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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /testing/web-platform/tests/dom/events/Event-timestamp-safe-resolution.html
parentInitial commit. (diff)
downloadfirefox-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.html49
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
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+++ 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> \ No newline at end of file