redback

redback - A high-level Redis library for Node.JS.

Follow redbackjs.com and @chris6F for updates.

npm install -g redback

What is it?

Redback provides an accessible and extensible interface to the Redis data types and allows you to roll your own structures with ease. Redback comes with the following built-in structures: List, Set, SortedSet, Hash, Channel, Cache

It also comes with the following advanced data structures:

• DensitySet - A sorted set where adding an element increments its score and removing it decrements it.
• KeyPair - Uses two hash structures and an auto-incrementing key to assign an ID to each unique value
• SocialGraph - Similar to Twitter's (following vs. followers)
• CappedList - A list with a fixed length
• FullText - A full text index with support for stop words, stemming and basic boolean search
• Queue - A simple FIFO or LIFO queue
• RateLimit - Count the number of times an event occurs over an interval. Can be used for IP rate limiting. See this blog post
• BloomFilter - A probabilistic structure used to test whether an an element exists in a set. Contributed by user sreeix

Have an idea for an advanced structure? Send a pull request and I'll add you as a contributor.

Usage

var redback = require('redback').createClient();

// or

var redis = require('redis').createClient();
var redback = require('redback').use(redis);

var user3 = redback.createSocialGraph(3);
user3.follow(1, callback);

var text = redback.createFullText('my_index');
text.indexFile({1: 'file1.txt', 2: 'file2.txt'}, callback);
text.search('foo bar -exclude -these -words', callback);

var user1 = redback.createHash('user1');
user.set({username:'chris', password:'redisisawesome'}, callback);

var log = redback.createCappedList('log', 1000);
log.push('Log message ...');

Creating your own structures

To create your own structure, use addStructure(name, methods).

Let's create a queue that can be either FIFO or LIFO

redback.addStructure('SimpleQueue', {
    init: function (is_fifo) {
        this.fifo = is_fifo;
    },
    add: function (value, callback) {
        this.client.lpush(this.key, value, callback);
    },
    next: function (callback) {
        var method = this.fifo ? 'rpop' : 'lpop';
        this.client[method](this.key, callback);
    }
});

To use the queue, call createSimpleQueue(key, is_fifo)

var queue = redback.createSimpleQueue('my_queue', true);
queue.add('awesome!');

Structures have access to a Redis key this.key and the Redis client this.client. If an init() method is defined then it is called after the structure is instantiated. Also note that init() receives any extra parameters from create<structure>().

Other uses

Cache backend

var cache = redback.createCache(namespace);
cache.set('foo', 'bar', callback);
cache.get('foo', function (err, foo) {
    console.log(foo); //bar
});

Pub/sub provider

var channel = redback.createChannel('chat').subscribe();

//To received messages
channel.on('message', function (msg) {
   console.log(msg);
});

//To send messages
channel.publish(msg);

Want to learn more?

For now, see the annotated source for more information.

Credits

• Matt Ranney for his awesome node_redis library.

License

(MIT License)

Copyright (c) 2010 Chris O'Hara [e-mail]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.