDSuite.scala
index 6baf9c7ece..413ea85322 100644
--- a/core/src/test/scala/org/apache/spark/rdd/RDDSuite.scala
+++ b/core/src/test/scala/org/apache/spark/rdd/RDDSuite.scala
@@ -63,17 +63,17 @@ class RDDSuite extends FunSuite with SharedSparkContext {
     }
   }
 
-  test("Approximate distinct count") {
+  test("countDistinct") {
 
-    def error(est: Long, size: Long) = math.abs(est - size)/size.toDouble
+    def error(est: Long, size: Long) = math.abs(est - size) / size.toDouble
 
     val size = 100
     val uniformDistro = for (i <- 1 to 100000) yield i % size
     val simpleRdd = sc.makeRDD(uniformDistro)
-    assert( error(simpleRdd.countDistinct(0.2), size) < 0.2)
-    assert( error(simpleRdd.countDistinct(0.05), size) < 0.05)
-    assert( error(simpleRdd.countDistinct(0.01), size) < 0.01)
-    assert( error(simpleRdd.countDistinct(0.001), size) < 0.001)
+    assert(error(simpleRdd.countDistinct(0.2), size) < 0.2)
+    assert(error(simpleRdd.countDistinct(0.05), size) < 0.05)
+    assert(error(simpleRdd.countDistinct(0.01), size) < 0.01)
+    assert(error(simpleRdd.countDistinct(0.001), size) < 0.001)
   }
 
   test("SparkContext.union") {