[SPARK-6429] Implement hashCode and equals together

## What changes were proposed in this pull request?

Implement some `hashCode` and `equals` together in order to enable the scalastyle.
This is a first batch, I will continue to implement them but I wanted to know your thoughts.

Author: Joan <joan@goyeau.com>

Closes #12157 from joan38/SPARK-6429-HashCode-Equals.

1 files changed, 7 insertions, 3 deletions

diff --git a/streaming/src/main/scala/org/apache/spark/streaming/rdd/MapWithStateRDD.scala b/streaming/src/main/scala/org/apache/spark/streaming/rdd/MapWithStateRDD.scala
index 8119d808ff..58b7031d5e 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/rdd/MapWithStateRDD.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/rdd/MapWithStateRDD.scala
@@ -84,15 +84,19 @@ private[streaming] object MapWithStateRDDRecord {
  * RDD, and a partitioned keyed-data RDD
  */
 private[streaming] class MapWithStateRDDPartition(
-    idx: Int,
+    override val index: Int,
     @transient private var prevStateRDD: RDD[_],
     @transient private var partitionedDataRDD: RDD[_]) extends Partition {
 
   private[rdd] var previousSessionRDDPartition: Partition = null
   private[rdd] var partitionedDataRDDPartition: Partition = null
 
-  override def index: Int = idx
-  override def hashCode(): Int = idx
+  override def hashCode(): Int = index
+
+  override def equals(other: Any): Boolean = other match {
+    case that: MapWithStateRDDPartition => index == that.index
+    case _ => false
+  }
 
   @throws(classOf[IOException])
   private def writeObject(oos: ObjectOutputStream): Unit = Utils.tryOrIOException {