org.apache.spark.sql.execution.streaming.sources.PackedRowWriterFactory.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.execution.streaming.sources
import scala.collection.mutable
import org.apache.spark.internal.Logging
import org.apache.spark.sql.Row
import org.apache.spark.sql.sources.v2.writer.{DataSourceWriter, DataWriter, DataWriterFactory, WriterCommitMessage}
/**
* A simple [[DataWriterFactory]] whose tasks just pack rows into the commit message for delivery
* to a [[DataSourceWriter]] on the driver.
*
* Note that, because it sends all rows to the driver, this factory will generally be unsuitable
* for production-quality sinks. It's intended for use in tests.
*/
case object PackedRowWriterFactory extends DataWriterFactory[Row] {
def createDataWriter(partitionId: Int, attemptNumber: Int): DataWriter[Row] = {
new PackedRowDataWriter()
}
}
/**
* Commit message for a [[PackedRowDataWriter]], containing all the rows written in the most
* recent interval.
*/
case class PackedRowCommitMessage(rows: Array[Row]) extends WriterCommitMessage
/**
* A simple [[DataWriter]] that just sends all the rows it's received as a commit message.
*/
class PackedRowDataWriter() extends DataWriter[Row] with Logging {
private val data = mutable.Buffer[Row]()
override def write(row: Row): Unit = data.append(row)
override def commit(): PackedRowCommitMessage = {
val msg = PackedRowCommitMessage(data.toArray)
data.clear()
msg
}
override def abort(): Unit = data.clear()
}