private static async Task ReadAsync(FileStreamReader state)
{
if (state._cancellationToken.IsCancellationRequested)
{
state._writer.Complete();
}
Read:
var buffer = state._writer.GetMemory(state._bufferSize);
var numBytes = await state._file.ReadAsync(buffer, state._cancellationToken.Token);
state._writer.Advance(numBytes);
var awaitable = state._writer.FlushAsync(state._cancellationToken.Token);
if (numBytes == 0)
{
state._writer.Complete();
// The operation can be disposed when there's nothing more to produce
state.Dispose();
}
else if (awaitable.IsCompleted)
{
// No back pressure being applied to continue reading
goto Read;
}
else
{
var flushResult = await awaitable;
if (!flushResult.IsCompleted)
{
goto Read;
}
else
{
state._writer.Complete();
state.Dispose();
}
}
}
public static FileStreamReader ReadFile(string path, int bufferSize = 4069, FileOptions fileOptions = FileOptions.Asynchronous)
{
var file = new FileStreamReader(path, bufferSize, fileOptions);
return(file);
}