[SPARK-10865] [SPARK-10866] [SQL] Fix bug of ceil/floor, which should returns long instead of the Double type

Floor & Ceiling function should returns Long type, rather than Double.

Verified with MySQL & Hive.

Author: Cheng Hao <hao.cheng@intel.com>

Closes #8933 from chenghao-intel/ceiling.

Author: chenghao-intel

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/mathExpressions.scala

@@ -52,7 +52,7 @@ abstract class LeafMathExpression(c: Double, name: String)
  * @param f The math function.
  * @param name The short name of the function
  */
-abstract class UnaryMathExpression(f: Double => Double, name: String)
+abstract class UnaryMathExpression(val f: Double => Double, name: String)
   extends UnaryExpression with Serializable with ImplicitCastInputTypes {
 
   override def inputTypes: Seq[DataType] = Seq(DoubleType)
@@ -152,7 +152,16 @@ case class Atan(child: Expression) extends UnaryMathExpression(math.atan, "ATAN"
 
 case class Cbrt(child: Expression) extends UnaryMathExpression(math.cbrt, "CBRT")
 
-case class Ceil(child: Expression) extends UnaryMathExpression(math.ceil, "CEIL")
+case class Ceil(child: Expression) extends UnaryMathExpression(math.ceil, "CEIL") {
+  override def dataType: DataType = LongType
+  protected override def nullSafeEval(input: Any): Any = {
+    f(input.asInstanceOf[Double]).toLong
+  }
+
+  override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
+    defineCodeGen(ctx, ev, c => s"(long)(java.lang.Math.${funcName}($c))")
+  }
+}
 
 case class Cos(child: Expression) extends UnaryMathExpression(math.cos, "COS")
 
@@ -195,7 +204,16 @@ case class Exp(child: Expression) extends UnaryMathExpression(math.exp, "EXP")
 
 case class Expm1(child: Expression) extends UnaryMathExpression(math.expm1, "EXPM1")
 
-case class Floor(child: Expression) extends UnaryMathExpression(math.floor, "FLOOR")
+case class Floor(child: Expression) extends UnaryMathExpression(math.floor, "FLOOR") {
+  override def dataType: DataType = LongType
+  protected override def nullSafeEval(input: Any): Any = {
+    f(input.asInstanceOf[Double]).toLong
+  }
+
+  override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
+    defineCodeGen(ctx, ev, c => s"(long)(java.lang.Math.${funcName}($c))")
+  }
+}
 
 object Factorial {
 

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/MathFunctionsSuite.scala

@@ -244,12 +244,12 @@ class MathFunctionsSuite extends SparkFunSuite with ExpressionEvalHelper {
   }
 
   test("ceil") {
-    testUnary(Ceil, math.ceil)
+    testUnary(Ceil, (d: Double) => math.ceil(d).toLong)
     checkConsistencyBetweenInterpretedAndCodegen(Ceil, DoubleType)
   }
 
   test("floor") {
-    testUnary(Floor, math.floor)
+    testUnary(Floor, (d: Double) => math.floor(d).toLong)
     checkConsistencyBetweenInterpretedAndCodegen(Floor, DoubleType)
   }
 

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

@@ -37,9 +37,11 @@ class MathExpressionsSuite extends QueryTest with SharedSQLContext {
   private lazy val nullDoubles =
     Seq(NullDoubles(1.0), NullDoubles(2.0), NullDoubles(3.0), NullDoubles(null)).toDF()
 
-  private def testOneToOneMathFunction[@specialized(Int, Long, Float, Double) T](
+  private def testOneToOneMathFunction[
+  @specialized(Int, Long, Float, Double) T,
+  @specialized(Int, Long, Float, Double) U](
       c: Column => Column,
-      f: T => T): Unit = {
+      f: T => U): Unit = {
     checkAnswer(
       doubleData.select(c('a)),
       (1 to 10).map(n => Row(f((n * 0.2 - 1).asInstanceOf[T])))
@@ -165,10 +167,10 @@ class MathExpressionsSuite extends QueryTest with SharedSQLContext {
   }
 
   test("ceil and ceiling") {
-    testOneToOneMathFunction(ceil, math.ceil)
+    testOneToOneMathFunction(ceil, (d: Double) => math.ceil(d).toLong)
     checkAnswer(
       sql("SELECT ceiling(0), ceiling(1), ceiling(1.5)"),
-      Row(0.0, 1.0, 2.0))
+      Row(0L, 1L, 2L))
   }
 
   test("conv") {
@@ -184,7 +186,7 @@ class MathExpressionsSuite extends QueryTest with SharedSQLContext {
   }
 
   test("floor") {
-    testOneToOneMathFunction(floor, math.floor)
+    testOneToOneMathFunction(floor, (d: Double) => math.floor(d).toLong)
   }
 
   test("factorial") {
@@ -228,7 +230,7 @@ class MathExpressionsSuite extends QueryTest with SharedSQLContext {
   }
 
   test("signum / sign") {
-    testOneToOneMathFunction[Double](signum, math.signum)
+    testOneToOneMathFunction[Double, Double](signum, math.signum)
 
     checkAnswer(
       sql("SELECT sign(10), signum(-11)"),