[GitHub] [arrow] jorgecarleitao commented on a change in pull request #9086: [Rust] [DataFusion] [Experiment] Blocking threads filter

[GitBox <gi...@apache.org>]

jorgecarleitao commented on a change in pull request #9086:
URL: https://github.com/apache/arrow/pull/9086#discussion_r551054627



##########
File path: rust/datafusion/src/physical_plan/sized_stream.rs
##########
@@ -0,0 +1,75 @@
+// 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.
+
+//! SizedRecordBatchStream is a stream of [arrow::record_batch::RecordBatch] that knows its schema.
+
+use std::{
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+use arrow::record_batch::RecordBatch;
+use arrow::{datatypes::SchemaRef, error::Result as ArrowResult};
+use futures::stream::{Stream, StreamExt};
+
+use super::RecordBatchStream;
+
+/// A schema-aware [Stream] of [`RecordBatch`]es.
+pub struct SizedRecordBatchStream<S: Stream<Item = ArrowResult<RecordBatch>>> {
+    stream: Pin<Box<S>>,
+    schema: SchemaRef,
+}

Review comment:
       This is just a way of encapsulating a stream into something that implements `RecordBatchStream`. Not really relevant for this PR's idea, just simplifies some common code.




----------------------------------------------------------------
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:
users@infra.apache.org