The chromeperf dashboard does not cache any data in the browser.
Many important users monitor the same timeseries over time.
Caching timeseries data in the browser will greatly speed up loading charts and enable offline use.
Timeseries data is generally keyed by timeseries identifier (composed of test suite name, measurement name, bot name, test case name, build type) and x-coordinate (generally commit position or timestamp), and contains summary statistics (avg, std, sample count, min, max, etc), annotations (alerts, sparse diagnostics), and full Histogram objects (description, bins, diagnostics, etc).
Lighthouse recommends using a service worker to cache complex JSON data using IndexedDB.
"idb" will be used to promisify the IndexedDB API.
Comment 1 by bugdroid1@chromium.org
, Jun 22 2018