Smart Shared Cache System

Shared cache with TTL, background refresh and tab sync

Från och med 2026-02-23. Se den senaste versionen.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Smart Shared Cache System
// @namespace    smart.cache.shared
// @version      2.0
// @description  Shared cache with TTL, background refresh and tab sync
// @match        *://*/*
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_deleteValue
// @grant        GM_listValues
// @run-at       document-start
// @license      MIT
// ==/UserScript==

(function () {
    'use strict';

    const PREFIX = "GLOBAL_CACHE_";
    const channel = new BroadcastChannel("GLOBAL_CACHE_SYNC");

    const Cache = {

        // 📦 set with TTL
        set(key, value, ttl = 300) {
            const data = {
                value,
                expiry: Date.now() + ttl * 1000
            };

            GM_setValue(PREFIX + key, JSON.stringify(data));

            // уведомляем другие вкладки
            channel.postMessage({ type: "update", key });
        },

        // 📥 get with auto cleanup
        get(key) {
            const raw = GM_getValue(PREFIX + key, null);
            if (!raw) return null;

            try {
                const data = JSON.parse(raw);

                if (Date.now() > data.expiry) {
                    GM_deleteValue(PREFIX + key);
                    return null;
                }

                return data.value;

            } catch {
                GM_deleteValue(PREFIX + key);
                return null;
            }
        },

        // 🔄 get with background refresh
        async getOrRefresh(key, ttl, fetchFunction) {

            const existing = this.get(key);

            if (existing) return existing;

            // если нет — загружаем в фоне
            const fresh = await fetchFunction();
            this.set(key, fresh, ttl);
            return fresh;
        },

        // 🗑 удалить
        delete(key) {
            GM_deleteValue(PREFIX + key);
            channel.postMessage({ type: "delete", key });
        },

        // 🧹 очистить всё
        clearAll() {
            GM_listValues().forEach(k => {
                if (k.startsWith(PREFIX)) {
                    GM_deleteValue(k);
                }
            });

            channel.postMessage({ type: "clear" });
        }
    };

    // 🔔 Синхронизация вкладок
    channel.onmessage = (event) => {
        const msg = event.data;
        if (!msg) return;

        if (msg.type === "update") {
            console.log("Cache updated in another tab:", msg.key);
        }

        if (msg.type === "delete") {
            console.log("Cache deleted in another tab:", msg.key);
        }

        if (msg.type === "clear") {
            console.log("Cache cleared in another tab");
        }
    };

    // ====== Пример использования ======

    async function example() {
        const data = await Cache.getOrRefresh(
            "apiData",
            600,
            async () => {
                console.log("Fetching fresh data...");
                const response = await fetch("https://api.example.com/data");
                return await response.json();
            }
        );

        console.log("Data:", data);
    }

    // example(); // раскомментируй при необходимости

})();