Wisdom of Rails Wizards Study on Best Cache Store

rubyonrails-talk
1

Hi Shanti, I'm no rails expert. However I do quite a bit of fragment caching on my site. Just recently I had to deal with performance problems related to expiring fragment cache. If you use a regular expression to expire cache it will stat every file in your cache directory looking for matches. The more files you have the slower it gets. I had to write a trivial plugin to the fragment cache module to take a controller or path as an option to restrict this.

Cheers, Dallas

2

Shanti

Like I said I'm no rails expert, but if anyone else has this problem this is what I did for my plugin.

Cheers, Dallas

<% cache(:host => 'sportspyder.com', :action => 'team_articles', :action_suffix => "articles_#{@team.id}_#{@filter}_#{@page}") do -%>

expire_fragment(/articles_#{@team.id}_all/, :host => 'sportspyder.com', :controller => 'team')

expire_fragment(/headline/, :host => 'sportspyder.com', :path=> 'team/mlb/', :recursive=>false)

module ActionController   module Caching     module Fragments       class UnthreadedFileStore #:nodoc:         def delete_matched(matcher, options) #:nodoc:           path = @cache_path           if options[:controller] && options[:host]             path = "#{path}/#{options[:host]}/#{options[:controller]}"           elsif options[:path] && options[:host]             path = "#{path}/#{options[:host]}/#{options[:path]}"

          end

          return unless File.directory?(path)           recursive = [true, false].include?(options[:recursive]) ? options[:recursive] : true

          if path == @cache_path && recursive             ActionController::Base.logger.error("You are statting every file in the cache directory. You should specify a host and controller or path when using a regex for expiration. Regex [#{matcher}]")           end

          search_dir(path, recursive) do |f|

            if f =~ matcher               begin                 File.delete(f)               rescue Object => e                 # If there's no cache, then there's nothing to complain about               end             end           end         end

        def search_dir(dir, recursive=true, &callback)           Dir.foreach(dir) do |d|             next if d == "." || d == ".."             name = File.join(dir, d)             if File.directory?(name) && recursive               search_dir(name, recursive, &callback)             else               callback.call name             end           end         end       end     end   end end