File Cache Checks

Reviewed-on: #35

LightlessSync/FileCache/FileCacheManager.cs

@@ -189,7 +189,14 @@ public sealed class FileCacheManager : IHostedService
 
             Parallel.ForEach(allEntities, entity =>
             {
-                cacheDict[entity.PrefixedFilePath] = entity;
+                if (entity != null && entity.PrefixedFilePath != null)
+                {
+                    cacheDict[entity.PrefixedFilePath] = entity;
+                }
+                else
+                {
+                    _logger.LogWarning("Null FileCacheEntity or PrefixedFilePath encountered in cache population: {entity}", entity);
+                }
             });
 
             var cleanedPaths = new ConcurrentDictionary<string, string>(StringComparer.OrdinalIgnoreCase);
@@ -253,6 +260,7 @@ public sealed class FileCacheManager : IHostedService
     {
         if (_fileCaches.TryGetValue(hash, out var caches))
         {
+            _logger.LogTrace("Removing from DB: {hash} => {path}", hash, prefixedFilePath);
             var removedCount = caches?.RemoveAll(c => string.Equals(c.PrefixedFilePath, prefixedFilePath, StringComparison.Ordinal));
             _logger.LogTrace("Removed from DB: {count} file(s) with hash {hash} and file cache {path}", removedCount, hash, prefixedFilePath);
 
@@ -397,6 +405,12 @@ public sealed class FileCacheManager : IHostedService
 
     private FileCacheEntity? Validate(FileCacheEntity fileCache)
     {
+        if (string.IsNullOrWhiteSpace(fileCache.ResolvedFilepath))
+        {
+            _logger.LogWarning("FileCacheEntity has empty ResolvedFilepath for hash {hash}, prefixed path {prefixed}", fileCache.Hash, fileCache.PrefixedFilePath);
+            RemoveHashedFile(fileCache.Hash, fileCache.PrefixedFilePath);
+            return null;
+        }
         var file = new FileInfo(fileCache.ResolvedFilepath);
         if (!file.Exists)
         {