public async ReusableTask WriteAsync(ITorrentFileInfo file, long offset, byte[] buffer, int bufferOffset, int count)
{
Check.File(file);
Check.Buffer(buffer);
if (offset < 0 || offset + count > file.Length)
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
using (await Limiter.EnterAsync()) {
using var rented = await StreamCache.GetOrCreateStreamAsync(file, FileAccess.ReadWrite).ConfigureAwait(false);
// FileStream.WriteAsync does some work synchronously, according to the profiler.
// It looks like if the file is too small it is expanded (SetLength is called)
// synchronously before the asynchronous Write is performed.
//
// We also want the Seek operation to execute on the threadpool.
await MainLoop.SwitchToThreadpool();
await rented.Stream.SeekAsync(offset).ConfigureAwait(false);
await rented.Stream.WriteAsync(buffer, bufferOffset, count).ConfigureAwait(false);
WriteMonitor?.AddDelta(count);
}
}
public async ReusableTask <int> ReadAsync(ITorrentFileInfo file, long offset, byte[] buffer, int bufferOffset, int count)
{
Check.File(file);
Check.Buffer(buffer);
if (offset < 0 || offset + count > file.Length)
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
using (await Limiter.EnterAsync()) {
using var rented = await StreamCache.GetOrCreateStreamAsync(file, FileAccess.Read).ConfigureAwait(false);
await MainLoop.SwitchToThreadpool();
if (rented.Stream.Length < offset + count)
{
return(0);
}
if (rented.Stream.Position != offset)
{
await rented.Stream.SeekAsync(offset);
}
ReadMonitor?.AddDelta(count);
return(await rented.Stream.ReadAsync(buffer, bufferOffset, count));
}
}
