Github user rxin commented on a diff in the pull request:
https://github.com/apache/spark/pull/19269#discussion_r145579513
--- Diff:
sql/core/src/main/java/org/apache/spark/sql/sources/v2/writer/DataWriterFactory.java
---
@@ -0,0 +1,44 @@
+/*
+ * 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.sources.v2.writer;
+
+import java.io.Serializable;
+
+import org.apache.spark.annotation.InterfaceStability;
+
+/**
+ * A factory of {@link DataWriter} returned by {@link
DataSourceV2Writer#createWriterFactory()},
+ * which is responsible for creating and initializing the actual data
writer at executor side.
+ *
+ * Note that, the writer factory will be serialized and sent to executors,
then the data writer
+ * will be created on executors and do the actual writing. So {@link
DataWriterFactory} must be
+ * serializable and {@link DataWriter} doesn't need to be.
+ */
+@InterfaceStability.Evolving
+public interface DataWriterFactory<T> extends Serializable {
+
+ /**
+ * Returns a data writer to do the actual writing work.
+ *
+ * @param stageId The id of the Spark stage that runs the returned
writer.
+ * @param partitionId The id of the RDD partition that the returned
writer will process.
+ * @param attemptNumber The attempt number of the Spark task that runs
the returned writer, which
+ * is usually 0 if the task is not a retried task
or a speculative task.
+ */
+ DataWriter<T> createWriter(int stageId, int partitionId, int
attemptNumber);
--- End diff --
not sure why we have stageId here. I'd make it more generic, e.g. a string
for some job id, and then some numeric value (64 bit long) for epoch.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
