ripple

ripple is a rich Ruby toolkit for Riak, Basho’s distributed database. It consists of three gems:

• riak-client (Riak namespace) contains a basic wrapper around typical operations, including bucket manipulation, object CRUD, link-walking, and map-reduce.
• ripple (Ripple namespace) contains an ActiveModel-compatible modeling layer that is inspired by ActiveRecord, DataMapper, and MongoMapper.
• riak-sessions contains session stores for Rack and Rails 3 applications.

Dependencies

riak-client requires ActiveSupport 2.3.5 or later, but the version 3 is recommended. I highly recommend the curb gem for better HTTP client performance.

ripple requires Ruby 1.8.7 or later and versions 3 or above of ActiveModel and ActiveSupport (and their dependencies, including i18n).

riak-sessions requires Rack (any version > 1.0), and Rails 3.0 if you want the Rails-specific session store.

Development dependencies are handled with bundler. Install bundler (gem install bundler) and run this command in each sub-project to get started:

$ bundle install

Run the RSpec suite using bundle exec:

$ bundle exec rake spec

Basic Example

require 'riak'

# Create a client interface
client = Riak::Client.new

# Retrieve a bucket
bucket = client.bucket("doc")  # a Riak::Bucket

# Get an object from the bucket
object = bucket.get("index.html")   # a Riak::RObject

# Change the object's data and save
object.data = "Hello, world!"
object.store

# Reload an object you already have
object.reload                  # Works if you have the key and vclock, using conditional GET
object.reload :force => true   # Reloads whether you have the vclock or not

# Access more like a hash, client[bucket][key]
client['doc']['index.html']   # the Riak::RObject

# Create a new object
new_one = Riak::RObject.new(bucket, "application.js")
new_one.content_type = "application/javascript" # You must set the content type.
new_one.data = "alert('Hello, World!')"
new_one.store

Map-Reduce Example

# Assuming you've already instantiated a client, get the album titles for The Beatles
results = Riak::MapReduce.new(client).
                add("artists","Beatles").
                link(:bucket => "albums").
                map("function(v){ return [JSON.parse(v.values[0].data).title]; }", :keep => true).run

p results # => ["Please Please Me", "With The Beatles", "A Hard Day's Night", 
          #     "Beatles For Sale", "Help!", "Rubber Soul",
          #     "Revolver", "Sgt. Pepper's Lonely Hearts Club Band", "Magical Mystery Tour", 
          #     "The Beatles", "Yellow Submarine", "Abbey Road", "Let It Be"]

Document Model Examples

require 'ripple'

# Documents are stored as JSON objects in Riak but have rich
# semantics, including validations and associations.
class Email
  include Ripple::Document
  property :from,    String, :presence => true
  property :to,      String, :presence => true
  property :sent,    Time,   :default => proc { Time.now }
  property :body,    String
end

email = Email.find("37458abc752f8413e")  # GET /riak/emails/37458abc752f8413e
email.from = "someone@nowhere.net"
email.save                               # PUT /riak/emails/37458abc752f8413e

reply = Email.new
reply.from = "justin@bashoooo.com"
reply.to   = "sean@geeemail.com"
reply.body = "Riak is a good fit for scalable Ruby apps."
reply.save                               # POST /riak/emails (Riak-assigned key)

# Documents can contain embedded documents, and link to other standalone documents 
# via associations using the many and one class methods.
class Person
  include Ripple::Document
  property :name, String
  many :addresses
  many :friends, :class_name => "Person"
  one :account
end

# Account and Address are embeddable documents
class Account
  include Ripple::EmbeddedDocument
  property :paid_until, Time
  embedded_in :person # Adds "person" method to get parent document
end

class Address
  include Ripple::EmbeddedDocument
  property :street, String
  property :city, String
  property :state, String
  property :zip, String
end

person = Person.find("adamhunter")
person.friends << Person.find("seancribbs") # Links to people/seancribbs with tag "friend"
person.addresses << Address.new(:street => "100 Main Street") # Adds an embedded address
person.account.paid_until = 3.months.from_now

Configuration Example

When using Ripple with Rails 3, config/ripple.yml should contain your Riak connection information:

development:
  port: 8098
  host: localhost

production:
  port: 8098
  host: production.load-balancer.example.com

require 'ripple/railtie' from the top of your config/application.rb file to turn this on.

How to Contribute

• Fork the project on Github. If you have already forked, use git pull --rebase to reapply your changes on top of the mainline. Example:
  

  $ git checkout master
  $ git pull --rebase seancribbs master

• Create a topic branch. If you’ve already created a topic branch, rebase it on top of changes from the mainline “master” branch. Examples:
  • New branch:
    

    $ git checkout -b topic

  • Existing branch:
    

    $ git rebase master

• Write an RSpec example or set of examples that demonstrate the necessity and validity of your changes. Patches without specs will most often be ignored. Just do it, you’ll thank me later. Documentation patches need no specs, of course.
• Make your feature addition or bug fix. Make your specs and stories pass (green).
• Run the suite using multiruby or rvm to ensure cross-version compatibility.
• Cleanup any trailing whitespace in your code (try whitespace-mode in Emacs, or “Remove Trailing Spaces in Document” in the “Text” bundle in Textmate).
• Commit, do not mess with Rakefile or VERSION. If related to an existing issue in the tracker, include “Closes #X” in the commit message (where X is the issue number).
• Send me a pull request.

License & Copyright

Copyright ©2010 Sean Cribbs, Sonian Inc., and Basho Technologies, Inc.

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Auxillary Licenses

The included photo (spec/fixtures/cat.jpg) is Copyright ©2009 Sean Cribbs, and is licensed under the Creative Commons Attribution Non-Commercial 3.0 license.

The “Poor Man’s Fibers” implementation (lib/riak/util/fiber1.8.rb) is Copyright ©2008 Aman Gupta.