Merge commit 'refs/pull/6081/head' of github.com:apache/spark into range

core/src/main/scala/org/apache/spark/SparkContext.scala

@@ -697,6 +697,78 @@ class SparkContext(config: SparkConf) extends Logging with ExecutorAllocationCli
     new ParallelCollectionRDD[T](this, seq, numSlices, Map[Int, Seq[String]]())
   }
 
+  /**
+   * Creates a new RDD[Long] containing elements from `start` to `end`(exclusive), increased by
+   * `step` every element.
+   *
+   * @note if we need to cache this RDD, we should make sure each partition does not exceed limit.
+   *
+   * @param start the start value.
+   * @param end the end value.
+   * @param step the incremental step
+   * @param numSlices the partition number of the new RDD.
+   * @return
+   */
+  def range(
+      start: Long,
+      end: Long,
+      step: Long = 1,
+      numSlices: Int = defaultParallelism): RDD[Long] = withScope {
+    assertNotStopped()
+    // when step is 0, range will run infinitely
+    require(step != 0, "step cannot be 0")
+    val numElements: BigInt = {
+      val safeStart = BigInt(start)
+      val safeEnd = BigInt(end)
+      if ((safeEnd - safeStart) % step == 0 || safeEnd > safeStart ^ step > 0) {
+        (safeEnd - safeStart) / step
+      } else {
+        // the remainder has the same sign with range, could add 1 more
+        (safeEnd - safeStart) / step + 1
+      }
+    }
+    parallelize(0 until numSlices, numSlices).mapPartitionsWithIndex((i, _) => {
+      val partitionStart = (i * numElements) / numSlices * step + start
+      val partitionEnd = (((i + 1) * numElements) / numSlices) * step + start
+      def getSafeMargin(bi: BigInt): Long =
+        if (bi.isValidLong) {
+          bi.toLong
+        } else if (bi > 0) {
+          Long.MaxValue
+        } else {
+          Long.MinValue
+        }
+      val safePartitionStart = getSafeMargin(partitionStart)
+      val safePartitionEnd = getSafeMargin(partitionEnd)
+
+      new Iterator[Long] {
+        private[this] var number: Long = safePartitionStart
+        private[this] var overflow: Boolean = false
+
+        override def hasNext =
+          if (!overflow) {
+            if (step > 0) {
+              number < safePartitionEnd
+            } else {
+              number > safePartitionEnd
+            }
+          } else false
+
+        override def next() = {
+          val ret = number
+          number += step
+          if (number < ret ^ step < 0) {
+            // we have Long.MaxValue + Long.MaxValue < Long.MaxValue
+            // and Long.MinValue + Long.MinValue > Long.MinValue, so iff the step causes a step
+            // back, we are pretty sure that we have an overflow.
+            overflow = true
+          }
+          ret
+        }
+      }
+    })
+  }
+
   /** Distribute a local Scala collection to form an RDD.
    *
    * This method is identical to `parallelize`.

sql/core/src/main/scala/org/apache/spark/sql/SQLContext.scala

@@ -684,6 +684,37 @@ class SQLContext(@transient val sparkContext: SparkContext)
     catalog.unregisterTable(Seq(tableName))
   }
 
+  /**
+   * :: Experimental ::
+   * Creates a [[DataFrame]] with a single [[LongType]] column named `id`, containing elements
+   * in an range from `start` to `end`(exclusive) with step value 1.
+   *
+   * @since 1.4.0
+   * @group dataframe
+   */
+  @Experimental
+  def range(start: Long, end: Long): DataFrame = {
+    createDataFrame(
+      sparkContext.range(start, end).map(Row(_)),
+      StructType(StructField("id", LongType, nullable = false) :: Nil))
+  }
+
+  /**
+   * :: Experimental ::
+   * Creates a [[DataFrame]] with a single [[LongType]] column named `id`, containing elements
+   * in an range from `start` to `end`(exclusive) with an step value, with partition number
+   * specified.
+   *
+   * @since 1.4.0
+   * @group dataframe
+   */
+  @Experimental
+  def range(start: Long, end: Long, step: Long, numPartitions: Int): DataFrame = {
+    createDataFrame(
+      sparkContext.range(start, end, step, numPartitions).map(Row(_)),
+      StructType(StructField("id", LongType, nullable = false) :: Nil))
+  }
+
   /**
    * Executes a SQL query using Spark, returning the result as a [[DataFrame]]. The dialect that is
    * used for SQL parsing can be configured with 'spark.sql.dialect'.

sql/core/src/test/scala/org/apache/spark/sql/DataFrameSuite.scala

@@ -532,4 +532,44 @@ class DataFrameSuite extends QueryTest {
     val p = df.logicalPlan.asInstanceOf[Project].child.asInstanceOf[Project]
     assert(!p.child.isInstanceOf[Project])
   }
+
+  test("SPARK-7150 range api") {
+    // numSlice is greater than length
+    val res1 = TestSQLContext.range(0, 10, 1, 15).select("id")
+    assert(res1.count == 10)
+    assert(res1.agg(sum("id")).as("sumid").collect() === Seq(Row(45)))
+
+    val res2 = TestSQLContext.range(3, 15, 3, 2).select("id")
+    assert(res2.count == 4)
+    assert(res2.agg(sum("id")).as("sumid").collect() === Seq(Row(30)))
+
+    val res3 = TestSQLContext.range(1, -2).select("id")
+    assert(res3.count == 0)
+
+    // start is positive, end is negative, step is negative
+    val res4 = TestSQLContext.range(1, -2, -2, 6).select("id")
+    assert(res4.count == 2)
+    assert(res4.agg(sum("id")).as("sumid").collect() === Seq(Row(0)))
+
+    // start, end, step are negative
+    val res5 = TestSQLContext.range(-3, -8, -2, 1).select("id")
+    assert(res5.count == 3)
+    assert(res5.agg(sum("id")).as("sumid").collect() === Seq(Row(-15)))
+
+    // start, end are negative, step is positive
+    val res6 = TestSQLContext.range(-8, -4, 2, 1).select("id")
+    assert(res6.count == 2)
+    assert(res6.agg(sum("id")).as("sumid").collect() === Seq(Row(-14)))
+
+    val res7 = TestSQLContext.range(-10, -9, -20, 1).select("id")
+    assert(res7.count == 0)
+
+    val res8 = TestSQLContext.range(Long.MinValue, Long.MaxValue, Long.MaxValue, 100).select("id")
+    assert(res8.count == 3)
+    assert(res8.agg(sum("id")).as("sumid").collect() === Seq(Row(-3)))
+
+    val res9 = TestSQLContext.range(Long.MaxValue, Long.MinValue, Long.MinValue, 100).select("id")
+    assert(res9.count == 2)
+    assert(res9.agg(sum("id")).as("sumid").collect() === Seq(Row(Long.MaxValue - 1)))
+  }
 }