org.apache.spark.sql.util.MapperRowCounter.scala Maven / Gradle / Ivy
/*
* 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.util
import java.{lang => jl}
import org.apache.spark.util.AccumulatorV2
/**
* An AccumulatorV2 counter for collecting a list of (mapper index, row count).
*
* @since 3.4.0
*/
class MapperRowCounter extends AccumulatorV2[jl.Long, java.util.List[(jl.Integer, jl.Long)]] {
private var _agg: java.util.List[(jl.Integer, jl.Long)] = _
private def getOrCreate = {
_agg = Option(_agg).getOrElse(new java.util.ArrayList[(jl.Integer, jl.Long)]())
_agg
}
/**
* Returns false if this accumulator has had any values added to it or the sum is non-zero.
*/
override def isZero: Boolean = this.synchronized(getOrCreate.isEmpty)
override def copyAndReset(): MapperRowCounter = new MapperRowCounter
override def copy(): MapperRowCounter = {
val newAcc = new MapperRowCounter()
this.synchronized {
newAcc.getOrCreate.addAll(getOrCreate)
}
newAcc
}
override def reset(): Unit = {
this.synchronized {
_agg = null
}
}
override def add(v: jl.Long): Unit = {
this.synchronized {
assert(getOrCreate.size() == 1, "agg must have been initialized")
val p = getOrCreate.get(0)._1
val n = getOrCreate.get(0)._2 + 1
getOrCreate.set(0, (p, n))
}
}
def setPartitionId(id: jl.Integer): Unit = {
this.synchronized {
assert(isZero, "agg must not have been initialized")
getOrCreate.add((id, 0))
}
}
override def merge(
other: AccumulatorV2[jl.Long, java.util.List[(jl.Integer, jl.Long)]]): Unit
= other match {
case o: MapperRowCounter =>
this.synchronized(getOrCreate.addAll(o.value))
case _ =>
throw new UnsupportedOperationException(
s"Cannot merge ${this.getClass.getName} with ${other.getClass.getName}")
}
override def value: java.util.List[(jl.Integer, jl.Long)] = this.synchronized(getOrCreate)
}