三种方式 Page Caching, Action Caching和 Fragment Caching
缓存默认只在production 环境下启动
Page Caching
caches_page :public_content
以URL为准
expire_page :action =>"public_content"
Action Caching
caches_action :premium_content
以URL为准
expire_action :action => "premium_content", :id => article
Page Caching 和 Action Caching的实例:
class ContentController < ApplicationController
before_filter :verify_premium_user, :except => :public_content
caches_page :public_content
caches_action :premium_content
cache_sweeper :article_sweeper,
:only => [ :create_article,
:update_article,
:delete_article ]
def public_content
@articles = Article.list_public
end
def premium_content
@articles = Article.list_premium
end
private
def verify_premium_user
return
user = session[:user_id]
user = User.find(user)
if user
unless user && user.active?
redirect_to :controller => "login", :action => "signup_new"
end
end
end
删除过期缓存内容:
app/models中加article_sweeper.rb
class ArticleSweeper < ActionController::Caching::Sweeper
observe Article
def after_create(article)
expire_public_page
end
def after_update(article)
expire_article_page(article.id)
end
def after_destroy(article)
expire_public_page
expire_article_page(article.id)
end
private
def expire_public_page
expire_page(:controller => "content", :action => ‘public_content’)
end
def expire_article_page(article_id)
expire_action(:controller => "content",
:action => "premium_content",
:id => article_id)
end
end
app/public/content/show/1默认caches_page文件路径
app/public/content/show/1.html
Fragment Caching
controller:
class Blog1Controller < ApplicationController
def list
@dynamic_content = Time.now.to_s
unless read_fragment(:action => ‘list’)
logger.info("Creating fragment")
@articles = Article.find_recent
end
end
end
#read_fragment()查看一个action的fragment缓存是否存在
view:
<%= @dynamic_content %> <!– 动态内容 –>
<% cache do %> <!– 缓存开始–>
<ul>
<% for article in @articles -%>
<li><p><%= h(article.body) %></p></li>
<% end -%>
</ul>
<% end %> <!– 结束缓存 –>
<%= @dynamic_content %> <!– 其它动态内容 –>
使用多个缓存段:
<% cache(:action => ‘list’, :part => ‘articles’) do %>
<ul>
<% for article in @articles -%>
<li><p><%= h(article.body) %></p></li>
<% end -%>
</ul>
<% end %>
<% cache(:action => ‘list’, :part => ‘counts’) do %>
<p>There are a total of <%= @article_count %> articles.</p>
<% end %>
#使用:part参数区分同一action下的不同缓存段
缓存过期
controller:
class Blog2Controller < ApplicationController
def list
@dynamic_content = Time.now.to_s
@articles = Article.find_recent
@article_count = @articles.size
end
def edit
# 编辑文章时不更新统计缓存
expire_fragment(:action => ‘list’, :part => ‘articles’)
redirect_to(:action => ‘list’)
end
def delete
#删除文章时同时删除两个缓存
expire_fragment(:action => ‘list’, :part => ‘articles’)
expire_fragment(:action => ‘list’, :part => ‘counts’)
redirect_to(:action => ‘list’)
end
end
expire_fragment()可接正则表达式
expire_fragment(%r{/blog2/list. })
Fragment Caching存储选项设置:
ActionController::Base.fragment_cache_store = <下面的选项之一>
ActionController::Caching::Fragments::FileStore.new(path)
ActionController::Caching::Fragments::DRbStore.new(url)
ActionController::Caching::Fragments::MemCachedStore.new(host)
