be9/acts_as_redis_counter

Redis Counter Plugin for Rails

acts_as_redis_counter¶ ↑

The acts_as_redis_counter plugin implements high performance counters using write-back strategy with Redis key-value database.

Installation¶ ↑

Install Redis server (code.google.com/p/redis/) and redis-rb gem from github.com/ezmobius/redis-rb

Install acts_as_redis_counter plugin:

script/plugin install git://github.com/vitalie/acts_as_redis_counter.git

Howto use acts_as_redis_counter¶ ↑

Create migrations for your counters:

class PostsAddViewsCountColumn < ActiveRecord::Migration
  def self.up
    add_column :posts, :views_count, :integer, :default => 0
  end

  def self.down
    remove_column :posts, :views_count
  end
end

Define your Redis global connection in config/environment.rb:

Rails::Initializer.run do |config|
  config.gem "redis"
  ...
  config.after_initialize do
    REDIS = Redis.new :host => '127.0.0.1'
  end
end

In your models use acts_as_redis_counter to define your Redis counters.

# optional parametters :ttl and :hits
# writes to database will be delayed until one of the
# conditions are meet *ttl* seconds or new *hits* number
# Defaults:
#  - ttl: 5.minutes
#  - hits: 100

class Post < ActiveRecord::Base
  acts_as_redis_counter :views_count, :ttl => 5.minutes, :hits => 100
  ...
end

You can specify multiple counters on the same model:

class Post < ActiveRecord::Base
  acts_as_redis_counter :views_count, :edits_count
  ...
end

In your controllers increment and read your counters using plugin defined methods redis_counter_#{attribute} and redis_counter_#{attribute}_inc:

# increment counter
@post.redis_counter_views_count_inc

# read counter
@post.redis_counter_views_count