Merge pull request alteryx#103 from JoshRosen/unpersist-fix

Add unpersist() to JavaDoubleRDD and JavaPairRDD.

This fixes a minor inconsistency where [unpersist() was only available on JavaRDD](https://mail-archives.apache.org/mod_mbox/incubator-spark-user/201310.mbox/%3CCE8D8748.68C0%25YannLuppo%40livenation.com%3E) and not JavaPairRDD / JavaDoubleRDD.   I also added support for the new optional `blocking` argument added in 0.8.

Please merge this into branch-0.8, too.

core/src/main/scala/org/apache/spark/api/java/JavaDoubleRDD.scala

@@ -48,6 +48,19 @@ class JavaDoubleRDD(val srdd: RDD[scala.Double]) extends JavaRDDLike[Double, Jav
    */
   def persist(newLevel: StorageLevel): JavaDoubleRDD = fromRDD(srdd.persist(newLevel))
 
+  /**
+   * Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
+   * This method blocks until all blocks are deleted.
+   */
+  def unpersist(): JavaDoubleRDD = fromRDD(srdd.unpersist())
+
+  /**
+   * Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
+   *
+   * @param blocking Whether to block until all blocks are deleted.
+   */
+  def unpersist(blocking: Boolean): JavaDoubleRDD = fromRDD(srdd.unpersist(blocking))
+
   // first() has to be overriden here in order for its return type to be Double instead of Object.
   override def first(): Double = srdd.first()
 

core/src/main/scala/org/apache/spark/api/java/JavaPairRDD.scala

@@ -65,6 +65,19 @@ class JavaPairRDD[K, V](val rdd: RDD[(K, V)])(implicit val kManifest: ClassManif
   def persist(newLevel: StorageLevel): JavaPairRDD[K, V] =
     new JavaPairRDD[K, V](rdd.persist(newLevel))
 
+  /**
+   * Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
+   * This method blocks until all blocks are deleted.
+   */
+  def unpersist(): JavaPairRDD[K, V] = wrapRDD(rdd.unpersist())
+
+  /**
+   * Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
+   *
+   * @param blocking Whether to block until all blocks are deleted.
+   */
+  def unpersist(blocking: Boolean): JavaPairRDD[K, V] = wrapRDD(rdd.unpersist(blocking))
+
   // Transformations (return a new RDD)
 
   /**

core/src/main/scala/org/apache/spark/api/java/JavaRDD.scala

@@ -41,9 +41,17 @@ JavaRDDLike[T, JavaRDD[T]] {
 
   /**
    * Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
+   * This method blocks until all blocks are deleted.
    */
   def unpersist(): JavaRDD[T] = wrapRDD(rdd.unpersist())
 
+  /**
+   * Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
+   *
+   * @param blocking Whether to block until all blocks are deleted.
+   */
+  def unpersist(blocking: Boolean): JavaRDD[T] = wrapRDD(rdd.unpersist(blocking))
+
   // Transformations (return a new RDD)
 
   /**