spark-reviews mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From cloud-fan <...@git.apache.org>
Subject [GitHub] spark pull request: [SPARK-14275][SQL] Reimplement TypedAggregateE...
Date Thu, 14 Apr 2016 07:36:15 GMT
Github user cloud-fan commented on a diff in the pull request:

    https://github.com/apache/spark/pull/12067#discussion_r59673617
  
    --- 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 --
    
    they are same, see https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/AttributeSet.scala#L41-L46


---
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 infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org


Mime
View raw message