org.apache.spark.sql.avro.AvroOutputWriter.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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.sql.avro
import java.io.{IOException, OutputStream}
import org.apache.avro.Schema
import org.apache.avro.generic.GenericRecord
import org.apache.avro.mapred.AvroKey
import org.apache.avro.mapreduce.AvroKeyOutputFormat
import org.apache.hadoop.fs.Path
import org.apache.hadoop.io.NullWritable
import org.apache.hadoop.mapreduce.{RecordWriter, TaskAttemptContext}
import org.apache.spark.sql.catalyst.InternalRow
import org.apache.spark.sql.execution.datasources.OutputWriter
import org.apache.spark.sql.types._
// NOTE: This class is instantiated and used on executor side only, no need to be serializable.
private[avro] class AvroOutputWriter(
path: String,
context: TaskAttemptContext,
schema: StructType,
avroSchema: Schema) extends OutputWriter {
// The input rows will never be null.
private lazy val serializer = new AvroSerializer(schema, avroSchema, nullable = false)
/**
* Overrides the couple of methods responsible for generating the output streams / files so
* that the data can be correctly partitioned
*/
private val recordWriter: RecordWriter[AvroKey[GenericRecord], NullWritable] =
new AvroKeyOutputFormat[GenericRecord]() {
override def getDefaultWorkFile(context: TaskAttemptContext, extension: String): Path = {
new Path(path)
}
@throws(classOf[IOException])
override def getAvroFileOutputStream(c: TaskAttemptContext): OutputStream = {
val path = getDefaultWorkFile(context, ".avro")
path.getFileSystem(context.getConfiguration).create(path)
}
}.getRecordWriter(context)
override def write(row: InternalRow): Unit = {
val key = new AvroKey(serializer.serialize(row).asInstanceOf[GenericRecord])
recordWriter.write(key, NullWritable.get())
}
override def close(): Unit = recordWriter.close(context)
}