https://github.com/korzhev/eventloop-latency

Counting node.js eventloop latency.
https://github.com/korzhev/eventloop-latency

event-loop eventloop latency node nodejs

Last synced: 9 days ago
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Counting node.js eventloop latency.

• Host: GitHub
• URL: https://github.com/korzhev/eventloop-latency
• Owner: korzhev
• License: mit
• Created: 2016-02-22T10:30:53.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2016-04-16T13:56:52.000Z (about 8 years ago)
• Last Synced: 2024-06-03T02:44:58.372Z (25 days ago)
• Topics: event-loop, eventloop, latency, node, nodejs
• Language: JavaScript
• Homepage:
• Size: 18.6 KB
• Stars: 5
• Watchers: 1
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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• awesome-github-star - eventloop-latency

README

        
# eventloop-latency

[![Build Status](https://travis-ci.org/korzhev/eventloop-latency.svg?branch=master)](https://travis-ci.org/korzhev/eventloop-latency)

[![Coverage Status](https://coveralls.io/repos/github/korzhev/eventloop-latency/badge.svg?branch=master)](https://coveralls.io/github/korzhev/eventloop-latency?branch=master)

[![Code Climate](https://codeclimate.com/github/korzhev/eventloop-latency/badges/gpa.svg)](https://codeclimate.com/github/korzhev/eventloop-latency)

[![Issue Count](https://codeclimate.com/github/korzhev/eventloop-latency/badges/issue_count.svg)](https://codeclimate.com/github/korzhev/eventloop-latency)

This lib is part of [Bronitor](https://github.com/korzhev/bronitor) project. It counts eventloop latency using [process.hrtime](https://nodejs.org/dist/latest-v4.x/docs/api/process.html#process_process_hrtime)

## Requirements

**Code written using ECMAScript 2015. It tested on node >= 4**

Use babel if, you want to use it on node < 4

## Installation

```bash

$ npm i eventloop-latency --production

```

## Usage

```js

const EL = require('eventloop-latency'),

	interval = 5000, 

	hrInterval = 10, 

	monitoring = new EL(interval, hrInterval);

   

monitoring.start(true);   

monitoring.on('data', (data) => {

  console.log(data); // [49, 27, ..., 144, 923]

});

monitoring.stop();

  

monitoring.start();

setInterval(() => {

   console.log(monitoring.countLatency()); // [149, 7, ..., 14, 92]

}, 1000) 

```

## Docs

- **monitoring** - main object, eventemitter, takes two options:

    - **iterval** - interval in *ms* for emitting **'data' event**, optional, defaults to 5000 *ms*

    - **hrIntreval** - interval in *ms* using to count latency, should be in range 10-100, optional, defaults to 10 *ms*

- **start()** - function, that start monitoring, takes option:

    - **enableEmit** - if *true*, **monitoring** will emit **"data" event**, else function **countLatency()** is used to get latency info

- **stop()** - function, that stop monitoring

- **countLatency()** - function, that return array with latency

- **"data" event** - returns array of latency in *µs*(microseconds, 10e-6 s) during the **interval**

## Examples

You can see small example in **demos/server.js**. Run it:

```bash

$ npm run-script demo

```

## Tests

  To run the test suite, first install the dependencies, then run `npm test`:

```bash

$ npm install

$ npm test

```

## License

  [MIT](LICENSE)