redis-json

redis-json

Nodejs library to store/retreive JSON Objects in RedisDB

Description

Every time set is called JSON object is flattened(embeded objects are converted to path keys) and then stored in Redis(just like a normal hashset), on get the hashset is unflattened and converted back to the original JSON object(with the same types as the original object).

What's new in v4.3.0?

• In response to issue: #17, we now support incrementing values with the methods incr() & incrT()(for transactions)

Installation

npm install redis-json --save

API

Please visit this page for detailed API documentation.

Usage

Simple

import Redis from 'ioredis';
import JSONCache from 'redis-json';

const redis = new Redis() as any;

const jsonCache = new JSONCache<{
  name: string;
  age: number;
  address: {
    doorNo: string;
    locality: string;
    pincode: number;
  }
}>(redis, {prefix: 'cache:'});

const user = {
  name: 'redis-json',
  age: 25,
  address: {
    doorNo: '12B',
    locality: 'pentagon',
    pincode: 123456
  },
  cars: ['BMW 520i', 'Audo A8']
}

await jsonCache.set('123', user)

await jsonCache.get('123')
// output
// {
//   name: 'redis-json',
//   age: 25,
//   address: {
//     doorNo: '12B',
//     locality: 'pentagon',
//     pincode: 123456
//   },
//   cars: ['BMW 520i', 'Audo A8']
// }

await jsonCache.set('123', {gender: 'male'})
await jsonCache.get('123')
// output
// {
//   name: 'redis-json',
//   age: 25,
//   address: {
//     doorNo: '12B',
//     locality: 'pentagon',
//     pincode: 123456
//   },
//   cars: ['BMW 520i', 'Audo A8']
//   gender: 'male'
// }

await jsonCache.get('123', 'name', 'age');
// output
// {
//   name: 'redis-json',
//   age: 25,
// }

await jsonCache.get('123', 'name', 'address.doorNo');
// {
//   name: 'redis-json',
//   address: {
//     doorNo: '12B'
//   }
// }

await jsonCache.clearAll();

await jsonCache.get('123');
// undefined


await jsonCache.incr('123', {age: 1}) // increments age by 1

With custom stringifier and parser:

const jsonCache = new JSONCache(redis, {
  stringifier: {
    Date: (val: Date) => val.toISOString()
  },
  parser: {
    Date: (str: string) => new Date(str)
  }
})

const date = new Date()
await jsonCache.set('test', {
  date: date
})

// Redis hashset
> hgetall jc:test /// data
1) "date"
2) "2020-05-17T14:41:45.861Z"
> hgetall jc:test_t /// type info
1) "date"
2) "Date"


const result = await jsonCache.get('test')
result.date == date /// true

With transactions:

const transaction = redisClient.multi();

transaction
  .set('name', 'foo')
  .set('bar', 'baz')

jsonCache.setT(transaction, 'test', {name: 'testing'})
jsonCache.delT(transaction, 'test1')
jsonCache.rewriteT(transaction, 'test2', {name: 'testing', age: 25})

transaction
  .exec(function(err, replies) => {
    /// your logic here after
  })

Please note that only setT(), rewriteT() & delT() supports transaction, where as get() & clearAll() do NOT support transaction because we process those results before returning it to the calling function. Moreover there is no real usecase in adding get methods to a transaction!

Since v4.0.0

Types of the data are retained when retrieved from Redis.

Changelogs

Please refer to this page

Coverage Report

npm run coverage

Contributions

This is open-source, which makes it obvious for any PRs, but I would request you to add necessary test-cases for the same.

Pre-requisites:

Run your redis-server and then point the same client to the same. An easier way to start redis-server, provided you've already installed docker (else visit this page) is by running this command:

docker run --rm -it --name redis -p 6379:6379 redis

We follow TDD approach, so write your test cases first and then run the same paralelly during development by running the following command:

npm run test:dev

LICENCE

MIT License

Changelog

v5.0.0

• supports empty string as pre-fixes