From 74de4ad659e16db9bb9f41cec0c10a07b0523e63 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=BCrg=C3=BCn=20Day=C4=B1o=C4=9Flu?= <hey@gurgun.day>
Date: Mon, 17 Feb 2025 02:01:11 +0100
Subject: [PATCH 1/3] lib: optimize priority queue

---
 lib/internal/priority_queue.js | 44 +++++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 16 deletions(-)

diff --git a/lib/internal/priority_queue.js b/lib/internal/priority_queue.js
index e61cc04c101b7c..747c723afff592 100644
--- a/lib/internal/priority_queue.js
+++ b/lib/internal/priority_queue.js
@@ -47,20 +47,28 @@ module.exports = class PriorityQueue {
     const setPosition = this.#setPosition;
     const heap = this.#heap;
     const size = this.#size;
+    const hsize = size >> 1;
     const item = heap[pos];
 
-    while (pos * 2 <= size) {
-      let childIndex = pos * 2 + 1;
-      if (childIndex > size || compare(heap[pos * 2], heap[childIndex]) < 0)
-        childIndex = pos * 2;
-      const child = heap[childIndex];
-      if (compare(item, child) <= 0)
-        break;
+    while (pos <= hsize) {
+      let child = pos << 1;
+      const nextChild = child + 1;
+      let childItem = heap[child];
+
+      if (nextChild <= size && compare(heap[nextChild], childItem) < 0) {
+        child = nextChild;
+        childItem = heap[nextChild];
+      }
+
+      if (compare(item, childItem) <= 0) break;
+
       if (setPosition !== undefined)
-        setPosition(child, pos);
-      heap[pos] = child;
-      pos = childIndex;
+        setPosition(childItem, pos);
+
+      heap[pos] = childItem;
+      pos = child;
     }
+
     heap[pos] = item;
     if (setPosition !== undefined)
       setPosition(item, pos);
@@ -73,27 +81,31 @@ module.exports = class PriorityQueue {
     const item = heap[pos];
 
     while (pos > 1) {
-      const parent = heap[pos / 2 | 0];
-      if (compare(parent, item) <= 0)
+      const parent = pos >> 1;
+      const parentItem = heap[parent];
+      if (compare(parentItem, item) <= 0)
         break;
-      heap[pos] = parent;
+      heap[pos] = parentItem;
       if (setPosition !== undefined)
-        setPosition(parent, pos);
-      pos = pos / 2 | 0;
+        setPosition(parentItem, pos);
+      pos = parent;
     }
+
     heap[pos] = item;
     if (setPosition !== undefined)
       setPosition(item, pos);
   }
 
   removeAt(pos) {
+    if (pos > this.#size) return;
+
     const heap = this.#heap;
     const size = --this.#size;
     heap[pos] = heap[size + 1];
     heap[size + 1] = undefined;
 
     if (size > 0 && pos <= size) {
-      if (pos > 1 && this.#compare(heap[pos / 2 | 0], heap[pos]) > 0)
+      if (pos > 1 && this.#compare(heap[pos >> 1], heap[pos]) > 0)
         this.percolateUp(pos);
       else
         this.percolateDown(pos);

From be07d41871b2c00361dddb13d3eb5bb51f564cd8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=BCrg=C3=BCn=20Day=C4=B1o=C4=9Flu?= <hey@gurgun.day>
Date: Mon, 17 Feb 2025 08:29:14 +0100
Subject: [PATCH 2/3] coverage

---
 test/parallel/test-priority-queue.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/test/parallel/test-priority-queue.js b/test/parallel/test-priority-queue.js
index b98d228b08763b..a04d8016a587d7 100644
--- a/test/parallel/test-priority-queue.js
+++ b/test/parallel/test-priority-queue.js
@@ -102,6 +102,9 @@ const PriorityQueue = require('internal/priority_queue');
   // Check that removing the last item doesn't throw
   queue.removeAt(6);
 
+  // Check that removing an item that doesn't exist doesn't throw
+  queue.removeAt(15);
+
   assert.strictEqual(queue.shift().value, 1);
   assert.strictEqual(queue.shift().value, 2);
   assert.strictEqual(queue.shift().value, 2);

From db55a715dcde58ce6d87e9cbfd7f980b3e545fd1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=BCrg=C3=BCn=20Day=C4=B1o=C4=9Flu?= <hey@gurgun.day>
Date: Sun, 23 Feb 2025 11:57:24 +0100
Subject: [PATCH 3/3] remove breaking change

---
 lib/internal/priority_queue.js       | 9 ++++-----
 test/parallel/test-priority-queue.js | 3 ---
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/lib/internal/priority_queue.js b/lib/internal/priority_queue.js
index 747c723afff592..c172e2351c93ab 100644
--- a/lib/internal/priority_queue.js
+++ b/lib/internal/priority_queue.js
@@ -97,12 +97,11 @@ module.exports = class PriorityQueue {
   }
 
   removeAt(pos) {
-    if (pos > this.#size) return;
-
     const heap = this.#heap;
-    const size = --this.#size;
-    heap[pos] = heap[size + 1];
-    heap[size + 1] = undefined;
+    let size = this.#size;
+    heap[pos] = heap[size];
+    heap[size] = undefined;
+    size = --this.#size;
 
     if (size > 0 && pos <= size) {
       if (pos > 1 && this.#compare(heap[pos >> 1], heap[pos]) > 0)
diff --git a/test/parallel/test-priority-queue.js b/test/parallel/test-priority-queue.js
index a04d8016a587d7..b98d228b08763b 100644
--- a/test/parallel/test-priority-queue.js
+++ b/test/parallel/test-priority-queue.js
@@ -102,9 +102,6 @@ const PriorityQueue = require('internal/priority_queue');
   // Check that removing the last item doesn't throw
   queue.removeAt(6);
 
-  // Check that removing an item that doesn't exist doesn't throw
-  queue.removeAt(15);
-
   assert.strictEqual(queue.shift().value, 1);
   assert.strictEqual(queue.shift().value, 2);
   assert.strictEqual(queue.shift().value, 2);