Add array pool for sorted components (#6718)

* add pool

* move sort to module

src/core/sort.js

@@ -6,27 +6,10 @@
  */
 const cmpPriority = (a, b) => a.priority - b.priority;
 
-
-/**
- * @param {{order: number}} a - First object with `order` property.
- * @param {{order: number}} b - Second object with `order` property.
- * @returns {number} A number indicating the relative position.
- * @ignore
- */
-const cmpStaticOrder = (a, b) => a.constructor.order - b.constructor.order;
-
 /**
  * @param {Array<{priority: number}>} arr - Array to be sorted in place where each element contains
  * an object with at least a priority property.
  * @returns {Array<{priority: number}>} In place sorted array.
  * @ignore
  */
 export const sortPriority = arr => arr.sort(cmpPriority);
-
-/**
- * @param {Array<{order: number}>} arr - Array to be sorted in place where each element contains
- * an object with a static `order` property.
- * @returns {Array<{order: number}>} In place sorted array.
- * @ignore
- */
-export const sortStaticOrder = arr => arr.sort(cmpStaticOrder);

src/framework/entity.js

@@ -1,22 +1,54 @@
 import { Debug } from '../core/debug.js';
 import { guid } from '../core/guid.js';
-import { sortStaticOrder } from '../core/sort.js';
 
 import { GraphNode } from '../scene/graph-node.js';
 
 import { getApplication } from './globals.js';
 
+/**
+ * @typedef {import('./components/component.js').Component} Component
+ */
+
+/**
+ * @param {Component} a - First object with `order` property.
+ * @param {Component} b - Second object with `order` property.
+ * @returns {number} A number indicating the relative position.
+ * @ignore
+ */
+const cmpStaticOrder = (a, b) => a.constructor.order - b.constructor.order;
+
+/**
+ * @param {Array<Component>} arr - Array to be sorted in place where each element contains
+ * an object with a static `order` property.
+ * @returns {Array<Component>} In place sorted array.
+ * @ignore
+ */
+const sortStaticOrder = arr => arr.sort(cmpStaticOrder);
+
 /**
  * @type {GraphNode[]}
  * @ignore
  */
 const _enableList = [];
 
 /**
- * @type {Array<import('./components/component.js').Component>}
+ * @type {Array<Array<Component>>}
+ * @ignore
+ */
+const tmpPool = [];
+
+const getTempArray = () => {
+    return tmpPool.pop() ?? [];
+};
+
+/**
+ * @param {Array<Component>} a - Array to return back to pool.
  * @ignore
  */
-const _sortedArray = [];
+const releaseTempArray = (a) => {
+    a.length = 0;
+    tmpPool.push(a);
+};
 
 /**
  * The Entity is the core primitive of a PlayCanvas game. Generally speaking an object in your game
@@ -522,7 +554,7 @@ class Entity extends GraphNode {
             }
         }
 
-        components.length = 0;
+        releaseTempArray(components);
     }
 
     /** @private */
@@ -533,7 +565,7 @@ class Entity extends GraphNode {
             components[i].onPostStateChange();
         }
 
-        components.length = 0;
+        releaseTempArray(components);
     }
 
     /**
@@ -609,23 +641,22 @@ class Entity extends GraphNode {
     }
 
     _getSortedComponents() {
-        Debug.assert(_sortedArray.length === 0);
-
         const components = this.c;
+        const sortedArray = getTempArray();
         let needSort = 0;
         for (const type in components) {
             if (components.hasOwnProperty(type)) {
                 const component = components[type];
                 needSort |= component.constructor.order !== 0;
-                _sortedArray.push(component);
+                sortedArray.push(component);
             }
         }
 
-        if (needSort && _sortedArray.length > 1) {
-            sortStaticOrder(_sortedArray);
+        if (needSort && sortedArray.length > 1) {
+            sortStaticOrder(sortedArray);
         }
 
-        return _sortedArray;
+        return sortedArray;
     }
 
     /**