/// <summary>
/// Handles a single file.
/// </summary>
/// <param name="item">The item.</param>
/// <param name="configuration">The configuration.</param>
/// <param name="stats">The statistics.</param>
/// <param name="seenItems">The seen items.</param>
private static void _HandleFile(
FileInfo item,
Configuration configuration,
RuntimeStats stats,
ConcurrentDictionary <long, ConcurrentDictionary <string, FileEntry> > seenItems)
{
stats.IncrementFiles();
var length = item.Length;
stats.IncrementBytes(length);
if (length < configuration.MinimumFileSizeInBytes || length > configuration.MaximumFileSizeInBytes)
{
return;
}
var knownWithThisLength = seenItems.GetOrAdd(length, _ => new ConcurrentDictionary <string, FileEntry>());
// preventing othre threads from processing files with the same size
// avoiding a race condition where all known links to a file are removed at once, thus loosing data completely
lock (knownWithThisLength)
try {
_HandleFileWithGivenSize(item, configuration, stats, knownWithThisLength);
} catch (Exception e) {
Console.WriteLine($"[Error] Could not process file {item.FullName}: {e.Message}");
}
}
/// <summary>
/// Handles files which are already hardlinks.
/// </summary>
/// <param name="item">The item.</param>
/// <param name="configuration">The configuration.</param>
/// <param name="stats">The statistics.</param>
/// <param name="knownWithThisLength">Length of the known with this.</param>
private static void _HandleExistingHardLink(
FileInfo item,
Configuration configuration,
RuntimeStats stats,
ConcurrentDictionary <string, FileEntry> knownWithThisLength
)
{
if (configuration.DeleteHardLinkedFiles)
{
_RemoveFileEntry(item, knownWithThisLength);
_DeleteLink(item);
stats.HardLinkStats.IncreaseDeleted();
Console.WriteLine($"[Info] Deleted Hardlink {item.FullName}");
return;
}
if (configuration.RemoveHardLinks)
{
_RemoveFileEntry(item, knownWithThisLength);
try {
_ReplaceFileLinkWithFileContent(item);
stats.HardLinkStats.IncreaseRemoved();
Console.WriteLine($"[Info] Removed Hardlink {item.FullName}");
} catch (Exception e) {
Console.WriteLine($"[Error] Could not remove Hardlink {item.FullName}: {e.Message}");
}
return;
}
if (configuration.SetReadOnlyAttributeOnExistingHardLinks && ((item.Attributes & FileAttributes.ReadOnly) != FileAttributes.ReadOnly))
{
Console.WriteLine($"[Info] Setting read-only attribute on Hardlink {item.FullName}");
item.Attributes |= FileAttributes.ReadOnly;
return;
}
Console.WriteLine($"[Info] {item.FullName} is alrady a Hardlink");
}
/// <summary>
/// Handles a specific file along with a group of files already seen with the same size.
/// </summary>
/// <param name="item">The item.</param>
/// <param name="configuration">The configuration.</param>
/// <param name="stats">The statistics.</param>
/// <param name="knownWithThisLength">Length of the known with this.</param>
private static void _HandleFileWithGivenSize(
FileInfo item,
Configuration configuration,
RuntimeStats stats,
ConcurrentDictionary <string, FileEntry> knownWithThisLength)
{
var myKey = _GenerateKey(item);
var checksum = knownWithThisLength.GetOrAdd(myKey, new FileEntry(item));
var isHardLink = false;
IEnumerable <FileInfo> hardlinks;
try {
hardlinks = item.GetHardLinkTargets();
} catch (Exception e) {
_RemoveFileEntry(item, knownWithThisLength);
Console.WriteLine($"[Error] Could not enumerate HardLinks {item.FullName}: {e.Message}");
return;
}
foreach (var target in hardlinks)
{
isHardLink = true;
knownWithThisLength.TryAdd(_GenerateKey(target), new FileEntry(target));
}
if (isHardLink)
{
stats.HardLinkStats.IncreaseSeen();
if (configuration.ShowInfoOnly)
{
return;
}
_HandleExistingHardLink(item, configuration, stats, knownWithThisLength);
return;
}
string symlink;
try {
symlink = item.GetSymbolicLinkTarget();
} catch (Exception e) {
_RemoveFileEntry(item, knownWithThisLength);
Console.WriteLine($"[Error] Could not enumerate SymLink {item.FullName}: {e.Message}");
return;
}
if (symlink != null)
{
knownWithThisLength.TryAdd(symlink, new FileEntry(new FileInfo(symlink)));
stats.SymbolicLinkStats.IncreaseSeen();
if (configuration.ShowInfoOnly)
{
return;
}
_HandleExistingSymbolicLink(item, configuration, stats, knownWithThisLength);
return;
}
if (configuration.ShowInfoOnly)
{
return;
}
// find matching file in seen list and try to hard or symlink
var sameFiles =
knownWithThisLength
.Where(kvp => kvp.Key != myKey)
.Where(kvp => kvp.Value.Equals(checksum))
.Select(kvp => kvp.Key)
;
foreach (var sameFile in sameFiles)
{
var temporaryFile = _CreateTemporaryFileInSameDirectory(item);
temporaryFile.Delete();
var isSymlink = false;
try {
LinkExtensions.CreateHardLinkFrom((FileInfo)temporaryFile, (string)sameFile);
} catch (Exception e1) {
if (configuration.AlsoTrySymbolicLinks)
{
isSymlink = true;
try {
LinkExtensions.CreateSymbolicLinkFrom((FileInfo)temporaryFile, (string)sameFile);
} catch (Exception e2) {
Console.WriteLine(
$"[Warning] Could not Symlink {item.FullName}({FilesizeFormatter.FormatUnit(item.Length, true)}) --> {sameFile}: {e2.Message}");
continue;
}
}
else
{
Console.WriteLine(
$"[Warning] Could not Hardlink {item.FullName}({FilesizeFormatter.FormatUnit(item.Length, true)}) --> {sameFile}: {e1.Message}");
continue;
}
}
var isAlreadyDeleted = false;
try {
item.Attributes &= ~FileAttributes.ReadOnly;
item.Delete();
isAlreadyDeleted = true;
File.Move(temporaryFile.FullName, item.FullName);
} catch {
if (isAlreadyDeleted)
{
// undo file deletion
temporaryFile.CopyTo(item.FullName, true);
}
else
{
// undo temp file creation
temporaryFile.Delete();
}
throw;
}
if (isSymlink)
{
stats.SymbolicLinkStats.IncreaseCreated();
if (configuration.SetReadOnlyAttributeOnNewSymbolicLinks)
{
item.Attributes |= FileAttributes.ReadOnly;
}
}
else
{
stats.HardLinkStats.IncreaseCreated();
if (configuration.SetReadOnlyAttributeOnNewHardLinks)
{
item.Attributes |= FileAttributes.ReadOnly;
}
}
Console.WriteLine($"[Info] Created {(isSymlink ? "Symlink" : "Hardlink")} for {item.FullName}({FilesizeFormatter.FormatUnit(item.Length, true)}) --> {sameFile}");
return;
}
}
/// <summary>
/// A worker thread, pulling items from the stack, handling files and directories, etc.
/// </summary>
/// <param name="stack">The stack.</param>
/// <param name="configuration">The configuration.</param>
/// <param name="seenItems">The seen items.</param>
/// <param name="waiter">The waiter.</param>
/// <param name="state">The state.</param>
private static void _ThreadWorker(ConcurrentStack <DirectoryInfo> stack, Configuration configuration, RuntimeStats stats, ConcurrentDictionary <long, ConcurrentDictionary <string, FileEntry> > seenItems, AutoResetEvent waiter, int[] state)
{
while (true)
{
if (!stack.TryPop(out var current))
{
// when stack is empty, signal we're lazy and if all other threads are also, end thread
if (Interlocked.Decrement(ref state[0]) == 0)
{
// signal another thread to continue exiting
waiter.Set();
Console.WriteLine($"Ending Thread #{Thread.CurrentThread.ManagedThreadId}");
return;
}
waiter.WaitOne();
Interlocked.Increment(ref state[0]);
continue;
}
// push directories and wake up any sleeping threads
foreach (var directory in current.EnumerateDirectories())
{
stack.Push(directory);
stats.IncrementFolders();
// notify other threads which may be waiting for work
waiter.Set();
}
foreach (var item in current.EnumerateFiles())
{
_HandleFile(item, configuration, stats, seenItems);
}
}
}
/// <summary>
/// Processes the given folders with the given configuration.
/// </summary>
/// <param name="directories">The directories.</param>
/// <param name="configuration">The configuration.</param>
/// <param name="stats">The statistics.</param>
public static void ProcessFolders(IList <DirectoryInfo> directories, Configuration configuration, RuntimeStats stats)
{
var seenFiles = new ConcurrentDictionary <long, ConcurrentDictionary <string, FileEntry> >();
var stack = new ConcurrentStack <DirectoryInfo>();
stack.PushRange(directories);
stats.IncrementFolders(directories.Count);
var threads = new Thread[Math.Max(1, configuration.MaximumCrawlerThreads)];
using (var autoresetEvent = new AutoResetEvent(false)) {
var runningWorkers = new[] { threads.Length };
for (var i = 0; i < threads.Length; ++i)
{
threads[i] = new Thread(_ThreadWorker);
threads[i].Start(Tuple.Create(stack, configuration, stats, seenFiles, autoresetEvent, runningWorkers));
}
foreach (var thread in threads)
{
thread.Join();
}
}
}