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# Redis Key Slot Calculator

A high performance redis cluster key slot calculator for node redis clients e.g. [node_redis](https://github.com/NodeRedis/node_redis), [ioredis](https://github.com/luin/ioredis) and [redis-clustr](https://github.com/gosquared/redis-clustr/).

This also handles key tags such as `somekey{actualTag}`.

## Install

Install with [NPM](https://npmjs.org/):

```
npm install cluster-key-slot --save
```

## Usage

```js
const calculateSlot = require('cluster-key-slot');
const calculateMultipleSlots = require('cluster-key-slot').generateMulti;

// ...

// a single slot number
const slot = calculateSlot('test:key:{butOnlyThis}redis');

// multiple keys - multi returns a single key slot number, returns -1 if any
// of the keys does not match the base slot number (base is defaulted to first keys slot)
// This is useful to quickly determine a singe slot for multi keys operations.
const slotForRedisMulti = calculateMultipleSlots([
  'test:key:{butOnlyThis}redis',
  'something:key45:{butOnlyThis}hello',
  'example:key46:{butOnlyThis}foobar',
]);
```

## Benchmarks

`OLD` in these benchmarks refers to the `ioredis` crc calc and many of the other calculators that use `Buffer`.

```text
NEW tags x 472,156 ops/sec ±1.80% (90 runs sampled)
OLD tags x 413,725 ops/sec ±1.37% (93 runs sampled)
NEW without tags x 1,287,795 ops/sec ±2.06% (89 runs sampled)
OLD without tags x 633,340 ops/sec ±0.87% (93 runs sampled)
NEW without tags singular x 4,824,560 ops/sec ±1.71% (93 runs sampled)
OLD without tags singular x 2,981,057 ops/sec ±0.22% (96 runs sampled)
```