SecondLevelCache is a write-through and read-through caching library inspired by Cache Money and cache_fu, support only Rails3 and ActiveRecord.
Read-Through: Queries by ID, like
current_user.articles.find(params[:id]), will first look in cache store and then look in the database for the results of that query. If there is a cache miss, it will populate the cache.
Write-Through: As objects are created, updated, and deleted, all of the caches are automatically kept up-to-date and coherent.
SecondLevelCache is not fully test and verify in production enviroment right now. Use it at your own risk.
In your gem file:
gem "second_level_cache", "~> 1.5"
For example, cache User objects:
class User < ActiveRecord::Base acts_as_cached(:version => 1, :expires_in => 1.week) end
Then it will fetch cached object in this situations:
User.find(1) User.find_by_id(1) User.find_by_id!(1) User.find_by_id_and_name(1, "Hooopo") User.where(:status => 1).find_by_id(1) user.articles.find_by_id(1) user.articles.find(1) User.where(:status => 1).find(1) article.user
user = User.find 1 user.second_level_cache_key # We will get the key looks like "slc/user/1/0"
User.without_second_level_cache do user = User.find 1 # ... end
SELECT * query will be cached:
# this query will NOT be cached User.select("id, name").find(1)
- SecondLevelCache cache by model name and id, so only find_one query will work.
- only equal conditions query WILL get cache; and SQL string query like
User.where("name = 'Hooopo'").find(1)WILL NOT work.
cache_store: Default is Rails.cache
logger: Default is Rails.logger
cache_key_prefix: Avoid cache key conflict with other application, Default is 'slc'
You can config like this:
# config/initializers/second_level_cache.rb SecondLevelCache.configure do |config| config.cache_store = ActiveSupport::Cache::MemoryStore.new config.logger = Logger.new($stdout) config.cache_key_prefix = 'domain' end