Vendor lrbalt's fork of cache_digests

Gemfile

@@ -17,7 +17,7 @@ gem "aasm"
 gem "htmlentities"
 gem "swf_fu"
 gem "rails_autolink"
-gem "cache_digests", :git => 'git://github.com/lrbalt/cache_digests.git'
+gem "cache_digests", :path => 'vendor/gems/cache_digests-0.1.0' # vendored for Ruby 1.8.7 compatibility
 gem "rack-mini-profiler"
 
 # Gems used only for assets and not required

Gemfile.lock

@@ -1,6 +1,5 @@
-GIT
-  remote: git://github.com/lrbalt/cache_digests.git
-  revision: 8469c4153c84c0d918b01daccaa1e69747e93e89
+PATH
+  remote: vendor/gems/cache_digests-0.1.0
   specs:
     cache_digests (0.1.0)
       actionpack (>= 3.2)

vendor/gems/cache_digests-0.1.0/.gitignore

@@ -0,0 +1,2 @@
+bin
+test/tmp

vendor/gems/cache_digests-0.1.0/.rbenv-version

@@ -0,0 +1 @@
+1.9.3-p194

vendor/gems/cache_digests-0.1.0/Gemfile

@@ -0,0 +1,2 @@
+source 'https://rubygems.org'
+gemspec

vendor/gems/cache_digests-0.1.0/MIT-LICENSE

@@ -0,0 +1,20 @@
+Copyright (c) 2012 David Heinemeier Hansson
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/gems/cache_digests-0.1.0/README.md

@@ -0,0 +1,139 @@
+Cache Digests
+=============
+
+Russian-doll caching schemes are hard to maintain when nested templates are updated. The manual approach works something like this:
+
+```HTML+ERB
+# app/views/projects/show.html.erb
+<% cache [ "v1", project ] do %>
+  <h1>All documents</h1>
+  <%= render project.documents %>
+
+  <h1>All todolists</h1>
+  <%= render project.todolists %>
+<% end %>
+
+
+# app/views/documents/_document.html.erb
+<% cache [ "v1", document ] do %>
+  My document: <%= document.name %>
+
+  <%= render document.comments %>
+<% end %>
+
+
+# app/views/todolists/_todolist.html.erb
+<% cache [ "v1", todolist ] do %>
+  My todolist: <%= todolist.name %>
+
+  <%= render document.comments %>
+<% end %>
+
+# app/views/comments/_comment.html.erb
+<% cache [ "v1", comment ] do %>
+  My comment: <%= comment.body %>
+<% end %>
+```
+
+Now if I change app/views/comments/_comment.html.erb, I'll be forced to manually track down and bump the other three templates. And there's no visual reference in app/views/projects/show.html.erb that this template even depends on the comment template.
+
+That puts a serious cramp in our rocking caching style.
+
+Enter Cache Digests: With this plugin, all calls to #cache in the view will automatically append a digest of that template _and_ all of it's dependencies! So you no longer need to manually increment versions in the specific templates you're working on or care about what other templates are depending on the change you make.
+
+Our code from above can just look like:
+
+```HTML+ERB
+# app/views/projects/show.html.erb
+<% cache project do %>
+...
+
+# app/views/documents/_document.html.erb
+<% cache document do %>
+...
+
+# app/views/todolists/_todolist.html.erb
+<% cache todolist do %>
+...
+
+# app/views/comments/_comment.html.erb
+<% cache comment do %>
+...
+```
+
+The caching key for app/views/projects/show.html.erb will be something like `views/projects/605816632-20120810191209/d9fb66b120b61f46707c67ab41d93cb2`. That last bit is a MD5 of the template file itself and all of its dependencies. It'll change if you change either the template or any of the dependencies, and thus allow the cache to expire automatically.
+
+You can use these handy rake tasks to see how deep the rabbit hole goes:
+
+```
+$ rake cache_digests:dependencies TEMPLATE=projects/show
+[
+  "documents/document",
+  "todolists/todolist"
+]
+
+
+$ rake cache_digests:nested_dependencies TEMPLATE=projects/show
+[
+  {
+    "documents/document": [
+      "comments/comment"
+    ]
+  },
+  {
+    "todolists/todolist": [
+      "comments/comment"
+    ]
+  }
+]
+```
+
+Implicit dependencies
+---------------------
+
+Most template dependencies can be derived from calls to render in the template itself. Here are some examples of render calls that Cache Digests knows how to decode:
+
+```ruby
+render partial: "comments/comment", collection: commentable.comments
+render "comments/comments"
+render 'comments/comments'
+render('comments/comments')
+
+render "header" => render("comments/header")
+
+render(@topic)         => render("topics/topic")
+render(topics)         => render("topics/topic")
+render(message.topics) => render("topics/topic")
+```
+
+It's not possible to derive all render calls like that, though. Here are a few examples of things that can't be derived:
+
+```ruby
+render group_of_attachments
+render @project.documents.where(published: true).order('created_at')
+```
+
+You will have to rewrite those to the explicit form:
+
+```ruby
+render partial: 'attachments/attachment', collection: group_of_attachments
+render partial: 'documents/document', collection: @project.documents.where(published: true).order('created_at')
+```
+
+Explicit dependencies
+---------------------
+
+Some times you'll have template dependencies that can't be derived at all. This is typically the case when you have template rendering that happens in helpers. Here's an example:
+
+```HTML+ERB
+<%= render_sortable_todolists @project.todolists %>
+```
+
+You'll need to use a special comment format to call those out:
+
+```HTML+ERB
+<%# Template Dependency: todolists/todolist %>
+<%= render_sortable_todolists @project.todolists %>
+```
+
+The pattern used to match these is /# Template Dependency: ([^ ]+)/, so it's important that you type it out just so. You can only declare one template dependency per line.

vendor/gems/cache_digests-0.1.0/Rakefile

@@ -0,0 +1,11 @@
+require 'rubygems'
+require 'bundler/setup'
+require 'rake'
+require 'rake/testtask'
+
+task :default => :test
+
+Rake::TestTask.new do |t|
+  t.libs << 'test/lib'
+  t.pattern = 'test/*_test.rb'
+end

vendor/gems/cache_digests-0.1.0/cache_digests.gemspec

@@ -0,0 +1,16 @@
+Gem::Specification.new do |s|
+  s.name    = 'cache_digests'
+  s.version = '0.1.0'
+  s.author  = 'David Heinemeier Hansson'
+  s.email   = 'david@37signals.com'
+  s.summary = 'Nested fragment caches with (even) less situps'
+
+  s.required_ruby_version = '>= 1.8.7'
+
+  s.add_dependency 'actionpack', '>= 3.2'
+
+  s.add_development_dependency 'rake'
+  s.add_development_dependency 'minitest'
+
+  s.files = Dir["#{File.dirname(__FILE__)}/**/*"]
+end

vendor/gems/cache_digests-0.1.0/lib/cache_digests.rb

@@ -0,0 +1,4 @@
+require 'digest/md5'
+require 'cache_digests/template_digestor'
+require 'cache_digests/fragment_helper'
+require 'cache_digests/engine' if defined?(Rails)

vendor/gems/cache_digests-0.1.0/lib/cache_digests/engine.rb

@@ -0,0 +1,15 @@
+module CacheDigests
+  class Engine < ::Rails::Engine
+    initializer 'cache_digests' do |app|
+      require 'cache_digests'
+
+      ActiveSupport.on_load :action_view do
+        ActionView::Base.send :include, CacheDigests::FragmentHelper
+      end
+      
+      config.to_prepare do
+        CacheDigests::TemplateDigestor.logger = Rails.logger
+      end
+    end
+  end
+end

vendor/gems/cache_digests-0.1.0/lib/cache_digests/fragment_helper.rb

@@ -0,0 +1,17 @@
+module CacheDigests
+  module FragmentHelper
+    private
+      # Automatically include this template's digest -- and its childrens' -- in the cache key.
+      def fragment_for(key, options = nil, &block)
+        if !explicitly_versioned_cache_key?(key)
+          super [key, TemplateDigestor.digest(@virtual_path, formats.last.to_sym, lookup_context)], options, &block
+        else
+          super
+        end
+      end
+
+      def explicitly_versioned_cache_key?(key)
+        key.is_a?(Array) && key.first =~ /\Av\d+\Z/
+      end
+  end
+end

vendor/gems/cache_digests-0.1.0/lib/cache_digests/template_digestor.rb

@@ -0,0 +1,104 @@
+require 'active_support/core_ext'
+require 'logger'
+
+module CacheDigests
+  class TemplateDigestor
+    EXPLICIT_DEPENDENCY = /# Template Dependency: ([^ ]+)/
+
+    # Matches:
+    #   render partial: "comments/comment", collection: commentable.comments
+    #   render "comments/comments"
+    #   render 'comments/comments'
+    #   render('comments/comments')
+    #
+    #   render(@topic)         => render("topics/topic")
+    #   render(topics)         => render("topics/topic")
+    #   render(message.topics) => render("topics/topic")
+    RENDER_DEPENDENCY = /
+      render\s?                # render, followed by an optional space
+      \(?                      # start a optional parenthesis for the render call
+      (partial:)?\s?           # naming the partial, used with collection -- 1st capture
+      ([@a-z"'][@a-z_\/\."']+) # the template name itself -- 2nd capture
+    /x
+
+    cattr_accessor(:cache)  { Hash.new }
+    cattr_accessor(:logger, :instance_reader => true)
+
+    def self.digest(name, format, finder, options = {})
+      cache["#{name}.#{format}"] ||= new(name, format, finder, options).digest
+    end
+
+    attr_reader :name, :format, :finder, :options
+
+    def initialize(name, format, finder, options = {})
+      @name, @format, @finder, @options = name, format, finder, options
+    end
+
+    def digest
+      Digest::MD5.hexdigest("#{name}.#{format}-#{source}-#{dependency_digest}").tap do |digest|
+        logger.try :info, "Cache digest for #{name}.#{format}: #{digest}"
+      end
+    rescue ActionView::MissingTemplate
+      logger.try :error, "Couldn't find template for digesting: #{name}.#{format}"
+      ''
+    end
+
+    def dependencies
+      render_dependencies + explicit_dependencies
+    rescue ActionView::MissingTemplate
+      [] # File doesn't exist, so no dependencies
+    end
+
+    def nested_dependencies
+      dependencies.collect do |dependency|
+        dependencies = TemplateDigestor.new(dependency, format, finder, :partial => true).nested_dependencies
+        dependencies.any? ? { dependency => dependencies } : dependency
+      end
+    end
+
+
+    private
+      def logical_name
+        name.gsub(%r|/_|, "/")
+      end
+      
+      def directory
+        name.split("/").first
+      end
+
+      def partial?
+        options[:partial] || name.include?("/_")
+      end
+
+      def source
+        @source ||= finder.find(logical_name, [], partial?, :formats => [ format ]).source
+      end
+
+
+      def dependency_digest
+        dependencies.collect do |template_name|
+          TemplateDigestor.digest(template_name, format, finder, :partial => true)
+        end.join("-")
+      end
+
+      def render_dependencies
+        source.scan(RENDER_DEPENDENCY).
+          collect(&:second).uniq.
+
+          # render(@topic)         => render("topics/topic")
+          # render(topics)         => render("topics/topic")
+          # render(message.topics) => render("topics/topic")
+          collect { |name| name.sub(/\A@?([a-z]+\.)*([a-z_]+)\z/) { "#{$2.pluralize}/#{$2.singularize}" } }.
+
+          # render("headline") => render("message/headline")
+          collect { |name| name.include?("/") ? name : "#{directory}/#{name}" }.
+          
+          # replace quotes from string renders
+          collect { |name| name.gsub(/["']/, "") }
+      end
+
+      def explicit_dependencies
+        source.scan(EXPLICIT_DEPENDENCY).flatten.uniq
+      end
+  end
+end

vendor/gems/cache_digests-0.1.0/lib/tasks/dependencies.rake

@@ -0,0 +1,15 @@
+namespace :cache_digests do
+  desc 'Lookup nested dependencies for TEMPLATE (like messages/show or comments/_comment.html)'
+  task :nested_dependencies => :environment do
+    template, format = ENV['TEMPLATE'].split(".")
+    format ||= :html
+    puts JSON.pretty_generate CacheDigests::TemplateDigestor.new(template, format, ApplicationController.new.lookup_context).nested_dependencies
+  end
+
+  desc 'Lookup first-level dependencies for TEMPLATE (like messages/show or comments/_comment.html)'
+  task :dependencies => :environment do
+    template, format = ENV['TEMPLATE'].split(".")
+    format ||= :html
+    puts JSON.pretty_generate CacheDigests::TemplateDigestor.new(template, format, ApplicationController.new.lookup_context).dependencies
+  end
+end

vendor/gems/cache_digests-0.1.0/test/fixtures/comments/_comment.html.erb

@@ -0,0 +1 @@
+Great story, bro!

vendor/gems/cache_digests-0.1.0/test/fixtures/comments/_comments.html.erb

@@ -0,0 +1 @@
+<%= render partial: "comments/comment", collection: commentable.comments %>

vendor/gems/cache_digests-0.1.0/test/fixtures/messages/_message.html.erb

@@ -0,0 +1 @@
+THIS BE WHERE THEM MESSAGE GO, YO!

vendor/gems/cache_digests-0.1.0/test/fixtures/messages/index.html.erb

@@ -0,0 +1,2 @@
+<%= render @messages %>
+<%= render @events %>

vendor/gems/cache_digests-0.1.0/test/fixtures/messages/show.html.erb

@@ -0,0 +1,9 @@
+<%# Template Dependency: messages/message %>
+<%= render "header" %>
+<%= render "comments/comments" %>
+
+<%= render "messages/actions/move" %>
+
+<%= render @message.history.events %>
+
+<%# render "something_missing"  %>

vendor/gems/cache_digests-0.1.0/test/fragment_helper_test.rb

@@ -0,0 +1,4 @@
+require 'cache_digests/test_helper'
+
+class FragmentHelperTest < MiniTest::Unit::TestCase
+end

vendor/gems/cache_digests-0.1.0/test/lib/cache_digests/test_helper.rb

@@ -0,0 +1,6 @@
+require 'rubygems'
+require 'bundler/setup'
+require 'cache_digests'
+
+require 'minitest/unit'
+MiniTest::Unit.autorun

vendor/gems/cache_digests-0.1.0/test/template_digestor_test.rb

@@ -0,0 +1,133 @@
+require 'cache_digests/test_helper'
+require 'fileutils'
+
+module ActionView
+  class MissingTemplate < StandardError
+  end
+end
+
+class FixtureTemplate
+  attr_reader :source
+  
+  def initialize(template_path)
+    @source = File.read(template_path)
+  rescue Errno::ENOENT
+    raise ActionView::MissingTemplate
+  end
+end
+
+class FixtureFinder
+  FIXTURES_DIR = "#{File.dirname(__FILE__)}/fixtures"
+  TMP_DIR      = "#{File.dirname(__FILE__)}/tmp"
+  
+  def find(logical_name, keys, partial, options)
+    FixtureTemplate.new("#{TMP_DIR}/#{partial ? logical_name.gsub(%r|/([^/]+)$|, '/_\1') : logical_name}.#{options[:formats].first}.erb")
+  end
+end
+
+class TemplateDigestorTest < MiniTest::Unit::TestCase
+  def setup
+    FileUtils.cp_r FixtureFinder::FIXTURES_DIR, FixtureFinder::TMP_DIR
+  end
+  
+  def teardown
+    FileUtils.rm_r FixtureFinder::TMP_DIR
+    CacheDigests::TemplateDigestor.cache.clear
+  end
+
+  def test_top_level_change_reflected
+    assert_digest_difference("messages/show") do
+      change_template("messages/show")
+    end
+  end
+
+  def test_explicit_dependency
+    assert_digest_difference("messages/show") do
+      change_template("messages/_message")
+    end
+  end
+
+  def test_second_level_dependency
+    assert_digest_difference("messages/show") do
+      change_template("comments/_comments")
+    end
+  end
+
+  def test_second_level_dependency_within_same_directory
+    assert_digest_difference("messages/show") do
+      change_template("messages/_header")
+    end
+  end
+
+  def test_third_level_dependency
+    assert_digest_difference("messages/show") do
+      change_template("comments/_comment")
+    end
+  end
+
+  def test_logging_of_missing_template
+    assert_logged "Couldn't find template for digesting: messages/something_missing.html" do
+      digest("messages/show")
+    end
+  end
+
+  def test_nested_template_directory
+    assert_digest_difference("messages/show") do
+      change_template("messages/actions/_move")
+    end
+  end
+  
+  def test_dont_generate_a_digest_for_missing_templates
+    assert_equal '', digest("nothing/there")
+  end
+
+  def test_collection_dependency
+    assert_digest_difference("messages/index") do
+      change_template("messages/_message")
+    end
+
+    assert_digest_difference("messages/index") do
+      change_template("events/_event")
+    end
+  end
+  
+  def test_collection_derived_from_record_dependency
+    assert_digest_difference("messages/show") do
+      change_template("events/_event")
+    end
+  end
+
+
+  private
+    def assert_logged(message)
+      log = StringIO.new
+      CacheDigests::TemplateDigestor.logger = Logger.new(log)
+
+      yield
+      
+      log.rewind
+      assert_match message, log.read
+      
+      CacheDigests::TemplateDigestor.logger = nil
+    end
+
+    def assert_digest_difference(template_name)
+      previous_digest = digest(template_name)
+      CacheDigests::TemplateDigestor.cache.clear
+
+      yield
+
+      assert previous_digest != digest(template_name), "digest didn't change"
+      CacheDigests::TemplateDigestor.cache.clear
+    end
+  
+    def digest(template_name)
+      CacheDigests::TemplateDigestor.digest(template_name, :html, FixtureFinder.new)
+    end
+    
+    def change_template(template_name)
+      File.open("#{FixtureFinder::TMP_DIR}/#{template_name}.html.erb", "w") do |f|
+        f.write "\nTHIS WAS CHANGED!"
+      end
+    end
+end