[SuppressMessage("ReSharper", "AccessToDisposedClosure")] // Progress bar inside parallel code
private static void SyncFiles(
[NotNull] IReadOnlyDictionary <string, IReadOnlyCollection <string> > map,
[NotNull] string source, [NotNull] string target, [NotNull] string id,
[NotNull] StatisticsManager statistics,
int threads)
{
using (AsciiProgressBar bar = new AsciiProgressBar())
{
int progress = 0, total = map.Values.Sum(l => l.Count);
string name = Path.GetFileName(source); // Get the name of the source folder
// Copy the files in parallel, one task for each subdirectory in the source tree
IReadOnlyList <KeyValuePair <string, IReadOnlyCollection <string> > > files = map.ToArray();
Parallel.For(0, files.Count, new ParallelOptions {
MaxDegreeOfParallelism = threads
}, i =>
{
// Create the target directory
KeyValuePair <string, IReadOnlyCollection <string> > pair = files[i];
string
relative = pair.Key.Substring(source.Length),
folder = string.IsNullOrEmpty(relative)
? Path.Join(target, $"{name}{id}")
: Path.Join(target, $"{name}{id}", relative);
Directory.CreateDirectory(folder);
// Copy the original files, when needed
foreach (string file in pair.Value)
{
string copy = Path.Join(folder, Path.GetFileName(file));
try
{
if (!File.Exists(copy))
{
File.Copy(file, copy);
statistics.AddOperation(copy, FileUpdateType.Add);
}
else if (File.GetLastWriteTimeUtc(file).CompareTo(File.GetLastWriteTimeUtc(copy)) > 0)
{
if (File.GetAttributes(copy).HasFlag(FileAttributes.ReadOnly))
{
File.SetAttributes(copy, FileAttributes.Normal); // In the case the original file was locked
}
File.Copy(file, copy, true);
statistics.AddOperation(copy, FileUpdateType.Update);
}
}
catch (Exception e) when(e is UnauthorizedAccessException || e is IOException)
{
// Log the failure and carry on
statistics.AddOperation(copy, FileUpdateType.Failure);
}
bar.Report((double)Interlocked.Increment(ref progress) / total);
}
});
}
}
/// <summary>
/// Cleans up the backup directory, removing empty folders and unnecessary files
/// </summary>
/// <param name="map">The map of files to sync</param>
/// <param name="source">The original source directory</param>
/// <param name="target">The root target directory</param>
/// <param name="statistics">The statistics instance to track the performed operations</param>
private static void Cleanup(
[NotNull] IReadOnlyDictionary <string, IReadOnlyCollection <string> > map,
[NotNull] string source, [NotNull] string target, [NotNull] string id,
[NotNull] StatisticsManager statistics)
{
string
name = Path.GetFileName(source),
root = Path.Join(target, $"{name}{id}");
void Cleanup(string directory)
{
// Post-order cleanup for unnecessary files
string[] subdirectories = Directory.GetDirectories(directory);
foreach (string subdirectory in subdirectories)
{
Cleanup(subdirectory);
}
// Delete the files that don't belong to the source folder with the current settings
string
relative = directory.Substring(root.Length),
key = Path.Join(source, relative);
IReadOnlyCollection <string> files = map.TryGetValue(key, out IReadOnlyCollection <string> paths)
? new HashSet <string>(paths.Select(Path.GetFileName))
: null;
foreach (string file in Directory.GetFiles(directory))
{
if (files?.Contains(Path.GetFileName(file)) != true)
{
try
{
File.Delete(file);
statistics.AddOperation(file, FileUpdateType.Remove);
}
catch (UnauthorizedAccessException)
{
// Can happen in rare situations
}
}
}
// Delete the subfolders, if necessary
foreach (string subdirectory in subdirectories)
{
if (!Directory.EnumerateFiles(subdirectory).Any() && !Directory.EnumerateDirectories(subdirectory).Any())
{
Directory.Delete(subdirectory);
}
}
}
Cleanup(root);
}