public async Task PatchSingleItem(IArchiveFileEntry file, CancellationToken cancellationToken)
{
OnProgress(new ProgressUpdateEventArgs(file, 0, 0));
if (await PatchWriter.Exists(file).ConfigureAwait(false))
{
return;
}
int counter = 0;
Stream fileData = null;
List <Exception> exceptions = new List <Exception>();
do
{
try
{
fileData = await PatchSource.DownloadHashAsync((int)Index.RootIndex.BuildNumber, file.Hash,
cancellationToken);
}
catch (Exception ex)
{
counter++;
exceptions.Add(ex);
}
} while (fileData == null && counter < FileRetryCount);
if (fileData == null)
{
throw new AggregateException(exceptions);
}
counter = 0;
do
{
try
{
await PatchWriter.AppendAsync(fileData, file).ConfigureAwait(false);
break;
}
catch (Exception ex)
{
exceptions.Add(ex);
counter++;
}
} while (counter < FileRetryCount);
if (counter >= FileRetryCount)
{
throw new AggregateException(exceptions);
}
}
public async Task DownloadAndProcessPatchIndexAsync()
{
// This stuff here is bootstrap, we trust the files are correct, because we assume this was done first.
// Because it has to be done first, or we don't have the index files to begin with.
var patchFileName = Path.Combine(PatchPath, "Patch.index");
var serverBuild = await PatchSource.GetServerBuildAsync().ConfigureAwait(false);
var patchIndexHash = await PatchSource.GetFileHashAsync(Path.GetFileName(patchFileName)).ConfigureAwait(false);
bool downloadRequired = true;
if (File.Exists(patchFileName))
{
using (var sha1 = SHA1.Create())
using (var fileStream = File.Open(patchFileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
var fileHash = sha1.ComputeHash(fileStream);
downloadRequired = !fileHash.SequenceEqual(patchIndexHash);
}
}
if (downloadRequired)
{
void WriteProgress(long length, long progress)
{
var message = length <= 0 ? $"Downloaded {progress} bytes" : $"Downloaded {progress} of {length} bytes";
Output.WriteLine(message);
}
var dataStream = await PatchSource.DownloadHashAsync(serverBuild, patchIndexHash);
using (var fileStream =
File.Open(patchFileName, FileMode.Create, FileAccess.Write, FileShare.ReadWrite))
{
await dataStream.CopyToAsync(fileStream, WriteProgress);
}
}
// But right here, we can just reuse our existing stuff.
// So CoreData.archive is optional, and if it exists, we need to check it for existing data
// Before we just blindly re-download it.
await PatchIndex(patchFileName, PatchPath).ConfigureAwait(false);
}