Files
YellowLabTools/lib/tools/redownload/redownload.js
T

782 lines
26 KiB
JavaScript

/*
* Redownloading every files after Phantomas has finished
* Checks weight and every kind of compression
*
*/
/*jshint -W069 */
var debug = require('debug')('ylt:redownload');
var Q = require('q');
var http = require('http');
var zlib = require('zlib');
var async = require('async');
var request = require('request');
var md5 = require('md5');
var imageOptimizer = require('./imageOptimizer');
var fileMinifier = require('./fileMinifier');
var gzipCompressor = require('./gzipCompressor');
var contentTypeChecker = require('./contentTypeChecker');
var fontAnalyzer = require('./fontAnalyzer');
var Redownload = function() {
var MAX_PARALLEL_DOWNLOADS = 10;
var REQUEST_TIMEOUT = 15000; // 15 seconds
// This function will re-download every asset and check if it could be optimized
function recheckAllFiles(data) {
var startTime = Date.now();
debug('Redownload started');
var deferred = Q.defer();
var requestsList = JSON.parse(data.toolsResults.phantomas.offenders.requestsList);
delete data.toolsResults.phantomas.metrics.requestsList;
delete data.toolsResults.phantomas.offenders.requestsList;
var httpAuth = null;
if (data.params && data.params.options && data.params.options.authUser && data.params.options.authPass) {
httpAuth = {
username: data.params.options.authUser,
password: data.params.options.authPass
};
}
var proxy = null;
if (data.params && data.params.options && data.params.options.proxy) {
proxy = data.params.options.proxy;
if (proxy.indexOf('http:') === -1) {
proxy = 'http://' + proxy;
}
}
// Prevent a bug with the font analyzer on empty pages
var differentCharacters = '';
if (data.toolsResults.phantomas.offenders.differentCharacters && data.toolsResults.phantomas.offenders.differentCharacters.length > 0) {
differentCharacters = data.toolsResults.phantomas.offenders.differentCharacters[0];
}
// Transform every request into a download function with a callback when done
var redownloadList = requestsList.map(function(entry) {
return function(callback) {
redownloadEntry(entry, httpAuth, proxy)
.then(contentTypeChecker.checkContentType)
.then(imageOptimizer.optimizeImage)
.then(fileMinifier.minifyFile)
.then(gzipCompressor.compressFile)
.then(function(entry) {
return fontAnalyzer.analyzeFont(entry, differentCharacters);
})
.then(function(newEntry) {
debug('File %s - Redownloaded, optimized, minified, compressed, analyzed: done', entry.url);
callback(null, newEntry);
})
.fail(function(err) {
callback(err);
});
};
});
// Lanch all redownload functions and wait for completion
async.parallelLimit(redownloadList, MAX_PARALLEL_DOWNLOADS, function(err, results) {
if (err) {
debug(err);
deferred.reject(err);
} else {
debug('All files checked');
endTime = Date.now();
debug('Redownload took %d ms', endTime - startTime);
var metrics = {};
var offenders = {};
// Count requests
offenders.totalRequests = listRequestsByType(results);
metrics.totalRequests = offenders.totalRequests.total;
// Remove unwanted responses (redownload failed, about:blank)
results = results.filter(function(result) {
return (result !== null && result.weightCheck && result.url.indexOf('about:blank') !== 0);
});
// Wrong contentType
offenders.incorrectContentTypes = listIncorrectContentTypes(results);
metrics.incorrectContentTypes = offenders.incorrectContentTypes.length;
// Total weight
offenders.totalWeight = listRequestWeight(results);
metrics.totalWeight = offenders.totalWeight.totalWeight;
// Empty files
offenders.emptyRequests = listEmptyRequests(results);
metrics.emptyRequests = offenders.emptyRequests.length;
// Now remove unwanted responses (redirections and empty files)
results = results.filter(function(result) {
return ((result.status < 300 || result.status >= 400) && result.weightCheck.bodySize > 0);
});
// Image compression
offenders.imageOptimization = listImageNotOptimized(results);
metrics.imageOptimization = offenders.imageOptimization.totalGain;
// File minification
offenders.fileMinification = listFilesNotMinified(results);
metrics.fileMinification = offenders.fileMinification.totalGain;
// Gzip compression
offenders.gzipCompression = listFilesNotGzipped(results);
metrics.gzipCompression = offenders.gzipCompression.totalGain;
// Small requests
offenders.smallRequests = listSmallRequests(results);
metrics.smallRequests = offenders.smallRequests.total;
// Detect identical files
offenders.identicalFiles = listIdenticalFiles(results);
metrics.identicalFiles = offenders.identicalFiles.avoidableRequests;
// Fonts count
offenders.fontsCount = listFonts(results);
metrics.fontsCount = offenders.fontsCount.count;
// Heavy fonts
offenders.heavyFonts = listHeavyFonts(results);
metrics.heavyFonts = offenders.heavyFonts.totalGain;
// Unused Unicode ranges
offenders.unusedUnicodeRanges = listUnusedUnicodeRanges(results);
metrics.unusedUnicodeRanges = offenders.unusedUnicodeRanges.count;
data.toolsResults.redownload = {
metrics: metrics,
offenders: offenders
};
deferred.resolve(data);
}
});
return deferred.promise;
}
function listIncorrectContentTypes(requests) {
var results = [];
requests.forEach(function(req) {
if (req.oldContentType || req.oldContentType === null) {
results.push({
url: req.url,
current: req.oldContentType,
correct: req.contentType
});
}
});
return results;
}
function listEmptyRequests(requests) {
var results = [];
requests.forEach(function(req) {
var weight = req.weightCheck.bodySize || req.contentLength;
if (weight === 0 && req.method === 'GET' && req.status === 200) {
results.push(req.url);
}
});
return results;
}
function listRequestWeight(requests) {
var results = {
totalWeight: 0,
byType: {
html: {
totalWeight: 0,
requests: []
},
css: {
totalWeight: 0,
requests: []
},
js: {
totalWeight: 0,
requests: []
},
json: {
totalWeight: 0,
requests: []
},
image: {
totalWeight: 0,
requests: []
},
video: {
totalWeight: 0,
requests: []
},
webfont: {
totalWeight: 0,
requests: []
},
other: {
totalWeight: 0,
requests: []
}
}
};
requests.forEach(function(req) {
var weight = ((typeof req.weightCheck.bodySize === 'number') ? req.weightCheck.bodySize + req.weightCheck.headersSize : req.contentLength) || 0;
var type = req.type || 'other';
type = (results.byType[type]) ? type : 'other';
results.totalWeight += weight;
results.byType[type].totalWeight += weight;
results.byType[type].requests.push({
url: req.url,
weight: weight
});
});
return results;
}
function listImageNotOptimized(requests) {
var results = {
totalGain: 0,
images: []
};
requests.forEach(function(req) {
if (req.weightCheck.bodySize > 0 && imageOptimizer.entryTypeCanBeOptimized(req) && req.weightCheck.isOptimized === false) {
var before = req.weightCheck.afterCompression || req.weightCheck.bodySize;
var after = req.weightCheck.afterOptimizationAndCompression || req.weightCheck.optimized;
var gain = before - after;
if (gain > 200) {
results.totalGain += gain;
results.images.push({
url: req.url,
original: req.weightCheck.bodySize,
isCompressed: req.weightCheck.isCompressed,
afterCompression: req.weightCheck.afterCompression,
afterOptimizationAndCompression: req.weightCheck.afterOptimizationAndCompression,
lossless: req.weightCheck.lossless,
lossy: req.weightCheck.lossy,
gain: gain
});
}
}
});
return results;
}
function listFilesNotMinified(requests) {
var results = {
totalGain: 0,
files: []
};
requests.forEach(function(req) {
if (req.weightCheck.bodySize > 0 && fileMinifier.entryTypeCanBeMinified(req) && req.weightCheck.isOptimized === false) {
var before = req.weightCheck.afterCompression || req.weightCheck.bodySize;
var after = req.weightCheck.afterOptimizationAndCompression || req.weightCheck.optimized;
var gain = before - after;
if (gain > 200) {
results.totalGain += gain;
results.files.push({
url: req.url,
original: req.weightCheck.bodySize,
isCompressed: req.weightCheck.isCompressed,
afterCompression: req.weightCheck.afterCompression,
afterOptimizationAndCompression: req.weightCheck.afterOptimizationAndCompression,
optimized: req.weightCheck.optimized,
gain: gain
});
}
}
});
return results;
}
function listFilesNotGzipped(requests) {
var results = {
totalGain: 0,
files: []
};
requests.forEach(function(req) {
if (req.weightCheck.uncompressedSize && req.weightCheck.isCompressed === false && req.weightCheck.afterCompression) {
var gain = req.weightCheck.uncompressedSize - req.weightCheck.afterCompression;
results.totalGain += gain;
results.files.push({
url: req.url,
original: req.weightCheck.uncompressedSize,
gzipped: req.weightCheck.afterCompression,
gain: gain
});
}
});
return results;
}
function listRequestsByType(requests) {
var results = {
total: 0,
byType: {
html: [],
css: [],
js: [],
json: [],
image: [],
video: [],
webfont: [],
other: []
}
};
requests.forEach(function(req) {
if (req.url !== 'about:blank') {
var type = req.type || 'other';
type = (results.byType[type]) ? type : 'other';
results.byType[type].push(req.url);
results.total ++;
}
});
return results;
}
function listSmallRequests(requests) {
var results = {
total: 0,
byType: {
css: [],
js: [],
image: []
}
};
requests.forEach(function(req) {
if (req.weightCheck.bodySize > 0 && req.weightCheck.bodySize < 2048) {
if (req.isCSS || req.isJS || req.isImage) {
results.byType[req.type].push({
url: req.url,
size: req.weightCheck.bodySize
});
results.total ++;
}
}
});
return results;
}
function listIdenticalFiles(requests) {
var hashes = {};
var list = [];
var avoidableRequestsCount = 0;
requests.forEach(function(req) {
var requestHash = md5(req.weightCheck.bodyBuffer);
// Try to exclude tracking pixels
if (req.weightCheck.bodySize < 80 && req.type === 'image') {
return;
}
if (!hashes[requestHash]) {
hashes[requestHash] = {
weight: req.weightCheck.bodySize,
urls: []
};
}
if (hashes[requestHash].urls.indexOf(req.url) === -1) {
hashes[requestHash].urls.push(req.url);
}
});
for (var hash in hashes) {
if (hashes[hash].urls.length > 1) {
list.push(hashes[hash]);
avoidableRequestsCount += hashes[hash].urls.length - 1;
}
}
return {
avoidableRequests: avoidableRequestsCount,
count: list.length,
list: list
};
}
function listFonts(requests) {
var list = [];
requests.forEach(function(req) {
if (req.isWebFont) {
list.push({
url: req.url,
size: req.weightCheck.bodySize
});
}
});
return {
count: list.length,
list: list
};
}
function listHeavyFonts(requests) {
var list = [];
var totalGain = 0;
var heavyFontsCount = 0;
var MAX_FONT_WEIGHT = 40 * 1024;
requests.forEach(function(req) {
if (req.isWebFont && req.fontMetrics) {
list.push({
url: req.url,
weight: req.weightCheck.bodySize,
numGlyphs: req.fontMetrics.numGlyphs,
averageGlyphComplexity: req.fontMetrics.averageGlyphComplexity
});
if (req.weightCheck.bodySize > MAX_FONT_WEIGHT) {
totalGain += req.weightCheck.bodySize - MAX_FONT_WEIGHT;
heavyFontsCount ++;
}
}
});
return {
count: heavyFontsCount,
fonts: list,
totalGain: totalGain
};
}
function listUnusedUnicodeRanges(requests) {
var list = [];
var unusedUnicodeRanges = 0;
requests.forEach(function(req) {
if (req.isWebFont && req.fontMetrics && req.fontMetrics.unicodeRanges) {
var ranges = [];
var others = null;
var rangeNames = Object.keys(req.fontMetrics.unicodeRanges);
rangeNames.forEach(function(rangeName) {
var range = req.fontMetrics.unicodeRanges[rangeName];
// Exclude "Others"
if (rangeName === 'Others') {
if (range.numGlyphsInCommonWithPageContent === 0 && range.charset.length > 50) {
range.underused = true;
unusedUnicodeRanges ++;
}
others = range;
} else if (range.charset.length > 0) {
// Now lets detect if the current Unicode range is unused.
// Reminder: range.coverage = glyphs declared in this range, divided by the range size
if (range.coverage > 0.25 && range.numGlyphsInCommonWithPageContent === 0) {
range.underused = true;
unusedUnicodeRanges ++;
}
ranges.push(range);
}
});
// Detect if it's a icons font : if more than 90% of the icons are
// in the "Others", it looks like one.
if (others && others.charset.length / req.fontMetrics.numGlyphs > 0.9) {
list.push({
url: req.url,
weight: req.weightCheck.bodySize,
isIconFont: true,
glyphs: req.fontMetrics.numGlyphs,
numGlyphsInCommonWithPageContent: req.fontMetrics.numGlyphsInCommonWithPageContent
});
// And if less than 5% of the icons are used, let's report it as underused
if (others && others.numGlyphsInCommonWithPageContent / others.charset.length <= 0.05) {
unusedUnicodeRanges ++;
}
// Not an icons font
} else {
if (others) {
// Insert back "Others" at the end of the list
ranges.push(others);
}
list.push({
url: req.url,
weight: req.weightCheck.bodySize,
isIconFont: false,
unicodeRanges: ranges
});
}
}
});
return {
count: unusedUnicodeRanges,
fonts: list
};
}
function redownloadEntry(entry, httpAuth, proxy) {
var deferred = Q.defer();
function downloadError(message) {
debug('Could not download %s Error: %s', entry.url, message);
entry.weightCheck = {
message: message
};
deferred.resolve(entry);
}
// Not downloaded again but will be counted in totalWeight
function notDownloadableFile(message) {
entry.weightCheck = {
message: message
};
deferred.resolve(entry);
}
// Not counted in totalWeight
function unwantedFile(message) {
debug(message);
deferred.resolve(entry);
}
if (entry.method !== 'GET') {
notDownloadableFile('only downloading GET');
return deferred.promise;
}
if (entry.status !== 200) {
unwantedFile('only downloading requests with status code 200');
return deferred.promise;
}
if (entry.url === 'about:blank') {
unwantedFile('not downloading about:blank');
return deferred.promise;
}
debug('Downloading %s', entry.url);
// Always add a gzip header before sending, in case the server listens to it
var reqHeaders = entry.requestHeaders;
reqHeaders['Accept-Encoding'] = 'gzip, deflate';
reqHeaders['Connection'] = 'keep-alive';
var requestOptions = {
method: entry.method,
url: entry.url,
headers: reqHeaders,
timeout: REQUEST_TIMEOUT,
proxy: proxy
};
// Basic auth
if (httpAuth) {
requestOptions.auth = {
user: httpAuth.username,
pass: httpAuth.password,
sendImmediately: false // Tries a first time without auth, wait for a 401 error before resending
};
}
download(requestOptions, entry.contentType, function(error, result) {
if (error) {
if (error.code === 'ETIMEDOUT') {
downloadError('timeout after ' + REQUEST_TIMEOUT + 'ms');
} else {
downloadError('error while downloading: ' + error.code);
}
return;
}
debug('%s downloaded correctly', entry.url);
entry.weightCheck = result;
deferred.resolve(entry);
});
return deferred.promise;
}
// Inspired by https://github.com/cvan/fastHAR-api/blob/10cec585/app.js
function download(requestOptions, contentType, callback) {
var statusCode;
try {
request(requestOptions)
.on('response', function(res) {
// Raw headers were added in NodeJS v0.12
// (https://github.com/joyent/node/issues/4844), but let's
// reconstruct them for backwards compatibility.
var rawHeaders = ('HTTP/' + res.httpVersion + ' ' + res.statusCode +
' ' + http.STATUS_CODES[res.statusCode] + '\r\n');
Object.keys(res.headers).forEach(function(headerKey) {
rawHeaders += headerKey + ': ' + res.headers[headerKey] + '\r\n';
});
rawHeaders += '\r\n';
var uncompressedSize = 0; // size after uncompression
var bodySize = 0; // bytes size over the wire
var bodyChunks = []; // an array of buffers
var isCompressed = false;
function tally() {
if (statusCode !== 200) {
callback({code: statusCode});
return;
}
var body = Buffer.concat(bodyChunks);
var result = {
bodyBuffer: body,
headersSize: Buffer.byteLength(rawHeaders, 'utf8'),
bodySize: bodySize,
isCompressed: isCompressed,
uncompressedSize: uncompressedSize
};
callback(null, result);
}
switch (res.headers['content-encoding']) {
case 'gzip':
var gzip = zlib.createGunzip();
gzip.on('data', function (data) {
bodyChunks.push(data);
uncompressedSize += data.length;
}).on('end', function () {
isCompressed = true;
tally();
}).on('error', function(err) {
debug('Error while decoding %s', requestOptions.url);
debug(err);
callback(err);
});
res.on('data', function (data) {
bodySize += data.length;
}).pipe(gzip);
break;
case 'deflate':
res.setEncoding('utf8');
var deflate = zlib.createInflate();
deflate.on('data', function (data) {
bodyChunks.push(data);
uncompressedSize += data.length;
}).on('end', function () {
isCompressed = true;
tally();
}).on('error', function(err) {
debug('Error while decoding %s', requestOptions.url);
debug(err);
callback(err);
});
res.on('data', function (data) {
bodySize += data.length;
}).pipe(deflate);
break;
default:
res.on('data', function (data) {
bodyChunks.push(data);
uncompressedSize += data.length;
bodySize += data.length;
}).on('end', function () {
tally();
});
break;
}
})
.on('response', function(response) {
statusCode = response.statusCode;
})
.on('error', function(err) {
debug('Error while downloading %s', requestOptions.url);
debug(err);
callback(err);
});
} catch(err) {
debug('Error while downloading %s', requestOptions.url);
debug(err);
callback(err);
}
}
return {
recheckAllFiles: recheckAllFiles,
listRequestWeight: listRequestWeight,
redownloadEntry: redownloadEntry,
download: download
};
};
module.exports = new Redownload();