This proposal intends to make AsyncArrowWriter accepts a new trait called AsyncFileWriter instead like what we do for ParquetRecordBatchStream.

AsyncArrowWriter accepts AsyncWrite currently:

AsyncWrite is a low-level, poll-based API. Users with writers that provide async fn write() will need to encapsulate it within a manually written future state machine.

For example:

Describe the solution you'd like

I propose to make AsyncArrowWriter accepts a new trait called AsyncFileWriter:

pub struct AsyncArrowWriter<W> {
    /// Underlying sync writer
    sync_writer: ArrowWriter<Vec<u8>>,

    /// Async writer provided by caller
    async_writer: W,
}

impl<W: AsyncFileWriter + Unpin + Send> AsyncArrowWriter<W> {
  ...
}

pub trait AsyncFileWriter: Send {
    async fn write(&mut self, bs: Bytes) -> Result<()>;
    async fn complete(&mut self) -> Result<()>;
}

impl<T: AsyncWrite> AsyncFileWriter for T {
   ...
}

Describe alternatives you've considered

Not yet.

Additional context

ParquetRecordBatchStream accetps AsyncFileReader:

I'm willing help implement this proposal.