https://github.com/regular/pull-buffer

https://github.com/regular/pull-buffer

Last synced: 7 months ago
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• Host: GitHub
• URL: https://github.com/regular/pull-buffer
• Owner: regular
• Created: 2020-05-25T10:00:38.000Z (almost 6 years ago)
• Default Branch: master
• Last Pushed: 2020-06-13T17:57:15.000Z (almost 6 years ago)
• Last Synced: 2025-09-30T09:17:37.741Z (7 months ago)
• Language: JavaScript
• Homepage:
• Size: 8.79 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md

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README

          
# pull-buffer-until

[![NPM](https://nodei.co/npm/pull-buffer-until.png)](https://nodei.co/npm/pull-buffer-until/)

Group incoming items until either a condition is met or no new items arrived for a while. This is great for processing data in batches while still retaining realtime-ness. 

Like pull-group, but with a timeout, and like pull-debounce, but with collecting intermediate items.

## Example

``` js

const pull = require('pull-stream')

const bufferUntil = require('pull-buffer-unril')

function timedSource(data) {

  return pull(

    pull.values(data),

    pull.asyncMap(function(item, cb) {

      setTimeout(function() {

        cb(null, item[1])

      }, item[0])

    })

  )

}

pull(

  timedSource([

    [10,  5],

    [10,  6],

    [10,  7],

    [10,  8],

    [10,  9],

    [10, 10],

    [10, 11],

    [50, 15],

    [10, 16],

    [10, 17],

    [10, 18],

    [10, 19],

    [10, 20],

  ]),

  bufferUntil(buffer => buffer.length == 3, {timeout: 40}),

  pull.log()

)

/* => 

[5,6,7]

[8,9,10]

[11]

[15,16,17]

[18,19,20]

```

## API

`bufferUntil([condition], [opts])`

  - `condition` is called with the array of bufered items. If it returns a truthy value, the buffer is flushed (emitted downstream).

  - `opts`

    - `timeout`: If no new items arrive within the specified number of milliseconds, the buffer is flushed.

## License

MIT