cloud-fan commented on a change in pull request #23778: [SPARK-24935][SQL] : Problem with Executing Hive UDF's from Spark 2.2 Onwards URL: https://github.com/apache/spark/pull/23778#discussion_r266725039
########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/interfaces.scala ########## @@ -524,23 +524,142 @@ abstract class TypedImperativeAggregate[T] extends ImperativeAggregate { /** De-serializes the serialized format Array[Byte], and produces aggregation buffer object T */ def deserialize(storageFormat: Array[Byte]): T + override def initialize(buffer: InternalRow): Unit = { + buffer(mutableAggBufferOffset) = createAggregationBuffer() + } + + override def update(buffer: InternalRow, input: InternalRow): Unit = { + buffer(mutableAggBufferOffset) = update(getBufferObject(buffer), input) + } + + override def merge(buffer: InternalRow, inputBuffer: InternalRow): Unit = { + val bufferObject = getBufferObject(buffer) + // The inputBuffer stores serialized aggregation buffer object produced by partial aggregate + val inputObject = deserialize(inputBuffer.getBinary(inputAggBufferOffset)) + buffer(mutableAggBufferOffset) = merge(bufferObject, inputObject) + } + + override def eval(buffer: InternalRow): Any = { + eval(getBufferObject(buffer)) + } + + private[this] val anyObjectType = ObjectType(classOf[AnyRef]) + private def getBufferObject(bufferRow: InternalRow): T = { + bufferRow.get(mutableAggBufferOffset, anyObjectType).asInstanceOf[T] + } + + override lazy val aggBufferAttributes: Seq[AttributeReference] = { + // Underlying storage type for the aggregation buffer object + Seq(AttributeReference("buf", BinaryType)()) + } + + override lazy val inputAggBufferAttributes: Seq[AttributeReference] = + aggBufferAttributes.map(_.newInstance()) + + override def aggBufferSchema: StructType = StructType.fromAttributes(aggBufferAttributes) + + /** + * In-place replaces the aggregation buffer object stored at buffer's index + * `mutableAggBufferOffset`, with SparkSQL internally supported underlying storage format + * (BinaryType). + * + * This is only called when doing Partial or PartialMerge mode aggregation, before the framework + * shuffle out aggregate buffers. + */ + def serializeAggregateBufferInPlace(buffer: InternalRow): Unit = { + buffer(mutableAggBufferOffset) = serialize(getBufferObject(buffer)) + } +} + +/** + * Aggregation function which allows **arbitrary** user-defined java object to be used as internal + * aggregation buffer for Hive. + */ +abstract class HiveTypedImperativeAggregate[T] extends TypedImperativeAggregate[T] { + + /** + * Creates an empty aggregation buffer object for partial 1 mode. This is called + * before processing each key group(group by key). + * + * @return an aggregation buffer object + */ + def createAggregationBuffer(): T + + /** + * Creates an empty aggregation buffer object for partial 2 mode. + * + * @return an aggregation buffer object + */ + def createPartial2ModeAggregationBuffer(): T + + var partial2ModeBuffer: InternalRow = _ + + /** + * Updates the aggregation buffer object with an input row and returns a new buffer object. For + * performance, the function may do in-place update and return it instead of constructing new + * buffer object. + * + * This is typically called when doing Partial or Complete mode aggregation. + * + * @param buffer The aggregation buffer object. + * @param input an input row + */ + def update(buffer: T, input: InternalRow): T + + /** + * Merges an input aggregation object into aggregation buffer object and returns a new buffer + * object. For performance, the function may do in-place merge and return it instead of + * constructing new buffer object. + * + * This is typically called when doing PartialMerge or Final mode aggregation. + * + * @param buffer the aggregation buffer object used to store the aggregation result. + * @param input an input aggregation object. Input aggregation object can be produced by + * de-serializing the partial aggregate's output from Mapper side. + */ + def merge(buffer: T, input: T): T + + /** + * Generates the final aggregation result value for current key group with the aggregation buffer + * object. + * + * Developer note: the only return types accepted by Spark are: + * - primitive types + * - InternalRow and subclasses + * - ArrayData + * - MapData + * + * @param buffer aggregation buffer object. + * @return The aggregation result of current key group + */ + def eval(buffer: T): Any + + /** Serializes the aggregation buffer object T to Array[Byte] */ + def serialize(buffer: T): Array[Byte] + + /** De-serializes the serialized format Array[Byte], and produces aggregation buffer object T */ + def deserialize(storageFormat: Array[Byte]): T + final override def initialize(buffer: InternalRow): Unit = { + partial2ModeBuffer = buffer.copy() + partial2ModeBuffer(mutableAggBufferOffset) = createPartial2ModeAggregationBuffer() Review comment: to make it clear, the partial 1 buffer can only be used in `iterator` to consume records, and partial 2 buffer can only be used in `merge` to consume buffers, do I understand it correctly? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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