Unified media optimization and adaptive network scheduling layer that smooths playback performance, reduces DOM and network spikes, and improves overall browser stability without interfering with core site behavior.
// ==UserScript==
// @name Universal Browser & Script Governor
// @namespace ultralean.universal.browser.script.stability
// @version 1.4
// @description Unified media optimization and adaptive network scheduling layer that smooths playback performance, reduces DOM and network spikes, and improves overall browser stability without interfering with core site behavior.
// @author Michael Stutesman
// @license MIT
// @match *://*/*
// @grant GM_getValue
// @grant GM_setValue
// @grant GM_registerMenuCommand
// @run-at document-start
// ==/UserScript==
(() => {
'use strict';
/* ---------------- SINGLETON ---------------- */
if (window.__UNIVERSAL_STABILITY_ENGINE__) return;
window.__UNIVERSAL_STABILITY_ENGINE__ = true;
/* =========================================================
🚫 PERSISTENT SITE EXCLUSIONS (GM STORAGE)
========================================================= */
const HOST = location.hostname.toLowerCase();
const STORAGE_KEY = "ugb_excluded_sites";
let excluded = GM_getValue(STORAGE_KEY, []);
if (!Array.isArray(excluded)) excluded = [];
function isExcludedSite() {
for (let i = 0; i < excluded.length; i++) {
const site = excluded[i];
if (HOST === site || HOST.endsWith("." + site)) return true;
}
return false;
}
if (isExcludedSite()) return;
GM_registerMenuCommand("🚫 Exclude this site", () => {
if (!excluded.includes(HOST)) {
excluded.push(HOST);
GM_setValue(STORAGE_KEY, excluded);
}
location.reload();
});
GM_registerMenuCommand("🔄 Clear exclusions", () => {
if (!confirm("Clear all excluded sites?")) return;
GM_setValue(STORAGE_KEY, []);
location.reload();
});
/* =========================================================
🌐 NETWORK LAYER — SPIKE GOVERNOR
========================================================= */
const netConfig = {
baseDelay: 1,
maxConcurrent: 7,
burstThreshold: 14,
burstDelay: 9
};
const queue = [];
let active = 0;
let lastRun = 0;
function netDelay() {
const pressure = queue.length;
let d = netConfig.baseDelay;
if (pressure >= netConfig.burstThreshold) {
d += netConfig.burstDelay;
}
if (performance.now() - lastRun < 500) {
d += 10;
}
lastRun = performance.now();
return d;
}
function runQueue() {
if (active >= netConfig.maxConcurrent) return;
if (!queue.length) return;
active++;
const job = queue.shift();
setTimeout(async () => {
try {
const res = await job.exec();
job.resolve(res);
} catch (e) {
job.reject(e);
}
active--;
runQueue();
}, netDelay());
}
function enqueue(exec) {
return new Promise((resolve, reject) => {
queue.push({ exec, resolve, reject });
runQueue();
});
}
/* ---- Fetch Hook ---- */
const _fetch = window.fetch;
window.fetch = (...args) =>
enqueue(() => _fetch(...args));
/* ---- XHR Hook ---- */
const XHR = XMLHttpRequest;
function WrappedXHR() {
const xhr = new XHR();
const _open = xhr.open;
const _send = xhr.send;
let body;
xhr.open = function () {
return _open.apply(xhr, arguments);
};
xhr.send = function (b) {
body = b;
return enqueue(() => new Promise((resolve, reject) => {
xhr.onload = () => resolve(xhr);
xhr.onerror = () => reject(xhr);
_send.call(xhr, body);
}));
};
return xhr;
}
window.XMLHttpRequest = WrappedXHR;
/* =========================================================
🎥 MEDIA LAYER — OPTIMIZER
========================================================= */
const mediaConfig = {
maxVideosTracked: 60
};
const tracked = new WeakSet();
let videoCount = 0;
function applyVideoHints(video) {
if (!video || tracked.has(video)) return;
if (videoCount >= mediaConfig.maxVideosTracked) return;
tracked.add(video);
videoCount++;
video.preload = video.hasAttribute("autoplay") ? "auto" : "metadata";
video.playsInline = true;
video.disablePictureInPicture = true;
video.disableRemotePlayback = true;
video.decoding = "async";
if (navigator.connection?.saveData) {
video.preload = "none";
}
if ("fetchPriority" in video) {
video.fetchPriority = video.hasAttribute("autoplay") ? "high" : "low";
}
video.style.contentVisibility = "auto";
video.style.containIntrinsicSize = "480px 270px";
if (!video.__OBS__) {
video.__OBS__ = true;
observer.observe(video);
}
}
const observer = new IntersectionObserver((entries) => {
for (const e of entries) {
const v = e.target;
if (!v || v.tagName !== "VIDEO") continue;
v.dataset.visible = e.isIntersecting ? "1" : "0";
}
}, {
rootMargin: "300px"
});
function processNode(node) {
if (!node) return;
if (node.tagName === "VIDEO") {
applyVideoHints(node);
return;
}
if (node.querySelectorAll) {
const vids = node.querySelectorAll("video");
for (let i = 0; i < vids.length; i++) {
applyVideoHints(vids[i]);
}
}
}
/* ---- Mutation batching (media only) ---- */
let dirty = new Set();
let scheduled = false;
function flush() {
scheduled = false;
for (const n of dirty) {
processNode(n);
}
dirty.clear();
}
function schedule() {
if (scheduled) return;
scheduled = true;
setTimeout(flush, 120);
}
new MutationObserver(muts => {
for (const m of muts) {
for (const n of m.addedNodes) {
dirty.add(n);
}
}
schedule();
}).observe(document.documentElement, {
childList: true,
subtree: true
});
document.querySelectorAll("video").forEach(applyVideoHints);
})();