update cache

LightlessSync/FileCache/FileCacheManager.cs

@@ -16,6 +16,8 @@ public sealed class FileCacheManager : IHostedService
     public const string CachePrefix = "{cache}";
     public const string CsvSplit = "|";
     public const string PenumbraPrefix = "{penumbra}";
+    private const int FileCacheVersion = 1;
+    private const string FileCacheVersionHeaderPrefix = "#lightless-file-cache-version:";
     private readonly LightlessConfigService _configService;
     private readonly LightlessMediator _lightlessMediator;
     private readonly string _csvPath;
@@ -54,6 +56,62 @@ public sealed class FileCacheManager : IHostedService
         return NormalizeSeparators(prefixedPath).ToLowerInvariant();
     }
 
+    private static bool TryBuildPrefixedPath(string path, string? baseDirectory, string prefix, out string prefixedPath, out int matchedLength)
+    {
+        prefixedPath = string.Empty;
+        matchedLength = 0;
+
+        if (string.IsNullOrEmpty(path) || string.IsNullOrEmpty(baseDirectory))
+        {
+            return false;
+        }
+
+        var normalizedPath = NormalizeSeparators(path).ToLowerInvariant();
+        var normalizedBase = NormalizeSeparators(baseDirectory).TrimEnd('\\').ToLowerInvariant();
+
+        if (!normalizedPath.StartsWith(normalizedBase, StringComparison.Ordinal))
+        {
+            return false;
+        }
+
+        if (normalizedPath.Length > normalizedBase.Length)
+        {
+            if (normalizedPath[normalizedBase.Length] != '\\')
+            {
+                return false;
+            }
+
+            prefixedPath = prefix + normalizedPath.Substring(normalizedBase.Length);
+        }
+        else
+        {
+            prefixedPath = prefix;
+        }
+
+        prefixedPath = prefixedPath.Replace("\\\\", "\\", StringComparison.Ordinal);
+        matchedLength = normalizedBase.Length;
+        return true;
+    }
+
+    private static string BuildVersionHeader() => $"{FileCacheVersionHeaderPrefix}{FileCacheVersion}";
+
+    private static bool TryParseVersionHeader(string? line, out int version)
+    {
+        version = 0;
+        if (string.IsNullOrWhiteSpace(line))
+        {
+            return false;
+        }
+
+        if (!line.StartsWith(FileCacheVersionHeaderPrefix, StringComparison.OrdinalIgnoreCase))
+        {
+            return false;
+        }
+
+        var versionSpan = line.AsSpan(FileCacheVersionHeaderPrefix.Length);
+        return int.TryParse(versionSpan, NumberStyles.Integer, CultureInfo.InvariantCulture, out version);
+    }
+
     private string NormalizeToPrefixedPath(string path)
     {
         if (string.IsNullOrEmpty(path)) return string.Empty;
@@ -66,27 +124,25 @@ public sealed class FileCacheManager : IHostedService
             return NormalizePrefixedPathKey(normalized);
         }
 
-        var penumbraDir = _ipcManager.Penumbra.ModDirectory;
+        string? chosenPrefixed = null;
-        if (!string.IsNullOrEmpty(penumbraDir))
+        var chosenLength = -1;
+
+        if (TryBuildPrefixedPath(normalized, _ipcManager.Penumbra.ModDirectory, PenumbraPrefix, out var penumbraPrefixed, out var penumbraMatch))
         {
-            var normalizedPenumbra = NormalizeSeparators(penumbraDir);
+            chosenPrefixed = penumbraPrefixed;
-            var replacement = normalizedPenumbra.EndsWith("\\", StringComparison.Ordinal)
+            chosenLength = penumbraMatch;
-                ? PenumbraPrefix + "\\"
-                : PenumbraPrefix;
-            normalized = normalized.Replace(normalizedPenumbra, replacement, StringComparison.OrdinalIgnoreCase);
         }
 
-        var cacheFolder = _configService.Current.CacheFolder;
+        if (TryBuildPrefixedPath(normalized, _configService.Current.CacheFolder, CachePrefix, out var cachePrefixed, out var cacheMatch))
-        if (!string.IsNullOrEmpty(cacheFolder))
         {
-            var normalizedCache = NormalizeSeparators(cacheFolder);
+            if (cacheMatch > chosenLength)
-            var replacement = normalizedCache.EndsWith("\\", StringComparison.Ordinal)
+            {
-                ? CachePrefix + "\\"
+                chosenPrefixed = cachePrefixed;
-                : CachePrefix;
+                chosenLength = cacheMatch;
-            normalized = normalized.Replace(normalizedCache, replacement, StringComparison.OrdinalIgnoreCase);
+            }
         }
 
-        return NormalizePrefixedPathKey(normalized);
+        return NormalizePrefixedPathKey(chosenPrefixed ?? normalized);
     }
 
     public FileCacheEntity? CreateCacheEntry(string path)
@@ -94,7 +150,9 @@ public sealed class FileCacheManager : IHostedService
         FileInfo fi = new(path);
         if (!fi.Exists) return null;
         _logger.LogTrace("Creating cache entry for {path}", path);
-        return CreateFileEntity(_configService.Current.CacheFolder.ToLowerInvariant(), CachePrefix, fi);
+        var cacheFolder = _configService.Current.CacheFolder;
+        if (string.IsNullOrEmpty(cacheFolder)) return null;
+        return CreateFileEntity(cacheFolder, CachePrefix, fi);
     }
 
     public FileCacheEntity? CreateFileEntry(string path)
@@ -102,14 +160,18 @@ public sealed class FileCacheManager : IHostedService
         FileInfo fi = new(path);
         if (!fi.Exists) return null;
         _logger.LogTrace("Creating file entry for {path}", path);
-        return CreateFileEntity(_ipcManager.Penumbra.ModDirectory!.ToLowerInvariant(), PenumbraPrefix, fi);
+        var modDirectory = _ipcManager.Penumbra.ModDirectory;
+        if (string.IsNullOrEmpty(modDirectory)) return null;
+        return CreateFileEntity(modDirectory, PenumbraPrefix, fi);
     }
 
     private FileCacheEntity? CreateFileEntity(string directory, string prefix, FileInfo fi)
     {
-        var fullName = fi.FullName.ToLowerInvariant();
+        if (!TryBuildPrefixedPath(fi.FullName, directory, prefix, out var prefixedPath, out _))
-        if (!fullName.Contains(directory, StringComparison.Ordinal)) return null;
+        {
-        string prefixedPath = fullName.Replace(directory, prefix + "\\", StringComparison.Ordinal).Replace("\\\\", "\\", StringComparison.Ordinal);
+            return null;
+        }
+
         return CreateFileCacheEntity(fi, prefixedPath);
     }
 
@@ -367,6 +429,7 @@ public sealed class FileCacheManager : IHostedService
         lock (_fileWriteLock)
         {
             StringBuilder sb = new();
+            sb.AppendLine(BuildVersionHeader());
             foreach (var entry in _fileCaches.Values.SelectMany(k => k.Values).OrderBy(f => f.PrefixedFilePath, StringComparer.OrdinalIgnoreCase))
             {
                 sb.AppendLine(entry.CsvEntry);
@@ -389,6 +452,53 @@ public sealed class FileCacheManager : IHostedService
         }
     }
 
+    private void EnsureCsvHeaderLocked()
+    {
+        if (!File.Exists(_csvPath))
+        {
+            return;
+        }
+
+        string[] existingLines = File.ReadAllLines(_csvPath);
+        if (existingLines.Length > 0 && TryParseVersionHeader(existingLines[0], out var existingVersion) && existingVersion == FileCacheVersion)
+        {
+            return;
+        }
+
+        StringBuilder rebuilt = new();
+        rebuilt.AppendLine(BuildVersionHeader());
+        foreach (var line in existingLines)
+        {
+            if (TryParseVersionHeader(line, out _))
+            {
+                continue;
+            }
+
+            if (!string.IsNullOrEmpty(line))
+            {
+                rebuilt.AppendLine(line);
+            }
+        }
+
+        File.WriteAllText(_csvPath, rebuilt.ToString());
+    }
+
+    private void BackupUnsupportedCache(string suffix)
+    {
+        var sanitizedSuffix = string.IsNullOrWhiteSpace(suffix) ? "unsupported" : $"{suffix}.unsupported";
+        var backupPath = _csvPath + "." + sanitizedSuffix;
+
+        try
+        {
+            File.Move(_csvPath, backupPath, overwrite: true);
+            _logger.LogWarning("Backed up unsupported file cache to {path}", backupPath);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Failed to back up unsupported file cache to {path}", backupPath);
+        }
+    }
+
     internal FileCacheEntity MigrateFileHashToExtension(FileCacheEntity fileCache, string ext)
     {
         try
@@ -427,7 +537,15 @@ public sealed class FileCacheManager : IHostedService
         AddHashedFile(entity);
         lock (_fileWriteLock)
         {
-            File.AppendAllLines(_csvPath, new[] { entity.CsvEntry });
+            if (!File.Exists(_csvPath))
+            {
+                File.WriteAllLines(_csvPath, new[] { BuildVersionHeader(), entity.CsvEntry });
+            }
+            else
+            {
+                EnsureCsvHeaderLocked();
+                File.AppendAllLines(_csvPath, new[] { entity.CsvEntry });
+            }
         }
         var result = GetFileCacheByPath(fileInfo.FullName);
         _logger.LogTrace("Creating cache entity for {name} success: {success}", fileInfo.FullName, (result != null));
@@ -546,49 +664,111 @@ public sealed class FileCacheManager : IHostedService
                 _logger.LogWarning("Could not load entries from {path}, continuing with empty file cache", _csvPath);
             }
 
-            _logger.LogInformation("Found {amount} files in {path}", entries.Length, _csvPath);
+            bool rewriteRequired = false;
+            bool parseEntries = entries.Length > 0;
+            int startIndex = 0;
 
-            Dictionary<string, bool> processedFiles = new(StringComparer.OrdinalIgnoreCase);
+            if (entries.Length > 0)
-            foreach (var entry in entries)
             {
-                var splittedEntry = entry.Split(CsvSplit, StringSplitOptions.None);
+                var headerLine = entries[0];
-                try
+                var hasHeader = !string.IsNullOrEmpty(headerLine) &&
+                                headerLine.StartsWith(FileCacheVersionHeaderPrefix, StringComparison.OrdinalIgnoreCase);
+
+                if (hasHeader)
                 {
-                    var hash = splittedEntry[0];
+                    if (!TryParseVersionHeader(headerLine, out var parsedVersion))
-                    if (hash.Length != 40) throw new InvalidOperationException("Expected Hash length of 40, received " + hash.Length);
-                    var path = splittedEntry[1];
-                    var time = splittedEntry[2];
-
-                    if (processedFiles.ContainsKey(path))
                     {
-                        _logger.LogWarning("Already processed {file}, ignoring", path);
+                        _logger.LogWarning("Failed to parse file cache version header \"{header}\". Backing up existing cache.", headerLine);
-                        continue;
+                        BackupUnsupportedCache("invalid-version");
+                        parseEntries = false;
+                        rewriteRequired = true;
+                        entries = Array.Empty<string>();
                     }
-
+                    else if (parsedVersion != FileCacheVersion)
-                    processedFiles.Add(path, value: true);
-
-                    long size = -1;
-                    long compressed = -1;
-                    if (splittedEntry.Length > 3)
                     {
-                        if (long.TryParse(splittedEntry[3], CultureInfo.InvariantCulture, out long result))
+                        _logger.LogWarning("Unsupported file cache version {version} detected (expected {expected}). Backing up existing cache.", parsedVersion, FileCacheVersion);
-                        {
+                        BackupUnsupportedCache($"v{parsedVersion}");
-                            size = result;
+                        parseEntries = false;
-                        }
+                        rewriteRequired = true;
-                        if (long.TryParse(splittedEntry[4], CultureInfo.InvariantCulture, out long resultCompressed))
+                        entries = Array.Empty<string>();
-                        {
+                    }
-                            compressed = resultCompressed;
+                    else
-                        }
+                    {
+                        startIndex = 1;
                     }
-                    AddHashedFile(ReplacePathPrefixes(new FileCacheEntity(hash, path, time, size, compressed)));
                 }
-                catch (Exception ex)
+                else if (entries.Length > 0)
                 {
-                    _logger.LogWarning(ex, "Failed to initialize entry {entry}, ignoring", entry);
+                    _logger.LogInformation("File cache missing version header, scheduling rewrite.");
+                    rewriteRequired = true;
                 }
             }
 
-            if (processedFiles.Count != entries.Length)
+            var totalEntries = Math.Max(0, entries.Length - startIndex);
+            Dictionary<string, bool> processedFiles = new(StringComparer.OrdinalIgnoreCase);
+
+            if (parseEntries && totalEntries > 0)
+            {
+                _logger.LogInformation("Found {amount} files in {path}", totalEntries, _csvPath);
+
+                for (var index = startIndex; index < entries.Length; index++)
+                {
+                    var entry = entries[index];
+                    if (string.IsNullOrWhiteSpace(entry))
+                    {
+                        continue;
+                    }
+
+                    var splittedEntry = entry.Split(CsvSplit, StringSplitOptions.None);
+                    try
+                    {
+                        var hash = splittedEntry[0];
+                        if (hash.Length != 40)
+                            throw new InvalidOperationException("Expected Hash length of 40, received " + hash.Length);
+                        var path = splittedEntry[1];
+                        var time = splittedEntry[2];
+
+                        if (processedFiles.ContainsKey(path))
+                        {
+                            _logger.LogWarning("Already processed {file}, ignoring", path);
+                            continue;
+                        }
+
+                        processedFiles.Add(path, value: true);
+
+                        long size = -1;
+                        long compressed = -1;
+                        if (splittedEntry.Length > 3)
+                        {
+                            if (long.TryParse(splittedEntry[3], CultureInfo.InvariantCulture, out long result))
+                            {
+                                size = result;
+                            }
+                            if (splittedEntry.Length > 4 &&
+                                long.TryParse(splittedEntry[4], CultureInfo.InvariantCulture, out long resultCompressed))
+                            {
+                                compressed = resultCompressed;
+                            }
+                        }
+                        AddHashedFile(ReplacePathPrefixes(new FileCacheEntity(hash, path, time, size, compressed)));
+                    }
+                    catch (Exception ex)
+                    {
+                        _logger.LogWarning(ex, "Failed to initialize entry {entry}, ignoring", entry);
+                    }
+                }
+
+                if (processedFiles.Count != totalEntries)
+                {
+                    rewriteRequired = true;
+                }
+            }
+            else if (!parseEntries && entries.Length > 0)
+            {
+                _logger.LogInformation("Skipping existing file cache entries due to incompatible version.");
+            }
+
+            if (rewriteRequired)
             {
                 WriteOutFullCsv();
             }