bug: FuturesAsyncWriter does not properly close/shutdown the writer

[kyle-mccarthy]

Describe the bug

FuturesAsyncWriter does not properly close the underlying writer, causing the write to silently fail. This is contrary to the documentation "FuturesAsyncWriters are automatically closed when they go out of scope."¹.

Steps to Reproduce

Minimal Reproducible Example

Cargo.toml

[package]
name = "repro"
version = "0.1.0"
edition = "2021"

[dependencies]
tokio = { version = "1.39", features = ["full"] }
opendal = "0.47"
tokio-util = { version = "0.7", features = ["compat"] }

main.rs

use opendal::{services::Memory, Operator};
use tokio::io::AsyncWriteExt;
use tokio_util::compat::FuturesAsyncWriteCompatExt;

#[tokio::main]
async fn main() {
    let operator = Operator::new(Memory::default()).unwrap().finish();

    let mut reader: &[u8] = b"hello";
    let mut writer = operator
        .writer("test")
        .await
        .unwrap()
        .into_futures_async_write()
        .compat_write();

    tokio::io::copy(&mut reader, &mut writer).await.unwrap();

    // writer.shutdown().await.unwrap(); <-- uncomment to make it work

    operator.stat("test").await.unwrap(); // panics
}

Expected Behavior

FuturesAsyncWriters should work according to the documentation.

Additional Context

Note that explicitly dropping the writer (i.e., drop(writer);) does not fix the problem, close or shutdown has to be called.

No response

Are you willing to submit a PR to fix this bug?

• Yes, I would like to submit a PR.

Footnotes

1. https://github.com/apache/opendal/blob/f859bcea093678503b3150a0690eda7fae5f8061/core/src/types/write/writer.rs#L189 ↩

[Xuanwo]

Hi, thanks a lot for raising this. The comments for FuturesAsyncWriter are wrong. It's required for FuturesAsyncWriter to call shutdown(). I will fix the comment.