BodyDelegate

gistfile1.cs

// current delegate
Action /*cancel*/ BodyDelegate(
  Action<ArraySegment<byte>, Action, bool> next,
  Action<Exception> error,
  Action complete);

// node-like delegate
void BodyDelegate(
  Action<ArraySegment<byte>, bool> write,
  Action<Action, bool> flush,
  Action<Exception> end,
  CancellationToken cancel);

BodyDelegate WriteAndEndNonBlockingWithCatch()
{
  return (write, flush, end, cancel)=>
  {
    try
    {
      write(data1);
      write(data2);
      end(null);
    }
    catch(Exception ex)
    {
      end(ex);
    }
  };
}

BodyDelegate WriteAndEndWithAwaitableBackPressure()
{
  return async (write, flush, end, cancel)=>
  {
    try
    {
      await WriteAsync(write, data1, flush);
      await WriteAsync(write, data2, flush);
      end(null);
    }
    catch(Exception ex)
    {
      end(ex);
    }
  };
}

// helper method for async write
Task WriteAsync(Action<ArraySegment<byte>, bool> write, ArraySegment<byte> data, Action<Action, bool> flush)
{
  if (write(data))
  {
    if (flush(()=>{ /* signal incomplete awaitable here */ }))
    {
      // return incomplete awaitable here
    }
  }
  // return already-completed awaitable here
}