/* * 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.spark.sql.catalyst.InternalRow import org.apache.spark.sql.catalyst.expressions.{Attribute, JoinedRow} import org.apache.spark.sql.catalyst.expressions.codegen.GenerateSafeProjection /** * Evaluator for a [[DeclarativeAggregate]]. */ case class DeclarativeAggregateEvaluator(function: DeclarativeAggregate, input: Seq[Attribute]) { lazy val initializer = GenerateSafeProjection.generate(function.initialValues) lazy val updater = GenerateSafeProjection.generate( function.updateExpressions, function.aggBufferAttributes ++ input) lazy val merger = GenerateSafeProjection.generate( function.mergeExpressions, function.aggBufferAttributes ++ function.inputAggBufferAttributes) lazy val evaluator = GenerateSafeProjection.generate( function.evaluateExpression :: Nil, function.aggBufferAttributes) def initialize(): InternalRow = initializer.apply(InternalRow.empty).copy() def update(values: InternalRow*): InternalRow = { val joiner = new JoinedRow val buffer = values.foldLeft(initialize()) { (buffer, input) => updater(joiner(buffer, input)) } buffer.copy() } def merge(buffers: InternalRow*): InternalRow = { val joiner = new JoinedRow val buffer = buffers.foldLeft(initialize()) { (left, right) => merger(joiner(left, right)) } buffer.copy() } def eval(buffer: InternalRow): InternalRow = evaluator(buffer).copy() }