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[SPARK-8223][SPARK-8224][SQL] shift left and shift right #7178

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24 changes: 24 additions & 0 deletions python/pyspark/sql/functions.py
Original file line number Diff line number Diff line change
Expand Up @@ -412,6 +412,30 @@ def sha2(col, numBits):
return Column(jc)


@since(1.5)
def shiftLeft(col, numBits):
"""Shift the the given value numBits left.

>>> sqlContext.createDataFrame([(21,)], ['a']).select(shiftLeft('a', 1).alias('r')).collect()
[Row(r=42)]
"""
sc = SparkContext._active_spark_context
jc = sc._jvm.functions.shiftLeft(_to_java_column(col), numBits)
return Column(jc)


@since(1.5)
def shiftRight(col, numBits):
"""Shift the the given value numBits right.

>>> sqlContext.createDataFrame([(42,)], ['a']).select(shiftRight('a', 1).alias('r')).collect()
[Row(r=21)]
"""
sc = SparkContext._active_spark_context
jc = sc._jvm.functions.shiftRight(_to_java_column(col), numBits)
return Column(jc)


@since(1.4)
def sparkPartitionId():
"""A column for partition ID of the Spark task.
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -125,6 +125,8 @@ object FunctionRegistry {
expression[Pow]("power"),
expression[UnaryPositive]("positive"),
expression[Rint]("rint"),
expression[ShiftLeft]("shiftleft"),
expression[ShiftRight]("shiftright"),
expression[Signum]("sign"),
expression[Signum]("signum"),
expression[Sin]("sin"),
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -351,6 +351,104 @@ case class Pow(left: Expression, right: Expression)
}
}

case class ShiftLeft(left: Expression, right: Expression) extends BinaryExpression {

override def checkInputDataTypes(): TypeCheckResult = {
(left.dataType, right.dataType) match {
case (NullType, _) | (_, NullType) => return TypeCheckResult.TypeCheckSuccess
case (_, IntegerType) => left.dataType match {
case LongType | IntegerType | ShortType | ByteType =>
return TypeCheckResult.TypeCheckSuccess
case _ => // failed
}
case _ => // failed
}
TypeCheckResult.TypeCheckFailure(
s"ShiftLeft expects long, integer, short or byte value as first argument and an " +
s"integer value as second argument, not (${left.dataType}, ${right.dataType})")
}

override def eval(input: InternalRow): Any = {
val valueLeft = left.eval(input)
if (valueLeft != null) {
val valueRight = right.eval(input)
if (valueRight != null) {
valueLeft match {
case l: Long => l << valueRight.asInstanceOf[Integer]
case i: Integer => i << valueRight.asInstanceOf[Integer]
case s: Short => s << valueRight.asInstanceOf[Integer]
case b: Byte => b << valueRight.asInstanceOf[Integer]
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Should we handle overflow?

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What do you mean by overflow?
(1111 1111 << 1) = 1111 1110, is expected, isn't?

scala> Integer.toBinaryString(Integer.MAX_VALUE << 1)
res6: String = 11111111111111111111111111111110

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yes, thanks!

}
} else {
null
}
} else {
null
}
}

override def dataType: DataType = {
left.dataType match {
case LongType => LongType
case IntegerType | ShortType | ByteType => IntegerType
case _ => NullType
}
}

override protected def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
nullSafeCodeGen(ctx, ev, (result, left, right) => s"$result = $left << $right;")
}
}

case class ShiftRight(left: Expression, right: Expression) extends BinaryExpression {

override def checkInputDataTypes(): TypeCheckResult = {
(left.dataType, right.dataType) match {
case (NullType, _) | (_, NullType) => return TypeCheckResult.TypeCheckSuccess
case (_, IntegerType) => left.dataType match {
case LongType | IntegerType | ShortType | ByteType =>
return TypeCheckResult.TypeCheckSuccess
case _ => // failed
}
case _ => // failed
}
TypeCheckResult.TypeCheckFailure(
s"ShiftRight expects long, integer, short or byte value as first argument and an " +
s"integer value as second argument, not (${left.dataType}, ${right.dataType})")
}

override def eval(input: InternalRow): Any = {
val valueLeft = left.eval(input)
if (valueLeft != null) {
val valueRight = right.eval(input)
if (valueRight != null) {
valueLeft match {
case l: Long => l >> valueRight.asInstanceOf[Integer]
case i: Integer => i >> valueRight.asInstanceOf[Integer]
case s: Short => s >> valueRight.asInstanceOf[Integer]
case b: Byte => b >> valueRight.asInstanceOf[Integer]
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Should we use >>> (keeping the sign bit) or >> ?

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There is a special Jira ticket for that: https://issues.apache.org/jira/browse/SPARK-8226. Someone created already a PR.

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I see.

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Why not pattern matching the data type? instead of the value? Will that cause extra box/unbox for primtives?

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That might be a good hint. I am going to take a look on the generated code and will come back to this and create maybe a follow-up.

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@chenghao-intel I investigated it a little bit, see the gist: https://gist.github.com/tarekauel/6994983b83a51668c5dc . The interesting part is that the match on the value is even faster, did I something wrong?

}
} else {
null
}
} else {
null
}
}

override def dataType: DataType = {
left.dataType match {
case LongType => LongType
case IntegerType | ShortType | ByteType => IntegerType
case _ => NullType
}
}

override protected def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = {
nullSafeCodeGen(ctx, ev, (result, left, right) => s"$result = $left >> $right;")
}
}

/**
* Performs the inverse operation of HEX.
* Resulting characters are returned as a byte array.
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ package org.apache.spark.sql.catalyst.expressions

import org.apache.spark.SparkFunSuite
import org.apache.spark.sql.catalyst.dsl.expressions._
import org.apache.spark.sql.types.{DataType, DoubleType, LongType}
import org.apache.spark.sql.types.{IntegerType, DataType, DoubleType, LongType}

class MathFunctionsSuite extends SparkFunSuite with ExpressionEvalHelper {

Expand Down Expand Up @@ -225,6 +225,32 @@ class MathFunctionsSuite extends SparkFunSuite with ExpressionEvalHelper {
testBinary(Pow, math.pow, Seq((-1.0, 0.9), (-2.2, 1.7), (-2.2, -1.7)), expectNull = true)
}

test("shift left") {
checkEvaluation(ShiftLeft(Literal.create(null, IntegerType), Literal(1)), null)
checkEvaluation(ShiftLeft(Literal(21), Literal.create(null, IntegerType)), null)
checkEvaluation(
ShiftLeft(Literal.create(null, IntegerType), Literal.create(null, IntegerType)), null)
checkEvaluation(ShiftLeft(Literal(21), Literal(1)), 42)
checkEvaluation(ShiftLeft(Literal(21.toByte), Literal(1)), 42)
checkEvaluation(ShiftLeft(Literal(21.toShort), Literal(1)), 42)
checkEvaluation(ShiftLeft(Literal(21.toLong), Literal(1)), 42.toLong)

checkEvaluation(ShiftLeft(Literal(-21.toLong), Literal(1)), -42.toLong)
}

test("shift right") {
checkEvaluation(ShiftRight(Literal.create(null, IntegerType), Literal(1)), null)
checkEvaluation(ShiftRight(Literal(42), Literal.create(null, IntegerType)), null)
checkEvaluation(
ShiftRight(Literal.create(null, IntegerType), Literal.create(null, IntegerType)), null)
checkEvaluation(ShiftRight(Literal(42), Literal(1)), 21)
checkEvaluation(ShiftRight(Literal(42.toByte), Literal(1)), 21)
checkEvaluation(ShiftRight(Literal(42.toShort), Literal(1)), 21)
checkEvaluation(ShiftRight(Literal(42.toLong), Literal(1)), 21.toLong)

checkEvaluation(ShiftRight(Literal(-42.toLong), Literal(1)), -21.toLong)
}

test("hex") {
checkEvaluation(Hex(Literal(28)), "1C")
checkEvaluation(Hex(Literal(-28)), "FFFFFFFFFFFFFFE4")
Expand Down
38 changes: 38 additions & 0 deletions sql/core/src/main/scala/org/apache/spark/sql/functions.scala
Original file line number Diff line number Diff line change
Expand Up @@ -1298,6 +1298,44 @@ object functions {
*/
def rint(columnName: String): Column = rint(Column(columnName))

/**
* Shift the the given value numBits left. If the given value is a long value, this function
* will return a long value else it will return an integer value.
*
* @group math_funcs
* @since 1.5.0
*/
def shiftLeft(e: Column, numBits: Int): Column = ShiftLeft(e.expr, lit(numBits).expr)

/**
* Shift the the given value numBits left. If the given value is a long value, this function
* will return a long value else it will return an integer value.
*
* @group math_funcs
* @since 1.5.0
*/
def shiftLeft(columnName: String, numBits: Int): Column =
shiftLeft(Column(columnName), numBits)

/**
* Shift the the given value numBits right. If the given value is a long value, it will return
* a long value else it will return an integer value.
*
* @group math_funcs
* @since 1.5.0
*/
def shiftRight(e: Column, numBits: Int): Column = ShiftRight(e.expr, lit(numBits).expr)

/**
* Shift the the given value numBits right. If the given value is a long value, it will return
* a long value else it will return an integer value.
*
* @group math_funcs
* @since 1.5.0
*/
def shiftRight(columnName: String, numBits: Int): Column =
shiftRight(Column(columnName), numBits)

/**
* Computes the signum of the given value.
*
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -259,6 +259,40 @@ class MathExpressionsSuite extends QueryTest {
testOneToOneNonNegativeMathFunction(log1p, math.log1p)
}

test("shift left") {
val df = Seq[(Long, Integer, Short, Byte, Integer, Integer)]((21, 21, 21, 21, 21, null))
.toDF("a", "b", "c", "d", "e", "f")

checkAnswer(
df.select(
shiftLeft('a, 1), shiftLeft('b, 1), shiftLeft('c, 1), shiftLeft('d, 1),
shiftLeft('f, 1)),
Row(42.toLong, 42, 42.toShort, 42.toByte, null))

checkAnswer(
df.selectExpr(
"shiftLeft(a, 1)", "shiftLeft(b, 1)", "shiftLeft(b, 1)", "shiftLeft(d, 1)",
"shiftLeft(f, 1)"),
Row(42.toLong, 42, 42.toShort, 42.toByte, null))
}

test("shift right") {
val df = Seq[(Long, Integer, Short, Byte, Integer, Integer)]((42, 42, 42, 42, 42, null))
.toDF("a", "b", "c", "d", "e", "f")

checkAnswer(
df.select(
shiftRight('a, 1), shiftRight('b, 1), shiftRight('c, 1), shiftRight('d, 1),
shiftRight('f, 1)),
Row(21.toLong, 21, 21.toShort, 21.toByte, null))

checkAnswer(
df.selectExpr(
"shiftRight(a, 1)", "shiftRight(b, 1)", "shiftRight(c, 1)", "shiftRight(d, 1)",
"shiftRight(f, 1)"),
Row(21.toLong, 21, 21.toShort, 21.toByte, null))
}

test("binary log") {
val df = Seq[(Integer, Integer)]((123, null)).toDF("a", "b")
checkAnswer(
Expand Down