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    data-point-cache

    4.1.0 • Public • Published

    data-point-cache

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    DataPoint cache layer

    Factory method to create a simple cache API that you can use for data persistence.

    Requirements

    • Node 8 LTS (or higher)
    • Redis (Optional for development)

    Install

    $ npm install data-point-cache

    Usage

    const Cache = require('data-point-cache')
     
    Cache.create()
      .then(cache => {
        return cache.set('myKey', 'foo', '20m')
          .then(() => {
            return cache.get('myKey')
          })
      })
      .then(result => {
        console.log('foo')
      )

    Storage mechanism

    This cache API has an in-memory storage mechanism. The idea here is that every time a get/set operation happens, a short (TTL of 2 seconds) in-memory version of that key will be stored. After the TTL of the in-memory key has expired, the key will be removed. The swiping mechanism triggers every second and will kill every key that has its TTL has expired. The idea behind this is to try to be as optimal with our requests to redis, but also be careful not to store for too long in the in-memory layer.

    Like any software, see if this works for you and your use case before going to production.

    API

    Cache.create

    Create a cache instance.

    Cache.create({
      localTTL: Number,
      redis: Object,
    }):Promise<cache>

    This factory method returns a Promise that resolves to a cache instance.

    option type required description
    localTTL Number optional Value in Milliseconds of in memory TTL, by default is set to 2000 (2 seconds)
    redis Object optional Value passed to the ioredis constructor

    cache.set

    Adds a new entry to the cache. This method

    cache.set(key:String, value:Any, ttl:String):Promise

    Returns a promise.

    Parameter description:

    arguments:

    argument type required description
    key String yes key related to this entry.
    value Any yes Value to be stored, this value will be stringified when stored in redis.
    ttl String optional Time To Live of the entry. Defaults to 20 minutes.

    cache.get

    This method gets an entry from the cache. Every time this method gets executed it will:

    1. check if it exists in redis
    2. attempt to retrieve it from the in-memory cache
    3. if not found it will try to get it from redis
    4. if found in redis, it will re-store it back into the in-memory cache where it will be available for 2 seconds.
    cache.get(key:String):Promise<Any|undefined>

    Returns a promise, if the key does not exist it will resolve to undefined.

    Parameter description:

    arguments:

    argument type required description
    key String yes key related to this entry.

    Contributing

    Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

    License

    This project is licensed under the Apache License Version 2.0 - see the LICENSE file for details

    Install

    npm i data-point-cache

    DownloadsWeekly Downloads

    1,168

    Version

    4.1.0

    License

    Apache-2.0

    Unpacked Size

    43 kB

    Total Files

    13

    Last publish

    Collaborators

    • acatl