cloud-fan commented on a change in pull request #32881: URL: https://github.com/apache/spark/pull/32881#discussion_r655185788
########## File path: core/src/main/scala/org/apache/spark/internal/io/FileNamingProtocol.scala ########## @@ -0,0 +1,57 @@ +/* + * 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.internal.io + +import org.apache.hadoop.mapreduce.TaskAttemptContext + +/** + * An interface to define how a single Spark job names its outputs. Two notes: + * + * 1. Implementations must be serializable, as the instance instantiated on the driver + * will be used for tasks on executors. + * 2. An instance should not be reused across multiple Spark jobs. + * + * The proper way to call is: + * + * As part of each task's execution, whenever a new output file needs be created, executor calls + * [[getTaskTempPath]] to get a valid relative file path before commit. + */ +abstract class FileNamingProtocol { + + /** + * Gets the relative path should be used for the output file. + * + * Important: it is the caller's responsibility to add uniquely identifying content to + * "fileContext" if a task is going to write out multiple files to the same directory. The file + * naming protocol only guarantees that files written by different tasks will not conflict. + */ + def getTaskTempPath(taskContext: TaskAttemptContext, fileContext: FileContext): String +} + +/** + * The context for Spark output file. This is used by [[FileNamingProtocol]] to create file path. + * + * @param ext Source specific file extension, e.g. ".snappy.parquet". + * @param relativeDir Relative directory of file. Can be used for writing dynamic partitions. + * E.g., "a=1/b=2" is directory for partition (a=1, b=2). + * @param prefix file prefix. + */ +final case class FileContext( + ext: String, + relativeDir: Option[String], Review comment: same to `ext` and `prefix`: can we let the caller side to pretend/append `ext`/`prefix` to the generated file name? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
