cloud-fan commented on a change in pull request #23471: [SPARK-26550][SQL] New built-in datasource - noop URL: https://github.com/apache/spark/pull/23471#discussion_r248229730
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/noop/NoopDataSource.scala ########## @@ -0,0 +1,72 @@ +/* + * 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.datasources.noop + +import java.util.Optional + +import org.apache.spark.sql.SaveMode +import org.apache.spark.sql.catalyst.InternalRow +import org.apache.spark.sql.sources.DataSourceRegister +import org.apache.spark.sql.sources.v2._ +import org.apache.spark.sql.sources.v2.writer._ +import org.apache.spark.sql.types.StructType + +/** + * This is no-op datasource. It does not do anything besides consuming its input. + * This can be useful for benchmarking or to cache data without any additional overhead. + */ +class NoopDataSource + extends DataSourceV2 + with BatchWriteSupportProvider + with DataSourceRegister { + + override def shortName(): String = "noop" + + override def createBatchWriteSupport( + queryId: String, + schema: StructType, + mode: SaveMode, + options: DataSourceOptions): Optional[BatchWriteSupport] = { + Optional.of(new NoopWriteSupport()) + } +} + +private[noop] class NoopWriteSupport extends BatchWriteSupport { + override def createBatchWriterFactory(): DataWriterFactory = { + new NoopWriterFactory() + } + + override def useCommitCoordinator(): Boolean = false + override def commit(messages: Array[WriterCommitMessage]): Unit = () + override def abort(messages: Array[WriterCommitMessage]): Unit = () +} + +private[noop] class NoopWriterFactory extends DataWriterFactory { + override def createWriter(partitionId: Int, taskId: Long): DataWriter[InternalRow] = { + new NoopWriter() + } +} + +private[noop] case object NoopWriterCommitMessage extends WriterCommitMessage + +private[noop] class NoopWriter extends DataWriter[InternalRow] { + override def write(record: InternalRow): Unit = () + override def commit(): WriterCommitMessage = NoopWriterCommitMessage Review comment: we can return null here, to save network IO. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
