use with_capacity to reduce re-allocations fixes #3896

core/engine/src/builtins/array/mod.rs

@@ -190,6 +190,9 @@ impl BuiltInObject for Array {
 }
 
 impl BuiltInConstructor for Array {
+    const P: usize = 41;
+    const SP: usize = 5;
+
     const LENGTH: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =

core/engine/src/builtins/array_buffer/mod.rs

@@ -374,6 +374,8 @@ impl BuiltInObject for ArrayBuffer {
 }
 
 impl BuiltInConstructor for ArrayBuffer {
+    const P: usize = 9;
+    const SP: usize = 2;
     const LENGTH: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =

core/engine/src/builtins/array_buffer/shared.rs

@@ -155,6 +155,8 @@ impl BuiltInObject for SharedArrayBuffer {
 
 impl BuiltInConstructor for SharedArrayBuffer {
     const LENGTH: usize = 1;
+    const P: usize = 6;
+    const SP: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::shared_array_buffer;

core/engine/src/builtins/async_function/mod.rs

@@ -52,6 +52,8 @@ impl BuiltInObject for AsyncFunction {
 
 impl BuiltInConstructor for AsyncFunction {
     const LENGTH: usize = 1;
+    const P: usize = 1;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::async_function;

core/engine/src/builtins/async_generator_function/mod.rs

@@ -57,6 +57,8 @@ impl BuiltInObject for AsyncGeneratorFunction {
 
 impl BuiltInConstructor for AsyncGeneratorFunction {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::async_generator_function;

core/engine/src/builtins/bigint/mod.rs

@@ -65,6 +65,8 @@ impl BuiltInObject for BigInt {
 
 impl BuiltInConstructor for BigInt {
     const LENGTH: usize = 1;
+    const P: usize = 3;
+    const SP: usize = 2;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::bigint;

core/engine/src/builtins/boolean/mod.rs

@@ -51,6 +51,8 @@ impl BuiltInObject for Boolean {
 
 impl BuiltInConstructor for Boolean {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::boolean;

core/engine/src/builtins/builder.rs

@@ -135,6 +135,9 @@ impl ApplyToObject for OrdinaryObject {
     fn apply_to(self, _: &JsObject) {}
 }
 
+// The number of properties that are always present in a standard constructor. See build method
+const OWN_PROPS: usize = 3;
+
 /// Builder for creating built-in objects, like `Array`.
 ///
 /// The marker `ObjectType` restricts the methods that can be called depending on the
@@ -528,6 +531,7 @@ impl<'ctx> BuiltInBuilder<'ctx, OrdinaryObject> {
 }
 
 impl<'ctx> BuiltInBuilder<'ctx, Callable<Constructor>> {
+    /// Create a new builder for a constructor function setting the properties ahead of time for optimizations (less reallocations)
     pub(crate) fn from_standard_constructor<SC: BuiltInConstructor>(
         realm: &'ctx Realm,
     ) -> BuiltInConstructorWithPrototype<'ctx> {
@@ -537,11 +541,11 @@ impl<'ctx> BuiltInBuilder<'ctx, Callable<Constructor>> {
             function: SC::constructor,
             name: js_string!(SC::NAME),
             length: SC::LENGTH,
-            object_property_table: PropertyTableInner::default(),
-            object_storage: Vec::default(),
+            object_property_table: PropertyTableInner::with_capacity(SC::SP + OWN_PROPS),
+            object_storage: Vec::with_capacity(SC::SP + OWN_PROPS),
             object: constructor.constructor(),
-            prototype_property_table: PropertyTableInner::default(),
-            prototype_storage: Vec::default(),
+            prototype_property_table: PropertyTableInner::with_capacity(SC::P),
+            prototype_storage: Vec::with_capacity(SC::P),
             prototype: constructor.prototype(),
             __proto__: Some(realm.intrinsics().constructors().function().prototype()),
             inherits: Some(realm.intrinsics().constructors().object().prototype()),

core/engine/src/builtins/dataview/mod.rs

@@ -167,6 +167,8 @@ impl BuiltInObject for DataView {
 
 impl BuiltInConstructor for DataView {
     const LENGTH: usize = 1;
+    const P: usize = 24;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::data_view;

core/engine/src/builtins/date/mod.rs

@@ -185,6 +185,8 @@ impl BuiltInObject for Date {
 
 impl BuiltInConstructor for Date {
     const LENGTH: usize = 7;
+    const P: usize = 47;
+    const SP: usize = 3;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::date;

core/engine/src/builtins/error/aggregate.rs

@@ -52,6 +52,8 @@ impl BuiltInObject for AggregateError {
 
 impl BuiltInConstructor for AggregateError {
     const LENGTH: usize = 2;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::aggregate_error;

core/engine/src/builtins/error/eval.rs

@@ -54,6 +54,8 @@ impl BuiltInObject for EvalError {
 
 impl BuiltInConstructor for EvalError {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::eval_error;

core/engine/src/builtins/error/mod.rs

@@ -154,6 +154,8 @@ impl BuiltInObject for Error {
 
 impl BuiltInConstructor for Error {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::error;

core/engine/src/builtins/error/range.rs

@@ -52,6 +52,8 @@ impl BuiltInObject for RangeError {
 
 impl BuiltInConstructor for RangeError {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::range_error;

core/engine/src/builtins/error/reference.rs

@@ -51,6 +51,8 @@ impl BuiltInObject for ReferenceError {
 
 impl BuiltInConstructor for ReferenceError {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::reference_error;

core/engine/src/builtins/error/syntax.rs

@@ -54,6 +54,8 @@ impl BuiltInObject for SyntaxError {
 
 impl BuiltInConstructor for SyntaxError {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::syntax_error;

core/engine/src/builtins/error/type.rs

@@ -60,6 +60,8 @@ impl BuiltInObject for TypeError {
 
 impl BuiltInConstructor for TypeError {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::type_error;

core/engine/src/builtins/error/uri.rs

@@ -53,6 +53,8 @@ impl BuiltInObject for UriError {
 
 impl BuiltInConstructor for UriError {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::uri_error;

core/engine/src/builtins/function/mod.rs

@@ -356,6 +356,8 @@ impl BuiltInObject for BuiltInFunctionObject {
 
 impl BuiltInConstructor for BuiltInFunctionObject {
     const LENGTH: usize = 1;
+    const P: usize = 7;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::function;

core/engine/src/builtins/generator_function/mod.rs

@@ -62,6 +62,8 @@ impl BuiltInObject for GeneratorFunction {
 
 impl BuiltInConstructor for GeneratorFunction {
     const LENGTH: usize = 1;
+    const P: usize = 2;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::generator_function;

core/engine/src/builtins/intl/collator/mod.rs

@@ -188,6 +188,8 @@ impl BuiltInObject for Collator {
 
 impl BuiltInConstructor for Collator {
     const LENGTH: usize = 0;
+    const P: usize = 3;
+    const SP: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::collator;

core/engine/src/builtins/intl/date_time_format.rs

@@ -82,6 +82,8 @@ impl BuiltInObject for DateTimeFormat {
 
 impl BuiltInConstructor for DateTimeFormat {
     const LENGTH: usize = 0;
+    const P: usize = 0;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::date_time_format;

core/engine/src/builtins/intl/list_format/mod.rs

@@ -83,6 +83,8 @@ impl BuiltInObject for ListFormat {
 
 impl BuiltInConstructor for ListFormat {
     const LENGTH: usize = 0;
+    const P: usize = 4;
+    const SP: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::list_format;

core/engine/src/builtins/intl/locale/mod.rs

@@ -157,6 +157,8 @@ impl BuiltInObject for Locale {
 
 impl BuiltInConstructor for Locale {
     const LENGTH: usize = 1;
+    const P: usize = 14;
+    const SP: usize = 0;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::locale;

core/engine/src/builtins/intl/number_format/mod.rs

@@ -173,6 +173,8 @@ impl BuiltInObject for NumberFormat {
 
 impl BuiltInConstructor for NumberFormat {
     const LENGTH: usize = 0;
+    const P: usize = 3;
+    const SP: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::number_format;

core/engine/src/builtins/intl/plural_rules/mod.rs

@@ -83,6 +83,8 @@ impl BuiltInObject for PluralRules {
 
 impl BuiltInConstructor for PluralRules {
     const LENGTH: usize = 0;
+    const P: usize = 4;
+    const SP: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::plural_rules;

core/engine/src/builtins/intl/segmenter/mod.rs

@@ -119,6 +119,8 @@ impl BuiltInObject for Segmenter {
 
 impl BuiltInConstructor for Segmenter {
     const LENGTH: usize = 0;
+    const P: usize = 3;
+    const SP: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::segmenter;

core/engine/src/builtins/map/mod.rs

@@ -108,6 +108,8 @@ impl BuiltInObject for Map {
 
 impl BuiltInConstructor for Map {
     const LENGTH: usize = 0;
+    const P: usize = 11;
+    const SP: usize = 2;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::map;

core/engine/src/builtins/mod.rs

@@ -37,6 +37,7 @@ pub mod weak_set;
 mod builder;
 
 use boa_macros::js_str;
+use boa_profiler::Profiler;
 use builder::BuiltInBuilder;
 
 #[cfg(feature = "annex-b")]
@@ -157,6 +158,10 @@ pub(crate) trait BuiltInObject: IntrinsicObject {
 ///
 /// [built-in object]: https://tc39.es/ecma262/#sec-built-in-object
 pub(crate) trait BuiltInConstructor: BuiltInObject {
+    /// Const Generic `P` is the minimum storage capacity for the prototype's Property table.
+    const P: usize;
+    /// Const Generic `SP` is the minimum storage capacity for the object's Static Property table.
+    const SP: usize;
     /// The amount of arguments this function object takes.
     const LENGTH: usize;
 
@@ -304,6 +309,8 @@ impl Realm {
 ///
 /// [spec]: https://tc39.es/ecma262/#sec-setdefaultglobalbindings
 pub(crate) fn set_default_global_bindings(context: &mut Context) -> JsResult<()> {
+    let _timer =
+        Profiler::global().start_event("Builtins::set_default_global_bindings", "Builtins");
     let global_object = context.global_object();
 
     global_object.define_property_or_throw(

core/engine/src/builtins/number/mod.rs

@@ -108,6 +108,8 @@ impl BuiltInObject for Number {
 
 impl BuiltInConstructor for Number {
     const LENGTH: usize = 1;
+    const P: usize = 6;
+    const SP: usize = 14;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::number;

core/engine/src/builtins/object/mod.rs

@@ -150,6 +150,8 @@ impl BuiltInObject for OrdinaryObject {
 
 impl BuiltInConstructor for OrdinaryObject {
     const LENGTH: usize = 1;
+    const P: usize = 11;
+    const SP: usize = 23;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::object;

core/engine/src/builtins/promise/mod.rs

@@ -381,6 +381,8 @@ impl BuiltInObject for Promise {
 
 impl BuiltInConstructor for Promise {
     const LENGTH: usize = 1;
+    const P: usize = 4;
+    const SP: usize = 9;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::promise;

core/engine/src/builtins/proxy/mod.rs

@@ -106,6 +106,8 @@ impl BuiltInObject for Proxy {
 
 impl BuiltInConstructor for Proxy {
     const LENGTH: usize = 2;
+    const P: usize = 0;
+    const SP: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::proxy;

core/engine/src/builtins/regexp/mod.rs

@@ -177,6 +177,8 @@ impl BuiltInObject for RegExp {
 
 impl BuiltInConstructor for RegExp {
     const LENGTH: usize = 2;
+    const P: usize = 19;
+    const SP: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::regexp;

core/engine/src/builtins/set/mod.rs

@@ -109,6 +109,8 @@ impl BuiltInObject for Set {
 
 impl BuiltInConstructor for Set {
     const LENGTH: usize = 0;
+    const P: usize = 11;
+    const SP: usize = 1;
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::set;
 

core/engine/src/builtins/string/mod.rs

@@ -198,6 +198,8 @@ impl BuiltInObject for String {
 
 impl BuiltInConstructor for String {
     const LENGTH: usize = 1;
+    const P: usize = 36;
+    const SP: usize = 3;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::string;

core/engine/src/builtins/symbol/mod.rs

@@ -186,6 +186,8 @@ impl BuiltInObject for Symbol {
 
 impl BuiltInConstructor for Symbol {
     const LENGTH: usize = 0;
+    const P: usize = 5;
+    const SP: usize = 15;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::symbol;

core/engine/src/builtins/temporal/duration/mod.rs

@@ -201,6 +201,8 @@ impl IntrinsicObject for Duration {
 
 impl BuiltInConstructor for Duration {
     const LENGTH: usize = 0;
+    const P: usize = 22;
+    const SP: usize = 1;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::duration;

core/engine/src/builtins/temporal/instant/mod.rs

@@ -127,6 +127,8 @@ impl IntrinsicObject for Instant {
 
 impl BuiltInConstructor for Instant {
     const LENGTH: usize = 1;
+    const P: usize = 13;
+    const SP: usize = 4;
 
     const STANDARD_CONSTRUCTOR: fn(&StandardConstructors) -> &StandardConstructor =
         StandardConstructors::instant;