Prefetch links when hovered

Speculatively prefetches hovered links to speed up browsing.

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

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

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

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.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name           Prefetch links when hovered
// @description    Speculatively prefetches hovered links to speed up browsing.
// @author         Anon
// @version        0.1.6
// @license        CC0 1.0 Universal; http://creativecommons.org/publicdomain/zero/1.0/
// @include        *
// @require        https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js
// @grant          GM_xmlhttpRequest
// @grant          GM_log
// @namespace      https://greasyfork.org/users/4614
// ==/UserScript==

var alreadyPrefetched = {};
var excludedPatterns = /sign[\s_-]?in|sign[\s_-]?out|log[\s_-]?in|log[\s_-]?out|sign[\s_-]?up|(un)?subscribe|(un)?register|edit|delete|purge|remove|send|submit|apply|confirm|cancel/i;
var prefetchStartTimerID = 0;
var currentRequest = null;

function testRegExp(regexp, strings)
{
	for (var i = 0; i < strings.length; i++)
	{
		if (regexp.test(strings[i]))
			return true;
	}
	
	return false;
}

$("body").on("mouseenter", "a", function (e)
{
	var anchorObject = $(e.target);
	var anchorHref = anchorObject.attr("href");
	var anchorInnerText = anchorObject.text();
	var anchorTitle = anchorObject.attr("title");
	
	if (anchorHref === undefined || alreadyPrefetched[anchorHref])
		return;
		
	if (/^#/.test(anchorHref) || testRegExp(excludedPatterns, [anchorHref, anchorInnerText, anchorTitle]))
	{
		GM_log("Did not prefetch \"" + anchorHref + "\" because it contained an excluded pattern."); 
		
		return;
	}
	
	clearTimeout(prefetchStartTimerID);
	
	prefetchStartTimerID = setTimeout(function ()
	{
		GM_log("Prefetching \"" + anchorHref + "\"..");
		
		currentRequest = GM_xmlhttpRequest({ 
			method: "GET", 
			url: anchorHref, 
			onload: function() 
			{
				GM_log("Successfuly prefetched \"" + anchorHref + "\".");
				
				alreadyPrefetched[anchorHref] = true;
				currentRequest = null;
			},
			
			onabort: function()
			{
				GM_log("Aborted prefetching \"" + anchorHref + "\".");
			}
			});
	}, 200);
});

$("body").on("mouseout", "a", function (e)
{
	if (currentRequest)
	{
		GM_log("Aborting current request..");
		currentRequest.abort();
		currentRequest = null;
	}
	
	clearTimeout(prefetchStartTimerID);
});