I'm using this, slightly modified, to copy large files from a file share with the ability to continue copying, if the download was disrupted. It runs in a BackroudWorker and reports progress. This works fine, but I'd like to have the ability to write the current MD5 hash to disk (the current total, not once for each block) each time a block of file data is written to disk WITH MINIMAL ADDITIONAL OVERHEAD. If a partial file is discovered, I'd like to read the MD5 hash from file, and if it is identical to that of the partial file, continue copying. When the file has been copied completely, the MD5 hash in the file should be that of the completly copied file. I'd like to use that later to determine that the files in source and destination are identical. Thanks for any help!
This is my current copy method:
public static bool CopyFile(List<CopyObjects> FileList, FSObjToCopy job, BackgroundWorker BW)
{
Stopwatch sw = new Stopwatch();
long RestartPosition = 0;
bool Retry = false;
int BYTES_TO_READ = (0x200000)
foreach (CopyObjects co in FileList)
{
FileInfo fi = co.file;
FileInfo fo = null;
if (fi.Directory.FullName.StartsWith($@"{Test_Updater_Core.ServerName}\{Test_Updater_Core.ServerTemplateRoot}"))
{
if (File.Exists(fi.FullName.Replace($@"{Test_Updater_Core.ServerName}\{Test_Updater_Core.ServerTemplateRoot}", $@"{ Test_Updater_Core.USBStore_Drive.driveInfo.Name.Replace("\\", "")}\{Test_Updater_Core.UsbTemplateRoot}")))
{
fi = new FileInfo(fi.FullName.Replace($@"{Test_Updater_Core.ServerName}\{Test_Updater_Core.ServerTemplateRoot}", $@"{Test_Updater_Core.USBStore_Drive.driveInfo.Name.Replace("\\", "")}\{Test_Updater_Core.UsbTemplateRoot}"));
co.destination = co.destination.Replace($@"{Test_Updater_Core.USBStore_Drive.driveInfo.Name.Replace("\\", "")}\{Test_Updater_Core.UsbTemplateRoot}", $@"{Test_Updater_Core.LocalInstallDrive}\{Test_Updater_Core.LocalTemplateRoot}");
fo = new FileInfo($"{fi.FullName.Replace($@"{Test_Updater_Core.USBStore_Drive.driveInfo.Name.Replace("\\", "")}\{Test_Updater_Core.UsbTemplateRoot}", $@"{Test_Updater_Core.LocalInstallDrive}\{Test_Updater_Core.LocalTemplateRoot}")}{Test_Updater_Core.TempFileExtension}");
}
}
//If a clean cancellation was requested, we do it here, otherwise the BackgroundWorker will be killed
if (BW.CancellationPending)
{
job.Status = FSObjToCopy._Status.Complete;
return false;
}
//If a pause is requested, we loop here until resume or termination has been signaled
while (job.PauseBackgroundWorker == true)
{
Thread.Sleep(100);
if (BW.CancellationPending)
{
job.Status = FSObjToCopy._Status.Complete;
return false;
}
Application.DoEvents();
}
if (fo == null)
fo = new FileInfo($"{fi.FullName.Replace(job.Source, co.destination)}{Test_Updater_Core.TempFileExtension}");
if (fo.Exists)
{
Retry = true;
RestartPosition = fo.Length - BYTES_TO_READ;
}
else
{
RestartPosition = 0;
Retry = false;
}
if (RestartPosition <= 0)
{
Retry = false;
}
sw.Start();
try
{
// Read source files into file streams
FileStream source = new FileStream(fi.FullName, FileMode.Open, FileAccess.Read);
// Additional way to write to file stream
FileStream dest = new FileStream(fo.FullName, FileMode.OpenOrCreate, FileAccess.Write);
// Actual read file length
int destLength = 0;
// If the length of each read is less than the length of the source file, read in chunks
if (BYTES_TO_READ < source.Length)
{
byte[] buffer = new byte[BYTES_TO_READ];
long copied = 0;
if (Retry)
{
source.Seek(RestartPosition, SeekOrigin.Begin);
dest.Seek(RestartPosition, SeekOrigin.Begin);
Retry = false;
}
while (copied <= source.Length - BYTES_TO_READ)
{
destLength = source.Read(buffer, 0, BYTES_TO_READ);
source.Flush();
dest.Write(buffer, 0, BYTES_TO_READ);
dest.Flush();
// Current position of flow
dest.Position = source.Position;
copied += BYTES_TO_READ;
job.CopiedSoFar += BYTES_TO_READ;
if (sw.ElapsedMilliseconds > 250)
{
job.PercComplete = (int)(float)((float)job.CopiedSoFar / (float)job.TotalFileSize * 100);
sw.Restart();
sw.Start();
job.ProgressCell.Value = job.PercComplete;
BW.ReportProgress(job.PercComplete < 100 ? job.PercComplete : 99);
}
if (BW.CancellationPending)
{
job.Status = FSObjToCopy._Status.Complete;
return false;
}
while (job.PauseBackgroundWorker == true)
{
Thread.Sleep(100);
if (BW.CancellationPending)
{
job.Status = FSObjToCopy._Status.Complete;
return false;
}
Application.DoEvents();
}
}
int left = (int)(source.Length - copied);
destLength = source.Read(buffer, 0, left);
source.Flush();
dest.Write(buffer, 0, left);
dest.Flush();
job.CopiedSoFar += left;
}
else
{
// If the file length of each copy is longer than that of the source file, the actual file length is copied directly.
byte[] buffer = new byte[source.Length];
source.Read(buffer, 0, buffer.Length);
source.Flush();
dest.Write(buffer, 0, buffer.Length);
dest.Flush();
job.CopiedSoFar += source.Length;
job.PercComplete = (int)(float)((float)job.CopiedSoFar / (float)job.TotalFileSize * 100);
job.ProgressCell.Value = job.PercComplete;
BW.ReportProgress(job.PercComplete < 100 ? job.PercComplete : 99);
}
source.Close();
dest.Close();
fo.LastWriteTimeUtc = fi.LastWriteTimeUtc;
if (File.Exists(fo.FullName))
{
if (File.Exists(fo.FullName.Replace($"{Test_Updater_Core.TempFileExtension}", "")))
{
File.Delete(fo.FullName.Replace($"{Test_Updater_Core.TempFileExtension}", ""));
}
File.Move(fo.FullName, fo.FullName.Replace($"{Test_Updater_Core.TempFileExtension}", ""));
}
job.ProgressCell.Value = job.PercComplete;
BW.ReportProgress(job.PercComplete);
}
catch (Exception ex)
{
MessageBox.Show($"There was an error copying:{Environment.NewLine}{fi}{Environment.NewLine}to:" +
$"{Environment.NewLine}{fo}{Environment.NewLine}The error is: {Environment.NewLine}{ex.Message}",
"Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
job.Status = FSObjToCopy._Status.Error;
return false;
}
finally
{
sw.Stop();
}
}
return true;
}
