| <!doctype html> |
| <html> |
| <head> |
| <meta charset="utf-8"> |
| <title>Testing monotonically increasing WebRTC stats timestamps</title> |
| <script src="../resources/testharness.js"></script> |
| <script src="../resources/testharnessreport.js"></script> |
| </head> |
| <body> |
| <script src ="routines.js"></script> |
| <script> |
| // Get stats object of type that is expected to be |
| // found in the statsReport |
| function getRequiredStats(statsReport, type) { |
| for(const stats of statsReport.values()) { |
| if(stats.type === type) { |
| return stats; |
| } |
| } |
| |
| assert_unreached(`required stats of type ${type} is not found in stats report`); |
| } |
| |
| promise_test(async t => { |
| const kMinimumTimeElapsedBetweenGetStatsCallsMs = 500; |
| const pc = new RTCPeerConnection(); |
| t.add_cleanup(() => pc.close()); |
| const t0 = Math.floor(performance.now()); |
| const t0Stats = getRequiredStats(await pc.getStats(), 'peer-connection'); |
| assert_greater_than(t0Stats.timestamp, window.performance.timeOrigin + window.performance.now() - 100); |
| await new Promise( |
| r => t.step_timeout(r, kMinimumTimeElapsedBetweenGetStatsCallsMs)); |
| const t1Stats = getRequiredStats(await pc.getStats(), 'peer-connection'); |
| const t1 = Math.ceil(performance.now()); |
| const maximumTimeElapsedBetweenGetStatsCallsMs = t1 - t0; |
| const deltaTimestampMs = t1Stats.timestamp - t0Stats.timestamp; |
| // The delta must be at least the time we waited between calls. |
| assert_greater_than_equal(deltaTimestampMs, |
| kMinimumTimeElapsedBetweenGetStatsCallsMs); |
| // The delta must be at most the time elapsed before the first getStats() |
| // call and after the second getStats() call. |
| // We increase a bit maximumTimeElapsedBetweenGetStatsCallsMs as we reduce |
| // stat timestamp resolution by 1 ms. |
| assert_less_than_equal(deltaTimestampMs, |
| maximumTimeElapsedBetweenGetStatsCallsMs + 2); |
| }, `RTCStats.timestamp increases with time passing`); |
| </script> |
| </body> |
| </html> |
