File size: 2,448 Bytes
1e92f2d |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 |
import { getDomContentLoadedEventStart, getNavigationStart } from '../api/performance-timing';
import { getResources } from '../api/resources-timing';
import type { Collector } from '../types';
export const collector: Collector = ( report ) => {
const domContentLoaded = getDomContentLoadedEventStart() - getNavigationStart();
if ( domContentLoaded <= 0 ) {
return report;
}
/**
* Fetch resources that
* - are scripts
* - finish downloading before domContentLoaded
* - have a size (to exclude resources form a different origin)
*/
const blockingResources = getResources().filter(
( r ) =>
r.initiatorType === 'script' && r.responseEnd <= domContentLoaded && r.decodedBodySize > 0
);
const resourcesCount = blockingResources.length;
// Gets when the first resource starts, and when the last resource ends
const { start: resourcesStart, end: resourcesEnd } = blockingResources.reduce(
( { start, end }, resource ) => ( {
start: Math.min( start, resource.requestStart ),
end: Math.max( end, resource.responseEnd ),
} ),
{ start: Infinity, end: -Infinity }
);
const { resourcesCompressed, resourcesUncompressed, resourcesTransferred } =
blockingResources.reduce(
( acc, script ) => ( {
resourcesCompressed: acc.resourcesCompressed + script.encodedBodySize,
resourcesUncompressed: acc.resourcesUncompressed + script.decodedBodySize,
resourcesTransferred: acc.resourcesTransferred + script.transferSize,
} ),
{
resourcesCompressed: 0,
resourcesUncompressed: 0,
resourcesTransferred: 0,
}
);
// Hit ratio from 0 to 100 (0=nothing was cached, 100=everything comes from the cache).
// resourcesTransferred includes the headers, but resourcesCompressed does not, so the division is a
// bit off and can return values higher than 1. We cap it to 1 to avoid sending negative numbers
const resourcesCacheRatio =
100 - Math.round( Math.min( 1, resourcesTransferred / resourcesCompressed ) * 100 );
report.data.set( 'resourcesCount', resourcesCount );
report.data.set( 'resourcesStart', Math.round( resourcesStart ) );
report.data.set( 'resourcesEnd', Math.round( resourcesEnd ) );
report.data.set( 'resourcesCompressed', resourcesCompressed );
report.data.set( 'resourcesUncompressed', resourcesUncompressed );
report.data.set( 'resourcesTransferred', resourcesTransferred );
report.data.set( 'resourcesCacheRatio', resourcesCacheRatio );
return report;
};
|