Skip to content

[SPARK-4459] Change groupBy type parameter from K to U #3327

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 4 commits into from
Closed

[SPARK-4459] Change groupBy type parameter from K to U #3327

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
62ddd4b
SPARK-4459 added failing unit test
Nov 17, 2014
316ad77
SPARK-4459 changed type parameter for groupBy from K to U.
Nov 17, 2014
d5f73c3
[SPARK-4459] added keyBy test
Nov 18, 2014
54b1095
[SPARK-4459] changed type parameter for keyBy from K to U
Nov 18, 2014
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 7 additions & 7 deletions core/src/main/scala/org/apache/spark/api/java/JavaRDDLike.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -212,8 +212,8 @@ trait JavaRDDLike[T, This <: JavaRDDLike[T, This]] extends Serializable {
* Return an RDD of grouped elements. Each group consists of a key and a sequence of elements
* mapping to that key.
*/
def groupBy[K](f: JFunction[T, K]): JavaPairRDD[K, JIterable[T]] = {
implicit val ctagK: ClassTag[K] = fakeClassTag
def groupBy[U](f: JFunction[T, U]): JavaPairRDD[U, JIterable[T]] = {
implicit val ctagK: ClassTag[U] = fakeClassTag
implicit val ctagV: ClassTag[JList[T]] = fakeClassTag
JavaPairRDD.fromRDD(groupByResultToJava(rdd.groupBy(f)(fakeClassTag)))
}
Expand All @@ -222,10 +222,10 @@ trait JavaRDDLike[T, This <: JavaRDDLike[T, This]] extends Serializable {
* Return an RDD of grouped elements. Each group consists of a key and a sequence of elements
* mapping to that key.
*/
def groupBy[K](f: JFunction[T, K], numPartitions: Int): JavaPairRDD[K, JIterable[T]] = {
implicit val ctagK: ClassTag[K] = fakeClassTag
def groupBy[U](f: JFunction[T, U], numPartitions: Int): JavaPairRDD[U, JIterable[T]] = {
implicit val ctagK: ClassTag[U] = fakeClassTag
implicit val ctagV: ClassTag[JList[T]] = fakeClassTag
JavaPairRDD.fromRDD(groupByResultToJava(rdd.groupBy(f, numPartitions)(fakeClassTag[K])))
JavaPairRDD.fromRDD(groupByResultToJava(rdd.groupBy(f, numPartitions)(fakeClassTag[U])))
}

/**
Expand Down Expand Up @@ -459,8 +459,8 @@ trait JavaRDDLike[T, This <: JavaRDDLike[T, This]] extends Serializable {
/**
* Creates tuples of the elements in this RDD by applying `f`.
*/
def keyBy[K](f: JFunction[T, K]): JavaPairRDD[K, T] = {
implicit val ctag: ClassTag[K] = fakeClassTag
def keyBy[U](f: JFunction[T, U]): JavaPairRDD[U, T] = {
implicit val ctag: ClassTag[U] = fakeClassTag
JavaPairRDD.fromRDD(rdd.keyBy(f))
}

Expand Down
36 changes: 36 additions & 0 deletions core/src/test/java/org/apache/spark/JavaAPISuite.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -322,6 +322,42 @@ public Boolean call(Integer x) {
Assert.assertEquals(2, Iterables.size(oddsAndEvens.lookup(true).get(0))); // Evens
Assert.assertEquals(5, Iterables.size(oddsAndEvens.lookup(false).get(0))); // Odds
}

@Test
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

(Minor: indentation)

public void groupByOnPairRDD() {
JavaRDD<Integer> rdd = sc.parallelize(Arrays.asList(1, 1, 2, 3, 5, 8, 13));
Function<scala.Tuple2<Integer, Integer>, Boolean> areOdd = new Function<scala.Tuple2<Integer, Integer>, Boolean>() {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Also, you could just write Tuple2 instead of scala.Tuple2.

@Override
public Boolean call(scala.Tuple2<Integer, Integer> x) {
return x._1 % 2 == 0 && x._2 % 2 == 0;
}
};
JavaPairRDD<Integer, Integer> pairrdd = rdd.zip(rdd);
JavaPairRDD<Boolean, Iterable<scala.Tuple2<Integer, Integer>>> oddsAndEvens = pairrdd.groupBy(areOdd);
Assert.assertEquals(2, oddsAndEvens.count());
Assert.assertEquals(2, Iterables.size(oddsAndEvens.lookup(true).get(0))); // Evens
Assert.assertEquals(5, Iterables.size(oddsAndEvens.lookup(false).get(0))); // Odds

oddsAndEvens = pairrdd.groupBy(areOdd, 1);
Assert.assertEquals(2, oddsAndEvens.count());
Assert.assertEquals(2, Iterables.size(oddsAndEvens.lookup(true).get(0))); // Evens
Assert.assertEquals(5, Iterables.size(oddsAndEvens.lookup(false).get(0))); // Odds
}

@Test
public void keyByOnPairRDD() {
JavaRDD<Integer> rdd = sc.parallelize(Arrays.asList(1, 1, 2, 3, 5, 8, 13));
Function<scala.Tuple2<Integer, Integer>, String> areOdd = new Function<scala.Tuple2<Integer, Integer>, String>() {
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Also, why is this named areOdd?

@Override
public String call(scala.Tuple2<Integer, Integer> x) {
return ""+(x._1 +x._2);
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The spacing here is messy. Also, "" + x is messy; just do x.toString() instead if you want to convert an object in a string.

}
};
JavaPairRDD<Integer, Integer> pairrdd = rdd.zip(rdd);
JavaPairRDD<String, scala.Tuple2<Integer, Integer>> keyed = pairrdd.keyBy(areOdd);
Assert.assertEquals(7, keyed.count());
Assert.assertEquals(1, (long)keyed.lookup("2").get(0)._1);
}

@SuppressWarnings("unchecked")
@Test
Expand Down