Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/Level/memory-level
In-memory abstract-level database for Node.js and browsers.
https://github.com/Level/memory-level
abstract-level database javascript level memory
Last synced: about 2 months ago
JSON representation
In-memory abstract-level database for Node.js and browsers.
- Host: GitHub
- URL: https://github.com/Level/memory-level
- Owner: Level
- License: mit
- Created: 2022-01-29T19:43:03.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2023-03-01T23:57:26.000Z (over 1 year ago)
- Last Synced: 2024-04-14T00:27:00.835Z (5 months ago)
- Topics: abstract-level, database, javascript, level, memory
- Language: JavaScript
- Homepage:
- Size: 230 KB
- Stars: 24
- Watchers: 8
- Forks: 4
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# memory-level
**In-memory [`abstract-level`][abstract-level] database for Node.js and browsers, backed by a [fully persistent red-black tree](https://www.npmjs.com/package/functional-red-black-tree).** The successor to [`memdown`](https://github.com/Level/memdown) and [`level-mem`](https://github.com/Level/mem).
> :pushpin: Which module should I use? What is `abstract-level`? Head over to the [FAQ](https://github.com/Level/community#faq).
[![level badge][level-badge]](https://github.com/Level/awesome)
[](https://www.npmjs.com/package/memory-level)
[](https://www.npmjs.com/package/memory-level)
[](https://github.com/Level/memory-level/actions/workflows/test.yml)
[](https://codecov.io/gh/Level/memory-level)
[](https://standardjs.com)
[](https://common-changelog.org)
[](https://opencollective.com/level)
## Usage
_If you are upgrading: please see [`UPGRADING.md`](./UPGRADING.md)._
```js
const { MemoryLevel } = require('memory-level')
// Create a database
const db = new MemoryLevel({ valueEncoding: 'json' })
// Add an entry with key 'a' and value 1
await db.put('a', 1)
// Add multiple entries
await db.batch([{ type: 'put', key: 'b', value: 2 }])
// Get value of key 'a': 1
const value = await db.get('a')
// Iterate entries with keys that are greater than 'a'
for await (const [key, value] of db.iterator({ gt: 'a' })) {
console.log(value) // 2
}
```
With callbacks:
```js
db.put('example', { hello: 'world' }, (err) => {
if (err) throw err
db.get('example', (err, value) => {
if (err) throw err
console.log(value) // { hello: 'world' }
})
})
```
## API
The API of `memory-level` follows that of [`abstract-level`](https://github.com/Level/abstract-level) with a one additional constructor option (see below). The `createIfMissing` and `errorIfExists` options of `abstract-level` are not relevant here. Data is discarded when the last reference to the database is released (i.e. `db = null`). Closing or reopening the database has no effect on the data. Data is _not_ copied: when storing a Buffer value for example, subsequent mutations to that Buffer will affect the stored data too.
### `db = new MemoryLevel([options])`
Besides `abstract-level` options, the optional `options` object may contain:
- `storeEncoding` (string): one of `'buffer'`, `'view'`, `'utf8'`. How to store data internally. This affects which data types can be stored non-destructively. The default is `'buffer'` (that means Buffer) which is non-destructive. In browsers it may be preferable to use `'view'` (Uint8Array) to be able to exclude the [`buffer`](https://github.com/feross/buffer) shim. Or if there's no need to store binary data, then `'utf8'` (String). Regardless of the `storeEncoding`, `memory-level` supports input that is of any of the aforementioned types, but internally converts it to one type in order to provide a consistent sort order.
## Install
With [npm](https://npmjs.org) do:
```
npm install memory-level
```
## Contributing
[`Level/memory-level`](https://github.com/Level/memory-level) is an **OPEN Open Source Project**. This means that:
> Individuals making significant and valuable contributions are given commit-access to the project to contribute as they see fit. This project is more like an open wiki than a standard guarded open source project.
See the [Contribution Guide](https://github.com/Level/community/blob/master/CONTRIBUTING.md) for more details.
## License
[MIT](LICENSE)
[abstract-level]: https://github.com/Level/abstract-level
[level-badge]: https://leveljs.org/img/badge.svg