implement CacheEntry deinit to clean up code a bit

src/cache/Cache.zig

@@ -49,8 +49,7 @@ pub fn get(self: *Cache, key: []const u8) ?[]const u8 {
 
     // Check L2 (disk)
     const cached = self.loadFromFile(key) catch return null;
-    defer self.allocator.free(cached.key);
-    defer self.allocator.free(cached.value);
+    defer cached.deinit(self.allocator);
 
     // L2 exists - promote to L1
     self.lru.put(key, cached.value, cached.expires) catch return null;
@@ -86,6 +85,11 @@ const CacheEntry = struct {
     key: []const u8,
     value: []const u8,
     expires: i64,
+
+    pub fn deinit(self: CacheEntry, allocator: std.mem.Allocator) void {
+        allocator.free(self.key);
+        allocator.free(self.value);
+    }
 };
 
 /// Loads cached value from file (path calculated by the key). An error will be thrown
@@ -113,7 +117,7 @@ fn loadFromFilePath(self: *Cache, file_path: []const u8) !CacheEntry {
     const reader = &file_reader.interface;
 
     const cached = try deserialize(self.allocator, reader);
-    errdefer self.allocator.free(cached.value);
+    errdefer cached.deinit(self.allocator);
 
     // Check if expired
     const now = std.time.milliTimestamp();
@@ -179,8 +183,7 @@ fn loadFromDir(self: *Cache) !void {
         defer self.allocator.free(file_path);
 
         const cached = self.loadFromFilePath(file_path) catch continue;
-        defer self.allocator.free(cached.key);
-        defer self.allocator.free(cached.value);
+        defer cached.deinit(self.allocator);
 
         // Populate L1 cache from L2
         self.lru.put(cached.key, cached.value, cached.expires) catch continue;
@@ -218,8 +221,7 @@ test "serialize and deserialize" {
     var fixed_reader = std.Io.Reader.fixed(serialized);
 
     const cached = try deserialize(allocator, &fixed_reader);
-    defer allocator.free(cached.key);
-    defer allocator.free(cached.value);
+    defer cached.deinit(allocator);
 
     try std.testing.expectEqualStrings(key, cached.key);
     try std.testing.expectEqualStrings(value, cached.value);
@@ -234,8 +236,7 @@ test "deserialize handles integer expires" {
     var fixed_reader = std.Io.Reader.fixed(json);
 
     const cached = try deserialize(allocator, &fixed_reader);
-    defer allocator.free(cached.key);
-    defer allocator.free(cached.value);
+    defer cached.deinit(allocator);
 
     try std.testing.expectEqualStrings("k", cached.key);
     try std.testing.expectEqualStrings("v", cached.value);