CDN Test Script

cdntest.js

var API_PREFIX = '/api/v1';
var stats = [];
var TEST_CDN = '';

function recordStat(url, cdnName, statName, timeInMillis) {
    stats.push({
        "name": statName, 
        "cdn": cdnName,
        "timeTakenMillis": timeInMillis
    });
}

function measureImageSpeed(imageAddr, success, error) {
    setTimeout(function() {
        var startTime, endTime;
        var download = new Image();
        download.onload = function () {
            endTime = (new Date()).getTime();
            var duration = (endTime - startTime);
            success(imageAddr, duration);
        }
        
        download.onerror = function (err, msg) {
            error(imageAddr, err, msg);
        }
        
        startTime = (new Date()).getTime();
        var cacheBuster = "?nnn=" + startTime;
        download.src = imageAddr + cacheBuster;
    }, 500)
}

function getCookie(name) {
  var value = "; " + document.cookie;
  var parts = value.split("; " + name + "=");
  if (parts.length == 2) return parts.pop().split(";").shift();
}

function loadAndTime(url, statName, testType, cdnName) {
    var start = new Date().getTime();

    if (testType == 'api') {
        var requestDetails = {
            type: "GET",
            url:  API_PREFIX + url,
            cache: false,
            headers: {
                Authorization: getCookie('Authorization')
            },
            success: function(data) {
                if (data) {
                    var end = new Date().getTime();
                    recordStat(url, TEST_CDN, statName, (end-start));
                } else {
                    recordStat(url, TEST_CDN, statName, -1); // Failure!
                }
                runNext();
            },
            error: function() {
                recordStat(url, TEST_CDN, statName, -1); // Failure!
                runNext();
            },
            dataType: null
        };
        $.ajax(requestDetails);
    } else if (testType == 'apiAbsolute') {
        var requestDetails = {
            type: "GET",
            url: url,
            cache: false,
            headers: {
                Authorization: getCookie('Authorization')
            },
            success: function(data, textStatus, request) {
                if (data) {
                    var end = new Date().getTime();
                    recordStat(url, cdnName, statName, (end-start));
                } else {
                    recordStat(url, cdnName, statName, -1); // Failure!
                }
                runNext();
            },
            error: function(request, textStatus, err) {
                recordStat(url, cdnName, statName, -1); // Failure!
                runNext();
            },
            dataType: null
        };
        $.ajax(requestDetails);
    } else if (testType == 'image') {
        measureImageSpeed(url, function(url, duration) {
            recordStat(url, cdnName, statName, duration);
            runNext();
        },
        function(url, err, msg) {
            recordStat(url, cdnName, statName, -1); // Failure!
            runNext();
        })
    } else if (testType == 'measured') {
        var measuredCdnName = TEST_CDN;
        var measuredTimeTaken = -1;
        if (url) {
            var measures = url.split('|');
            if (measures.length == 2) {
                var begin = window[measures[0]];
                var end = window[measures[1]];
                if (begin && end) {
                    measuredTimeTaken = end - begin;
                }
            }
        }
        recordStat(url, measuredCdnName, statName, measuredTimeTaken);
        setTimeout(function(){
            runNext();
        }, 10);
    } else {
        setTimeout(function(){
            runNext();
        }, 10);
    }
}

function getCdnName(request) {
    var cdnName;
    if (isCloudFrontRequest(request)) {
        cdnName = 'CloudFront';
    } else if (isAliCloudRequest(request)){
        cdnName = 'AliCloud';
    } else {
        cdnName = 'Unknown';
    }
    return cdnName;
}

function isCloudFrontRequest(request) {
    if (request.getResponseHeader('x-amz-cf-id')) {
        return true;
    } else {
        return false;
    }
}
function isAliCloudRequest(request) {
    if (request.getResponseHeader('X-Swift-CacheTime')) {
        return true;
    } else {
        return false;
    }
}

function postStats() {
    var result = {
        "stats": stats
    };

    $.ajax({
        type: "POST",
        url: API_PREFIX + '/statscollector/save',
        data: JSON.stringify(result),
        headers: {
            "Content-Type": "application/json",
            "Accept": "application/json",
            "Authorization": getCookie('Authorization')
        },
        success: function(data) {
            //if (console && console.log) console.log("Test complete: " + cdn);
        },
        dataType: null
    });
}

var tests = []; //{url: '' (relative to API_PREFIX for 'api' testType, absolute for all others), name: 'Xyz' (e.g. img-large, json-small), testType: 'api|image|apiAbsolute', cdnName: 'CloudFront|Akamai|AliCloud' (determined from response header for 'api' testType)}
var nextIndex = 0;
function runNext(){
    if (nextIndex < tests.length) {
        loadAndTime(tests[nextIndex].url, tests[nextIndex].name, tests[nextIndex].testType, tests[nextIndex].cdnName)
        nextIndex++;
    } else {
        postStats();
    }
}

function loadAndRunTests() {
    $.ajax({
        type: "GET",
        url: API_PREFIX + '/statscollector/getTests.json',
        headers: {
            "Content-Type": "application/json",
            "Accept": "application/json",
            "Authorization": getCookie('Authorization')
        },
        success: function(data, textStatus, request) {
            TEST_CDN = getCdnName(request);
            if (data && data.tests) {
                tests = data.tests;
                //if (console && console.log) console.log("Running tests: " + JSON.stringify(data));
            } else {
                //console.log('Received invalid test data.')
            }
            
            runNext();
        },
        error: function() {
            //console.log('Failed to load tests.')
        }
    });
}

$( document ).ready(function() {
    setTimeout(function() {
        loadAndRunTests();
    }, 3000)
});