https://github.com/thlorenz/chunk-rate-readable

Measures the rate at which a given stream emits data chunks and streams the result.
https://github.com/thlorenz/chunk-rate-readable

Last synced: 26 days ago
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Measures the rate at which a given stream emits data chunks and streams the result.

• Host: GitHub
• URL: https://github.com/thlorenz/chunk-rate-readable
• Owner: thlorenz
• License: mit
• Created: 2013-09-28T15:57:42.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2013-09-28T17:31:39.000Z (over 11 years ago)
• Last Synced: 2024-11-22T23:49:48.533Z (about 1 month ago)
• Language: JavaScript
• Homepage:
• Size: 242 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# chunk-rate-readable [![build status](https://secure.travis-ci.org/thlorenz/chunk-rate-readable.png)](http://travis-ci.org/thlorenz/chunk-rate-readable)

[![testling badge](https://ci.testling.com/thlorenz/chunks-over-time-writable.png)](https://ci.testling.com/thlorenz/chunks-over-time-writable)

Measures the rate at which a given stream emits data chunks and streams the result.

```js

var chunkRate = require('chunk-rate-readable')

  , numbers = require('../test/fixtures/number-readable');

var numbersStream = numbers({ to: 20, throttle: 200 })

var last = 0;

chunkRate(numbersStream, { objectMode: true, interval: 500 })

  .on('data',  function (rate) {

    var indicator = rate === last 

      ? '='

      : rate > last ? '▲' : '▼';

    console.log(' %s  %d/500ms', indicator, rate);

    last = rate;

  });

```

![example output](https://github.com/thlorenz/chunk-rate-readable/raw/master/assets/chunk-rate-demo.gif)

## Installation

    npm install chunk-rate-readable

## API

###*function ChunkRateReadable (stream[, opts])*

Creates a readable stream that will emit how many chunks the given stream emitted during the given interval.

@name ChunkRateReadable

@function

**params:**

- stream *ReadableStream* whose chunk rate is measured

- opts *Object* with the following properties:

  - objectMode {Boolean} if true rate is emitted as actual numbers, otherwise as buffers

  - interval {Number} at which to measure the rate (default: rate/500ms)

**returns:**

*ReadableStream* that will emit updates about the chunk rate of the given stream.

###*chunkRateReadable.endSoon*

Call this in case you want to tell the rate stream to end.

Useful for testing and/or when you want to end your debugging session and allow the program to exit.

## Similar Modules

- [speed-meter](https://github.com/CrowdProcess/speed-meter) measures the number of emitted bytes (vs. number of chunks) over a given time period

## License

MIT