redmon-cache

tiny node.js module for caching objects using Redis.

Installation

$ npm install redmon-cache

##Purpose redmon-cache was created to easily cache objects in distributed environment (like micro-service application). I'm using it mostly to cache documents retrieved from MongoDB that are not changing too often but it's very important to be able to invalidate cache across all applications/services at once.

This module is work in progress.

Usage

Plain object example app.js:

var cache = require('redmon-cache')();

cache.set('my-data', { status: 'ok', iAm: 'Batman' }, 15)
  .then(function(data) {
    console.log('Data cached');
    
    cache.get('my-data')
        .then(function(cached) {
            console.log('Data from cache', cached);
        });
  });

Mongoose example app.js:

var someMongooseModel = require('./userModel');
var cache = require('redmon-cache')();

cache.mongoGet(someMongooseModel, '5475c628d4a04400009a2596', 10)
  .then(function(data) {
    console.log('data', data);
  })
  .catch(function(err) {
    console.log('error', err);
  });

Advanced Mongoose example app.js:

var redis = require("redis"),
  client = redis.createClient();
var someMongooseModel = require('./userModel');
var cache = require('redmon-cache')({
    redisClient: client,
    redisPrefix: 'my-app:',
    defaultTTL: 30
});

cache.mongoGet(someMongooseModel, '5475c628d4a04400009a2596', 10)
  .then(function(data) {
    console.log('data', data);
  })
  .catch(function(err) {
    console.log('error', err);
  });

##API

All methods are returning promisses. Resolved promise means that all operations are finished.

• get(key) - gets cached object. If there is nothing under this key it will return null
• set(key, data, ttl) - caches data under key
• del(mongooseModel, id) - deletes document from cache
• mongoGet(mongooseModel, id, ttl) - gets cached document. If it's not in cache it gets it from database and caches it.
  • mongooseModel - model of collection from whitch the object will be retreived
  • id - _id of object that will be retreived. This can be ObjectId or String
  • ttl - time (in seconds) after witch object will be dropped from cache

Options

Name	Default	Default
defaultTTL	60s	default time to live of object in cache.
redisClient	internal	client for connecting to redis (ioredis)
redisPrefix	none	custom prefix for cache keys
redisPort	6379	redis port for internal redis client connection (used if redisClient option is not set)
redisHost	localhost	redis host for internal redis client connection (used if redisClient option is not set)
log	debug	External logger. Must support debug and error methods

Authors

• Tomasz Marciszewski

License

(The ISC License)

Copyright (c) 2014 Tomasz Marciszewski

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.