1 files changed, 35 insertions, 0 deletions
diff --git a/extra/admin-api/Interop/Spacebar.Interop.Cdn.Abstractions/LruFileCache.cs b/extra/admin-api/Interop/Spacebar.Interop.Cdn.Abstractions/LruFileCache.cs
new file mode 100644
index 00000000..3bd4ec09
--- /dev/null
+++ b/extra/admin-api/Interop/Spacebar.Interop.Cdn.Abstractions/LruFileCache.cs
@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Spacebar.Interop.Cdn.Abstractions;
+
+public class LruFileCache(int maxSizeBytes) {
+    private readonly Dictionary<string, Entry> _entries = new();
+
+    public async Task<Entry?> GetOrAdd(string key, Func<Task<Entry>> factory) {
+        if (_entries.TryGetValue(key, out var entry)) {
+            entry.LastAccessed = DateTimeOffset.UtcNow;
+            return entry;
+        }
+
+        entry = await factory();
+        if (entry.Data.Length > 0 && entry.Data.Length <= maxSizeBytes)
+            _entries[key] = entry;
+
+        if (_entries.Sum(kv => kv.Value.Data.Length) > maxSizeBytes) {
+            var oldestKey = _entries.OrderBy(kv => kv.Value.LastAccessed).First().Key;
+            _entries.Remove(oldestKey);
+        }
+
+        return entry;
+    }
+
+    public class Entry {
+        public DateTimeOffset LastAccessed { get; set; }
+        public byte[] Data { get; set; }
+        public string MimeType { get; set; }
+    }
+}
+