osumirror.user.js

// ==UserScript==
// @name         m.zxq.co beatmap mirror
// @namespace    https://m.zxq.co/
// @version      0.1
// @description  faster osu! beatmaps downloads, yay!
// @author       Howl
// @match        http*://osu.ppy.sh/s/*
// @match        http*://osu.ppy.sh/b/*
// @grant        GM_xmlhttpRequest
// @connect      m.zxq.co
// @updateURL    https://gist.github.com/thehowl/e4ea9a1dc944b440e1feb482318c9f35/raw/osumirror.user.js
// ==/UserScript==

(function() {
    'use strict';

    var locs = $("img[src='//s.ppy.sh/images/osu-download-beatmap.png']").parent().attr("href").split("/");
    if (locs.length < 3)
        return;

    var match = /^(\d+)/.exec(locs[2]);

    GM_xmlhttpRequest ( {
        method:     "GET",
        url:        "https://m.zxq.co/s/" + match[1] + ".json",
        onload:     function (response) {
            if (response.status == 200) {
                var data = JSON.parse(response.responseText);
                $("img[src='//s.ppy.sh/images/osu-download-beatmap.png']").parent().attr("href", "https://m.zxq.co/" + match[1] + ".osz");
                if (typeof data.HasVideo != 'undefined' && data.HasVideo)
                    $("img[src='//s.ppy.sh/images/osu-download-beatmap-novid.png']").parent().attr("href", "https://m.zxq.co/" + match[1] + "n.osz");
            }
        }
    } );
})();