Github user davies commented on a diff in the pull request:
https://github.com/apache/spark/pull/7365#discussion_r35127256
--- Diff:
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Cast.scala
---
@@ -418,51 +418,518 @@ case class Cast(child: Expression, dataType:
DataType)
protected override def nullSafeEval(input: Any): Any = cast(input)
override def genCode(ctx: CodeGenContext, ev: GeneratedExpressionCode):
String = {
- // TODO: Add support for more data types.
- (child.dataType, dataType) match {
+ val nullSafeCast = nullSafeCastFunction(child.dataType, dataType, ctx)
+ if (nullSafeCast != null) {
+ val eval = child.gen(ctx)
+ eval.code +
+ castCode(ctx, eval.primitive, eval.isNull, ev.primitive,
ev.isNull, dataType, nullSafeCast)
+ } else {
+ super.genCode(ctx, ev)
+ }
+ }
+
+ // three function arguments are: child.primitive, result.primitive and
result.isNull
+ // it returns the code snippets to be put in null safe evaluation region
+ private[this] type CastFunction = (String, String, String) => String
+
+ private[this] def nullSafeCastFunction(
+ from: DataType,
+ to: DataType,
+ ctx: CodeGenContext): CastFunction = to match {
+
+ case _ if from == NullType => (c, evPrim, evNull) => s"$evNull = true;"
+ case _ if to == from => (c, evPrim, evNull) => s"$evPrim = $c;"
+ case StringType => castToStringCode(from, ctx)
+ case BinaryType => castToBinaryCode(from)
+ case DateType => castToDateCode(from, ctx)
+ case decimal: DecimalType => castToDecimalCode(from, decimal)
+ case TimestampType => castToTimestampCode(from, ctx)
+ case IntervalType => castToIntervalCode(from)
+ case BooleanType => castToBooleanCode(from)
+ case ByteType => castToByteCode(from)
+ case ShortType => castToShortCode(from)
+ case IntegerType => castToIntCode(from)
+ case FloatType => castToFloatCode(from)
+ case LongType => castToLongCode(from)
+ case DoubleType => castToDoubleCode(from)
+
+ case array: ArrayType => castArrayCode(from.asInstanceOf[ArrayType],
array, ctx)
+ case map: MapType => castMapCode(from.asInstanceOf[MapType], map, ctx)
+ case struct: StructType =>
castStructCode(from.asInstanceOf[StructType], struct, ctx)
+ case other => null
+ }
+
+ private[this] def castCode(ctx: CodeGenContext, childPrim: String,
childNull: String,
+ resultPrim: String, resultNull: String, resultType: DataType, cast:
CastFunction): String = {
--- End diff --
This function is short, I'd like to inline it into `genCode()`, it will be
easier to understand.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
