forked from apache/arrow-rs
-
Notifications
You must be signed in to change notification settings - Fork 1
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Minor: move
FallibleRequestStream and FallibleTonicResponseStream…
… to a module (apache#6258) * Minor: move FallibleRequestStream and FallibleTonicResponseStream to their own modules * Improve documentation and add links
- Loading branch information
Showing
4 changed files
with
138 additions
and
106 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,134 @@ | ||
| // 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. | ||
|
|
||
| //! [`FallibleRequestStream`] and [`FallibleTonicResponseStream`] adapters | ||
|
|
||
| use crate::error::FlightError; | ||
| use futures::{ | ||
| channel::oneshot::{Receiver, Sender}, | ||
| FutureExt, Stream, StreamExt, | ||
| }; | ||
| use std::pin::Pin; | ||
| use std::task::{ready, Poll}; | ||
|
|
||
| /// Wrapper around a fallible stream (one that returns errors) that makes it infallible. | ||
| /// | ||
| /// Any errors encountered in the stream are ignored are sent to the provided | ||
| /// oneshot sender. | ||
| /// | ||
| /// This can be used to accept a stream of `Result<_>` from a client API and send | ||
| /// them to the remote server that wants only the successful results. | ||
| pub(crate) struct FallibleRequestStream<T, E> { | ||
| /// sender to notify error | ||
| sender: Option<Sender<E>>, | ||
| /// fallible stream | ||
| fallible_stream: Pin<Box<dyn Stream<Item = std::result::Result<T, E>> + Send + 'static>>, | ||
| } | ||
|
|
||
| impl<T, E> FallibleRequestStream<T, E> { | ||
| pub(crate) fn new( | ||
| sender: Sender<E>, | ||
| fallible_stream: Pin<Box<dyn Stream<Item = std::result::Result<T, E>> + Send + 'static>>, | ||
| ) -> Self { | ||
| Self { | ||
| sender: Some(sender), | ||
| fallible_stream, | ||
| } | ||
| } | ||
| } | ||
|
|
||
| impl<T, E> Stream for FallibleRequestStream<T, E> { | ||
| type Item = T; | ||
|
|
||
| fn poll_next( | ||
| self: std::pin::Pin<&mut Self>, | ||
| cx: &mut std::task::Context<'_>, | ||
| ) -> std::task::Poll<Option<Self::Item>> { | ||
| let pinned = self.get_mut(); | ||
| let mut request_streams = pinned.fallible_stream.as_mut(); | ||
| match ready!(request_streams.poll_next_unpin(cx)) { | ||
| Some(Ok(data)) => Poll::Ready(Some(data)), | ||
| Some(Err(e)) => { | ||
| // in theory this should only ever be called once | ||
| // as this stream should not be polled again after returning | ||
| // None, however we still check for None to be safe | ||
| if let Some(sender) = pinned.sender.take() { | ||
| // an error means the other end of the channel is not around | ||
| // to receive the error, so ignore it | ||
| let _ = sender.send(e); | ||
| } | ||
| Poll::Ready(None) | ||
| } | ||
| None => Poll::Ready(None), | ||
| } | ||
| } | ||
| } | ||
|
|
||
| /// Wrapper for a tonic response stream that maps errors to `FlightError` and | ||
| /// returns errors from a oneshot channel into the stream. | ||
| /// | ||
| /// The user of this stream can inject an error into the response stream using | ||
| /// the one shot receiver. This is used to propagate errors in | ||
| /// [`FlightClient::do_put`] and [`FlightClient::do_exchange`] from the client | ||
| /// provided input stream to the response stream. | ||
| /// | ||
| /// # Error Priority | ||
| /// Error from the receiver are prioritised over the response stream. | ||
| /// | ||
| /// [`FlightClient::do_put`]: crate::FlightClient::do_put | ||
| /// [`FlightClient::do_exchange`]: crate::FlightClient::do_exchange | ||
| pub(crate) struct FallibleTonicResponseStream<T> { | ||
| /// Receiver for FlightError | ||
| receiver: Receiver<FlightError>, | ||
| /// Tonic response stream | ||
| response_stream: Pin<Box<dyn Stream<Item = Result<T, tonic::Status>> + Send + 'static>>, | ||
| } | ||
|
|
||
| impl<T> FallibleTonicResponseStream<T> { | ||
| pub(crate) fn new( | ||
| receiver: Receiver<FlightError>, | ||
| response_stream: Pin<Box<dyn Stream<Item = Result<T, tonic::Status>> + Send + 'static>>, | ||
| ) -> Self { | ||
| Self { | ||
| receiver, | ||
| response_stream, | ||
| } | ||
| } | ||
| } | ||
|
|
||
| impl<T> Stream for FallibleTonicResponseStream<T> { | ||
| type Item = Result<T, FlightError>; | ||
|
|
||
| fn poll_next( | ||
| self: Pin<&mut Self>, | ||
| cx: &mut std::task::Context<'_>, | ||
| ) -> Poll<Option<Self::Item>> { | ||
| let pinned = self.get_mut(); | ||
| let receiver = &mut pinned.receiver; | ||
| // Prioritise sending the error that's been notified over | ||
| // polling the response_stream | ||
| if let Poll::Ready(Ok(err)) = receiver.poll_unpin(cx) { | ||
| return Poll::Ready(Some(Err(err))); | ||
| }; | ||
|
|
||
| match ready!(pinned.response_stream.poll_next_unpin(cx)) { | ||
| Some(Ok(res)) => Poll::Ready(Some(Ok(res))), | ||
| Some(Err(status)) => Poll::Ready(Some(Err(FlightError::Tonic(status)))), | ||
| None => Poll::Ready(None), | ||
| } | ||
| } | ||
| } |