Github user tdas commented on a diff in the pull request:
https://github.com/apache/spark/pull/21200#discussion_r185365453
--- Diff:
sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/continuous/ContinuousQueuedDataReader.scala
---
@@ -0,0 +1,89 @@
+/*
+ * 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.continuous
+
+import java.io.Closeable
+import java.util.concurrent.{ArrayBlockingQueue, TimeUnit}
+import java.util.concurrent.atomic.AtomicBoolean
+
+import org.apache.spark.{Partition, TaskContext}
+import org.apache.spark.sql.catalyst.expressions.UnsafeRow
+import org.apache.spark.sql.execution.datasources.v2.DataSourceRDDPartition
+import org.apache.spark.sql.sources.v2.reader.streaming.PartitionOffset
+import org.apache.spark.util.ThreadUtils
+
+/**
+ * A wrapper for a continuous processing data reader, including a reading
queue and epoch markers.
+ *
+ * This will be instantiated once per partition - successive calls to
compute() in the
+ * [[ContinuousDataSourceRDD]] will reuse the same reader. This is
required to get continuity of
+ * offsets across epochs.
+ *
+ * For performance reasons, this is very weakly encapsulated. There are
six handles for the RDD:
--- End diff --
This can be much more strongly encapsulated. There is no need to expose
`queue`, `epochPollFailed` and `dataReaderFailed`. See comment in the RDD class.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
