cache in rails 2.1

http://railscasts.com/episodes/115-caching-in-rails-2-1
http://thewebfellas.com/blog/2008/6/9/rails-2-1-now-with-better-integrated-caching

cache的用法
<br /><br /># Write a string to the cache<br />Rails.cache.write('test_key', 'test_value')<br />=> true<br /><br /># Read it back in<br />Rails.cache.read('test_key')<br />=> 'test_value'<br /><br /># Delete the item<br />Rails.cache.delete('test_key')<br />=> true<br /><br />#find, if does not exist create<br />Rails.cache.fetch('now') { Time.now}<br /><br /><br />

有幾種cache 機制
<br /><br /># Use the memory store - this store has no options<br />config.cache_store = :memory_store<br /><br /># Use the file store with a custom storage path (if the directory doesn’t already exist it will be created)<br />config.cache_store = :file_store, '/my_cache_path'<br /><br /># Use the memcached store with default options (localhost, TCP port 11211)<br />config.cache_store = :mem_cache_store<br /><br /># Use the memcached store with an options hash<br />config.cache_store = :mem_cache_store, 'localhost', '192.168.1.1:1001', :namespace => 'test'<br /><br />

自己生個cache object
<br /><br /># Create a separate memory cache in addition to the global Rails cache<br />my_cache = ActiveSupport::Cache.lookup_store(:memory_cache)<br /><br />

幫助你生cache_key
<br /><br />>> u = User.first<br />=> #<user><br />>> u.cache_key<br />=> "users/1-20081114035214"<br />

memcachestore 是production 常選用的方式, default 存入是存成marshal
<br /># Write a raw value to the cache<br />Rails.cache.write('test_key', 1, :raw => true)<br /><br /># Read a raw value from the cache<br />Rails.cache.read('test_key', :raw => true)<br /><br /># Write a value using the add method and setting expiry to 15 minutes<br />Rails.cache.write('test_key', 'test_value', :unless_exist => true, :expires_in => 15.minutes)<br /><br />