fl-cache-manager-redis

Frameworkstein's Node Cache Manager store for Redis

An alternate Redis store for the node-cache-manager module.

This module is a fork of node-cache-manager-redis. It has been altered to allow storing keys in hash sets rather than on their own to allow simpler deletion of grouped keys.

Why do this? When we're caching the results of some calls to a REST API and someone updates a model we'd like to wipe the caches for that model type and its relations. Boom!

Installation

npm install cache-manager-redis --save

Usage examples

Here are examples that demonstrate how to implement the Redis cache store.

Single store

var cacheManager = require('cache-manager');
var redisStore = require('cache-manager-redis');

var redisCache = cacheManager.caching({
  store: redisStore,
  host: 'localhost', // default value
  port: 6379, // default value
  auth_pass: 'XXXXX',
  db: 0,
  ttl: 600
});

var ttl = 5;

// listen for redis connection error event
redisCache.store.events.on('redisError', function(error) {
  // handle error here
  console.log(error);
});

redisCache.set('foo', 'bar', ttl, function(err) {
    if (err) {
      throw err;
    }

    redisCache.get('foo', function(err, result) {
        console.log(result);
        // >> 'bar'
        redisCache.del('foo', function(err) {});
    });
});

function getUser(id, cb) {
    setTimeout(function () {
        console.log("Returning user from slow database.");
        cb(null, {id: id, name: 'Bob'});
    }, 100);
}

var userId = 123;
var key = 'user_' + userId;

// Note: ttl is optional in wrap()
redisCache.wrap(key, function (cb) {
    getUser(userId, cb);
}, ttl, function (err, user) {
    console.log(user);

    // Second time fetches user from redisCache
    redisCache.wrap(key, function (cb) {
        getUser(userId, cb);
    }, function (err, user) {
        console.log(user);
    });
});

Multi-store

var cacheManager = require('cache-manager');
var redisStore = require('cache-manager-redis');

var redisCache = cacheManager.caching({store: redisStore, db: 0, ttl: 600});
var memoryCache = cacheManager.caching({store: 'memory', max: 100, ttl: 60});

var multiCache = cacheManager.multiCaching([memoryCache, redisCache]);


userId2 = 456;
key2 = 'user_' + userId;
ttl = 5;

// Sets in all caches.
multiCache.set('foo2', 'bar2', ttl, function(err) {
    if (err) { throw err; }

    // Fetches from highest priority cache that has the key.
    multiCache.get('foo2', function(err, result) {
        console.log(result);
        // >> 'bar2'

        // Delete from all caches
        multiCache.del('foo2');
    });
});

// Note: ttl is optional in wrap()
multiCache.wrap(key2, function (cb) {
    getUser(userId2, cb);
}, ttl, function (err, user) {
    console.log(user);

    // Second time fetches user from memoryCache, since it's highest priority.
    // If the data expires in the memory cache, the next fetch would pull it from
    // the 'someOtherCache', and set the data in memory again.
    multiCache.wrap(key2, function (cb) {
        getUser(userId2, cb);
    }, function (err, user) {
        console.log(user);
    });
});

Using a URL instead of options (if url is correct it overrides options host, port, db, auth_pass and ttl)

Urls should be in this format redis://[:password@]host[:port][/db-number][?ttl=value]

var cacheManager = require('cache-manager');
var redisStore = require('cache-manager-redis');

var redisCache = cacheManager.caching({
  store: redisStore,
  url: 'redis://:XXXX@localhost:6379/0?ttl=600'
});

// proceed with redisCache

Tests

1. Run a Redis server
2. Run tests npm test or npm run coverage

Contribution

If you would like to contribute to the project, please fork it and send us a pull request. Please add tests for any new features or bug fixes. Also make sure the code coverage is not impacted.

License

node-cache-manager-redis is licensed under the MIT license.