Ruby on Rails页面缓存

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 %>

<% cache do %>

 <% for article in @articles -%>

<%= h(article.body) %>

 <% end -%>

<% end %>

<%= @dynamic_content %>

使用多个缓存段:

<% cache(:action => 'list', :part => 'articles') do %>

 <% for article in @articles -%>

<%= h(article.body) %>

 <% end -%>

<% end %>

<% cache(:action => 'list', :part => 'counts') do %>

There are a total of <%= @article_count %> articles.

<% 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)