谷歌 analytics.js 简要分析

下面是部分翻译过的JS，看起来好看些。

(function () {
    function setHref(a, b) {
        return a.href = b;
    }
    function setName(a, b) {
        return a.name = b;
    }
    //使用情况的埋点
    var allusage = new function () {
        var array = [];
        this.set = function (b) {
            array[b]= true;
        };
        this.usageFlag = function () {
            for(var b = [], c = 0; c < array.length; c++) {
                array[c]&& (b[Math.floor(c / 6)] = b[Math.floor(c / 6)] ^ 1 << c % 6);
            }
            for (c = 0; c < b.length; c++) {
                b[c]= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_".charAt(b[c]|| 0);
            }
            return b.join("") + "~";
        };
    };

    //设置信息标志
    function setMsgCode(a) {
        allusage.set(a);
    };

    function isFunction(a) {
        return "function" == typeof a;
    }

    function isArray(a) {
        return "[object Array]" == Object.prototype.toString.call(Object(a));
    }

    function isString(a) {

        return void 0 != a && - 1 < (a.constructor + "").indexOf("String");
    }

    function inString(a, b) {
        return 0 == a.indexOf(b);
    }

    //去除空格
    function removeBlank(a) {
        return a ? a.replace(/^[\s\xa0]+|[\s\xa0]+$/g, ""): "";
    }

    function Td() {
        return [roundCode() ^ Mc() & 0x7FFFFFFF, Math.round((new Date).getTime() / 1E3)].join(".");
    }

    function createImg(a) {
        var b = document.createElement("img");
        b.width = 1;
        b.height = 1;
        b.src = a;
        return b;
    }

    function emptyFunction() {
    }

    function encodeUri(a) {
        if(encodeURIComponent instanceof Function) return encodeURIComponent(a);
        setMsgCode(28);
        return a;
    }

    //对括号进行编码
    function encodeBracket(a) {
        return encodeUri(a).replace(/\(/g, "%28").replace(/\)/g, "%29");
    }

    var addEvent = function (a, b, c, d) {
        try {
            a.addEventListener ? a.addEventListener(b, c, !!d): a.attachEvent && a.attachEvent("on" +b, c);
        } catch (e) {
            setMsgCode(27);
        }
    };
    var removeEvent = function (a, b, c) {
        a.removeEventListener ? a.removeEventListener(b, c, false): a.detachEvent && a.detachEvent("on" +b, c);
    };

    function createScript(a, b) {
        if(a) {
            var c = document.createElement("script");
            c.type = "text/javascript";
            c.async = true;
            c.src = a;
            c.id = b;
            var d = document.getElementsByTagName("script")[0];
            d.parentNode.insertBefore(c, d);
        }
    }

    function getProtocol() {
        return Ba || "https:" == document.location.protocol ? "https:" : "http:";
    }

    function getHostname() {
        var a = "" + document.location.hostname;
        return 0 == a.indexOf("www.") ? a.substring(4): a;
    }

    function getReferrer(a) {
        var b = document.referrer;
        if (/^https?:\/\//i.test(b)) {
            if (a) return b;
            a = "//" + document.location.hostname;
            var c = b.indexOf(a);
            if (5 == c || 6 == c) if (a = b.charAt(c +a.length), "/" == a || "?" == a || "" == a || ":" == a) return;
            return b;
        }
    }

    function preParameters(a, b) {

        if(1 == b.length && null != b[0] && "object" === typeof b[0]) return b[0];
        for (var c = { },
            d = Math.min(a.length +1, b.length),
            e = 0; e < d; e++)
            if ("object" === typeof b[e]) {
                for (var g in b[e]) b[e].hasOwnProperty(g) &&(c[g] = b[e][g]);
                break;
            } else e < a.length && (c[a[e]]= b[e]);
        return c;
    };

    //用于存在储键值对应的容器
    var kVContainer = function () {
        this.keys =[];
        this.w = { };
        this.m = { };
    };
    kVContainer.prototype.set = function (a, b, c) {
        this.keys.push(a);
        c ? this.m[":" +a] = b: this.w[":" +a] = b;
    };
    kVContainer.prototype.get = function (a) {
        return this.m.hasOwnProperty(":" +a) ? this.m[":" +a] : this.w[":" +a];
    };
    kVContainer.prototype.map = function (a) {
        for(var b = 0; b < this.keys.length; b++) {
            var c = this.keys[b];
            var d = this.get(c);
            d && a(c, d);
        }
    };

    //是否禁用了跟踪，参见帮助文档
    var isDisabledTrack = function (a) {


        return false;
    };
    var fb = function (a) {
        setTimeout(a, 100);
    };
    var getCookieValue = function (a) {

        var b = [],
            c = document.cookie.split(";");
        a = new RegExp("^\\s*" +a + "=\\s*(.*?)\\s*$");
        for (var d = 0; d < c.length; d++) {
            var e = c[d].match(a);
            e && b.push(e[1]);
        }

        return b;
    };
    var getsetCookie = function (a, b, c, d, e, g) {
        //如果被禁用或自身几个网站，不进行跟踪，返回False
        e = isDisabledTrack(e) ? false : regDoubleclick.test(document.location.hostname) || "/" == c && regGoogleSite.test(d) ? false : true;
        if (!e) return false;

        b && 1200 < b.length && (b = b.substring(0, 1200), setMsgCode(24));
        c = a + "=" + b + "; path=" +c + "; ";
        g && (c += "expires=" +(new Date((new Date).getTime() +g)).toGMTString() + "; ");
        d && "none" != d && (c += "domain=" +d + ";");
        d = document.cookie;
        document.cookie = c;
        if (!(d = d != document.cookie))
            t: {
            a = getCookieValue(a);
            for (d = 0; d < a.length; d++)
                if (b == a[d]) {
                    d = true;
                    break t;
                }
            d = false;
        }
        return d;
    };
    var regGoogleSite = new RegExp(/^(www\.)?google(\.com?)?(\.[a-z]{2})?$/);
    var regDoubleclick = new RegExp(/(^|\.)doubleclick\.net$/i);
    var Mc = function () {
        //debugger;
        for(var a = window.navigator.userAgent
                     + (document.cookie ? document.cookie: "")
                     + (document.referrer ? document.referrer: ""),
            b = a.length,
            c = window.history.length;
            0 < c;) {
            a += c-- ^ b++;
        }
        return La(a);
    };
    var oc = function () {
        return getProtocol() + "//localhost:25388";
        //return getProtocol() + "//www.google-analytics.com";
    };
    var lenException = function (a) {
        setName(this, "len");
        this.message = a + "-8192";
    };
    //firefox error
    var ff2postException = function (a) {
        setName(this, "ff2post");
        this.message = a + "-2036";
    };
    //如果支持sendBeacon 就使用它,
    var sendRequest = function (targetUrl, datas, callback, sendBeaconCallback) {
        callback = callback || emptyFunction;
        //优先使用sendBeaconCallback
        sendBeaconCallback && (sendBeaconCallback = callback, window.navigator.sendBeacon ?
            window.navigator.sendBeacon(targetUrl, datas) ?
            (sendBeaconCallback(), sendBeaconCallback = true) : sendBeaconCallback = false : sendBeaconCallback = false);

        if (!sendBeaconCallback) {
            if (2036 >= datas.length) {
                imageRequest(targetUrl, datas, callback);
            } else if (8192 >= datas.length) {

                if (0 <= window.navigator.userAgent.indexOf("Firefox") && ![].reduce) {
                    throw new ff2postException(datas.length);
                }

                XMLHttpRequest(targetUrl, datas, callback) || XDomainRequest(targetUrl, datas, callback) || IframeRequest(datas, callback) || callback();
            } else {
                throw new lenException(datas.length);
            }
        }
    };
    //图片的请求方式
    var imageRequest = function (a, b, c) {
        var d = createImg(a + "?" + b);
        d.onload = d.onerror = function () {
            d.onload = null;
            d.onerror = null;
            c();
        };
    };
    //XDomainRequest 
    var XDomainRequest = function (a, b, c) {
        var d;
        d = window.XDomainRequest;
        if (!d) return false;
        d = new d;
        d.open("POST", a);
        d.onerror = function () {
            c();
        };
        d.onload = c;
        d.send(b);
        return true;
    };
    var XMLHttpRequest = function (a, b, c) {
        var d = window.XMLHttpRequest;
        if (!d) return false;
        var e = new d;
        if (!("withCredentials" in e)) return false;
        e.open("POST", a, true);
        e.withCredentials = true;
        e.setRequestHeader("Content-Type", "text/plain");
        e.onreadystatechange = function () {
            4 == e.readyState && (c(), e = null);
        };
        e.send(b);
        return true;
    };
    var IframeRequest = function (a, b) {
        if(!document.body)
            return fb(function () {
                IframeRequest(a, b);
            }),
                true;
        a = encodeURIComponent(a);
        try {
            var c = document.createElement(‘<iframe name="‘ +a + ‘"></iframe>‘);
        } catch (d) {
            c = document.createElement("iframe"),
                setName(c, a);
        }
        c.height = "0";
        c.width = "0";
        c.style.display = "none";
        c.style.visibility = "hidden";
        var e = document.location,
            e = oc() + "/analytics_iframe.html#" + encodeURIComponent(e.protocol + "//" + e.host + "/favicon.ico"),
            g = function () {
                c.src = "";
                c.parentNode && c.parentNode.removeChild(c);
            };
        addEvent(window, "beforeunload", g);
        var ca = false,
            l = 0,
            k = function () {
                if(!ca) {
                    try {
                        if (9 < l || c.contentWindow.location.host == document.location.host) {
                            ca = true;
                            g();
                            removeEvent(window, "beforeunload", g);
                            b();
                            return;
                        }
                    } catch (a) {
                    }
                    l++;
                    setTimeout(k, 200);
                }
            };
        addEvent(c, "load", k);
        document.body.appendChild(c);
        c.src = e;
        return true;
    };
    var Ha = function () {
        this.t =[];
    };
    Ha.prototype.add = function (a) {
        this.t.push(a);
    };
    Ha.prototype.D = function (a) {
        try {
            for (var b = 0; b < this.t.length; b++) {
                var c = a.get(this.t[b]);
                c && isFunction(c) && c.call(window, a);
            }
        } catch (d) {
        }
        b = a.get(hitCallback);
        b != emptyFunction && isFunction(b) &&(a.set(hitCallback, emptyFunction, true), setTimeout(b, 10));
    };

    function checksampler(a) {
        if(100 != a.get(sampleRate) && La(getStrConfig(a, clientId)) % 1E4 >= 100 * getIntConfig(a, sampleRate)) throw "abort";
    }

    function checkisDisabledTrack(a) {
        if(isDisabledTrack(getStrConfig(a, trackingId))) throw "abort";
    }

    function checkProtocol() {
        var a = document.location.protocol;
        if ("http:" != a && "https:" != a) throw "abort";
    }

    function buildHitTasks(a) {

        try {
            window.XMLHttpRequest && "withCredentials" in new window.XMLHttpRequest ? setMsgCode(40): window.XDomainRequest && setMsgCode(41),
                window.navigator.sendBeacon && setMsgCode(42);
        } catch (b) {
        }
        a.set(stepInPage, getIntConfig(a, stepInPage) +1);
        var c = [];
        Qa.map(function(b, d) {
            if(d.p) {
                var e = a.get(b);
                void 0 != e && e != d.defaultValue && ("boolean" == typeof e && (e *= 1), c.push(d.p + "=" + encodeUri("" +e)));
            }
        });
        if (Ed(new Od(1E4))) {
            var d = [];
            d.push(round1());
            d.push.apply(d, Td().split("."));
            d.push(round2());
            var e;
            e = window.crypto ? true : false;
            d.push(e ? "c": "b");
            c.push("z=" +d.join("."));
        } else c.push("z=" +round2());
        a.set(hitPayload, c.join("&"), true);
    }

    function sendHitTasks(a) {

        var b = getStrConfig(a, transportUrl) || oc() + "/collect";
        sendRequest(b, getStrConfig(a, hitPayload), a.get(hitCallback), a.get(useBeacon));
        a.set(hitCallback, emptyFunction, true);
    }

    function Hc(a) {
        var b = window.gaData;
        b && (b.expId && a.set(Nc, b.expId), b.expVar && a.set(Oc, b.expVar));
    }

    function checkpreviewTask() {
        if(window.navigator && "preview" == window.navigator.loadPurpose) throw "abort";
    }


    function checkTrackidexist(a) {
        if(!a.get(trackingId)) throw "abort";
    };

    var round1 = function () {
        return Math.round(0x7FFFFFFF * Math.random());
    };
    var round2 = function () {
        try {
            var a = new Uint32Array(1);
            window.crypto.getRandomValues(a);
            return a[0]& 0x7FFFFFFF;
        } catch (b) {
            return round1();
        }
    };
    var roundCode = round1;

    function Ta(a) {
        var b = getIntConfig(a, Ua);
        500 <= b && setMsgCode(15);
        var c = getStrConfig(a, hitType);
        if ("transaction" != c && "item" != c) {
            var c = getIntConfig(a, Wa),
                d = (new Date).getTime(),
                e = getIntConfig(a, Xa);
            0 == e && a.set(Xa, d);
            e = Math.round(2 * (d - e) / 1E3);
            0 < e && (c = Math.min(c +e, 20), a.set(Xa, d));
            if (0 >= c) throw "abort";
            a.set(Wa, --c);
        }
        a.set(Ua, ++b);
    };

    var settings = function () {
        this.data = new kVContainer;
    };
    var Qa = new kVContainer;
    var Za = [];
    settings.prototype.get = function (a) {
        var b = $a(a);
        var c = this.data.get(a);
        b && void 0 == c && (c = isFunction(b.defaultValue) ? b.defaultValue(): b.defaultValue);
        return b && b.n ? b.n(this, a, c): c;
    };
    settings.prototype.set = function (a, b, c) {
        if(a)
            if ("object" == typeof a) {
                for (var d in a) {
                    a.hasOwnProperty(d) && ab(this, d, a[d], c);
                }
            } else {
                ab(this, a, b, c);
            }
    };
    var getStrConfig = function (a, b) {
        var c = a.get(b);
        return void 0 == c ? "" : "" + c;
    };
    var getIntConfig = function (a, b) {

        var c = a.get(b);
        return void 0 == c || "" === c ? 0 : 1 * c;
    };

    var ab = function (a, b, c, d) {
        if(void 0 != c)
            switch (b) {
                case trackingId:
                    wb.test(c);
                }
        var e = $a(b);
        e && e.o ? e.o(a, b, c, d): a.data.set(b, c, d);
    };
    var bb = function (aName, bshortName, cdefaultValue, d, e) {
        setName(this, aName);
        this.p = bshortName;
        this.n = d;
        this.o = e;
        this.defaultValue = cdefaultValue;
    };
    var $a = function (a) {
        var b = Qa.get(a);
        if (!b)
            for (var c = 0; c < Za.length; c++) {
                var d = Za[c],
                    e = d[0].exec(a);
                if (e) {
                    b = d[1](e);
                    Qa.set(b.name, b);
                    break;
                }
            }
        return b;
    };
    var yc = function (a) {
        var b;
        Qa.map(function(c, d) {
            d.p == a && (b = d);
        });
        return b && b.name;
    };
    var S = function (aName, bshortName, cdefaultValue, d, e) {
        aName = new bb(aName, bshortName, cdefaultValue, d, e);
        Qa.set(aName.name, aName);
        return aName.name;
    };
    var cb = function (a, b) {
        Za.push([new RegExp("^" +a + "$"), b]);
    };
    var T = function (aName, bshortName, cdefaultValue) {

        return S(aName, bshortName, cdefaultValue, void 0, db);
    };
    var db = function () {
    };

    var WXAnalyticsObjectName = isString(window.WXAnalyticsObject) && removeBlank(window.WXAnalyticsObject) || "wa";
    var Ba = false;
    var apiVersion = T("apiVersion", "v");
    var clientVersion = T("clientVersion", "_v");
    S("anonymizeIp", "aip");

    var hitType = S("hitType", "t");

    var hitCallback = S("hitCallback");
    var hitPayload = S("hitPayload");
    S("nonInteraction", "ni");
    S("currencyCode", "cu");
    var useBeacon = S("useBeacon", void 0, false);
    S("dataSource", "ds");
    S("sessionControl", "sc", "");
    S("sessionGroup", "sg");
    S("queueTime", "qt");
    var stepInPage = S("_s", "_s");
    S("screenName", "cd");
    var kb = S("location", "dl", "");
    var lb = S("referrer", "dr");
    var mb = S("page", "dp", "");
    S("hostname", "dh");
    var nb = S("language", "ul");
    var ob = S("encoding", "de");
    S("title", "dt",
        function () {
            return document.title || void 0;
        });
    cb("contentGroup([0-9]+)",
        function (a) {
            return new bb(a[0], "cg" +a[1]);
        });
    var pb = S("screenColors", "sd");
    var qb = S("screenResolution", "sr");
    var rb = S("viewportSize", "vp");
    var sb = S("javaEnabled", "je");
    var tb = S("flashVersion", "fl");
    S("campaignId", "ci");
    S("campaignName", "cn");
    S("campaignSource", "cs");
    S("campaignMedium", "cm");
    S("campaignKeyword", "ck");
    S("campaignContent", "cc");
    var ub = S("eventCategory", "ec");
    var xb = S("eventAction", "ea");
    var yb = S("eventLabel", "el");
    var zb = S("eventValue", "ev");
    var Bb = S("socialNetwork", "sn");
    var Cb = S("socialAction", "sa");
    var Db = S("socialTarget", "st");
    var Eb = S("l1", "plt");
    var Fb = S("l2", "pdt");
    var Gb = S("l3", "dns");
    var Hb = S("l4", "rrt");
    var Ib = S("l5", "srt");
    var Jb = S("l6", "tcp");
    var Kb = S("l7", "dit");
    var Lb = S("l8", "clt");
    var Mb = S("timingCategory", "utc");
    var Nb = S("timingVar", "utv");
    var Ob = S("timingLabel", "utl");
    var Pb = S("timingValue", "utt");
    S("appName", "an");
    S("appVersion", "av", "");
    S("appId", "aid", "");
    S("appInstallerId", "aiid", "");
    S("exDescription", "exd");
    S("exFatal", "exf");
    var Nc = S("expId", "xid");
    var Oc = S("expVar", "xvar");

    var Ua = S("_hc", void 0, 0);
    var Xa = S("_ti", void 0, 0);
    var Wa = S("_to", void 0, 20);
    cb("dimension([0-9]+)",
        function (a) {
            return new bb(a[0], "cd" +a[1]);
        });
    cb("metric([0-9]+)",
        function (a) {
            return new bb(a[0], "cm" +a[1]);
        });
    S("linkerParam", void 0, void 0, Bc, db);
    var ld = S("usage", "_u", void 0, function () {
        return allusage.usageFlag();
    }, db);

    S("forceSSL", void 0, void 0,
        function () {
            return Ba;
        },
        function (a, b, c) {
            setMsgCode(34);
            Ba = !!c;
        });
    //var ed = S("_j1", "jid");
    //var Hd = S("_j2", "gjid");
    cb("\\&(.*)",
        function (a) {
            var b = new bb(a[0], a[1]),
                c = yc(a[0].substring(1));
            c && (b.n = function (a) {
                return a.get(c);
            },
                b.o = function (a, b, g, ca) {
                    a.set(c, g, ca);
                },
                b.p = void 0);
            return b;
        });
    var _oot = T("_oot");
    var previewTask = S("previewTask");
    var checkProtocolTask = S("checkProtocolTask");
    var validationTask = S("validationTask");
    var checkStorageTask = S("checkStorageTask");
    //var historyImportTask = S("historyImportTask");
    var samplerTask = S("samplerTask");
    var _rlt = T("_rlt");
    var buildHitTask = S("buildHitTask");
    var sendHitTask = S("sendHitTask");
    var ceTask = S("ceTask");
    //var devIdTask = S("devIdTask");
    var timingTask = S("timingTask");
    //var displayFeaturesTask = S("displayFeaturesTask");
    var V = T("name");
    var clientId = T("clientId", "cid");
    var userId = S("userId", "uid");
    var trackingId = T("trackingId", "tid");
    var cookieName = T("cookieName", void 0, "_wa");
    var cookieDomain = T("cookieDomain");
    var cookiePath = T("cookiePath", void 0, "/");
    var cookieExpires = T("cookieExpires", void 0, 63072E3);
    var legacyCookieDomain = T("legacyCookieDomain");
    //var legacyHistoryImport = T("legacyHistoryImport", void 0, true);
    var storage = T("storage", void 0, "cookie");
    //var allowLinker = T("allowLinker", void 0, false);
    //var allowAnchor = T("allowAnchor", void 0, true);
    var sampleRate = T("sampleRate", "sf", 100);
    var siteSpeedSampleRate = T("siteSpeedSampleRate", void 0, 1);
    var alwaysSendReferrer = T("alwaysSendReferrer", void 0, false);
    var transportUrl = S("transportUrl");

    //var _r = S("_r", "_r");
    //var _dfr = S("_dfr", void 0, 1);

    function createCommands(commandName, b, c, d) {
        b[commandName]= function () {
            try {
                return d && setMsgCode(d),
                    c.apply(this, arguments);
            } catch (b) {
                var g = b && b.name;
                if (!(1 <= 100 * Math.random() || isDisabledTrack("?"))) {
                    var ca = ["t=error", "_e=exc", "_v=j30", "sr=1"];
                    commandName && ca.push("_f=" + commandName);
                    g && ca.push("_m=" + encodeUri(g.substring(0, 100)));
                    ca.push("aip=1");
                    ca.push("z=" +roundCode());
                    sendRequest(oc() + "/collect", ca.join("&"));
                }
                throw b;
            }
        };
    };

    var Od = function (a) {
        this.V = a;
        this.fa = void 0;
        this.$ = false;
        this.ha = void 0;
        this.ea = 1;
    };
    var Ed = function (a, b, c) {
        if(a.fa && a.$) return 0;
        a.$ = true;
        if (b) {
            if (a.ha && getIntConfig(b, a.ha)) return getIntConfig(b, a.ha);
            if (0 == b.get(siteSpeedSampleRate)) return 0;
        }
        if (0 == a.V) return 0;
        void 0 === c && (c = round2());
        return 0 == c % a.V ? Math.floor(c / a.V) % a.ea + 1: 0;
    };

    function flashVersion() {
        var a, b, c;
        if ((c = (c = window.navigator) ? c.plugins : null) && c.length)
            for (var d = 0; d < c.length && !b; d++) {
                var e = c[d];
                -1 < e.name.indexOf("Shockwave Flash") && (b = e.description);
            }
        if (!b)
            try {
                a = new ActiveXObject("ShockwaveFlash.ShockwaveFlash.7"),
                    b = a.GetVariable("$version");
            } catch (g) {

            }
        if (!b)
            try {
                a = new ActiveXObject("ShockwaveFlash.ShockwaveFlash.6"),
                    b = "WIN 6,0,21,0",
                    a.AllowScriptAccess = "always",
                    b = a.GetVariable("$version");
            } catch (ca) {
            }
        if (!b)
            try {
                a = new ActiveXObject("ShockwaveFlash.ShockwaveFlash"),
                    b = a.GetVariable("$version");
            } catch (l) {
            }
        b && (a = b.match(/[\d]+/g)) && 3 <= a.length && (b = a[0] + "." + a[1] + " r" + a[2]);
        return b || void 0;
    };

    var collectPerformance = function (a, b) {
        var c = Math.min(getIntConfig(a, siteSpeedSampleRate), 100);
        if (!(La(getStrConfig(a, clientId)) % 100 >= c) && (c = { },
            getperformance(c) || getperformance2(c))) {
            var d = c[Eb];
            void 0 == d || Infinity == d || isNaN(d) ||
            (0 < d ? (Y(c, Gb), Y(c, Jb), Y(c, Ib), Y(c, Fb), Y(c, Hb), Y(c, Kb), Y(c, Lb), b(c)):
                addEvent(window, "load",
                    function () {
                        collectPerformance(a, b);
                    },
                    false));
        }
    };
    var getperformance = function (a) {
        var b = window.performance || window.webkitPerformance,
            b = b && b.timing;
        if (!b) return false;
        var c = b.navigationStart;
        if (0 == c) return false;
        a[Eb]= b.loadEventStart -c;
        a[Gb]= b.domainLookupEnd -b.domainLookupStart;
        a[Jb]= b.connectEnd -b.connectStart;
        a[Ib]= b.responseStart -b.requestStart;
        a[Fb]= b.responseEnd -b.responseStart;
        a[Hb]= b.fetchStart -c;
        a[Kb]= b.domInteractive -c;
        a[Lb]= b.domContentLoadedEventStart -c;
        return true;
    };
    var getperformance2 = function (a) {
        if(window.top != window) return false;
        var b = window.external,
            c = b && b.onloadT;
        b && !b.isValidLoadTime && (c = void 0);
        2147483648 < c && (c = void 0);
        0 < c && b.setPageReadyTime();
        if (void 0 == c) return false;
        a[Eb]= c;
        return true;
    };
    var Y = function (a, b) {
        var c = a[b];
        if (isNaN(c) || Infinity == c || 0 > c) a[b]= void 0;
    };
    var sendTiming = function (a) {
        return function (b) {
            "pageview" != b.get(hitType) || a.I || (a.I = true, collectPerformance(b,
                function (b) {
                    a.send("timing", b);
                }));
        };
    };
    var hc = false;
    var mc = function (a) {
        if("cookie" == getStrConfig(a, storage)) {
            var b = getStrConfig(a, cookieName),
                c = nd(a),
                d = kc(getStrConfig(a, cookiePath)),
                e = lc(getStrConfig(a, cookieDomain)),
                g = 1E3 * getIntConfig(a, cookieExpires),
                ca = getStrConfig(a, trackingId);
            if ("auto" != e) getsetCookie(b, c, d, e, ca, g) && (hc = true);
            else {
                setMsgCode(32);
                var l;
                t: {
                    c =[];
                    e = getHostname().split(".");
                    if (4 == e.length && (l = e[e.length -1], parseInt(l, 10) == l)) {
                        l =["none"];
                        break t;
                    }
                    for (l = e.length -2; 0 <= l; l--) c.push(e.slice(l).join("."));
                    c.push("none");
                    l = c;
                    }
                for (var k = 0; k < l.length; k++)
                    if (e = l[k], a.data.set(cookieDomain, e), c = nd(a), getsetCookie(b, c, d, e, ca, g)) {
                        hc = true;
                        return;
                    }
                a.data.set(cookieDomain, "auto");
            }
        }
    };
    var checkStorage = function (a) {
        if("cookie" == getStrConfig(a, storage) && !hc && (mc(a), !hc)) throw "abort";
    };

    var nd = function (a) {

        var b = encodeBracket(getStrConfig(a, clientId));
        var c = ic(getStrConfig(a, cookieDomain));
        a = jc(getStrConfig(a, cookiePath));
        1 < a && (c += "-" + a);
        return ["MY_A1", c, b].join(".");
    };
    var Gc = function (a, b, c) {
        for(var d = [], e =[], g, ca = 0; ca < a.length; ca++) {
            var l = a[ca];
            if (l.r[c]== b) d.push(l);
            else void 0 == g || l.r[c] < g ? (e = [l], g = l.r[c]): l.r[c] == g && e.push(l);
        }
        return 0 < d.length ? d: e;
    };
    var lc = function (a) {
        return 0 == a.indexOf(".") ? a.substr(1): a;
    };
    var ic = function (a) {
        return lc(a).split(".").length;
    };
    var kc = function (a) {
        if(!a) return "/";
        1 < a.length && a.lastIndexOf("/") == a.length -1 && (a = a.substr(0, a.length -1));
        0 != a.indexOf("/") &&(a = "/" + a);
        return a;
    };
    var jc = function (a) {
        a = kc(a);
        return "/" == a ? 1 : a.split("/").length;
    };

    function Xc(a, b, c) {
        "none" == b && (b = "");
        var d = [],
            e = getCookieValue(a);
        a = "__utma" == a ? 6 : 2;
        for (var g = 0; g < e.length; g++) {
            var ca = ("" + e[g]).split(".");
            ca.length >= a && d.push({
                    hash: ca[0],
                    R: e[g],
                    O: ca
                });
        }
        return 0 == d.length ? void 0 : 1 == d.length ? d[0] : Zc(b, d) || Zc(c, d) || Zc(null, d) || d[0];
    }

    function Zc(a, b) {
        var c, d;
        null == a ? c = d = 1 : (c = La(a), d = La(inString(a, ".") ? a.substring(1): "." + a));
        for (var e = 0; e < b.length; e++) if (b[e].hash == c || b[e].hash == d) return b[e];
    };

    var od = new RegExp(/^https?:\/\/([^\/:]+)/);
    var pd = /(.*)([?&#])(?:_wa=[^&#]*)(?:&?)(.*)/;

    function Bc(a) {
        a = a.get(clientId);
        var b = Ic(a, 0);
        return "_wa=1." + encodeUri(b + "." + a);
    }

    function Ic(a, b) {
        for(var c = new Date,
            d = window.navigator,
            e = d.plugins ||[],
            c =[a, d.userAgent, c.getTimezoneOffset(), c.getYear(), c.getDate(), c.getHours(), c.getMinutes() +b],
            d = 0; d < e.length; ++d) c.push(e[d].description);
        return La(c.join("."));
    }

    var Dc = function (a) {
        setMsgCode(48);
        this.target = a;
        this.T = false;
    };
    Dc.prototype.Q = function (a, b) {
        if(a.tagName) {
            if ("a" == a.tagName.toLowerCase()) {
                a.href && setHref(a, qd(this, a.href, b));
                return;
            }
            if ("form" == a.tagName.toLowerCase()) return rd(this, a);
        }
        if ("string" == typeof a) return qd(this, a, b);
    };
    var qd = function (a, b, c) {
        var d = pd.exec(b);
        d && 3 <= d.length && (b = d[1] + (d[3] ? d[2] + d[3] : ""));
        a = a.target.get("linkerParam");
        var e = b.indexOf("?"),
            d = b.indexOf("#");
        c ? b += (- 1 == d ? "#" : "&") + a : (c = - 1 == e ? "?" : "&", b = -1 == d ? b + (c + a) : b.substring(0, d) +c + a + b.substring(d));
        return b;
    };
    var rd = function (a, b) {
        if(b && b.action) {
            var c = a.target.get("linkerParam").split("=")[1];
            if ("get" == b.method.toLowerCase()) {
                for (var d = b.childNodes ||[], e = 0; e < d.length; e++)
                    if ("_wa" == d[e].name) {
                        d[e].setAttribute("value", c);
                        return;
                    }
                d = document.createElement("input");
                d.setAttribute("type", "hidden");
                d.setAttribute("name", "_wa");
                d.setAttribute("value", c);
                b.appendChild(d);
            } else "post" == b.method.toLowerCase() &&(b.action = qd(a, b.action));
        }
    };
    Dc.prototype.S = function (a, b, c) {
        function d(c) {
            try {
                c = c || window.event;
                var d;
                t: {
                    var g = c.target || c.srcElement;
                    for (c = 100; g && 0 < c;) {
                        if (g.href && g.nodeName.match(/^a(?:rea)?$/i)) {
                            d = g;
                            break t;
                        }
                        g = g.parentNode;
                        c--;
                    }
                    d = {
                    };
                    }
                ("http:" == d.protocol || "https:" == d.protocol) && sd(a, d.hostname || "") && d.href && setHref(d, qd(e, d.href, b));
            } catch (w) {
                setMsgCode(26);
            }
        }

        var e = this;
        this.T || (this.T = true, addEvent(document, "mousedown", d, false), addEvent(document, "touchstart", d, false), addEvent(document, "keyup", d, false));
        if (c) {
            c = function (b) {
                b = b || window.event;
                if ((b = b.target || b.srcElement) && b.action) {
                    var c = b.action.match(od);
                    c && sd(a, c[1]) && rd(e, b);
                }
            };
            for (var g = 0; g < document.forms.length; g++) addEvent(document.forms[g], "submit", c);
        }
        };

    function sd(a, b) {
        if(b == document.location.hostname) return false;
        for (var c = 0; c < a.length; c++)
            if (a[c]instanceof RegExp) {
                if (a[c].test(b)) return true;
            } else if (0 <= b.indexOf(a[c])) return true;
        return false;
    };

    var wb = /^(UA|YT|MO|GP)-(\d+)-(\d+)$/;
    var pc = function (a) {
        function bind(a, b) {
            d.b.data.set(a, b);
        }

        function bindfilters(a, c) {
            bind(a, c);
            d.filters.add(a);
        }


        var d = this;
        this.b = new settings;
        this.filters = new Ha;
        bind(V, a[V]);
        bind(trackingId, removeBlank(a[trackingId]));
        bind(cookieName, a[cookieName]);
        bind(cookieDomain, a[cookieDomain]|| getHostname());
        bind(cookiePath, a[cookiePath]);
        bind(cookieExpires, a[cookieExpires]);

        bind(sampleRate, a[sampleRate]);
        bind(siteSpeedSampleRate, a[siteSpeedSampleRate]);
        bind(alwaysSendReferrer, a[alwaysSendReferrer]);
        bind(storage, a[storage]);
        bind(userId, a[userId]);
        bind(apiVersion, 1);
        bind(clientVersion, "j30");
        bindfilters(_oot, checkisDisabledTrack);
        bindfilters(previewTask, checkpreviewTask);
        bindfilters(checkProtocolTask, checkProtocol);
        bindfilters(validationTask, checkTrackidexist);
        bindfilters(checkStorageTask, checkStorage);

        bindfilters(samplerTask, checksampler);
        bindfilters(_rlt, Ta);
        bindfilters(ceTask, Hc);

        bindfilters(buildHitTask, buildHitTasks);
        bindfilters(sendHitTask, sendHitTasks);
        bindfilters(timingTask, sendTiming(this));
        Jc(this.b, a[clientId]);
        preCommRequestArgs(this.b);

        };
    var Jc = function (a, b) {
        if("cookie" == getStrConfig(a, storage)) {
            hc = false;
            var c;
            i: {
                var d = getCookieValue(getStrConfig(a, cookieName));
                if (d && !(1 > d.length)) {
                    c =[];
                    for (var e = 0; e < d.length; e++) {
                        var g;
                        g = d[e].split(".");
                        var ca = g.shift();
                        ("GA1" == ca || "1" == ca) && 1 < g.length ? (ca = g.shift().split("-"), 1 == ca.length && (ca[1] = "1"), ca[0]*= 1, ca[1]*= 1, g = {
                                r: ca,
                                s: g.join(".")
                            }): g = void 0;
                        g && c.push(g);
                    }
                    if (1 == c.length) {
                        setMsgCode(13);
                        c = c[0].s;
                        break i;
                    }
                    if (0 == c.length) setMsgCode(12);
                    else {
                        setMsgCode(14);
                        d = ic(getStrConfig(a, cookieDomain));
                        c = Gc(c, d, 0);
                        if (1 == c.length) {
                            c = c[0].s;
                            break i;
                        }
                        d = jc(getStrConfig(a, cookiePath));
                        c = Gc(c, d, 1);
                        c = c[0] && c[0].s;
                        break i;
                    }
                }
                c = void 0;
                }
            c || (c = getStrConfig(a, cookieDomain), d = getStrConfig(a, legacyCookieDomain) || getHostname(), c = Xc("__utma", d, c), (c = void 0 == c ? void 0 : c.O[1] + "." + c.O[2]) && setMsgCode(10));
            c && (a.data.set(clientId, c), hc = true);
        }

        b && (setMsgCode(9), a.data.set(clientId, encodeUri(b)));
        a.get(clientId)
            || ((c =
                (c = window.gaGlobal && window.gaGlobal.vid) && - 1 != c.search(/^(?:utma\.)?\d+\.\d+$/)
                ? c : void 0) ? (setMsgCode(17), a.data.set(clientId, c)): (setMsgCode(8), a.data.set(clientId, Td())));
        mc(a);
    };
    //准备通用的请请求参数
    var preCommRequestArgs = function (a) {

        var b = window.navigator,
            c = window.screen,
            d = document.location;
        a.set(lb, getReferrer(a.get(alwaysSendReferrer)));
        if (d) {
            var e = d.pathname || "";
            "/" != e.charAt(0) &&(setMsgCode(31), e = "/" + e);
            a.set(kb, d.protocol + "//" + d.hostname +e + d.search);
        }
        c && a.set(qb, c.width + "x" + c.height);
        c && a.set(pb, c.colorDepth + "-bit");
        var c = document.documentElement,
            g = (e = document.body) && e.clientWidth && e.clientHeight,
            ca =[];
        c && c.clientWidth && c.clientHeight && ("CSS1Compat" === document.compatMode || !g) ? ca = [c.clientWidth, c.clientHeight]: g && (ca = [e.clientWidth, e.clientHeight]);
        c = 0 >= ca[0] || 0 >= ca[1] ? "" : ca.join("x");
        a.set(rb, c);
        a.set(tb, flashVersion());
        a.set(ob, document.characterSet || document.charset);
        a.set(sb, b && "function" === typeof b.javaEnabled && b.javaEnabled() || false);
        a.set(nb, (b && (b.language || b.browserLanguage) || "").toLowerCase());

    };
    pc.prototype.get = function (a) {
        return this.b.get(a);
    };
    pc.prototype.set = function (a, b) {
        this.b.set(a, b);
    };
    var qc = {
            pageview: [mb],
        event: [ub, xb, yb, zb],
            social: [Bb, Cb, Db],
            timing: [Mb, Nb, Pb, Ob]
        };
    pc.prototype.send = function (a) {
        if(!(1 > arguments.length)) {
            var b, c;
            if ("string" === typeof arguments[0]) {
                (b = arguments[0], c =[].slice.call(arguments, 1));
            } else {
                (b = arguments[0]&& arguments[0][hitType], c = arguments);
            }
            if (b) {
                c = preParameters(qc[b]||[], c),
                    c[hitType]= b,
                    this.b.set(c, void 0, true),
                    this.filters.D(this.b),
                    this.b.data.m = { },
                    setMsgCode(44);
            }
        }
    };
    var onPageIsVisibility = function (funcrun) {
        if("prerender" == document.visibilityState) return false;
        funcrun();
        return true;
    };
    var td = /^(?:(\w+)\.)?(?:(\w+):)?(\w+)$/;
    var sc = function (a) {
        if(isFunction(a[0])) this.u = a[0];
        else {
            var b = td.exec(a[0]);
            null != b && 4 == b.length && (this.c = b[1]
                || "t0", this.e = b[2]
                || "", this.d = b[3], this.a =[].slice.call(a, 1), this.e
                || (this.A = "create" == this.d, this.i = "require" == this.d, this.g = "provide" == this.d, this.ba = "remove" == this.d), this.i && (3 <= this.a.length ? (this.X = this.a[1], this.W = this.a[2]): this.a[1]&& (isString(this.a[1]) ? this.X = this.a[1]: this.W = this.a[1])));
            b = a[1];
            a = a[2];
            if (!this.d) throw "abort";
            if (this.i && (!isString(b) || "" == b)) throw "abort";
            if (this.g && (!isString(b) || "" == b || !isFunction(a))) throw "abort";
            if (ud(this.c) || ud(this.e)) throw "abort";
            if (this.g && "t0" != this.c) throw "abort";
        }
    };

    function ud(a) {
        return 0 <= a.indexOf(".") || 0 <= a.indexOf(":");
    };

    var Yd;
    var Zd;
    var $d;
    Yd = new kVContainer;
    $d = new kVContainer;
    Zd = {
            ec: 45,
            ecommerce: 46,
            linkid: 47
        };
    var tc = function (a, b, c) {
        b == $ ? setMsgCode(35): b.get(V);
        var d = Yd.get(a);
        if (!isFunction(d)) return false;
        b.plugins_ = b.plugins_ || new kVContainer;
        if (b.plugins_.get(a)) return true;
        b.plugins_.set(a, new d(b, c || {
        }));
        return true;
    };
    var parseUrl = function (a) {
        function b(a) {
            var b = (a.hostname || "").split(":")[0].toLowerCase(),
                c = (a.protocol || "").toLowerCase(),
                c = 1 * a.port || ("http:" == c ? 80 : "https:" == c ? 443 : "");
            a = a.pathname || "";
            inString(a, "/") || (a = "/" + a);
            return [b, "" +c, a];
        }

        var c = document.createElement("a");
        setHref(c, document.location.href);
        var d = (c.protocol || "").toLowerCase(),
            e = b(c),
            g = c.search || "",
            ca = d + "//" + e[0] + (e[1] ? ":" + e[1] : "");
        inString(a, "//") ? a = d + a : inString(a, "/") ? a = ca + a : !a || inString(a, "?") ? a = ca + e[2] + (a || g) : 0 > a.split("/")[0].indexOf(":") &&(a = ca + e[2].substring(0, e[2].lastIndexOf("/")) + "/" + a);
        setHref(c, a);
        d = b(c);
        return {
                protocol: (c.protocol || "").toLowerCase(),
                host: d[0],
                port: d[1],
                path: d[2],
                G: c.search || "",
                url: a || ""
            };
        };
    var Z = {
            wa: function () {
                Z.f =[];
            }
        };
    Z.wa();
    Z.D = function (a) {
        var b = Z.J.apply(Z, arguments),
            b = Z.f.concat(b);
        for (Z.f =[]; 0 < b.length && !Z.v(b[0]) && !(b.shift(), 0 < Z.f.length););
        Z.f = Z.f.concat(b);
    };
    Z.J = function (a) {
        for(var b = [], c = 0; c < arguments.length; c++)
            try {
                var d = new sc(arguments[c]);
                if (d.g) Yd.set(d.a[0], d.a[1]);
                else {
                    if (d.i) {
                        var e = d,
                            g = e.a[0];
                        if (!isFunction(Yd.get(g)) && !$d.get(g)) {
                            Zd.hasOwnProperty(g) && setMsgCode(Zd[g]);
                            var ca = e.X;
                            !ca && Zd.hasOwnProperty(g) ?(setMsgCode(39), ca = g + ".js") : setMsgCode(43);
                            if (ca) {

                                ca && 0 <= ca.indexOf("/") ||(ca = "/plugins/ua/" +ca);
                                var l = parseUrl(ca);
                                var e = void 0;
                                var k = l.protocol;
                                var w = document.location.protocol;
                                e = "https:" == k || k == w ? true : "http:" != k ? false : "http:" == w;
                                var xd;
                                if (xd = e) {
                                    var e = l,
                                        be = parseUrl(document.location.href);
                                    if (e.G || 0 <= e.url.indexOf("?") || 0 <= e.path.indexOf("://")) xd = false;
                                    else if (e.host == be.host && e.port == be.port) xd = true;
                                    else {
                                        var ce = "http:" == e.protocol ? 80 : 443;

                                        xd = "localhost:25388" == e.host && (e.port || ce) == ce && inString(e.path, "/plugins/") ? true : false;
                                    }
                                }
                                xd && (createScript(l.url), $d.set(g, true));
                            }
                        }
                    }
                    b.push(d);
                }
            } catch (de) {
                //
                throw de;
            }
        return b;
    };
    Z.v = function (a) {
        try {
            if (a.u) a.u.call(window, $.j("t0"));
            else {
                var b = a.c == WXAnalyticsObjectName ? $: $.j(a.c);
                if (a.A) "t0" == a.c && $.create.apply($, a.a);
                else if (a.ba) $.remove(a.c);
                else if (b)
                    if (a.i) {
                        if (!tc(a.a[0], b, a.W)) return true;
                    } else if (a.e) {
                        var c = a.d,
                            d = a.a,
                            e = b.plugins_.get(a.e);
                        e[c].apply(e, d);
                    } else b[a.d].apply(b, a.a);
            }
        } catch (g) {
            //
            throw g;
        }
    };
    var $ = function (a) {
        setMsgCode(1);
        Z.D.apply(Z, [arguments]);
    };
    $.h = { };
    $.P =[];
    $.L = 0;
    $.answer = 42;
    var uc = [trackingId, cookieDomain, V];
    $.create = function (a) {
        var b = preParameters(uc, [].slice.call(arguments));
        b[V]|| (b[V] = "t0");
        var c = "" + b[V];
        if ($.h[c]) return $.h[c];
        b = new pc(b);
        $.h[c]= b;
        $.P.push(b);
        return b;
    };
    $.remove = function (a) {
        for(var b = 0; b < $.P.length; b++)
            if ($.P[b].get(V) == a) {
                $.P.splice(b, 1);
                $.h[a]= null;
                break;
            }
    };
    $.j = function (a) {
        return $.h[a];
    };
    $.K = function () {
        return $.P.slice(0);
    };
    $.N = function () {
        "wa" != WXAnalyticsObjectName && setMsgCode(49);
        var a = window[WXAnalyticsObjectName];
        if (!a || 42 != a.answer) {
            $.L = a && a.l;
            $.loaded = true;
            var b = window[WXAnalyticsObjectName]= $;
            createCommands("create", b, b.create, 3);
            createCommands("remove", b, b.remove);
            createCommands("getByName", b, b.j, 5);
            createCommands("getAll", b, b.K, 6);
            b = pc.prototype;
            createCommands("get", b, b.get, 7);
            createCommands("set", b, b.set, 4);
            createCommands("send", b, b.send, 2);
            b = settings.prototype;
            createCommands("get", b, b.get);
            createCommands("set", b, b.set);
            (window.waplugins = window.waplugins || { }).Linker = Dc;
            b = Dc.prototype;
            Yd.set("linker", Dc);
            createCommands("decorate", b, b.Q, 20);
            createCommands("autoLink", b, b.S, 25);
            //Yd.set("displayfeatures", fd);
            //Yd.set("adfeatures", Kd);
            a = a && a.q;
            if (isArray(a)) {
                Z.D.apply($, a);
            } else {
                setMsgCode(50);
            }
        }
    };
    //启动入口
    (function () {
        var a = $.N;
        if (!onPageIsVisibility(a)) {
            setMsgCode(16);
            var b = false;
            var c = function () {
                !b && onPageIsVisibility(a) &&(b = true, removeEvent(document, "visibilitychange", c));
            };
            addEvent(document, "visibilitychange", c);
        }
    }) ();

    //这个是干什么的？我不知道。
    function La(a) {
        var b = 1,
            c = 0,
            d;
        if (a)
            for (b = 0, d = a.length -1; 0 <= d; d--) {
                c = a.charCodeAt(d),
                    b = (b << 0x6 & 0xFFFFFFF) +c + (c << 14),
                    c = b & 0xFE00000,
                    b = 0 != c ? b ^ c >> 21 : b;
            }
        return b;
    };
    }) (window);

最后说一下，谷歌代码编译工具。

http://closure-compiler.appspot.com/home

编译后，代码长度明显变短了。。。