sigma update

LightlessSync/FileCache/FileCacheManager.cs

@@ -115,6 +115,35 @@ public sealed class FileCacheManager : IHostedService
         return true;
     }
 
+    private static bool TryGetHashFromFileName(FileInfo fileInfo, out string hash)
+    {
+        hash = Path.GetFileNameWithoutExtension(fileInfo.Name);
+        if (string.IsNullOrWhiteSpace(hash))
+        {
+            return false;
+        }
+
+        if (hash.Length is not (40 or 64))
+        {
+            return false;
+        }
+
+        for (var i = 0; i < hash.Length; i++)
+        {
+            var c = hash[i];
+            var isHex = (c >= '0' && c <= '9')
+                || (c >= 'a' && c <= 'f')
+                || (c >= 'A' && c <= 'F');
+            if (!isHex)
+            {
+                return false;
+            }
+        }
+
+        hash = hash.ToUpperInvariant();
+        return true;
+    }
+
     private static string BuildVersionHeader() => $"{FileCacheVersionHeaderPrefix}{FileCacheVersion}";
 
     private static bool TryParseVersionHeader(string? line, out int version)
@@ -288,6 +317,11 @@ public sealed class FileCacheManager : IHostedService
         _logger.LogTrace("Creating cache entry for {path}", path);
         var cacheFolder = _configService.Current.CacheFolder;
         if (string.IsNullOrEmpty(cacheFolder)) return null;
+        if (TryGetHashFromFileName(fi, out var hash))
+        {
+            return CreateCacheEntryWithKnownHash(fi.FullName, hash);
+        }
+
         return CreateFileEntity(cacheFolder, CachePrefix, fi);
     }