[#778] Properly cache Liquid markup

This commit moves the markup caching into Liquid rendering. As Liquid allows to return different results depending on the environment (variables, logged user, ...) we only cache the page if it contains no active content. Unfortunetely, active content currently also includes the TOC in wiki pages.

[#778] Properly cache Liquid markup
This commit moves the markup caching into Liquid rendering. As Liquid allows to return different results depending on the environment (variables, logged user, ...) we only cache the page if it contains no active content. Unfortunetely, active content currently also includes the TOC in wiki pages.
e91a1e01 · Holger Just · 637ca24a · e91a1e01 · e91a1e01 · e91a1e01
Commit e91a1e01 authored Jan 16, 2012 by Holger Just
4 changed files
--- a/lib/chili_project/liquid/liquid_ext/block.rb
+++ b/lib/chili_project/liquid/liquid_ext/block.rb
@@ -19,15 +19,19 @@ module ChiliProject
        def self.included(base)
          base.send(:include, InstanceMethods)
          base.class_eval do
-            alias_method_chain :render_all, :cleaned_whitespace
+            alias_method_chain :render_all, :cleaned_whitespace_and_cache
          end
        end

        module InstanceMethods
-          def render_all_with_cleaned_whitespace(list, context)
+          def render_all_with_cleaned_whitespace_and_cache(list, context)
            # Remove the leading newline in a block's content
            list[0].sub!(/\A\r?\n/, "") if list[0].is_a?(String)
-            render_all_without_cleaned_whitespace(list, context)
+
+            # prevent caching if there are any potentially active elements
+            context.not_cachable! if list.any? { |token| token.respond_to?(:render) }
+
+            render_all_without_cleaned_whitespace_and_cache(list, context)
          end
        end
      end

--- a/lib/chili_project/liquid/liquid_ext/context.rb
+++ b/lib/chili_project/liquid/liquid_ext/context.rb
@@ -47,6 +47,14 @@ module ChiliProject
          def html_results
            registers[:html_results] ||= {}
          end
+
+          def cacheable?
+            registers.has_key?(:cachable) ? !!registers[:cachable] : true
+          end
+
+          def not_cachable!
+            registers[:cachable] = false
+          end
        end
      end
    end

--- a/lib/chili_project/liquid/template.rb
+++ b/lib/chili_project/liquid/template.rb
@@ -74,6 +74,26 @@ module ChiliProject
        context = context_from_render_options(*args)
        context.registers[:html_results] ||= {}

+        obj = context.registers[:object]
+        attribute = context.registers[:attribute]
+
+        if Setting.cache_formatted_text? && cache_key = cache_key_for(Setting.text_formatting, obj, attribute)
+          # Text retrieved from the cache store may be frozen
+          # We need to dup it so we can do in-place substitutions with gsub!
+          result = Rails.cache.fetch(cache_key)
+          result ||= begin
+            result = render_context(context)
+            Rails.cache.write(cache_key, result) if context.cacheable?
+            result
+          end.dup
+        else
+          render_context(context)
+        end
+      end
+
+      def render_context(context)
+        return '' if @root.nil?
+
        # ENTER THE RENDERING STAGE

        # 1. Render the input as Liquid
@@ -88,8 +108,8 @@ module ChiliProject

        # 2. Perform the Wiki markup transformation (e.g. Textile)
        obj = context.registers[:object]
-        attr = context.registers[:attribute]
-        result = Redmine::WikiFormatting.to_html(Setting.text_formatting, result, :object => obj, :attribute => attr)
+        attribute = context.registers[:attribute]
+        result = Redmine::WikiFormatting.to_html(Setting.text_formatting, result, :object => obj, :attribute => attribute)

        # 3. Now finally, replace the captured raw HTML bits in the final content
        length = nil
@@ -105,6 +125,13 @@ module ChiliProject

        result
      end
+
+    private
+      def cache_key_for(format, object, attribute)
+        if object && attribute && !object.new_record? && object.respond_to?(:updated_on) && !format.blank?
+          "formatted_text/#{format}/#{object.class.model_name.cache_key}/#{object.id}-#{attribute}-#{object.updated_on.to_s(:number)}"
+        end
+      end
    end
  end
 end
--- a/lib/redmine/wiki_formatting.rb
+++ b/lib/redmine/wiki_formatting.rb
@@ -41,27 +41,7 @@ module Redmine
      end

      def to_html(format, text, options = {}, &block)
-        if Setting.cache_formatted_text? && text.size > 2.kilobyte && cache_store && cache_key = cache_key_for(format, options[:object], options[:attribute])
-          # Text retrieved from the cache store may be frozen
-          # We need to dup it so we can do in-place substitutions with gsub!
-          cache_store.fetch cache_key do
-            formatter_for(format).new(text).to_html
-          end.dup
-        else
-          formatter_for(format).new(text).to_html
-        end
-      end
-
-      # Returns a cache key for the given text +format+, +object+ and +attribute+ or nil if no caching should be done
-      def cache_key_for(format, object, attribute)
-        if object && attribute && !object.new_record? && object.respond_to?(:updated_on) && !format.blank?
-          "formatted_text/#{format}/#{object.class.model_name.cache_key}/#{object.id}-#{attribute}-#{object.updated_on.to_s(:number)}"
-        end
-      end
-
-      # Returns the cache store used to cache HTML output
-      def cache_store
-        ActionController::Base.cache_store
+        formatter_for(format).new(text).to_html
      end
    end
  end