Copilot commented on code in PR #3638: URL: https://github.com/apache/thrift/pull/3638#discussion_r3594158585
########## lib/rs/src/transport/shared.rs: ########## @@ -0,0 +1,85 @@ +// 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. + +use std::io::{self, Read, Write}; +use std::sync::{Arc, Mutex, MutexGuard}; + +use super::{ReadHalf, TIoChannel, WriteHalf}; + +/// A clonable channel that serializes access to an underlying I/O stream. +/// +/// This adapter allows a bidirectional stream that cannot be cloned, such as a +/// TLS session, to implement [`TIoChannel`]. Every read, write, and flush holds +/// the same lock for the duration of that operation. It is intended for +/// synchronous request-response traffic, where a caller writes and flushes a +/// complete request before reading its response. +/// +/// The shared lock makes access memory-safe across threads, but it does not +/// provide full-duplex progress: a blocking read holds the lock and prevents a +/// concurrent write until that read finishes. +#[derive(Debug)] +pub struct TSharedChannel<C> { + inner: Arc<Mutex<C>>, +} + +impl<C> TSharedChannel<C> { + /// Wrap `inner` in a shared channel. + pub fn new(inner: C) -> Self { + Self { + inner: Arc::new(Mutex::new(inner)), + } + } + + pub(crate) fn lock(&self) -> io::Result<MutexGuard<'_, C>> { + self.inner + .lock() + .map_err(|_| io::Error::from(io::ErrorKind::Other)) + } +} Review Comment: When the mutex is poisoned, `lock()` currently returns `io::ErrorKind::Other` with the default message (typically just "other error"), which is hard to diagnose. Returning a specific message makes downstream `TransportError.message` much more actionable without changing control flow. ########## lib/rs/src/transport/shared.rs: ########## @@ -0,0 +1,85 @@ +// 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. + +use std::io::{self, Read, Write}; +use std::sync::{Arc, Mutex, MutexGuard}; + +use super::{ReadHalf, TIoChannel, WriteHalf}; + +/// A clonable channel that serializes access to an underlying I/O stream. Review Comment: Doc comment uses nonstandard spelling "clonable"; use "cloneable" for clarity/consistency with Rust terminology. ########## lib/rs/tests/shared_channel.rs: ########## @@ -0,0 +1,97 @@ +// 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. + +use std::collections::VecDeque; +use std::io::{self, Read, Write}; +use std::panic::{catch_unwind, AssertUnwindSafe}; +use std::sync::{Arc, Mutex}; + +use thrift::transport::{TIoChannel, TSharedChannel}; + +struct TestIo { + readable: VecDeque<u8>, + written: Arc<Mutex<Vec<u8>>>, +} + +impl Read for TestIo { + fn read(&mut self, buffer: &mut [u8]) -> io::Result<usize> { + let count = buffer.len().min(self.readable.len()); + for target in &mut buffer[..count] { + *target = self.readable.pop_front().unwrap(); + } + Ok(count) + } +} + +impl Write for TestIo { + fn write(&mut self, buffer: &[u8]) -> io::Result<usize> { + self.written.lock().unwrap().extend_from_slice(buffer); + Ok(buffer.len()) + } + + fn flush(&mut self) -> io::Result<()> { + Ok(()) + } +} + +#[test] +fn split_supports_an_inner_channel_that_is_not_clone() { Review Comment: Test name reads awkwardly ("is_not_clone") and is easy to misread; using "cloneable" matches the trait name and makes the intent clearer. -- This is an automated message from the Apache Git Service. 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