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From yhuai <...@git.apache.org>
Subject [GitHub] spark pull request: [SPARK-9240] [SQL] Hybrid aggregate operator u...
Date Wed, 05 Aug 2015 01:09:45 GMT
Github user yhuai commented on a diff in the pull request:

    https://github.com/apache/spark/pull/7813#discussion_r36260944
  
    --- Diff: sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/UnsafeHybridAggregationIterator.scala
---
    @@ -0,0 +1,398 @@
    +/*
    + * 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.execution.aggregate
    +
    +import org.apache.spark.sql.execution.{UnsafeKeyValueSorter, UnsafeFixedWidthAggregationMap}
    +import org.apache.spark.unsafe.KVIterator
    +import org.apache.spark.{SparkEnv, TaskContext}
    +import org.apache.spark.sql.catalyst.InternalRow
    +import org.apache.spark.sql.catalyst.expressions._
    +import org.apache.spark.sql.catalyst.expressions.aggregate._
    +import org.apache.spark.sql.types.StructType
    +
    +/**
    + * An iterator used to evaluate [[AggregateFunction2]].
    + * It first tries to use in-memory hash-based aggregation. If we cannot allocate more
    + * space for the hash map, we spill the sorted map entries, free the map, and then
    + * switch to sort-based aggregation.
    + */
    +class UnsafeHybridAggregationIterator(
    +    groupingKeyAttributes: Seq[Attribute],
    +    valueAttributes: Seq[Attribute],
    +    inputKVIterator: KVIterator[UnsafeRow, InternalRow],
    +    nonCompleteAggregateExpressions: Seq[AggregateExpression2],
    +    nonCompleteAggregateAttributes: Seq[Attribute],
    +    completeAggregateExpressions: Seq[AggregateExpression2],
    +    completeAggregateAttributes: Seq[Attribute],
    +    initialInputBufferOffset: Int,
    +    resultExpressions: Seq[NamedExpression],
    +    newMutableProjection: (Seq[Expression], Seq[Attribute]) => (() => MutableProjection),
    +    outputsUnsafeRows: Boolean)
    +  extends AggregationIterator(
    +    groupingKeyAttributes,
    +    valueAttributes,
    +    nonCompleteAggregateExpressions,
    +    nonCompleteAggregateAttributes,
    +    completeAggregateExpressions,
    +    completeAggregateAttributes,
    +    initialInputBufferOffset,
    +    resultExpressions,
    +    newMutableProjection,
    +    outputsUnsafeRows) {
    +
    +  require(groupingKeyAttributes.nonEmpty)
    +
    +  ///////////////////////////////////////////////////////////////////////////
    +  // Unsafe Aggregation buffers
    +  ///////////////////////////////////////////////////////////////////////////
    +
    +  // This is the Unsafe Aggregation Map used to store all buffers.
    +  private[this] val buffers = new UnsafeFixedWidthAggregationMap(
    +    newBuffer,
    +    StructType.fromAttributes(allAggregateFunctions.flatMap(_.bufferAttributes)),
    +    StructType.fromAttributes(groupingKeyAttributes),
    +    TaskContext.get.taskMemoryManager(),
    +    SparkEnv.get.shuffleMemoryManager,
    +    1024 * 16, // initial capacity
    +    SparkEnv.get.conf.getSizeAsBytes("spark.buffer.pageSize", "64m"),
    +    false // disable tracking of performance metrics
    +  )
    +
    +  override protected def newBuffer: UnsafeRow = {
    +    val bufferSchema = allAggregateFunctions.flatMap(_.bufferAttributes)
    +    val bufferRowSize: Int = bufferSchema.length
    +
    +    val genericMutableBuffer = new GenericMutableRow(bufferRowSize)
    +    val unsafeProjection =
    +      UnsafeProjection.create(bufferSchema.map(_.dataType))
    +    val buffer = unsafeProjection.apply(genericMutableBuffer)
    +    initializeBuffer(buffer)
    +    buffer
    +  }
    +
    +  ///////////////////////////////////////////////////////////////////////////
    +  // Methods and variables related to switching to sort-based aggregation
    +  ///////////////////////////////////////////////////////////////////////////
    +  private[this] var sortBased = false
    +
    +  private[this] var sortBasedAggregationIterator: SortBasedAggregationIterator = _
    +
    +  // The value part of the input KV iterator is used to store original input values of
    +  // aggregate functions, we need to convert them to aggregation buffers.
    +  private def processOriginalInput(
    --- End diff --
    
    Done.


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