owenthereal/message_queue

A common interface to multiple message queues libraries.

MessageQueue

A common interface to multiple message queues libraries. Think of it as the ORM to message queues.

Installation

Add this line to your application's Gemfile:

gem 'message_queue'

And then execute:

$ bundle

Or install it yourself as:

$ gem install message_queue

Adapters

• In memory through Observable
• RabbitMQ through bunny

Serializers

• Plain text
• JSON through multi_json
• Message pack through msgpack

Usage

with_connection

with_connection initializes a connection using the specified adapter and serializer, connects to the message queue, runs a block of code and disconnects.

MessageQueue.with_connection(:adapter => :bunny, :serializer => :message_pack) do |conn|
  producer = conn.new_producer(
    :exchange => {
      :name => "time",
      :type => :topic
    },
    :message => {
      :routing_key => "time.now"
    }
  )

  consumer = conn.new_consumer(
    :queue => {
      :name => "print_time_now"
    },
    :exchange => {
      :name => "time",
      :routing_key => "time.#"
    }
  )

  consumer.subscribe do |delivery_info, metadata, payload|
    puts "Received message: #{payload}"
  end

  producer.publish Time.now.to_s

  sleep 1
end

You could maintain a global connection by using the connect method on MessageQueue.

MessageQueue.connect(:adater => :bunny, :serializer => :json)
puts MessageQueue.connected? # => true

producer = MessageQueue.new_producer(
  :exchange => {
    :name => "time",
    :type => :topic
  },
  :message => {
    :routing_key => "time.now"
  }
)

consumer = MessageQueue.new_consumer(
  :queue => {
    :name => "print_time_now"
  },
  :exchange => {
    :name => "time",
    :routing_key => "time.#"
  }
)

consumer.subscribe do |delivery_info, metadata, payload|
  puts "Received message: #{payload}"
end

producer.publish Time.now.to_s

sleep 1

MessageQueue.disconnect
puts MessageQueue.connected? # => false

You could also mix in the MessageQueue::Producible module and the MessageQueue::Consumable module to your producer and consumer respectively. The consumer needs to implement a process method which will be passed a MessageQueue::Message object when it receives a message.

class Producer
  include MessageQueue::Producible

  exchange :name => "time", :type => :topic
  message :routing_key => "time.now", :mandatory => true
end

class Consumer
  include MessageQueue::Consumable

  queue :name => "print_time_now"
  exchange :name => "time", :routing_key => "time.#"

  def process(message)
    puts "Received message #{message.payload}"
  end
end

MessageQueue.connect(:adater => :bunny, :serializer => :json)
Producer.new.publish(Time.now.to_s)

sleep 1

MessageQueue.disconnect

Examples

See examples.

Rails

For Rails, message_queue automatically loads settings from RAILS_ROOT/config/message_queue.yml. If the file doesn't exist, it initializes the queue with in-memory mode.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request