Github user davies commented on a diff in the pull request:
https://github.com/apache/spark/pull/12067#discussion_r59662054
--- Diff:
sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/TypedAggregateExpression.scala
---
@@ -19,133 +19,153 @@ package org.apache.spark.sql.execution.aggregate
import scala.language.existentials
-import org.apache.spark.internal.Logging
import org.apache.spark.sql.Encoder
-import org.apache.spark.sql.catalyst.InternalRow
-import org.apache.spark.sql.catalyst.encoders.{encoderFor,
ExpressionEncoder, OuterScopes}
+import org.apache.spark.sql.catalyst.analysis.{UnresolvedAttribute,
UnresolvedDeserializer, UnresolvedExtractValue}
+import org.apache.spark.sql.catalyst.encoders.encoderFor
import org.apache.spark.sql.catalyst.expressions._
-import
org.apache.spark.sql.catalyst.expressions.aggregate.ImperativeAggregate
+import
org.apache.spark.sql.catalyst.expressions.aggregate.DeclarativeAggregate
import org.apache.spark.sql.expressions.Aggregator
import org.apache.spark.sql.types._
object TypedAggregateExpression {
- def apply[A, B : Encoder, C : Encoder](
- aggregator: Aggregator[A, B, C]): TypedAggregateExpression = {
+ def apply[BUF : Encoder, OUT : Encoder](
+ aggregator: Aggregator[_, BUF, OUT]): TypedAggregateExpression = {
+ val bufferEncoder = encoderFor[BUF]
+ // We will insert the deserializer and function call expression at the
bottom of each serializer
+ // expression while executing `TypedAggregateExpression`, which means
multiply serializer
+ // expressions will all evaluate the same sub-expression at bottom.
To avoid the re-evaluating,
+ // here we always use one single serializer expression to serialize
the buffer object into a
+ // single-field row, no matter whether the encoder is flat or not. We
also need to update the
+ // deserializer to read in all fields from that single-field row.
+ // TODO: remove this trick after we have better integration of
subexpression elimination and
+ // whole stage codegen.
+ val bufferSerializer = if (bufferEncoder.flat) {
+ bufferEncoder.namedExpressions.head
+ } else {
+ Alias(CreateStruct(bufferEncoder.serializer), "buffer")()
+ }
+
+ val bufferDeserializer = if (bufferEncoder.flat) {
+ bufferEncoder.deserializer transformUp {
+ case b: BoundReference => bufferSerializer.toAttribute
+ }
+ } else {
+ bufferEncoder.deserializer transformUp {
+ case UnresolvedAttribute(nameParts) =>
+ assert(nameParts.length == 1)
+ UnresolvedExtractValue(bufferSerializer.toAttribute,
Literal(nameParts.head))
+ case BoundReference(ordinal, dt, _) =>
GetStructField(bufferSerializer.toAttribute, ordinal)
+ }
+ }
+
+ val outputEncoder = encoderFor[OUT]
+ val outputType = if (outputEncoder.flat) {
+ outputEncoder.schema.head.dataType
+ } else {
+ outputEncoder.schema
+ }
+
new TypedAggregateExpression(
aggregator.asInstanceOf[Aggregator[Any, Any, Any]],
None,
- encoderFor[B].asInstanceOf[ExpressionEncoder[Any]],
- encoderFor[C].asInstanceOf[ExpressionEncoder[Any]],
- Nil,
- 0,
- 0)
+ bufferSerializer,
+ bufferDeserializer,
+ outputEncoder.serializer,
+ outputEncoder.deserializer.dataType,
+ outputType)
}
}
/**
- * This class is a rough sketch of how to hook `Aggregator` into the
Aggregation system. It has
- * the following limitations:
- * - It assumes the aggregator has a zero, `0`.
+ * A helper class to hook [[Aggregator]] into the aggregation system.
*/
case class TypedAggregateExpression(
aggregator: Aggregator[Any, Any, Any],
- aEncoder: Option[ExpressionEncoder[Any]], // Should be bound.
- unresolvedBEncoder: ExpressionEncoder[Any],
- cEncoder: ExpressionEncoder[Any],
- children: Seq[Attribute],
- mutableAggBufferOffset: Int,
- inputAggBufferOffset: Int)
- extends ImperativeAggregate with Logging {
-
- override def withNewMutableAggBufferOffset(newMutableAggBufferOffset:
Int): ImperativeAggregate =
- copy(mutableAggBufferOffset = newMutableAggBufferOffset)
-
- override def withNewInputAggBufferOffset(newInputAggBufferOffset: Int):
ImperativeAggregate =
- copy(inputAggBufferOffset = newInputAggBufferOffset)
+ inputDeserializer: Option[Expression],
+ bufferSerializer: NamedExpression,
+ bufferDeserializer: Expression,
+ outputSerializer: Seq[Expression],
+ outputExternalType: DataType,
+ dataType: DataType) extends DeclarativeAggregate with NonSQLExpression
{
override def nullable: Boolean = true
- override def dataType: DataType = if (cEncoder.flat) {
- cEncoder.schema.head.dataType
- } else {
- cEncoder.schema
- }
-
override def deterministic: Boolean = true
- override lazy val resolved: Boolean = aEncoder.isDefined
-
- override lazy val inputTypes: Seq[DataType] = Nil
+ override def children: Seq[Expression] = inputDeserializer.toSeq :+
bufferDeserializer
- override val aggBufferSchema: StructType = unresolvedBEncoder.schema
+ override lazy val resolved: Boolean = inputDeserializer.isDefined &&
childrenResolved
- override val aggBufferAttributes: Seq[AttributeReference] =
aggBufferSchema.toAttributes
+ override def references: AttributeSet =
AttributeSet(inputDeserializer.toSeq)
--- End diff --
Should this be AttributeSet(inputDeserializer.flatMap(_.references))
---
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 infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
