private FileStream OpenSource()
{
var stream = Source.Open(FileMode.Open, FileAccess.Read, FileShare.Read);
if (Destination.Exists && Options.HasFlag(FileCopyOptions.Restartable))
{
stream.Seek(Destination.Length - BufferSize, SeekOrigin.Begin);
}
return(stream);
}
private FileStream OpenDestination()
{
if (!Destination.Exists || !Options.HasFlag(FileCopyOptions.Restartable))
{
return(Destination.Open(FileMode.Create, FileAccess.Write, FileShare.None));
}
var stream = Destination.Open(FileMode.Open, FileAccess.Write, FileShare.None);
stream.Seek(BufferSize, SeekOrigin.End);
return(stream);
}
public async Task CopyAsync(CancellationToken cancellation = default)
{
if (Options.HasFlag(FileCopyOptions.VerifyFileHash) && HashAlgorithm == default)
{
throw new Exception($"The {FileCopyOptions.VerifyFileHash} bit flag was set, but no hashing algorithm was specified.");
}
stopwatch.Start();
OnStarted(this, new FileCopyStartedEventArgs2(Source, Destination));
try
{
using (var freader = OpenSource())
using (var fwriter = OpenDestination())
{
if (freader.Position != fwriter.Position)
{
freader.Position = fwriter.Position;
}
var inputBuffer = new byte[BufferSize];
var bytesWritten = 0;
var tries = 0;
while (true)
{
try
{
int bytesRead;
while (0 != (bytesRead = await freader.ReadAsync(inputBuffer, 0, inputBuffer.Length, cancellation)) &&
!cancellation.IsCancellationRequested)
{
cancellation.ThrowIfCancellationRequested();
bytesWritten += await CopyBytesAsync(inputBuffer, bytesRead, fwriter);
if (Options.HasFlag(FileCopyOptions.VerifyFileHash))
{
HashAlgorithm.TransformBlock(inputBuffer, 0, bytesRead, inputBuffer, 0);
OnChunkHashed(this, new FileHashProgressEventArgs(Source, new FileHashProgressData(Source.Length, bytesRead, sourceHash.Count, stopwatch.Elapsed)));
}
OnChunkTransferred(this, new FileTransferProgressEventArgs(Source, Destination, new FileTransferProgressData(Source.Length, bytesRead, bytesWritten, stopwatch.Elapsed)));
}
if (Options.HasFlag(FileCopyOptions.VerifyFileHash))
{
HashAlgorithm.TransformFinalBlock(inputBuffer, 0, inputBuffer.Length);
sourceHash = HashAlgorithm.Hash.ToList();
}
break;
}
catch (Exception e)
{
if (e is OperationCanceledException)
{
throw;
}
if (!RetrySettings.Retry || tries >= RetrySettings.RetryCount)
{
throw;
}
OnRetryStarted(this, new FileCopyRetryStartedEventArgs(tries++, RetrySettings.RetryInterval, e));
}
}
}
cancellation.ThrowIfCancellationRequested();
if (Options.HasFlag(FileCopyOptions.VerifyFileHash))
{
stopwatch.Reset();
Destination.Refresh();
EnsureChecksumsMatch(cancellation);
}
}
catch (OperationCanceledException)
{
if (!Options.HasFlag(FileCopyOptions.Restartable))
{
Destination.Delete();
}
throw;
}
if (Options.HasFlag(FileCopyOptions.DeleteSourceOnSuccessfulCopy))
{
Source.Delete();
}
OnCompleted(this, EventArgs.Empty);
}
