resources pretty done

zig-ecs/src/ecs/utils.zig

@@ -49,8 +49,9 @@ pub fn typeId64(comptime T: type) u64 {
     return hashStringFnv(u64, @typeName(T));
 }
 
+/// u32 Fowler-Noll-Vo string hash
 pub fn hashString(comptime str: []const u8) u32 {
-    return @truncate(u32, std.hash.Wyhash.hash(0, str));
+    return hashStringFnv(u32, str);
 }
 
 /// Fowler–Noll–Vo string hash. ReturnType should be u32/u64

zig-ecs/src/resources/assets.zig

@@ -23,22 +23,26 @@ pub const Assets = struct {
         self.caches.deinit();
     }
 
-    pub fn registerCache(self: *Assets, comptime AssetT: type, comptime LoaderT: type) *Cache(AssetT) {
-        var cache = Cache(AssetT).initPtr(self.allocator, LoaderT);
+    pub fn get(self: *Assets, comptime AssetT: type) *Cache(AssetT) {
+        if (self.caches.getValue(utils.typeId(AssetT))) |tid| {
+            return @intToPtr(*Cache(AssetT), tid);
+        }
+
+        var cache = Cache(AssetT).initPtr(self.allocator);
         _ = self.caches.put(utils.typeId(AssetT), @ptrToInt(cache)) catch unreachable;
         return cache;
     }
 
-    pub fn get(self: Assets, comptime AssetT: type) *Cache(AssetT) {
-        if (self.caches.getValue(utils.typeId(AssetT))) |tid| {
-            return @intToPtr(*Cache(AssetT), tid);
-        }
-        unreachable;
+    pub fn load(self: *Assets, id: u16, comptime loader: var) ReturnType(loader, false) {
+        return self.get(ReturnType(loader, true)).load(id, loader);
     }
 
-    pub fn load(self: Assets, comptime AssetT: type, comptime LoaderT: type, args: LoaderT.LoadArgs) *AssetT {
-        var cache = self.get(AssetT);
-        return cache.load(666, LoaderT, args);
+    fn ReturnType(comptime loader: var, strip_ptr: bool) type {
+        var ret = @typeInfo(@TypeOf(@field(loader, "load"))).BoundFn.return_type.?;
+        if (strip_ptr) {
+            return ret.Child;
+        }
+        return ret;
     }
 };
 
@@ -50,13 +54,6 @@ test "assets" {
         }
     };
 
-    const ThingLoader = struct {
-        pub const LoadArgs = struct {};
-        pub fn load(self: @This(), args: var) *Thing {
-            return std.testing.allocator.create(Thing) catch unreachable;
-        }
-    };
-
     const OtherThing = struct {
         fart: i32,
         pub fn deinit(self: *@This()) void {
@@ -64,20 +61,33 @@ test "assets" {
         }
     };
 
-    const OtherThingLoader = struct {
-        pub const LoadArgs = struct {};
-        pub fn load(self: @This(), args: var) *OtherThing {
+    const OtherThingLoadArgs = struct {
+        pub fn load(self: @This()) *OtherThing {
             return std.testing.allocator.create(OtherThing) catch unreachable;
         }
     };
 
+    const ThingLoadArgs = struct {
+        pub fn load(self: @This()) *Thing {
+            return std.testing.allocator.create(Thing) catch unreachable;
+        }
+    };
+
     var assets = Assets.init(std.testing.allocator);
     defer assets.deinit();
 
-    var cache = assets.registerCache(Thing, ThingLoader);
-    var thing = assets.get(Thing).load(6, ThingLoader, ThingLoader.LoadArgs{});
-    std.testing.expectEqual(cache.size(), 1);
+    var thing = assets.get(Thing).load(6, ThingLoadArgs{});
+    std.testing.expectEqual(assets.get(Thing).size(), 1);
+
+    var thing2 = assets.load(4, ThingLoadArgs{});
+    std.testing.expectEqual(assets.get(Thing).size(), 2);
+
+    var other_thing = assets.get(OtherThing).load(6, OtherThingLoadArgs{});
+    std.testing.expectEqual(assets.get(OtherThing).size(), 1);
+
+    var other_thing2 = assets.load(8, OtherThingLoadArgs{});
+    std.testing.expectEqual(assets.get(OtherThing).size(), 2);
 
-    var thing2 = assets.load(Thing, ThingLoader, ThingLoader.LoadArgs{});
-    std.testing.expectEqual(cache.size(), 2);
+    assets.get(OtherThing).clear();
+    std.testing.expectEqual(assets.get(OtherThing).size(), 0);
 }

zig-ecs/src/resources/cache.zig

@@ -1,24 +1,18 @@
 const std = @import("std");
 const ErasedPtr = @import("../ecs/utils.zig").ErasedPtr;
 
-/// Simple cache for resources of a given type. TLoader should be a struct that implements a single
-/// method: load(args: var) *T. If any resource has a deinit method it will be called when clear
-/// or remove is called.
+/// Simple cache for resources of a given type. If any resource has a deinit method it will be called when clear
+/// or remove is called. Implementing a "loader" which is passed to "load" is a struct with one method:
+/// - load(self: @This()) *T.
 pub fn Cache(comptime T: type) type {
     return struct {
         const Self = @This();
 
         safe_deinit: fn (*@This()) void,
-        resources: std.AutoHashMap(u16, *T),
-        loader: ErasedPtr,
+        resources: std.AutoHashMap(u32, *T),
         allocator: ?*std.mem.Allocator = null,
 
-        pub fn initPtr(allocator: *std.mem.Allocator, comptime LoaderT: type) *@This() {
-            const ptr = if (@sizeOf(LoaderT) > 0)
-                ErasedPtr.init(allocator.create(LoaderT) catch unreachable)
-            else
-                ErasedPtr.init(LoaderT);
-
+        pub fn initPtr(allocator: *std.mem.Allocator) *@This() {
             var cache = allocator.create(@This()) catch unreachable;
             cache.safe_deinit = struct {
                 fn deinit(self: *Self) void {
@@ -27,18 +21,12 @@ pub fn Cache(comptime T: type) type {
                     self.allocator.?.destroy(self);
                 }
             }.deinit;
-            cache.loader = ptr;
-            cache.resources = std.AutoHashMap(u16, *T).init(allocator);
+            cache.resources = std.AutoHashMap(u32, *T).init(allocator);
             cache.allocator = allocator;
             return cache;
         }
 
-        pub fn init(allocator: *std.mem.Allocator, comptime LoaderT: type) @This() {
-            const ptr = if (@sizeOf(LoaderT) > 0)
-                ErasedPtr.init(std.testing.allocator.create(LoaderT) catch unreachable)
-            else
-                ErasedPtr.init(LoaderT);
-
+        pub fn init(allocator: *std.mem.Allocator) @This() {
             return .{
                 .safe_deinit = struct {
                     fn deinit(self: *Self) void {
@@ -46,8 +34,7 @@ pub fn Cache(comptime T: type) type {
                         self.resources.deinit();
                     }
                 }.deinit,
-                .loader = ptr,
-                .resources = std.AutoHashMap(u16, *T).init(allocator),
+                .resources = std.AutoHashMap(u32, *T).init(allocator),
             };
         }
 
@@ -55,21 +42,21 @@ pub fn Cache(comptime T: type) type {
             self.safe_deinit(self);
         }
 
-        fn load(self: *@This(), id: u16, comptime LoaderT: type, args: LoaderT.LoadArgs) *T {
+        pub fn load(self: *@This(), id: u32, comptime loader: var) @typeInfo(@TypeOf(@field(loader, "load"))).BoundFn.return_type.? {
             if (self.resources.getValue(id)) |resource| {
                 return resource;
             }
 
-            var resource = self.loader.as(LoaderT).load(args);
+            var resource = loader.load();
             _ = self.resources.put(id, resource) catch unreachable;
             return resource;
         }
 
-        pub fn contains(self: *@This(), id: u16) bool {
+        pub fn contains(self: *@This(), id: u32) bool {
             return self.resources.contains(id);
         }
 
-        pub fn remove(self: *@This(), id: u16) void {
+        pub fn remove(self: *@This(), id: u32) void {
             if (self.resources.remove(id)) |kv| {
                 if (@hasDecl(T, "deinit")) {
                     @call(.{ .modifier = .always_inline }, @field(kv.value, "deinit"), .{});
@@ -95,6 +82,8 @@ pub fn Cache(comptime T: type) type {
 }
 
 test "cache" {
+    const utils = @import("../ecs/utils.zig");
+
     const Thing = struct {
         fart: i32,
         pub fn deinit(self: *@This()) void {
@@ -102,21 +91,20 @@ test "cache" {
         }
     };
 
-    const ThingLoader = struct {
-        pub const LoadArgs = struct {};
-        pub fn load(self: @This(), args: var) *Thing {
+    const ThingLoadArgs = struct {
+        pub fn load(self: @This()) *Thing {
             return std.testing.allocator.create(Thing) catch unreachable;
         }
     };
 
-    var cache = Cache(Thing).init(std.testing.allocator, ThingLoader);
+    var cache = Cache(Thing).init(std.testing.allocator);
     defer cache.deinit();
 
-    var thing = cache.load(6, ThingLoader, ThingLoader.LoadArgs{});
-    var thing2 = cache.load(2, ThingLoader, ThingLoader.LoadArgs{});
+    var thing = cache.load(utils.hashString("my/id"), ThingLoadArgs{});
+    var thing2 = cache.load(utils.hashString("another/id"), ThingLoadArgs{});
     std.testing.expectEqual(cache.size(), 2);
 
-    cache.remove(2);
+    cache.remove(utils.hashString("my/id"));
     std.testing.expectEqual(cache.size(), 1);
 
     cache.clear();