Merge pull request formtastic#784 from SaschaKonietzke/cache-i18n-loo…

…kups

Performance Improvement formtastic#2: Cache I18n lookups in Formtastic::Localizer (formtastic#744)

lib/formtastic/form_builder.rb

@@ -23,6 +23,7 @@ def self.configure(name, value = nil)
     configure :file_metadata_suffixes, ['content_type', 'file_name', 'file_size']
     configure :priority_countries, ["Australia", "Canada", "United Kingdom", "United States"]
     configure :i18n_lookups_by_default, true
+    configure :i18n_cache_lookups, true
     configure :i18n_localizer, Formtastic::Localizer
     configure :escape_html_entities_in_hints_and_labels, true
     configure :default_commit_button_accesskey

lib/formtastic/localizer.rb

@@ -24,27 +24,59 @@ module Formtastic
   #   'formtastic.labels.post.title'
   #   'formtastic.labels.title'
   class Localizer
-
+    class Cache
+      def get(key)
+        cache[key]
+      end
+
+      def has_key?(key)
+        cache.has_key?(key)
+      end
+
+      def set(key, result)
+        cache[key] = result
+      end
+
+      def cache
+        @cache ||= {}
+      end
+
+      def clear!
+        cache.clear
+      end
+    end
+
     attr_accessor :builder
-
+
+    def self.cache
+      @cache ||= Cache.new
+    end
+
     def initialize(current_builder)
       self.builder = current_builder 
     end
 
     def localize(key, value, type, options = {}) #:nodoc:
       key = value if value.is_a?(::Symbol)
-
+      
       if value.is_a?(::String)
         escape_html_entities(value)
       else
         use_i18n = value.nil? ? i18n_lookups_by_default : (value != false)
-
+        use_cache = i18n_cache_lookups
+        cache = self.class.cache
+
         if use_i18n
           model_name, nested_model_name  = normalize_model_name(builder.model_name.underscore)
 
           action_name = builder.template.params[:action].to_s rescue ''
           attribute_name = key.to_s
-
+
+          # look in the cache first
+          if use_cache
+            cache_key = [::I18n.locale, action_name, model_name, nested_model_name, attribute_name, key, value, type, options]
+            return cache.get(cache_key) if cache.has_key?(cache_key)
+          end
 
           defaults = Formtastic::I18n::SCOPES.reject do |i18n_scope|
             nested_model_name.nil? && i18n_scope.match(/nested_model/)
@@ -71,7 +103,11 @@ def localize(key, value, type, options = {}) #:nodoc:
             options[:default] = defaults
             i18n_value = ::I18n.t(default_key, options)
           end
-          (i18n_value.is_a?(::String) && i18n_value.present?) ? escape_html_entities(i18n_value) : nil
+
+          # save the result to the cache
+          result = (i18n_value.is_a?(::String) && i18n_value.present?) ? escape_html_entities(i18n_value) : nil
+          cache.set(cache_key, result) if use_cache
+          result
         end
       end
     end
@@ -105,6 +141,10 @@ def escape_html_entities(string) #:nodoc:
     def i18n_lookups_by_default
       builder.i18n_lookups_by_default
     end
+
+    def i18n_cache_lookups
+      builder.i18n_cache_lookups
+    end
 
   end
 end

lib/generators/templates/formtastic.rb

@@ -68,6 +68,10 @@
 # i.e. :label => true, or :hint => true (or opposite depending on initialized value)
 # Formtastic::FormBuilder.i18n_lookups_by_default = false
 
+# Specifies if I18n lookups of the default I18n Localizer should be cached to improve performance.
+# Defaults to false.
+# Formtastic::FormBuilder.i18n_cache_lookups = true
+
 # Specifies the class to use for localization lookups. You can create your own
 # class and use it instead by subclassing Formtastic::Localizer (which is the default).
 # Formtastic::FormBuilder.i18n_localizer = MyOwnLocalizer

spec/actions/generic_action_spec.rb

@@ -213,6 +213,7 @@ def to_html
                       }
                     }
                  }
+
              concat(semantic_form_for(:post, :url => 'http://example.com') do |builder|
                concat(builder.action(:submit, :as => :generic))
                concat(builder.action(:reset, :as => :generic))

spec/localizer_spec.rb

@@ -0,0 +1,108 @@
+# encoding: utf-8
+require 'spec_helper'
+
+describe 'Formtastic::Localizer' do
+  describe "Cache" do
+    before do
+      @cache = Formtastic::Localizer::Cache.new
+      @key = ['model', 'name']
+      @undefined_key = ['model', 'undefined']
+      @cache.set(@key, 'value')
+    end
+
+    it "should get value" do
+      @cache.get(@key).should == 'value'
+      @cache.get(@undefined_key).should be_nil
+    end
+
+    it "should check if key exists?" do
+      @cache.has_key?(@key).should be_true
+      @cache.has_key?(@undefined_key).should be_false
+    end
+
+    it "should set a key" do
+      @cache.set(['model', 'name2'], 'value2')
+      @cache.get(['model', 'name2']).should == 'value2'
+    end
+
+    it "should return hash" do
+      @cache.cache.should be_an_instance_of(Hash)
+    end
+
+    it "should clear the cache" do
+      @cache.clear!
+      @cache.get(@key).should be_nil
+    end
+  end
+
+  describe "Localizer" do
+    include FormtasticSpecHelper      
+
+    before do
+      mock_everything    
+
+      with_config :i18n_lookups_by_default, true do
+        semantic_form_for(@new_post) do |builder|
+          @localizer = Formtastic::Localizer.new(builder)
+        end
+      end
+    end
+
+    after do
+      ::I18n.backend.reload!
+    end
+
+    it "should be defined" do
+      lambda { Formtastic::Localizer }.should_not raise_error(::NameError)
+    end
+
+    it "should have a cache" do
+      Formtastic::Localizer.cache.should be_an_instance_of(Formtastic::Localizer::Cache)
+    end
+
+    describe "localize" do
+      def store_post_translations(value)
+        ::I18n.backend.store_translations :en, {:formtastic => {
+            :labels => {
+              :post => { :name => value }
+            }
+          }
+        }        
+      end
+
+      before do
+        store_post_translations('POST.NAME')
+      end
+
+      it "should translate key with i18n" do
+        @localizer.localize(:name, :name, :label).should == 'POST.NAME'
+      end
+
+      describe "with caching" do
+        it "should not update translation when stored translations change" do
+          with_config :i18n_cache_lookups, true do
+            @localizer.localize(:name, :name, :label).should == 'POST.NAME'
+            store_post_translations('POST.NEW_NAME')
+
+            @localizer.localize(:name, :name, :label).should == 'POST.NAME'       
+
+            Formtastic::Localizer.cache.clear!
+            @localizer.localize(:name, :name, :label).should == 'POST.NEW_NAME'                  
+          end
+        end        
+      end
+
+      describe "without caching" do
+        it "should update translation when stored translations change" do
+          with_config :i18n_cache_lookups, false do
+            @localizer.localize(:name, :name, :label).should == 'POST.NAME'
+            store_post_translations('POST.NEW_NAME')
+            @localizer.localize(:name, :name, :label).should == 'POST.NEW_NAME'            
+          end
+        end
+      end
+    end
+
+  end
+
+end

spec/spec_helper.rb

@@ -419,10 +419,14 @@ def with_config(config_method_name, value, &block)
 ::ActiveSupport::Deprecation.silenced = false
 
 RSpec.configure do |config|
+  config.before(:each) do
+    Formtastic::Localizer.cache.clear!    
+  end
+
   config.before(:all) do
     DeferredGarbageCollection.start unless ENV["DEFER_GC"] == "false"
   end
   config.after(:all) do
-    DeferredGarbageCollection.reconsider unless ENV["DEFER_GC"] == "false"
+    DeferredGarbageCollection.reconsider unless ENV["DEFER_GC"] == "false"    
   end
 end