Github user rxin commented on a diff in the pull request:
https://github.com/apache/spark/pull/7813#discussion_r36063658
--- Diff:
sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/SortBasedAggregationIterator.scala
---
@@ -0,0 +1,236 @@
+/*
+ * 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.catalyst.InternalRow
+import org.apache.spark.sql.catalyst.expressions._
+import
org.apache.spark.sql.catalyst.expressions.aggregate.{AggregateExpression2,
AggregateFunction2}
+import org.apache.spark.sql.execution.UnsafeFixedWidthAggregationMap
+import org.apache.spark.sql.types.StructType
+import org.apache.spark.unsafe.KVIterator
+
+/**
+ * An iterator used to evaluate [[AggregateFunction2]]. It assumes the
input rows have been
+ * sorted by values of [[groupingKeyAttributes]].
+ */
+class SortBasedAggregationIterator(
+ groupingKeyAttributes: Seq[Attribute],
+ valueAttributes: Seq[Attribute],
+ inputKVIterator: KVIterator[InternalRow, 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) {
+
+ override protected def newBuffer: MutableRow = {
+ val bufferSchema = allAggregateFunctions.flatMap(_.bufferAttributes)
+ val bufferRowSize: Int = bufferSchema.length
+
+ val genericMutableBuffer = new GenericMutableRow(bufferRowSize)
+ val useUnsafeBuffer =
bufferSchema.map(_.dataType).forall(UnsafeRow.isFixedLength)
+
+ val buffer = if (useUnsafeBuffer) {
+ val unsafeProjection =
+ UnsafeProjection.create(bufferSchema.map(_.dataType))
+ unsafeProjection.apply(genericMutableBuffer)
+ } else {
+ genericMutableBuffer
+ }
+ initializeBuffer(buffer)
+ buffer
+ }
+
+
///////////////////////////////////////////////////////////////////////////
+ // Mutable states for sort based aggregation.
+
///////////////////////////////////////////////////////////////////////////
+
+ // The partition key of the current partition.
+ private[this] var currentGroupingKey: InternalRow = _
+
+ // The partition key of next partition.
+ private[this] var nextGroupingKey: InternalRow = _
+
+ // The first row of next partition.
+ private[this] var firstRowInNextGroup: InternalRow = _
+
+ // Indicates if we has new group of rows from the sorted input iterator
+ private[this] var sortedInputHasNewGroup: Boolean = false
+
+ // The aggregation buffer used by the sort-based aggregation.
+ private[this] val sortBasedAggregationBuffer: MutableRow = newBuffer
+
+ /** Processes rows in the current group. It will stop when it find a new
group. */
+ protected def processCurrentSortedGroup(): Unit = {
+ currentGroupingKey = nextGroupingKey
+ // Now, we will start to find all rows belonging to this group.
+ // We create a variable to track if we see the next group.
+ var findNextPartition = false
+ // firstRowInNextGroup is the first row of this group. We first
process it.
+ processRow(sortBasedAggregationBuffer, firstRowInNextGroup)
+
+ // The search will stop when we see the next group or there is no
+ // input row left in the iter.
+ var hasNext = inputKVIterator.next()
+ while (!findNextPartition && hasNext) {
+ // Get the grouping key.
+ val groupingKey = inputKVIterator.getKey
+ val currentRow = inputKVIterator.getValue
+
+ // Check if the current row belongs the current input row.
+ if (currentGroupingKey == groupingKey) {
+ processRow(sortBasedAggregationBuffer, currentRow)
+
+ hasNext = inputKVIterator.next()
+ } else {
+ // We find a new group.
+ findNextPartition = true
+ nextGroupingKey = groupingKey.copy()
+ firstRowInNextGroup = currentRow.copy()
+ }
+ }
+ // We have not seen a new group. It means that there is no new row in
the input
+ // iter. The current group is the last group of the iter.
+ if (!findNextPartition) {
+ sortedInputHasNewGroup = false
+ }
+ }
+
+
///////////////////////////////////////////////////////////////////////////
+ // Iterator's public methods
+
///////////////////////////////////////////////////////////////////////////
+
+ override final def hasNext: Boolean = sortedInputHasNewGroup
+
+ override final def next(): InternalRow = {
+ if (hasNext) {
+ // Process the current group.
+ processCurrentSortedGroup()
+ // Generate output row for the current group.
+ val outputRow = generateOutput(currentGroupingKey,
sortBasedAggregationBuffer)
+ // Initialize buffer values for the next group.
+ initializeBuffer(sortBasedAggregationBuffer)
+
+ outputRow
+ } else {
+ // no more result
+ throw new NoSuchElementException
+ }
+ }
+
+ protected def initialize(): Unit = {
--- End diff --
initialize is a bad name. maybe processInputs
---
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 [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
