avm2: Elide some copies when iterating vtable properties

Author: moulins

core/src/avm2/amf.rs

@@ -189,10 +189,11 @@ pub fn recursive_serialize<'gc>(
     if let Some(static_properties) = static_properties {
         let vtable = obj.vtable();
         // TODO: respect versioning
-        let mut props = vtable.public_properties();
         // Flash appears to use vtable iteration order, but we sort ours
         // to make our test output consistent.
-        props.sort_by_key(|(name, _)| name.to_utf8_lossy().to_string());
+        let mut props = vtable.public_properties().collect::<Vec<_>>();
+        props.sort_by_key(|(name, _)| *name);
+
         for (name, prop) in props {
             if let Property::Method { .. } = prop {
                 continue;

core/src/avm2/vtable.rs

@@ -549,15 +549,11 @@ impl<'gc> VTable<'gc> {
         )
     }
 
-    pub fn public_properties(self) -> Vec<(AvmString<'gc>, Property)> {
-        let mut props = Vec::new();
-
-        for (name, ns, prop) in self.resolved_traits().iter() {
-            if ns.is_public() {
-                props.push((name, *prop));
-            }
-        }
-        props
+    pub fn public_properties(self) -> impl Iterator<Item = (AvmString<'gc>, Property)> {
+        self.resolved_traits()
+            .iter()
+            .filter(|(_, ns, _)| ns.is_public())
+            .map(|(name, _, prop)| (name, *prop))
     }
 }
 

core/src/debug_ui/avm2.rs

@@ -302,13 +302,12 @@ impl Avm2ObjectWindow {
         activation: &mut Activation<'_, 'gc>,
         ui: &mut Ui,
     ) {
-        let mut entries = Vec::<(String, Namespace<'gc>, Property)>::new();
-        // We can't access things whilst we iterate the vtable, so clone and sort it all here
-        let vtable = object.vtable();
-
-        for (name, ns, prop) in vtable.resolved_traits().iter() {
-            entries.push((name.to_string(), ns, *prop));
-        }
+        let mut entries: Vec<(Cow<'gc, str>, Namespace<'gc>, Property)> = object
+            .vtable()
+            .resolved_traits()
+            .iter()
+            .map(|(name, ns, prop)| (name.as_wstr().to_utf8_lossy(), ns, *prop))
+            .collect();
         entries.sort_by(|a, b| a.0.cmp(&b.0));
 
         ui.horizontal(|ui| {