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Diffstat (limited to 'actionpack/lib/action_controller/caching.rb')
-rw-r--r-- | actionpack/lib/action_controller/caching.rb | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/actionpack/lib/action_controller/caching.rb b/actionpack/lib/action_controller/caching.rb new file mode 100644 index 0000000000..45d162d2be --- /dev/null +++ b/actionpack/lib/action_controller/caching.rb @@ -0,0 +1,186 @@ +require 'fileutils' + +module ActionController #:nodoc: + module Caching #:nodoc: + def self.append_features(base) + super + base.send(:include, Pages) + base.send(:include, Fragments) + end + + # Page caching is an approach to caching where the entire action output of is stored as a HTML file that the web server + # can serve without going through the Action Pack. This can be as much as 100 times faster than going the process of dynamically + # generating the content. Unfortunately, this incredible speed-up is only available to stateless pages where all visitors + # are treated the same. Content management systems -- including weblogs and wikis -- have many pages that are a great fit + # for this approach, but account-based systems where people log in and manipulate their own data are often less likely candidates. + # + # Specifying which actions to cach is done through the <tt>caches</tt> class method: + # + # class WeblogController < ActionController::Base + # caches :show, :new + # end + # + # This will generate cache files such as weblog/show/5 and weblog/new, which match the URLs used to trigger the dynamic + # generation. This is how the web server is able pick up a cache file when it exists and otherwise let the request pass on to + # the Action Pack to generate it. + # + # Expiration of the cache is handled by deleting the cached file, which results in a lazy regeneration approach where the cache + # is not restored before another hit is made against it. The API for doing so mimics the options from url_for and friends: + # + # class WeblogController < ActionController::Base + # def update + # List.update(@params["list"]["id"], @params["list"]) + # expire_page :action => "show", :id => @params["list"]["id"] + # redirect_to :action => "show", :id => @params["list"]["id"] + # end + # end + # + # Additionally, you can expire caches -- or even record new caches -- from outside of the controller, such as from a Active + # Record observer: + # + # class PostObserver < ActiveRecord::Observer + # def after_update(post) + # WeblogController.expire_page "/weblog/show/#{post.id}" + # end + # end + module Pages + def self.append_features(base) + super + base.extend(ClassMethods) + base.class_eval do + @@page_cache_directory = defined?(RAILS_ROOT) ? "#{RAILS_ROOT}/public" : "" + cattr_accessor :page_cache_directory + end + end + + module ClassMethods + def cache_page(content, path) + FileUtils.makedirs(File.dirname(page_cache_directory + path)) + File.open(page_cache_directory + path, "w+") { |f| f.write(content) } + logger.info "Cached page: #{path}" unless logger.nil? + end + + def expire_page(path) + File.delete(page_cache_directory + path) if File.exists?(page_cache_directory + path) + logger.info "Expired page: #{path}" unless logger.nil? + end + + def caches(*actions) + actions.each do |action| + class_eval "after_filter { |c| c.cache_page if c.action_name == '#{action}' }" + end + end + end + + def expire_page(options = {}) + self.class.expire_page(url_for(options.merge({ :only_path => true }))) + end + + # Expires more than one page at the time. Example: + # expire_pages( + # { :controller => "lists", :action => "public", :id => list_id }, + # { :controller => "lists", :action => "show", :id => list_id } + # ) + def expire_pages(*options) + options.each { |option| expire_page(option) } + end + + def cache_page(content = nil, options = {}) + self.class.cache_page(content || @response.body, url_for(options.merge({ :only_path => true }))) + end + end + + module Fragments + def self.append_features(base) + super + base.class_eval do + @@cache_store = MemoryStore.new + cattr_accessor :fragment_cache_store + end + end + + def cache_fragment(binding, name, key = nil) + buffer = eval("_erbout", binding) + if cache = fragment_cache_store.read(name, key) + buffer.concat(cache) + logger.info "Fragment hit: #{name}/#{key}" unless logger.nil? + else + pos = buffer.length + yield + fragment_cache_store.write(name, key, buffer[pos..-1]) + logger.info "Cached fragment: #{name}/#{key}" unless logger.nil? + end + end + + def expire_fragment(name, key = nil) + fragment_cache_store.delete(name, key) + logger.info "Expired fragment: #{name}/#{key}" unless logger.nil? + end + + class MemoryStore + def initialize + @data = { } + end + + def read(name, key) + begin + key ? @data[name][key] : @data[name] + rescue + nil + end + end + + def write(name, key, value) + if key + @data[name] ||= {} + @data[name][key] = value + else + @data[name] = value + end + end + + def delete(name, key) + key ? @data[name].delete(key) : @data.delete(name) + end + end + + class DRbStore < MemoryStore + def initialize(address = 'druby://localhost:9192') + @data = DRbObject.new(nil, address) + end + end + + class FileStore + def initialize(cache_path) + @cache_path = cache_path + end + + def write(name, key, value) + ensure_cache_path(File.dirname(cache_file_path(name, key))) + File.open(cache_file_path(name, key), "w+") { |f| f.write(value) } + end + + def read(name, key) + begin + IO.read(cache_file_path(name, key)) + rescue + nil + end + end + + def delete(name, key) + File.delete(cache_file_path(name, key)) if File.exist?(cache_file_path(name, key)) + end + + private + def cache_file_path(name, key) + key ? "#{@cache_path}/#{name}/#{key}" : "#{@cache_path}/#{name}" + end + + def ensure_cache_path(path) + FileUtils.makedirs(path) unless File.exists?(path) + end + end + end + end +end
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