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SPARK-1165 RDD.intersection in java

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1 parent d6effee commit d0c71f3a24ea1cec336c9bb4820a6f3fb317953a @ScrapCodes ScrapCodes committed Mar 5, 2014
@@ -140,6 +140,12 @@ class JavaDoubleRDD(val srdd: RDD[scala.Double]) extends JavaRDDLike[JDouble, Ja
*/
def union(other: JavaDoubleRDD): JavaDoubleRDD = fromRDD(srdd.union(other.srdd))
+ /**
+ * Return the intersection of this RDD and another one. The output will not contain any duplicate
+ * elements, even if the input RDDs did.
+ */
+ def intersection(other: JavaDoubleRDD): JavaDoubleRDD = fromRDD(srdd.intersection(other.srdd))
+
// Double RDD functions
/** Add up the elements in this RDD. */
@@ -126,6 +126,14 @@ class JavaPairRDD[K, V](val rdd: RDD[(K, V)])
def union(other: JavaPairRDD[K, V]): JavaPairRDD[K, V] =
new JavaPairRDD[K, V](rdd.union(other.rdd))
+ /**
+ * Return the intersection of this RDD and another one. The output will not contain any duplicate
+ * elements, even if the input RDDs did.
+ */
+ def intersection(other: JavaPairRDD[K, V]): JavaPairRDD[K, V] =
+ new JavaPairRDD[K, V](rdd.intersection(other.rdd))
+
+
// first() has to be overridden here so that the generated method has the signature
// 'public scala.Tuple2 first()'; if the trait's definition is used,
// then the method has the signature 'public java.lang.Object first()',
@@ -106,6 +106,13 @@ class JavaRDD[T](val rdd: RDD[T])(implicit val classTag: ClassTag[T])
*/
def union(other: JavaRDD[T]): JavaRDD[T] = wrapRDD(rdd.union(other.rdd))
+
+ /**
+ * Return the intersection of this RDD and another one. The output will not contain any duplicate
+ * elements, even if the input RDDs did.
+ */
+ def intersection(other: JavaRDD[T]): JavaRDD[T] = wrapRDD(rdd.intersection(other.rdd))
+
/**
* Return an RDD with the elements from `this` that are not in `other`.
*
@@ -110,6 +110,37 @@ public void sparkContextUnion() {
Assert.assertEquals(4, pUnion.count());
}
+ @SuppressWarnings("unchecked")
+ @Test
+ public void intersection() {
+ List<Integer> ints1 = Arrays.asList(1, 10, 2, 3, 4, 5);
+ List<Integer> ints2 = Arrays.asList(1, 6, 2, 3, 7, 8);
+ JavaRDD<Integer> s1 = sc.parallelize(ints1);
+ JavaRDD<Integer> s2 = sc.parallelize(ints2);
+
+ JavaRDD<Integer> intersections = s1.intersection(s2);
+ Assert.assertEquals(3, intersections.count());
+
+ ArrayList<Integer> list = new ArrayList<Integer>();
+ JavaRDD<Integer> empty = sc.parallelize(list);
+ JavaRDD<Integer> emptyIntersection = empty.intersection(s2);
+ Assert.assertEquals(0, emptyIntersection.count());
+
+ List<Double> doubles = Arrays.asList(1.0, 2.0);
+ JavaDoubleRDD d1 = sc.parallelizeDoubles(doubles);
+ JavaDoubleRDD d2 = sc.parallelizeDoubles(doubles);
+ JavaDoubleRDD dIntersection = d1.intersection(d2);
+ Assert.assertEquals(2, dIntersection.count());
+
+ List<Tuple2<Integer, Integer>> pairs = new ArrayList<Tuple2<Integer, Integer>>();
+ pairs.add(new Tuple2<Integer, Integer>(1, 2));
+ pairs.add(new Tuple2<Integer, Integer>(3, 4));
+ JavaPairRDD<Integer, Integer> p1 = sc.parallelizePairs(pairs);
+ JavaPairRDD<Integer, Integer> p2 = sc.parallelizePairs(pairs);
+ JavaPairRDD<Integer, Integer> pIntersection = p1.intersection(p2);
+ Assert.assertEquals(2, pIntersection.count());
+ }
+
@Test
public void sortByKey() {
List<Tuple2<Integer, Integer>> pairs = new ArrayList<Tuple2<Integer, Integer>>();
View
@@ -323,6 +323,9 @@ def intersection(self, other):
"""
Return the intersection of this RDD and another one.
+ Note: The output will not contain any duplicate elements, even if the
+ input RDDs did.
+
>>> rdd1 = sc.parallelize([1, 10, 2, 3, 4, 5])
>>> rdd2 = sc.parallelize([1, 6, 2, 3, 7, 8])
>>> rdd1.intersection(rdd2).collect()

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