let response = (component, err, superres) => {
k--
if (err != null) {
if (mostImportantError == null) {
mostImportantError = err
} else {
if (err.status >= 400 && err.status < 600 && err.status < mostImportantError.status) {
mostImportantError = err
}
}
} else {
data[component.component] = superres.body
if (superres.header['cache-control'] != null) {
var cache = parseCacheControl(superres.header['cache-control'])
if (cache != null) {
if (cache['max-age'] != null && typeof cache['max-age'] === 'number' && (header.cache.maxAge == null || header.cache.maxAge > cache['max-age'])) {
header.cache.maxAge = cache['max-age']
}
if (cache.private === true) {
header.cache.private = true
}
if (cache.public === true) {
header.cache.public = true
}
if (cache['no-cache'] === true) {
header.cache.noCache = true
}
if (cache['no-store'] === true) {
header.cache.noStore = true
}
}
}
if (superres.header['set-cookie'] != null) {
var cookieArray = superres.header['set-cookie']
header.cookie = header.cookie.concat(superres.header['set-cookie'])
}
}
if (k < 1) {
if (mostImportantError == null) {
var cacheValue = generateCacheHeader(header.cache);
if (cacheValue.length > 0) {
res.set('Cache-Control', cacheValue)
}
if (header.cookie.length > 0) {
res.set('Set-Cookie', header.cookie)
}
}
cb(mostImportantError, data)
}
}
return artifacts.requestNetworkRecords(devtoolsLogs).then(records => {
const results = [];
let queryStringCount = 0;
let totalWastedBytes = 0;
for (const record of records) {
if (!CacheHeaders.isCacheableAsset(record)) continue;
/** @type {Map<string, string>} */
const headers = new Map();
for (const header of record._responseHeaders || []) {
headers.set(header.name.toLowerCase(), header.value);
}
const cacheControl = parseCacheControl(headers.get('cache-control'));
let cacheLifetimeInSeconds = CacheHeaders.computeCacheLifetimeInSeconds(
headers,
cacheControl
);
// Ignore assets with an explicit no-cache policy
if (cacheLifetimeInSeconds === 0) continue;
cacheLifetimeInSeconds = cacheLifetimeInSeconds || 0;
const cacheHitProbability = CacheHeaders.getCacheHitProbability(cacheLifetimeInSeconds);
if (cacheHitProbability > IGNORE_THRESHOLD_IN_PERCENT) continue;
const url = URL.elideDataURI(record._url);
const totalBytes = record._transferSize || 0;
const wastedBytes = (1 - cacheHitProbability) * totalBytes;
totalWastedBytes += wastedBytes;
if (url.includes('?')) queryStringCount++;
results.push({
url,
cacheControl,
cacheLifetimeMs: cacheLifetimeInSeconds * 1000,
cacheHitProbability,
totalBytes,
wastedBytes,
});
}
results.sort(
(a, b) => a.cacheLifetimeMs - b.cacheLifetimeMs || b.totalBytes - a.totalBytes
);
const score = Audit.computeLogNormalScore(
totalWastedBytes,
context.options.scorePODR,
context.options.scoreMedian
);
const headings = [
{key: 'url', itemType: 'url', text: 'URL'},
{key: 'cacheLifetimeMs', itemType: 'ms', text: 'Cache TTL', displayUnit: 'duration'},
{key: 'totalBytes', itemType: 'bytes', text: 'Size (KB)', displayUnit: 'kb',
granularity: 1},
];
const summary = {wastedBytes: totalWastedBytes};
const details = Audit.makeTableDetails(headings, results, summary);
return {
score,
rawValue: totalWastedBytes,
displayValue: `${results.length} asset${results.length !== 1 ? 's' : ''} found`,
extendedInfo: {
value: {
results,
queryStringCount,
},
},
details,
};
});
return NetworkRecords.request(devtoolsLogs, context).then(records => {
const results = [];
let queryStringCount = 0;
let totalWastedBytes = 0;
for (const record of records) {
if (!CacheHeaders.isCacheableAsset(record)) continue;
/** @type {Map<string, string>} */
const headers = new Map();
for (const header of record.responseHeaders || []) {
if (headers.has(header.name.toLowerCase())) {
const previousHeaderValue = headers.get(header.name.toLowerCase());
headers.set(header.name.toLowerCase(),
`${previousHeaderValue}, ${header.value}`);
} else {
headers.set(header.name.toLowerCase(), header.value);
}
}
const cacheControl = parseCacheControl(headers.get('cache-control'));
if (this.shouldSkipRecord(headers, cacheControl)) {
continue;
}
// Ignore if cacheLifetimeInSeconds is a nonpositive number.
let cacheLifetimeInSeconds = CacheHeaders.computeCacheLifetimeInSeconds(
headers, cacheControl);
if (cacheLifetimeInSeconds !== null &&
(!Number.isFinite(cacheLifetimeInSeconds) || cacheLifetimeInSeconds <= 0)) {
continue;
}
cacheLifetimeInSeconds = cacheLifetimeInSeconds || 0;
// Ignore assets whose cache lifetime is already high enough
const cacheHitProbability = CacheHeaders.getCacheHitProbability(cacheLifetimeInSeconds);
if (cacheHitProbability > IGNORE_THRESHOLD_IN_PERCENT) continue;
const url = URL.elideDataURI(record.url);
const totalBytes = record.transferSize || 0;
const wastedBytes = (1 - cacheHitProbability) * totalBytes;
totalWastedBytes += wastedBytes;
if (url.includes('?')) queryStringCount++;
// Include cacheControl info (if it exists) per url as a diagnostic.
/** @type {LH.Audit.Details.Diagnostic|undefined} */
let diagnostic;
if (cacheControl) {
diagnostic = {
type: 'diagnostic',
...cacheControl,
};
}
results.push({
url,
diagnostic,
cacheLifetimeMs: cacheLifetimeInSeconds * 1000,
cacheHitProbability,
totalBytes,
wastedBytes,
});
}
results.sort((a, b) => {
return a.cacheLifetimeMs - b.cacheLifetimeMs ||
b.totalBytes - a.totalBytes ||
a.url.localeCompare(b.url);
});
const score = Audit.computeLogNormalScore(
totalWastedBytes,
context.options.scorePODR,
context.options.scoreMedian
);
/** @type {LH.Audit.Details.Table['headings']} */
const headings = [
{key: 'url', itemType: 'url', text: str_(i18n.UIStrings.columnURL)},
// TODO(i18n): pre-compute localized duration
{key: 'cacheLifetimeMs', itemType: 'ms', text: str_(i18n.UIStrings.columnCacheTTL),
displayUnit: 'duration'},
{key: 'totalBytes', itemType: 'bytes', text: str_(i18n.UIStrings.columnSize),
displayUnit: 'kb', granularity: 1},
];
const summary = {wastedBytes: totalWastedBytes};
const details = Audit.makeTableDetails(headings, results, summary);
return {
score,
rawValue: totalWastedBytes,
displayValue: str_(UIStrings.displayValue, {itemCount: results.length}),
extendedInfo: {
value: {
results,
queryStringCount,
},
},
details,
};
});