fix cache related segfault

src/cache/Cache.zig

@@ -14,18 +14,21 @@ pub const Config = struct {
     cache_dir: []const u8,
 };
 
-pub fn init(allocator: std.mem.Allocator, config: Config) !Cache {
+pub fn init(allocator: std.mem.Allocator, config: Config) !*Cache {
     std.fs.makeDirAbsolute(config.cache_dir) catch |err| {
         if (err != error.PathAlreadyExists) return err;
     };
 
-    var cache = Cache{
+    const cache = try allocator.create(Cache);
+    errdefer allocator.destroy(cache);
+
+    cache.* = Cache{
         .allocator = allocator,
         .lru = try Lru.init(allocator, config.max_entries),
         .cache_dir = try allocator.dupe(u8, config.cache_dir),
     };
 
-    cache.lru.setEvictionCallback(&cache, evictCallback);
+    cache.lru.setEvictionCallback(cache, evictCallback);
 
     // Clean up expired files and populate L1 cache from L2
     cache.loadFromDir() catch |err| {
@@ -69,6 +72,7 @@ pub fn put(self: *Cache, key: []const u8, value: []const u8, ttl_seconds: u64) !
 pub fn deinit(self: *Cache) void {
     self.lru.deinit();
     self.allocator.free(self.cache_dir);
+    self.allocator.destroy(self);
 }
 
 fn getCacheFilename(self: *Cache, key: []const u8) ![]const u8 {
@@ -247,7 +251,7 @@ test "L1/L2 cache flow" {
     var path_buf: [std.fs.max_path_bytes]u8 = undefined;
     const cache_dir = try tmp_dir.dir.realpath(".", &path_buf);
 
-    var cache = try Cache.init(allocator, .{ .max_entries = 10, .cache_dir = cache_dir });
+    const cache = try Cache.init(allocator, .{ .max_entries = 10, .cache_dir = cache_dir });
     defer cache.deinit();
 
     // Put item in cache
@@ -271,3 +275,33 @@ test "L1/L2 cache flow" {
     // Now it should be in L1
     try std.testing.expectEqualStrings("value1", cache.lru.get("key1").?);
 }
+
+test "expired cache entry returns null" {
+    const allocator = std.testing.allocator;
+
+    var tmp_dir = std.testing.tmpDir(.{});
+    defer tmp_dir.cleanup();
+
+    var path_buf: [std.fs.max_path_bytes]u8 = undefined;
+    const cache_dir = try tmp_dir.dir.realpath(".", &path_buf);
+
+    const cache = try Cache.init(allocator, .{ .max_entries = 10, .cache_dir = cache_dir });
+    defer cache.deinit();
+
+    // Put item with past expiration time
+    const now = std.time.milliTimestamp();
+    const past_expires = now - 1000;
+
+    // Manually insert expired entry into L1
+    const key_copy = try allocator.dupe(u8, "key1");
+    const value_copy = try allocator.dupe(u8, "value1");
+    try cache.lru.map.put(key_copy, .{
+        .value = value_copy,
+        .expires = past_expires,
+        .access_count = 0,
+    });
+
+    // Get should return null for expired entry
+    const result = cache.get("key1");
+    try std.testing.expect(result == null);
+}

src/main.zig

@@ -49,7 +49,7 @@ pub fn main() !void {
     // Initialize location resolver
     var resolver = Resolver.init(allocator, &geoip, &geocache, &airports_db);
 
-    var cache = try Cache.init(allocator, .{
+    const cache = try Cache.init(allocator, .{
         .max_entries = cfg.cache_size,
         .cache_dir = cfg.cache_dir,
     });
@@ -66,7 +66,7 @@ pub fn main() !void {
     defer metno.deinit();
 
     var server = try Server.init(allocator, cfg.listen_host, cfg.listen_port, .{
-        .provider = metno.provider(&cache),
+        .provider = metno.provider(cache),
         .resolver = &resolver,
         .geoip = &geoip,
     }, &rate_limiter);