Move global setup to the Env (Isolate)

Previously, we were doing some global setup in the Snapshot, but this was
always being overwritten when creating a context. This meaningless setup in
the snapshot was removed.

The global setup is now done once per isolate, rather than once per context.

src/browser/js/Env.zig

@@ -29,6 +29,8 @@ const Snapshot = @import("Snapshot.zig");
 const Inspector = @import("Inspector.zig");
 const ExecutionWorld = @import("ExecutionWorld.zig");
 
+const Window = @import("../webapi/Window.zig");
+
 const JsApis = bridge.JsApis;
 const Allocator = std.mem.Allocator;
 const ArenaAllocator = std.heap.ArenaAllocator;
@@ -59,6 +61,9 @@ eternal_function_templates: []v8.Eternal,
 // Dynamic slice to avoid circular dependency on JsApis.len at comptime
 templates: []*const v8.FunctionTemplate,
 
+// Global template created once per isolate and reused across all contexts
+global_template: v8.Eternal,
+
 pub fn init(allocator: Allocator, platform: *const Platform, snapshot: *Snapshot) !Env {
     var params = try allocator.create(v8.CreateParams);
     errdefer allocator.destroy(params);
@@ -91,6 +96,7 @@ pub fn init(allocator: Allocator, platform: *const Platform, snapshot: *Snapshot
     const templates = try allocator.alloc(*const v8.FunctionTemplate, JsApis.len);
     errdefer allocator.free(templates);
 
+    var global_eternal: v8.Eternal = undefined;
     {
         var temp_scope: js.HandleScope = undefined;
         temp_scope.init(isolate);
@@ -107,6 +113,29 @@ pub fn init(allocator: Allocator, platform: *const Platform, snapshot: *Snapshot
             const eternal_ptr = v8.v8__Eternal__Get(&eternal_function_templates[i], isolate.handle);
             templates[i] = @ptrCast(@alignCast(eternal_ptr.?));
         }
+
+        // Create global template once per isolate
+        const js_global = v8.v8__FunctionTemplate__New__DEFAULT(isolate.handle);
+        const window_name = v8.v8__String__NewFromUtf8(isolate.handle, "Window", v8.kNormal, 6);
+        v8.v8__FunctionTemplate__SetClassName(js_global, window_name);
+
+        // Find Window in JsApis by name (avoids circular import)
+        const window_index = comptime bridge.JsApiLookup.getId(Window.JsApi);
+        v8.v8__FunctionTemplate__Inherit(js_global, templates[window_index]);
+
+        const global_template_local = v8.v8__FunctionTemplate__InstanceTemplate(js_global).?;
+        v8.v8__ObjectTemplate__SetNamedHandler(global_template_local, &.{
+            .getter = bridge.unknownPropertyCallback,
+            .setter = null,
+            .query = null,
+            .deleter = null,
+            .enumerator = null,
+            .definer = null,
+            .descriptor = null,
+            .data = null,
+            .flags = v8.kOnlyInterceptStrings | v8.kNonMasking,
+        });
+        v8.v8__Eternal__New(isolate.handle, @ptrCast(global_template_local), &global_eternal);
     }
 
     return .{
@@ -117,6 +146,7 @@ pub fn init(allocator: Allocator, platform: *const Platform, snapshot: *Snapshot
         .templates = templates,
         .isolate_params = params,
         .eternal_function_templates = eternal_function_templates,
+        .global_template = global_eternal,
     };
 }
 

src/browser/js/ExecutionWorld.zig

@@ -80,21 +80,8 @@ pub fn createContext(self: *ExecutionWorld, page: *Page, enter: bool) !*Context
     hs.init(isolate);
     defer hs.deinit();
 
-    // Getting this into the snapshot is tricky (anything involving the
-    // global is tricky). Easier to do here
-    const global_template = @import("Snapshot.zig").createGlobalTemplate(isolate.handle, env.templates);
-    v8.v8__ObjectTemplate__SetNamedHandler(global_template, &.{
-        .getter = bridge.unknownPropertyCallback,
-        .setter = null,
-        .query = null,
-        .deleter = null,
-        .enumerator = null,
-        .definer = null,
-        .descriptor = null,
-        .data = null,
-        .flags = v8.kOnlyInterceptStrings | v8.kNonMasking,
-    });
-
+    // Get the global template that was created once per isolate
+    const global_template: *const v8.ObjectTemplate = @ptrCast(@alignCast(v8.v8__Eternal__Get(&env.global_template, isolate.handle).?));
     const v8_context = v8.v8__Context__New(isolate.handle, global_template, null).?;
 
     // Create the v8::Context and wrap it in a v8::Global

src/browser/js/Snapshot.zig

@@ -22,7 +22,6 @@ const bridge = @import("bridge.zig");
 const log = @import("../../log.zig");
 
 const IS_DEBUG = @import("builtin").mode == .Debug;
-const Window = @import("../webapi/Window.zig");
 
 const v8 = js.v8;
 const JsApis = bridge.JsApis;
@@ -114,20 +113,6 @@ fn isValid(self: Snapshot) bool {
     return v8.v8__StartupData__IsValid(self.startup_data);
 }
 
-pub fn createGlobalTemplate(isolate: *v8.Isolate, templates: anytype) *const v8.ObjectTemplate {
-    // Set up the global template to inherit from Window's template
-    // This way the global object gets all Window properties through inheritance
-    const js_global = v8.v8__FunctionTemplate__New__DEFAULT(isolate);
-    const window_name = v8.v8__String__NewFromUtf8(isolate, "Window", v8.kNormal, 6);
-    v8.v8__FunctionTemplate__SetClassName(js_global, window_name);
-
-    // Find Window in JsApis by name (avoids circular import)
-    const window_index = comptime bridge.JsApiLookup.getId(Window.JsApi);
-    v8.v8__FunctionTemplate__Inherit(js_global, templates[window_index]);
-
-    return v8.v8__FunctionTemplate__InstanceTemplate(js_global).?;
-}
-
 pub fn create() !Snapshot {
     var external_references = collectExternalReferences();
 
@@ -169,8 +154,7 @@ pub fn create() !Snapshot {
 
         // Set up the global template to inherit from Window's template
         // This way the global object gets all Window properties through inheritance
-        const global_template = createGlobalTemplate(isolate, templates[0..]);
-        const context = v8.v8__Context__New(isolate, global_template, null);
+        const context = v8.v8__Context__New(isolate, null, null);
         v8.v8__Context__Enter(context);
         defer v8.v8__Context__Exit(context);