gh_2215_make_GM_xhr_more_parallel_again

Go to https://github.com/Tampermonkey/tampermonkey/issues/2215 for more.

Dieses Skript sollte nicht direkt installiert werden. Es handelt sich hier um eine Bibliothek für andere Skripte, welche über folgenden Befehl in den Metadaten eines Skriptes eingebunden wird // @require https://update.greasyfork.org/scripts/515994/1478507/gh_2215_make_GM_xhr_more_parallel_again.js 

// ==UserScript==
// @name        gh_2215_make_GM_xhr_more_parallel_again
// @namespace   https://github.com/Tampermonkey/tampermonkey/issues/2215
// @version     1.0
// @description Go to https://github.com/Tampermonkey/tampermonkey/issues/2215 for more.
// @author      Tampermonkey
// ==/UserScript==

/*
 * https://github.com/Tampermonkey/tampermonkey/issues/2215
 *
 * This script provides a workaround for a Chrome MV3 issue (https://github.com/w3c/webextensions/issues/694)
 * where extensions can't set/delete headers that are preserved over redirects.
 *
 * By setting `redirect: 'manual'` and following redirects manually, this script ensures request redirects work
 * as intended and requests to different URLs are made in parallel (again).
 *
 * Userscript authors should include this as a `@require` when they need to make parallel requests with GM_xmlhttpRequest,
 * especially if requests might take a long time to complete.
 *
 * Including this script will modify the behavior of GM_xmlhttpRequest and GM.xmlHttpRequest in Tampermonkey only.
 *
 * Usage:
 *
 * Add this to the metadata block of your userscript:
 *
 * // @grant     GM_xmlhttpRequest
 * // @require   https://raw.githubusercontent.com/Tampermonkey/utils/refs/heads/main/requires/gh_2215_make_GM_xhr_more_parallel_again.js
 *
**/

/* global GM_info, GM_xmlhttpRequest, GM */

const HAS_GM = typeof GM !== 'undefined';
const NEW_GM = ((scope, GM) => {
    // Check if running in Tampermonkey and if version supports redirect control
    if (GM_info.scriptHandler !== "Tampermonkey" || compareVersions(GM_info.version, "5.3.2") < 0) return;

    // Backup original functions
    const GM_xmlhttpRequestOrig = GM_xmlhttpRequest;
    const GM_xmlHttpRequestOrig = GM.xmlHttpRequest;

    function compareVersions(v1, v2) {
        const parts1 = v1.split('.').map(Number);
        const parts2 = v2.split('.').map(Number);
        const length = Math.max(parts1.length, parts2.length);

        for (let i = 0; i < length; i++) {
            const num1 = parts1[i] || 0;
            const num2 = parts2[i] || 0;

            if (num1 > num2) return 1;
            if (num1 < num2) return -1;
        }
        return 0;
    }

    // Wrapper for GM_xmlhttpRequest
    function GM_xmlhttpRequestWrapper(odetails) {
        // If redirect is manually set, simply pass odetails to the original function
        if (odetails.redirect !== undefined) {
            return GM_xmlhttpRequestOrig(odetails);
        }

        // Warn if onprogress is used with settings incompatible with fetch mode used in background
        if (odetails.onprogress || odetails.fetch === false) {
            console.warn("Fetch mode does not support onprogress in the background.");
        }

        const {
            onload,
            onloadend,
            onerror,
            onabort,
            ontimeout,
            ...details
        } = odetails;

        // Set redirect to manual and handle redirects
        const handleRedirects = (initialDetails) => {
            const request = GM_xmlhttpRequestOrig({
                ...initialDetails,
                redirect: 'manual',
                onload: function(response) {
                    if (response.status >= 300 && response.status < 400) {
                        const m = response.responseHeaders.match(/Location:\s*(\S+)/i);
                        // Follow redirect manually
                        const redirectUrl = m && m[1];
                        if (redirectUrl) {
                            const absoluteUrl = new URL(redirectUrl, initialDetails.url).href;
                            handleRedirects({ ...initialDetails, url: absoluteUrl });
                            return;
                        }
                    }

                    if (onload) onload.call(this, response);
                    if (onloadend) onloadend.call(this, response);
                },
                onerror: function(response) {
                    if (onerror) onerror.call(this, response);
                    if (onloadend) onloadend.call(this, response);
                },
                onabort: function(response) {
                    if (onabort) onabort.call(this, response);
                    if (onloadend) onloadend.call(this, response);
                },
                ontimeout: function(response) {
                    if (ontimeout) ontimeout.call(this, response);
                    if (onloadend) onloadend.call(this, response);
                }
            });
            return request;
        };

        return handleRedirects(details);
    }

    // Wrapper for GM.xmlHttpRequest
    function GM_xmlHttpRequestWrapper(odetails) {
        let abort;

        const p = new Promise((resolve, reject) => {
            const { onload, ontimeout, onerror, ...send } = odetails;

            send.onerror = function(r) {
                if (onerror) {
                    resolve(r);
                    onerror.call(this, r);
                } else {
                    reject(r);
                }
            };
            send.ontimeout = function(r) {
                if (ontimeout) {
                    // See comment above
                    resolve(r);
                    ontimeout.call(this, r);
                } else {
                    reject(r);
                }
            };
            send.onload = function(r) {
                resolve(r);
                if (onload) onload.call(this, r);
            };

            const a = GM_xmlhttpRequestWrapper(send).abort;
            if (abort === true) {
                a();
            } else {
                abort = a;
            }
        });

        p.abort =  () => {
            if (typeof abort === 'function') {
                abort();
            } else {
                abort = true;
            }
        };

        return p;
    }

    // Export wrappers
    GM_xmlhttpRequest = GM_xmlhttpRequestWrapper;
    scope.GM_xmlhttpRequestOrig = GM_xmlhttpRequestOrig;

    const gopd = Object.getOwnPropertyDescriptor(GM, 'xmlHttpRequest');
    if (gopd && gopd.configurable === false) {
        return {
            __proto__: GM,
            xmlHttpRequest: GM_xmlHttpRequestWrapper,
            xmlHttpRequestOrig: GM_xmlHttpRequestOrig
        };
    } else {
        GM.xmlHttpRequest = GM_xmlHttpRequestWrapper;
        GM.xmlHttpRequestOrig = GM_xmlHttpRequestOrig;
    }
})(this, HAS_GM ? GM : {});

if (HAS_GM && NEW_GM) GM = NEW_GM;