lib: optimize priority queue

PR-URL: #60039
Reviewed-By: Juan José Arboleda <[email protected]>
Reviewed-By: Antoine du Hamel <[email protected]>

Author: gurgunday

lib/internal/priority_queue.js

@@ -1,9 +1,5 @@
 'use strict';
 
-const {
-  Array,
-} = primordials;
-
 // The PriorityQueue is a basic implementation of a binary heap that accepts
 // a custom sorting function via its constructor. This function is passed
 // the two nodes to compare, similar to the native Array#sort. Crucially
@@ -12,7 +8,7 @@ const {
 
 module.exports = class PriorityQueue {
   #compare = (a, b) => a - b;
-  #heap = new Array(64);
+  #heap = [undefined, undefined];
   #setPosition;
   #size = 0;
 
@@ -28,9 +24,6 @@ module.exports = class PriorityQueue {
     const pos = ++this.#size;
     heap[pos] = value;
 
-    if (heap.length === pos)
-      heap.length *= 2;
-
     this.percolateUp(pos);
   }
 
@@ -45,6 +38,7 @@ module.exports = class PriorityQueue {
   percolateDown(pos) {
     const compare = this.#compare;
     const setPosition = this.#setPosition;
+    const hasSetPosition = setPosition !== undefined;
     const heap = this.#heap;
     const size = this.#size;
     const hsize = size >> 1;
@@ -62,22 +56,23 @@ module.exports = class PriorityQueue {
 
       if (compare(item, childItem) <= 0) break;
 
-      if (setPosition !== undefined)
+      if (hasSetPosition)
         setPosition(childItem, pos);
 
       heap[pos] = childItem;
       pos = child;
     }
 
     heap[pos] = item;
-    if (setPosition !== undefined)
+    if (hasSetPosition)
       setPosition(item, pos);
   }
 
   percolateUp(pos) {
     const heap = this.#heap;
     const compare = this.#compare;
     const setPosition = this.#setPosition;
+    const hasSetPosition = setPosition !== undefined;
     const item = heap[pos];
 
     while (pos > 1) {
@@ -86,13 +81,13 @@ module.exports = class PriorityQueue {
       if (compare(parentItem, item) <= 0)
         break;
       heap[pos] = parentItem;
-      if (setPosition !== undefined)
+      if (hasSetPosition)
         setPosition(parentItem, pos);
       pos = parent;
     }
 
     heap[pos] = item;
-    if (setPosition !== undefined)
+    if (hasSetPosition)
       setPosition(item, pos);
   }