diff --git a/core/src/main/scala/org/apache/spark/api/java/JavaRDDLike.scala b/core/src/main/scala/org/apache/spark/api/java/JavaRDDLike.scala index 574a98636a619..af06d1dca94f4 100644 --- a/core/src/main/scala/org/apache/spark/api/java/JavaRDDLike.scala +++ b/core/src/main/scala/org/apache/spark/api/java/JavaRDDLike.scala @@ -18,7 +18,7 @@ package org.apache.spark.api.java import java.util.{Comparator, List => JList, Iterator => JIterator} -import java.lang.{Iterable => JIterable} +import java.lang.{Iterable => JIterable, Long => JLong} import scala.collection.JavaConversions._ import scala.reflect.ClassTag @@ -264,6 +264,26 @@ trait JavaRDDLike[T, This <: JavaRDDLike[T, This]] extends Serializable { rdd.zipPartitions(other.rdd)(fn)(other.classTag, fakeClassTag[V]))(fakeClassTag[V]) } + /** + * Zips this RDD with generated unique Long ids. Items in the kth partition will get ids k, n+k, + * 2*n+k, ..., where n is the number of partitions. So there may exist gaps, but this method + * won't trigger a spark job, which is different from [[org.apache.spark.rdd.RDD#zipWithIndex]]. + */ + def zipWithUniqueId(): JavaPairRDD[T, JLong] = { + JavaPairRDD.fromRDD(rdd.zipWithUniqueId()).asInstanceOf[JavaPairRDD[T, JLong]] + } + + /** + * Zips this RDD with its element indices. The ordering is first based on the partition index + * and then the ordering of items within each partition. So the first item in the first + * partition gets index 0, and the last item in the last partition receives the largest index. + * This is similar to Scala's zipWithIndex but it uses Long instead of Int as the index type. + * This method needs to trigger a spark job when this RDD contains more than one partitions. + */ + def zipWithIndex(): JavaPairRDD[T, JLong] = { + JavaPairRDD.fromRDD(rdd.zipWithIndex()).asInstanceOf[JavaPairRDD[T, JLong]] + } + // Actions (launch a job to return a value to the user program) /** diff --git a/core/src/test/java/org/apache/spark/JavaAPISuite.java b/core/src/test/java/org/apache/spark/JavaAPISuite.java index 76c6f5af82a5e..c3e03cea917b3 100644 --- a/core/src/test/java/org/apache/spark/JavaAPISuite.java +++ b/core/src/test/java/org/apache/spark/JavaAPISuite.java @@ -182,13 +182,30 @@ public void call(String s) { Assert.assertEquals(2, foreachCalls); } - @Test - public void toLocalIterator() { - List correct = Arrays.asList(1, 2, 3, 4); - JavaRDD rdd = sc.parallelize(correct); - List result = Lists.newArrayList(rdd.toLocalIterator()); - Assert.assertTrue(correct.equals(result)); - } + @Test + public void toLocalIterator() { + List correct = Arrays.asList(1, 2, 3, 4); + JavaRDD rdd = sc.parallelize(correct); + List result = Lists.newArrayList(rdd.toLocalIterator()); + Assert.assertTrue(correct.equals(result)); + } + + @Test + public void zipWithUniqueId() { + List dataArray = Arrays.asList(1, 2, 3, 4); + JavaPairRDD zip = sc.parallelize(dataArray).zipWithUniqueId(); + JavaRDD indexes = zip.values(); + Assert.assertTrue(new HashSet(indexes.collect()).size() == 4); + } + + @Test + public void zipWithIndex() { + List dataArray = Arrays.asList(1, 2, 3, 4); + JavaPairRDD zip = sc.parallelize(dataArray).zipWithIndex(); + JavaRDD indexes = zip.values(); + List correctIndexes = Arrays.asList(0L, 1L, 2L, 3L); + Assert.assertTrue(indexes.collect().equals(correctIndexes)); + } @SuppressWarnings("unchecked") @Test