https://github.com/vweevers/keyspace
Get keys and values based on a probability distribution and seed.
https://github.com/vweevers/keyspace
benchmarking key-value-store keys level nodejs random values zipfian
Last synced: 8 months ago
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Get keys and values based on a probability distribution and seed.
- Host: GitHub
- URL: https://github.com/vweevers/keyspace
- Owner: vweevers
- License: mit
- Created: 2019-06-02T17:38:30.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2020-11-20T17:59:00.000Z (almost 5 years ago)
- Last Synced: 2025-02-05T07:41:51.994Z (8 months ago)
- Topics: benchmarking, key-value-store, keys, level, nodejs, random, values, zipfian
- Language: JavaScript
- Size: 402 KB
- Stars: 3
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
Awesome Lists containing this project
README
# keyspace
> **Get keys and values based on a probability distribution and seed.**
> For deterministic input to benchmarks.
[](https://www.npmjs.org/package/keyspace)
[](https://www.npmjs.org/package/keyspace)
[](http://travis-ci.org/vweevers/keyspace)
[](https://standardjs.com)
## Usage
```js
const keyspace = require('keyspace')
const db = mydb()
// To prepare the database, we'll write 1M sequential
// keys, with random values of 100 bytes
const writer = keyspace(1e6, {
keys: 'seq',
values: 'random',
valueSize: 100,
// Always generate the same keys and values
seed: 'a seed'
})
for (let i = 0; i < 1e6; i++) {
db.put(writer.key(i), writer.value())
}
// Get a random key based on a Zipfian distribution
const reader = keyspace(1e6, {
keys: 'random',
distribution: 'zipfian',
seed: 'a seed',
// Favor latest keys
skew: -1
})
db.get(reader.key())
db.get(reader.key())
```
## Visual Example
## API
_**Stability:** experimental. API may change or split up._
### `generator = keyspace(n, [options])`
Create a key and value generator for a keyspace of size N (aka cardinality). Uses xorshift128+ internally to be fast and random _enough_. Keys are encoded with `lexicographic-integer` to preserve order.
Options:
- `keys` (string): one of:
- `random` (default): generate pseudo-random numeric keys with a certain probability `distribution`
- `seq`: non-random, sequential numeric keys (0-N)
- `seqReverse`: same keys but in reverse (N-0)
- `values` (string): one of:
- `random` (default): generate pseudo-random values
- `empty`: zero-length values or zero-filled if `valueSize` is set
- `seed` (string or Buffer): if not provided one will be generated.
- `distribution` (string): one of [`zipfian`](https://github.com/vweevers/zipfian-integer), `uniform` (default)
- `skew` (floating-point number): Zipfian skew (default 0)
- `offset` (number): offset keys (for example to simulate timestamps)
- `valueSize` (number): size of values in bytes
- `keyAsBuffer`, `valueAsBuffer`, `keyAsNumber` (boolean): if not set, keys and values are returned as strings (hex encoded).
### `key = generator.key([index])`
Get a key. The `index` argument is required for `seq` and `seqReverse`.
### `value = generator.value()`
Get a value.
## Install
With [npm](https://npmjs.org) do:
```
npm install keyspace
```
## License
[MIT](LICENSE.md) © 2019-present Vincent Weevers