Fix incorrectly cleaning up data archive memory in app context

src/oar.zig

@@ -3,7 +3,7 @@ const sys = @import("./sys.zig");
 const table = @import("./table.zig");
 
 ///
-///
+/// Thin file-wrapper and in-memory layout cache of an OAR archive file.
 ///
 pub const Archive = struct {
     file_access: sys.FileAccess,
@@ -17,15 +17,28 @@ pub const Archive = struct {
     };
 
     ///
-    ///
+    /// See [std.mem.Allocator.Error].
     ///
     pub const InitError = std.mem.Allocator.Error;
 
     ///
+    /// In-memory archive layout cache.
     ///
+    /// As the archive is queried via [find], the cache is lazily assembled with the absolute
+    /// offsets of each queried file.
     ///
     const IndexCache = table.Hashed([]const u8, u64, table.string_context);
 
+    ///
+    /// Deinitializes the index cache of `archive`, freeing all associated memory.
+    ///
+    /// **Note** that this does nothing to the [FileAccess] value that was provided as part of
+    /// [init].
+    ///
+    pub fn deint(archive: *Archive) void {
+        archive.index_cache.deinit();
+    }
+
     ///
     /// Finds an entry matching `entry_path` in `archive`.
     ///
@@ -90,11 +103,17 @@ pub const Archive = struct {
     }
 
     ///
+    /// Attempts to initialize a new [Archive] with `cache_allocator` as the allocator for managing
+    /// the in-memory archive layout caches and `archive_file_access` as the currently open archive
+    /// file.
     ///
+    /// **Note** that `archive_file_access` does nothing to manage the lifetime of the open file.
     ///
-    pub fn init(allocator: std.mem.Allocator, archive_file_access: sys.FileAccess) InitError!Archive {
+    pub fn init(cache_allocator: std.mem.Allocator,
+        archive_file_access: sys.FileAccess) InitError!Archive {
+
         return Archive{
-            .index_cache = try IndexCache.init(allocator),
+            .index_cache = try IndexCache.init(cache_allocator),
             .file_access = archive_file_access,
         };
     }

src/sys.zig

@@ -102,9 +102,10 @@ pub const AppContext = opaque {
                 }
             }
 
+            implementation.data_file_system.archive.instance.deint();
+            ext.SDL_free(implementation.user_path_prefix);
             ext.SDL_DestroyMutex(implementation.message_mutex);
             ext.SDL_DestroySemaphore(implementation.message_semaphore);
-            ext.SDL_free(implementation.user_path_prefix);
         }
 
         ///