cboumalh commented on code in PR #52800: URL: https://github.com/apache/spark/pull/52800#discussion_r2481460247
########## sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/kllAggregates.scala: ########## @@ -0,0 +1,405 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.spark.sql.catalyst.expressions.aggregate + +import org.apache.datasketches.kll._ +import org.apache.datasketches.memory.Memory + +import org.apache.spark.SparkUnsupportedOperationException +import org.apache.spark.sql.catalyst.InternalRow +import org.apache.spark.sql.catalyst.expressions.{ExpectsInputTypes, Expression, ExpressionDescription} +import org.apache.spark.sql.catalyst.trees.UnaryLike +import org.apache.spark.sql.errors.QueryExecutionErrors +import org.apache.spark.sql.types._ + +/** This represents the aggregation buffer for the below aggregate functions. */ +case class KllBufferBigint(sketch: KllLongsSketch = KllLongsSketch.newHeapInstance()) { + def serialize(): Array[Byte] = sketch.toByteArray + def eval(): Array[Byte] = sketch.toByteArray +} +case class KllBufferFloat(sketch: KllFloatsSketch = KllFloatsSketch.newHeapInstance()) { + def serialize(): Array[Byte] = sketch.toByteArray + def eval(): Array[Byte] = sketch.toByteArray +} +case class KllBufferDouble(sketch: KllDoublesSketch = KllDoublesSketch.newHeapInstance()) { + def serialize(): Array[Byte] = sketch.toByteArray + def eval(): Array[Byte] = sketch.toByteArray +} + +/** + * The KllSketchAggBigint function utilizes an Apache DataSketches KllLongsSketch instance to + * compute quantiles of the values of an input expression (such as an input column in a table). + * It outputs the binary representation of the KllLongsSketch. + * + * See [[https://datasketches.apache.org/docs/KLL/KLLSketch.html]] for more information. + * + * @param child + * child expression against which quantile computation will occur + * @param mutableAggBufferOffset + * offset for mutable aggregation buffer + * @param inputAggBufferOffset + * offset for input aggregation buffer + */ +// scalastyle:off line.size.limit +@ExpressionDescription( + usage = """ + _FUNC_(expr) - Returns the KllLongsSketch compact binary representation. + """, + examples = """ + Examples: + > SELECT LENGTH(kll_sketch_to_string_bigint(_FUNC_(col))) > 0 FROM VALUES (1), (2), (3), (4), (5) tab(col); + true + """, + group = "agg_funcs", + since = "4.1.0") +// scalastyle:on line.size.limit +case class KllSketchAggBigint( + override val child: Expression, + override val mutableAggBufferOffset: Int = 0, + override val inputAggBufferOffset: Int = 0) + extends TypedImperativeAggregate[KllBufferBigint] + with UnaryLike[Expression] + with ExpectsInputTypes { + def this(child: Expression) = this(child, 0, 0) + + override def withNewMutableAggBufferOffset(newMutableAggBufferOffset: Int): KllSketchAggBigint = + copy(mutableAggBufferOffset = newMutableAggBufferOffset) + override def withNewInputAggBufferOffset(newInputAggBufferOffset: Int): KllSketchAggBigint = + copy(inputAggBufferOffset = newInputAggBufferOffset) + override protected def withNewChildInternal(newInput: Expression): KllSketchAggBigint = + copy(child = newInput) + + override def dataType: DataType = BinaryType + override def inputTypes: Seq[AbstractDataType] = + Seq( + TypeCollection( + ByteType, + IntegerType, + LongType, + ShortType)) + override def nullable: Boolean = false + override def prettyName: String = "kll_sketch_agg_bigint" + override def createAggregationBuffer(): KllBufferBigint = KllBufferBigint() + + /** + * Evaluate the input row and update the KllLongsSketch instance with the row's value. The update + * function only supports a subset of Spark SQL types, and an exception will be thrown for + * unsupported types. + * Note, null values are ignored. + */ + override def update(updateBuffer: KllBufferBigint, input: InternalRow): KllBufferBigint = { + // Return early for null values. + val v = child.eval(input) + if (v == null) { + return updateBuffer + } + // Handle the different data types for sketch updates. + val sketch: KllLongsSketch = updateBuffer.sketch + child.dataType match { + case ByteType => + sketch.update(v.asInstanceOf[Byte].toLong) + case IntegerType => + sketch.update(v.asInstanceOf[Int].toLong) + case LongType => + sketch.update(v.asInstanceOf[Long]) + case ShortType => + sketch.update(v.asInstanceOf[Short].toLong) + case _ => + throw KllSketchAgg.unexpectedInputDataTypeError(child) + } + + updateBuffer + } + + /** Merges an input sketch into the current aggregation buffer. */ + override def merge(updateBuffer: KllBufferBigint, input: KllBufferBigint): KllBufferBigint = { + try { + updateBuffer.sketch.merge(input.sketch) + updateBuffer + } catch { + case e: Exception => + throw QueryExecutionErrors.kllSketchIncompatibleMergeError(prettyName, e.getMessage) + } + } + + /** Returns a sketch derived from the input column or expression. */ + override def eval(sketchState: KllBufferBigint): Any = sketchState.eval() + + /** Converts the underlying sketch state into a byte array. */ + override def serialize(sketchState: KllBufferBigint): Array[Byte] = sketchState.serialize() + + /** Wraps the byte array into a sketch instance. */ + override def deserialize(buffer: Array[Byte]): KllBufferBigint = if (buffer.nonEmpty) { + try { + KllBufferBigint(KllLongsSketch.wrap(Memory.wrap(buffer))) + } catch { + case e: Exception => + throw QueryExecutionErrors.kllSketchInvalidInputError(prettyName, e.getMessage) + } + } else { + this.createAggregationBuffer() + } +} + +/** + * The KllSketchAggFloat function utilizes an Apache DataSketches KllFloatsSketch instance to + * compute quantiles of the values of an input expression (such as an input column in a table). + * It outputs the binary representation of the KllFloatsSketch. + * + * See [[https://datasketches.apache.org/docs/KLL/KLLSketch.html]] for more information. + * + * @param child + * child expression against which quantile computation will occur + * @param mutableAggBufferOffset + * offset for mutable aggregation buffer + * @param inputAggBufferOffset + * offset for input aggregation buffer + */ +// scalastyle:off line.size.limit +@ExpressionDescription( + usage = """ + _FUNC_(expr) - Returns the KllFloatsSketch compact binary representation. + """, + examples = """ + Examples: + > SELECT LENGTH(kll_sketch_to_string_float(_FUNC_(col))) > 0 FROM VALUES (1), (2), (3), (4), (5) tab(col); + true + """, + group = "agg_funcs", + since = "4.1.0") +// scalastyle:on line.size.limit +case class KllSketchAggFloat( + override val child: Expression, + override val mutableAggBufferOffset: Int = 0, + override val inputAggBufferOffset: Int = 0) + extends TypedImperativeAggregate[KllBufferFloat] + with UnaryLike[Expression] + with ExpectsInputTypes { + def this(child: Expression) = this(child, 0, 0) + + override def withNewMutableAggBufferOffset(newMutableAggBufferOffset: Int): KllSketchAggFloat = + copy(mutableAggBufferOffset = newMutableAggBufferOffset) + override def withNewInputAggBufferOffset(newInputAggBufferOffset: Int): KllSketchAggFloat = + copy(inputAggBufferOffset = newInputAggBufferOffset) + override protected def withNewChildInternal(newInput: Expression): KllSketchAggFloat = + copy(child = newInput) + + override def dataType: DataType = BinaryType + override def inputTypes: Seq[AbstractDataType] = + Seq( + TypeCollection( + ByteType, + FloatType, + IntegerType, + LongType, + ShortType + )) + override def nullable: Boolean = false + override def prettyName: String = "kll_sketch_agg_float" + override def createAggregationBuffer(): KllBufferFloat = KllBufferFloat() + + /** + * Evaluate the input row and update the KllFloatsSketch instance with the row's value. The update + * function only supports a subset of Spark SQL types, and an exception will be thrown for + * unsupported types. + * Note, Null values are ignored. + */ + override def update(updateBuffer: KllBufferFloat, input: InternalRow): KllBufferFloat = { + // Return early for null values. + val v = child.eval(input) + if (v == null) { + return updateBuffer + } + // Handle the different data types for sketch updates. + val sketch: KllFloatsSketch = updateBuffer.sketch + child.dataType match { + case ByteType => + sketch.update(v.asInstanceOf[Byte].toFloat) + case IntegerType => + sketch.update(v.asInstanceOf[Int].toFloat) + case FloatType => + sketch.update(v.asInstanceOf[Float]) + case LongType => + sketch.update(v.asInstanceOf[Long].toFloat) + case ShortType => + sketch.update(v.asInstanceOf[Short].toFloat) + case _ => + throw KllSketchAgg.unexpectedInputDataTypeError(child) + } + + updateBuffer + } + + /** Merges an input sketch into the current aggregation buffer. */ + override def merge(updateBuffer: KllBufferFloat, input: KllBufferFloat): KllBufferFloat = { + try { + updateBuffer.sketch.merge(input.sketch) + updateBuffer + } catch { + case e: Exception => + throw QueryExecutionErrors.kllSketchIncompatibleMergeError(prettyName, e.getMessage) + } + } + + /** Returns a sketch derived from the input column or expression. */ + override def eval(sketchState: KllBufferFloat): Any = sketchState.eval() + + /** Converts the underlying sketch state into a byte array. */ + override def serialize(sketchState: KllBufferFloat): Array[Byte] = sketchState.serialize() + + /** Wraps the byte array into a sketch instance. */ + override def deserialize(buffer: Array[Byte]): KllBufferFloat = if (buffer.nonEmpty) { + try { + KllBufferFloat(KllFloatsSketch.wrap(Memory.wrap(buffer))) Review Comment: I believe calling `KllFloatsSketch.heapify` may be the safer option here and in the other aggregate functions. The sketches are going to be rebuilt anyway before the merge operation, might as well be safe and build them here instead of rather than risk holding a dangling memory reference. The memory reference could be corrupted or garbage collected (maybe?) after the deserialize call. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
