diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/conditionalExpressions.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/conditionalExpressions.scala index 8cc7bc1da2fc3735cd7b11f3279a72deda5876f7..83abbcdc61175eb11c3685fd60d3b462a3e24ed4 100644 --- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/conditionalExpressions.scala +++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/conditionalExpressions.scala @@ -137,45 +137,55 @@ case class CaseWhen(branches: Seq[(Expression, Expression)], elseValue: Option[E } override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode): String = { - val got = ctx.freshName("got") - - val cases = branches.map { case (condition, value) => - val cond = condition.gen(ctx) - val res = value.gen(ctx) + // Generate code that looks like: + // + // condA = ... + // if (condA) { + // valueA + // } else { + // condB = ... + // if (condB) { + // valueB + // } else { + // condC = ... + // if (condC) { + // valueC + // } else { + // elseValue + // } + // } + // } + val cases = branches.map { case (condExpr, valueExpr) => + val cond = condExpr.gen(ctx) + val res = valueExpr.gen(ctx) s""" - if (!$got) { - ${cond.code} - if (!${cond.isNull} && ${cond.value}) { - $got = true; - ${res.code} - ${ev.isNull} = ${res.isNull}; - ${ev.value} = ${res.value}; - } + ${cond.code} + if (!${cond.isNull} && ${cond.value}) { + ${res.code} + ${ev.isNull} = ${res.isNull}; + ${ev.value} = ${res.value}; } """ - }.mkString("\n") + } - val elseCase = { - if (elseValue.isDefined) { - val res = elseValue.get.gen(ctx) + var generatedCode = cases.mkString("", "\nelse {\n", "\nelse {\n") + + elseValue.foreach { elseExpr => + val res = elseExpr.gen(ctx) + generatedCode += s""" - if (!$got) { ${res.code} ${ev.isNull} = ${res.isNull}; ${ev.value} = ${res.value}; - } """ - } else { - "" - } } + generatedCode += "}\n" * cases.size + s""" - boolean $got = false; boolean ${ev.isNull} = true; ${ctx.javaType(dataType)} ${ev.value} = ${ctx.defaultValue(dataType)}; - $cases - $elseCase + $generatedCode """ }