https://github.com/yoshuawuyts/hyperreduce

Distributed reduce on top of hypercore
https://github.com/yoshuawuyts/hyperreduce

Last synced: 4 months ago
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Distributed reduce on top of hypercore

• Host: GitHub
• URL: https://github.com/yoshuawuyts/hyperreduce
• Owner: yoshuawuyts
• License: mit
• Created: 2016-11-03T14:42:36.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2016-11-05T16:28:29.000Z (over 7 years ago)
• Last Synced: 2024-01-16T06:20:50.427Z (5 months ago)
• Language: JavaScript
• Size: 5.86 KB
• Stars: 17
• Watchers: 4
• Forks: 4
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Lists

• awesome-peer-to-peer - hyperreduce
• awesome-peer-to-peer - hyperreduce

README

        
# hyperreduce [![stability][0]][1]

[![npm version][2]][3] [![build status][4]][5]

[![downloads][8]][9] [![js-standard-style][10]][11]

Distributed reduce on top of hypercore.

## Usage

```js

const hypercore = require('hypercore')

const memdb = require('memdb')

const reduce = require('./')

const core = hypercore(memdb())

const inp = core.createFeed()

const head = reduce(inp, memdb({ valueEncoding: 'json' }), reducer)

head(function (err, last) {

  if (err) throw err

  console.log('head:', last || 'no data')

})

function reducer (last, data, next) {

  last = last || 0

  console.log('last:', last)

  next(null, last + data.length)

}

inp.append('hello planet')

inp.append('hello planet')

inp.append('hello planet')

```

## Why

We believe ops doesn't need to be complicated. If `hypercore` is distributed

streams, `hyperreduce` is a distributed reducer for streams. We needed this to

to turn our feed of server errors into a single meaningful value.

## API

### getLasthyperReduce(inputFeed, db, reducer(last, data, next), done?)

Create a new reduce function that reads data from an input `hypercore` feed to

and applies the `reducer` function.

### getLast(cb(err, last))

Get the last value from `hyperreduce`.

## Installation

```sh

$ npm install hyperreduce

```

## See Also

- https://github.com/mafintosh/hypercore

- https://github.com/mafintosh/hyperpipe

- https://github.com/mafintosh/hypername

- https://github.com/mafintosh/hyperfilter

- https://github.com/yoshuawuyts/hypertail

## License

[MIT](https://tldrlegal.com/license/mit-license)

[0]: https://img.shields.io/badge/stability-experimental-orange.svg?style=flat-square

[1]: https://nodejs.org/api/documentation.html#documentation_stability_index

[2]: https://img.shields.io/npm/v/hyperreduce.svg?style=flat-square

[3]: https://npmjs.org/package/hyperreduce

[4]: https://img.shields.io/travis/yoshuawuyts/hyperreduce/master.svg?style=flat-square

[5]: https://travis-ci.org/yoshuawuyts/hyperreduce

[6]: https://img.shields.io/codecov/c/github/yoshuawuyts/hyperreduce/master.svg?style=flat-square

[7]: https://codecov.io/github/yoshuawuyts/hyperreduce

[8]: http://img.shields.io/npm/dm/hyperreduce.svg?style=flat-square

[9]: https://npmjs.org/package/hyperreduce

[10]: https://img.shields.io/badge/code%20style-standard-brightgreen.svg?style=flat-square

[11]: https://github.com/feross/standard