Github user davies commented on a diff in the pull request:
https://github.com/apache/spark/pull/12067#discussion_r59788972
--- 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)
- val bEncoder = unresolvedBEncoder
- .resolve(aggBufferAttributes, OuterScopes.outerScopes)
- .bind(aggBufferAttributes)
+ override def inputTypes: Seq[AbstractDataType] = Nil
- // Note: although this simply copies aggBufferAttributes, this common
code can not be placed
- // in the superclass because that will lead to initialization ordering
issues.
- override val inputAggBufferAttributes: Seq[AttributeReference] =
- aggBufferAttributes.map(_.newInstance())
+ private def aggregatorLiteral =
+ Literal.create(aggregator, ObjectType(classOf[Aggregator[Any, Any,
Any]]))
- // We let the dataset do the binding for us.
- lazy val boundA = aEncoder.get
+ private def bufferExternalType = bufferDeserializer.dataType
- private def updateBuffer(buffer: MutableRow, value: InternalRow): Unit =
{
- var i = 0
- while (i < aggBufferAttributes.length) {
- val offset = mutableAggBufferOffset + i
- aggBufferSchema(i).dataType match {
- case BooleanType => buffer.setBoolean(offset, value.getBoolean(i))
- case ByteType => buffer.setByte(offset, value.getByte(i))
- case ShortType => buffer.setShort(offset, value.getShort(i))
- case IntegerType => buffer.setInt(offset, value.getInt(i))
- case LongType => buffer.setLong(offset, value.getLong(i))
- case FloatType => buffer.setFloat(offset, value.getFloat(i))
- case DoubleType => buffer.setDouble(offset, value.getDouble(i))
- case other => buffer.update(offset, value.get(i, other))
- }
- i += 1
- }
- }
+ override lazy val aggBufferAttributes: Seq[AttributeReference] =
+ bufferSerializer.toAttribute.asInstanceOf[AttributeReference] :: Nil
- override def initialize(buffer: MutableRow): Unit = {
- val zero = bEncoder.toRow(aggregator.zero)
- updateBuffer(buffer, zero)
+ override lazy val initialValues: Seq[Expression] = {
+ val zero = Literal.fromObject(aggregator.zero, bufferExternalType)
+ ReferenceToExpressions(bufferSerializer, zero :: Nil) :: Nil
}
- override def update(buffer: MutableRow, input: InternalRow): Unit = {
- val inputA = boundA.fromRow(input)
- val currentB = bEncoder.shift(mutableAggBufferOffset).fromRow(buffer)
- val merged = aggregator.reduce(currentB, inputA)
- val returned = bEncoder.toRow(merged)
+ override lazy val updateExpressions: Seq[Expression] = {
+ val reduced = Invoke(
+ aggregatorLiteral,
+ "reduce",
+ bufferExternalType,
+ bufferDeserializer :: inputDeserializer.get :: Nil)
- updateBuffer(buffer, returned)
+ ReferenceToExpressions(bufferSerializer, reduced :: Nil) :: Nil
}
- override def merge(buffer1: MutableRow, buffer2: InternalRow): Unit = {
- val b1 = bEncoder.shift(mutableAggBufferOffset).fromRow(buffer1)
- val b2 = bEncoder.shift(inputAggBufferOffset).fromRow(buffer2)
- val merged = aggregator.merge(b1, b2)
- val returned = bEncoder.toRow(merged)
+ override lazy val mergeExpressions: Seq[Expression] = {
+ val leftBuffer = bufferDeserializer transform {
+ case a: AttributeReference => a.left
+ }
+ val rightBuffer = bufferDeserializer transform {
+ case a: AttributeReference => a.right
+ }
+ val merged = Invoke(
+ aggregatorLiteral,
+ "merge",
+ bufferExternalType,
+ leftBuffer :: rightBuffer :: Nil)
- updateBuffer(buffer1, returned)
+ ReferenceToExpressions(bufferSerializer, merged :: Nil) :: Nil
}
- override def eval(buffer: InternalRow): Any = {
- val b = bEncoder.shift(mutableAggBufferOffset).fromRow(buffer)
- val result = cEncoder.toRow(aggregator.finish(b))
+ override lazy val evaluateExpression: Expression = {
+ val resultObj = Invoke(
+ aggregatorLiteral,
+ "finish",
+ outputExternalType,
+ bufferDeserializer :: Nil)
+
dataType match {
- case _: StructType => result
- case _ => result.get(0, dataType)
+ case s: StructType =>
+ ReferenceToExpressions(CreateStruct(outputSerializer), resultObj
:: Nil)
+ case _ =>
+ assert(outputSerializer.length == 1)
+ outputSerializer.head transform {
+ case b: BoundReference => resultObj
+ }
}
}
override def toString: String = {
- s"""${aggregator.getClass.getSimpleName}(${children.mkString(",")})"""
+ val input = inputDeserializer match {
+ case Some(UnresolvedDeserializer(deserializer, _)) =>
deserializer.dataType.simpleString
--- End diff --
Could you remove it when merging?
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