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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html')
-rw-r--r-- | testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html b/testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html new file mode 100644 index 0000000000..24f2dec93c --- /dev/null +++ b/testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html @@ -0,0 +1,49 @@ +<!DOCTYPE html> +<script src="/resources/testharness.js"></script> +<script src="/resources/testharnessreport.js"></script> +<script type="text/javascript"> +'use strict'; + +// Computes greatest common divisor of a and b using Euclid's algorithm +function computeGCD(a, b) { + if (!Number.isInteger(a) || !Number.isInteger(b)) { + throw new Error('Parameters must be integer numbers'); + } + + var r; + while (b != 0) { + r = a % b; + a = b; + b = r; + } + return (a < 0) ? -a : a; +} + +// Finds minimum resolution Δ given a set of samples which are known to be in the form of N*Δ. +// We use GCD of all samples as a simple estimator. +function estimateMinimumResolution(samples) { + var gcd; + for (const sample of samples) { + gcd = gcd ? computeGCD(gcd, sample) : sample; + } + + return gcd; +} + +test(function() { + const samples = []; + for (var i = 0; i < 1e3; i++) { + var deltaInMicroSeconds = 0; + const e1 = new MouseEvent('test1'); + do { + const e2 = new MouseEvent('test2'); + deltaInMicroSeconds = Math.round((e2.timeStamp - e1.timeStamp) * 1000); + } while (deltaInMicroSeconds == 0) // only collect non-zero samples + + samples.push(deltaInMicroSeconds); + } + + const minResolution = estimateMinimumResolution(samples); + assert_greater_than_equal(minResolution, 5); +}, 'Event timestamp should not have a resolution better than 5 microseconds'); +</script>
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