https://github.com/vweevers/level-probe

Get the first result in a range, using an iterator or stream
https://github.com/vweevers/level-probe

Last synced: 12 months ago
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Get the first result in a range, using an iterator or stream

• Host: GitHub
• URL: https://github.com/vweevers/level-probe
• Owner: vweevers
• License: mit
• Created: 2016-02-05T14:30:24.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2016-02-07T03:03:10.000Z (over 10 years ago)
• Last Synced: 2025-06-22T19:08:52.665Z (12 months ago)
• Language: JavaScript
• Size: 4.88 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md
  • License: LICENSE

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README

          
# level-probe

**Get the first result in a range, using an [iterator](https://github.com/vweevers/level-iterator) or stream.**

[![npm status](http://img.shields.io/npm/v/level-probe.svg?style=flat-square)](https://www.npmjs.org/package/level-probe) [![Travis build status](https://img.shields.io/travis/vweevers/level-probe.svg?style=flat-square&label=travis)](http://travis-ci.org/vweevers/level-probe) [![AppVeyor build status](https://img.shields.io/appveyor/ci/vweevers/level-probe.svg?style=flat-square&label=appveyor)](https://ci.appveyor.com/project/vweevers/level-probe) [![Dependency status](https://img.shields.io/david/vweevers/level-probe.svg?style=flat-square)](https://david-dm.org/vweevers/level-probe)

## example

```js

const probe = require('level-probe')

const disk = require('test-level')({ clean: true })

const db = disk()

db.batch([

  { key: 'a', value: 'value a' },

  { key: 'b', value: 'value b' },

  { key: 'c', value: 'value c' }

], function(err) {

  probe(db, { gte: 'b' }, function(err, kv){

    console.log(kv)

  })

  probe.value(db, { lt: 'x', reverse: true }, function(err, val){

    console.log(val)

  })

  probe(db, { gt: 'd', lt: 'x' }, function(err){

    console.log(err.message)

    console.log(err.notFound)

  })

})

```

Output:

```

{ key: 'b', value: 'value b' }

value c

No result in range { gt: "d", lt: "x" }

true

```

## `probe(db, [opts], callback)`

- If `opts.iterate` is `false`, `level-probe` will use a stream. If `true`, it will use an iterator or throw if iterators are not available. If not specified, it will prefer iterators and fall back to streams.

- Other options are passed to [level-iterator](https://github.com/vweevers/level-iterator) or `db.createReadStream()`

## `probe.key(db, [opts], callback)`

Shortcut to `probe(db, { values: false }, callback)`.

## `probe.value(db, [opts], callback)`

Shortcut to `probe(db, { keys: false }, callback)`.

## install

With [npm](https://npmjs.org) do:

```

npm install level-probe

```

## license

[MIT](http://opensource.org/licenses/MIT) © Vincent Weevers