https://github.com/majido/high-resolution-timestamp-polyfill

https://github.com/majido/high-resolution-timestamp-polyfill

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• Host: GitHub
• URL: https://github.com/majido/high-resolution-timestamp-polyfill
• Owner: majido
• Created: 2016-01-27T18:45:08.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2016-03-17T18:58:24.000Z (over 8 years ago)
• Last Synced: 2023-10-20T21:29:39.287Z (about 1 year ago)
• Language: JavaScript
• Size: 21.5 KB
• Stars: 5
• Watchers: 2
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
# High-Resolution Timestamp Polyfill [![Build Status](https://travis-ci.org/majido/high-resolution-timestamp-polyfill.svg?branch=master)](https://travis-ci.org/majido/high-resolution-timestamp-polyfill)

## Introduction

This repository hosts utilities to help with Event.timeStamp transition from

[```DOMTimeStamp```][timestamp-mdn] to

[```DOMHighResTimeStamp```][highres-timestamp-mdn].

## Background

Browsers ([Chrome][chrome-bug], [Firefox][firefox-bug]) and the [DOM spec]

[spec-bug] are in the process of updating event timestamp from being a

```DOMTimeStamp``` to a ```DOMHighResTimeStamp```.

[```DOMTimeStamp```][timestamp-mdn] is a time value in milliseconds relative to

an arbitrary epoch. Most browsers use system epoch making the value comparable

to ```Date.now()``` in those browsers. In contrast [```DOMHighResTimeStamp```]

[highres-timestamp-mdn] is a time value in milliseconds but with microseconds

precision (i.e., decimal component) which is relative to

[performance.timing.navigationStart][navigation-start-mdn] making it comparable

to ```performance.now()```.

To better understand the potential impact of this change in existing code please

read the more detailed [blog post][blogpost] by [Jeff Posnick](https://twitter.com/jeffposnick)

on Chrome Developer's blog.

## Details

* [Conversion function][conversion]: A simple cross-browser utility function

  that allows translation of event timestamp to a DOMHighResTimeStamp.

* [Polyfill (work in progress)][polyfill]: Makes Event.timeStamp to always be

  a DOMHighResTimeStamp. This is WIP as it does not work well in Safari yet. Safari support requires a fix for [this WebKit bug][webkit-limitation] that

  prevents overriding getter and setter on the prototype.

## License

[The MIT License (MIT)](http://opensource.org/licenses/MIT)

[timestamp-mdn]: https://developer.mozilla.org/en-US/docs/Web/API/DOMTimeStamp

[highres-timestamp-mdn]: https://developer.mozilla.org/en-US/docs/Web/API/DOMHighResTimeStamp

[navigation-start-mdn]: https://developer.mozilla.org/en-US/docs/Web/API/PerformanceTiming/navigationStart

[chrome-bug]: https://www.chromestatus.com/features/5523910145605632

[firefox-bug]: https://bugzilla.mozilla.org/show_bug.cgi?id=1026804

[spec-bug]: https://github.com/whatwg/dom/issues/23

[webkit-limitation]: https://bugs.webkit.org/show_bug.cgi?id=49739

[blogpost]: https://developers.google.com/web/updates/2016/01/high-res-timestamps?hl=en

[conversion]: https://github.com/majido/high-resolution-timestamp-polyfill/blob/master/translate-timeStamp.js

[polyfill]: https://github.com/majido/high-resolution-timestamp-polyfill/blob/master/high-resolution-timestamp-polyfill.js