Initial work on using Liquid::Drops instead of Hashes.

The properties of Liquid::Drops are only evaluated when they're asked for
and therefore save computation time. This prevents a lot of GC time cleaning
up objects that are not needed, because they're not created unless requested.
Additionally, this saves time for actual computation of those values because
they can be computed only if needed.

It's funny how much it helps when you only do what is needed. Far less overhead.

lib/jekyll.rb

@@ -172,6 +172,7 @@ end
 require_all 'jekyll/commands'
 require_all 'jekyll/converters'
 require_all 'jekyll/converters/markdown'
+require_all 'jekyll/drops'
 require_all 'jekyll/generators'
 require_all 'jekyll/tags'
 

lib/jekyll/collection.rb

@@ -170,14 +170,7 @@ module Jekyll
     #
     # Returns a representation of this collection for use in Liquid.
     def to_liquid
-      metadata.merge({
+      Drops::CollectionDrop.new self
-        "label"     => label,
-        "docs"      => docs,
-        "files"     => files,
-        "directory" => directory,
-        "output"    => write?,
-        "relative_directory" => relative_directory
-      })
     end
 
     # Whether the collection's documents ought to be written as individual

lib/jekyll/convertible.rb

@@ -210,13 +210,8 @@ module Jekyll
 
       while layout
         Jekyll.logger.debug "Rendering Layout:", path
-        payload = Utils.deep_merge_hashes(
+        payload.content = output
-          payload,
+        payload.layout  = layout.data
-          {
-            "content" => output,
-            "layout"  => layout.data
-          }
-        )
 
         self.output = render_liquid(layout.content,
                                          payload,
@@ -250,11 +245,11 @@ module Jekyll
 
       Jekyll.logger.debug "Pre-Render Hooks:", self.relative_path
       Jekyll::Hooks.trigger hook_owner, :pre_render, self, payload
-      info = { :filters => [Jekyll::Filters], :registers => { :site => site, :page => payload['page'] } }
+      info = { :filters => [Jekyll::Filters], :registers => { :site => site, :page => payload.page } }
 
       # render and transform content (this becomes the final content of the object)
-      payload["highlighter_prefix"] = converters.first.highlighter_prefix
+      payload.highlighter_prefix = converters.first.highlighter_prefix
-      payload["highlighter_suffix"] = converters.first.highlighter_suffix
+      payload.highlighter_suffix = converters.first.highlighter_suffix
 
       if render_with_liquid?
         Jekyll.logger.debug "Rendering Liquid:", self.relative_path

lib/jekyll/document.rb

@@ -38,12 +38,10 @@ module Jekyll
     end
 
     def output=(output)
-      @to_liquid = nil
       @output = output
     end
 
     def content=(content)
-      @to_liquid = nil
       @content = content
     end
 
@@ -181,27 +179,7 @@ module Jekyll
     #
     # Returns the Hash of key-value pairs for replacement in the URL.
     def url_placeholders
-      {
+      @url_placeholders ||= Drops::UrlDrop.new(self)
-        collection:  collection.label,
-        path:        cleaned_relative_path,
-        output_ext:  output_ext,
-        name:        Utils.slugify(basename_without_ext),
-        title:       Utils.slugify(data['slug'], mode: "pretty", cased: true) || Utils
-                       .slugify(basename_without_ext, mode: "pretty", cased: true),
-        slug:        Utils.slugify(data['slug']) || Utils.slugify(basename_without_ext),
-        year:        date.strftime("%Y"),
-        month:       date.strftime("%m"),
-        day:         date.strftime("%d"),
-        hour:        date.strftime("%H"),
-        minute:      date.strftime("%M"),
-        second:      date.strftime("%S"),
-        i_day:       date.strftime("%-d"),
-        i_month:     date.strftime("%-m"),
-        categories:  (data['categories'] || []).map { |c| c.to_s.downcase }.uniq.join('/'),
-        short_month: date.strftime("%b"),
-        short_year:  date.strftime("%y"),
-        y_day:       date.strftime("%j"),
-      }
     end
 
     # The permalink for this Document.
@@ -278,8 +256,6 @@ module Jekyll
     #
     # Returns nothing.
     def read(opts = {})
-      @to_liquid = nil
-
       Jekyll.logger.debug "Reading:", relative_path
 
       if yaml_file?
@@ -353,21 +329,7 @@ module Jekyll
     #
     # Returns a Hash representing this Document's data.
     def to_liquid
-      @to_liquid ||= if data.is_a?(Hash)
+      @to_liquid ||= Drops::DocumentDrop.new(self)
-        Utils.deep_merge_hashes Utils.deep_merge_hashes({
-          "output"        => output,
-          "content"       => content,
-          "relative_path" => relative_path,
-          "path"          => relative_path,
-          "url"           => url,
-          "collection"    => collection.label,
-          "next"          => next_doc,
-          "previous"      => previous_doc,
-          "id"            => id,
-        }, data), { 'excerpt' => data['excerpt'].to_s }
-      else
-        data
-      end
     end
 
     # The inspect string for this document.

lib/jekyll/drops/collection_drop.rb

@@ -0,0 +1,22 @@
+# encoding: UTF-8
+require "jekyll/drops/immutable_drop"
+
+module Jekyll
+  module Drops
+    class CollectionDrop < ImmutableDrop
+      extend Forwardable
+
+      def_delegators :@obj, :label, :docs, :files, :directory, :relative_directory
+
+      def output
+        @obj.write?
+      end
+
+      private
+      def data
+        @obj.metadata
+      end
+
+    end
+  end
+end

lib/jekyll/drops/document_drop.rb

@@ -0,0 +1,50 @@
+# encoding: UTF-8
+
+module Jekyll
+  module Drops
+    class DocumentDrop < ImmutableDrop
+
+      def output
+        @obj.output
+      end
+
+      def content
+        @obj.content
+      end
+
+      def relative_path
+        @obj.relative_path
+      end
+      alias_method :path, :relative_path
+
+      def url
+        @obj.url
+      end
+
+      def collection
+        @obj.collection.label
+      end
+
+      def next
+        @obj.next_doc
+      end
+
+      def previous
+        @obj.previous_doc
+      end
+
+      def id
+        @obj.id
+      end
+
+      def excerpt
+        data['excerpt'].to_s
+      end
+
+      def data
+        @obj.data
+      end
+
+    end
+  end
+end

lib/jekyll/drops/immutable_drop.rb

@@ -0,0 +1,29 @@
+# encoding: UTF-8
+
+module Jekyll
+  module Drops
+    class ImmutableDrop < Liquid::Drop
+
+      def initialize(obj)
+        @obj = obj
+      end
+
+      def [](key)
+        if respond_to? key
+          public_send key
+        else
+          data[key]
+        end
+      end
+
+      def []=(key, val)
+        if respond_to? key
+          raise ArgumentError.new("Key #{key} cannot be set in the drop.")
+        else
+          data[key] = val
+        end
+      end
+
+    end
+  end
+end

lib/jekyll/drops/jekyll_drop.rb

@@ -0,0 +1,21 @@
+# encoding: UTF-8
+
+module Jekyll
+  module Drops
+    class JekyllDrop < Liquid::Drop
+      class << self
+        def global
+          @global ||= JekyllDrop.new
+        end
+      end
+
+      def version
+        Jekyll::VERSION
+      end
+
+      def environment
+        Jekyll.env
+      end
+    end
+  end
+end

lib/jekyll/drops/mutable_drop.rb

@@ -0,0 +1,28 @@
+# encoding: UTF-8
+
+module Jekyll
+  module Drops
+    class MutableDrop < Liquid::Drop
+
+      def initialize(obj)
+        @obj = obj
+        @mutations = {}
+      end
+
+      def [](key)
+        if @mutations.key? key
+          @mutations[key]
+        elsif respond_to? key
+          public_send key
+        else
+          data[key]
+        end
+      end
+
+      def []=(key, val)
+        @mutations[key] = val
+      end
+
+    end
+  end
+end

lib/jekyll/drops/site_drop.rb

@@ -0,0 +1,38 @@
+# encoding: UTF-8
+
+module Jekyll
+  module Drops
+    class SiteDrop < ImmutableDrop
+      extend Forwardable
+
+      def_delegator  :@obj, :site_data, :data
+      def_delegators :@obj, :time, :pages, :static_files, :documents
+
+      def posts
+        @site_posts ||= @obj.posts.docs.sort { |a, b| b <=> a }
+      end
+
+      def html_pages
+        @site_html_pages ||= @obj.pages.select { |page| page.html? || page.url.end_with?("/") }
+      end
+
+      def categories
+        @site_categories ||= @obj.post_attr_hash('categories')
+      end
+
+      def tags
+        @site_tags ||= @obj.post_attr_hash('tags')
+      end
+
+      def collections
+        @site_collections ||= @obj.collections.values.map(&:to_liquid)
+      end
+
+      private
+      def data
+        @obj.config
+      end
+
+    end
+  end
+end

lib/jekyll/drops/unified_payload_drop.rb

@@ -0,0 +1,24 @@
+# encoding: UTF-8
+
+module Jekyll
+  module Drops
+    class UnifiedPayloadDrop < Liquid::Drop
+
+      attr_accessor :page, :layout, :content, :paginator
+      attr_accessor :highlighter_prefix, :highlighter_suffix
+
+      def initialize(site)
+        @site = site
+      end
+
+      def jekyll
+        JekyllDrop.global
+      end
+
+      def site
+        @site_drop ||= SiteDrop.new(@site)
+      end
+
+    end
+  end
+end

lib/jekyll/drops/url_drop.rb

@@ -0,0 +1,52 @@
+# encoding: UTF-8
+
+module Jekyll
+  module Drops
+    class UrlDrop < ImmutableDrop
+      def collection
+        @obj.collection.label
+      end
+
+      def path
+        @obj.cleaned_relative_path
+      end
+
+      def output_ext
+        @obj.output_ext
+      end
+
+      def name
+        Utils.slugify(@obj.basename_without_ext)
+      end
+
+      def title
+        Utils.slugify(@obj.data['slug'], mode: "pretty", cased: true) ||
+          Utils.slugify(@obj.basename_without_ext, mode: "pretty", cased: true)
+      end
+
+      def slug
+        Utils.slugify(@obj.data['slug']) || Utils.slugify(@obj.basename_without_ext)
+      end
+
+      def categories
+        category_set = Set.new
+        Array(@obj.data['categories']).each do |category|
+          category_set << category.to_s.downcase
+        end
+        category_set.to_a.join('/')
+      end
+
+      def year;        @obj.date.strftime("%Y"); end
+      def month;       @obj.date.strftime("%m"); end
+      def day;         @obj.date.strftime("%d"); end
+      def hour;        @obj.date.strftime("%H"); end
+      def minute;      @obj.date.strftime("%M"); end
+      def second;      @obj.date.strftime("%S"); end
+      def i_day;       @obj.date.strftime("%-d"); end
+      def i_month;     @obj.date.strftime("%-m"); end
+      def short_month; @obj.date.strftime("%b"); end
+      def short_year;  @obj.date.strftime("%y"); end
+      def y_day;       @obj.date.strftime("%j"); end
+    end
+  end
+end

lib/jekyll/page.rb

@@ -117,12 +117,10 @@ module Jekyll
     #
     # Returns nothing.
     def render(layouts, site_payload)
-      payload = Utils.deep_merge_hashes({
+      site_payload.page = to_liquid
-        "page" => to_liquid,
+      site_payload.paginator = pager.to_liquid
-        'paginator' => pager.to_liquid
-      }, site_payload)
 
-      do_layout(payload, layouts)
+      do_layout(site_payload, layouts)
     end
 
     # The path to the source file

lib/jekyll/renderer.rb

@@ -3,12 +3,12 @@
 module Jekyll
   class Renderer
 
-    attr_reader :document, :site, :site_payload
+    attr_reader :document, :site, :payload
 
     def initialize(site, document, site_payload = nil)
       @site     = site
       @document = document
-      @site_payload = site_payload
+      @payload  = site_payload || site.site_payload
     end
 
     # Determine which converters to use based on this document's
@@ -33,12 +33,10 @@ module Jekyll
     def run
       Jekyll.logger.debug "Rendering:", document.relative_path
 
-      payload = Utils.deep_merge_hashes({
+      payload.page = document.to_liquid
-        "page" => document.to_liquid
-      }, site_payload || site.site_payload)
 
       if document.collection.label == 'posts' && document.is_a?(Document)
-        payload['site']['related_posts'] = document.related_posts
+        payload.site['related_posts'] = document.related_posts
       end
 
       Jekyll.logger.debug "Pre-Render Hooks:", document.relative_path
@@ -46,12 +44,12 @@ module Jekyll
 
       info = {
         filters:   [Jekyll::Filters],
-        registers: { :site => site, :page => payload['page'] }
+        registers: { :site => site, :page => payload.page }
       }
 
       # render and transform content (this becomes the final content of the object)
-      payload["highlighter_prefix"] = converters.first.highlighter_prefix
+      payload.highlighter_prefix = converters.first.highlighter_prefix
-      payload["highlighter_suffix"] = converters.first.highlighter_suffix
+      payload.highlighter_suffix = converters.first.highlighter_suffix
 
       output = document.content
 
@@ -135,14 +133,9 @@ module Jekyll
       used   = Set.new([layout])
 
       while layout
-        payload = Utils.deep_merge_hashes(
+        payload.content = output
-          payload,
+        payload.page = document.to_liquid
-          {
+        payload.layout = layout.data
-            "content" => output,
-            "page"    => document.to_liquid,
-            "layout"  => layout.data
-          }
-        )
 
         output = render_liquid(
           layout.content,

lib/jekyll/site.rb

@@ -259,25 +259,7 @@ module Jekyll
     #   "tags"       - The Hash of tag values and Posts.
     #                  See Site#post_attr_hash for type info.
     def site_payload
-      {
+      Drops::UnifiedPayloadDrop.new self
-        "jekyll" => {
-          "version" => Jekyll::VERSION,
-          "environment" => Jekyll.env
-        },
-        "site"   => Utils.deep_merge_hashes(config,
-          Utils.deep_merge_hashes(Hash[collections.map{|label, coll| [label, coll.docs]}], {
-            "time"         => time,
-            "posts"        => posts.docs.sort { |a, b| b <=> a },
-            "pages"        => pages,
-            "static_files" => static_files,
-            "html_pages"   => pages.select { |page| page.html? || page.url.end_with?("/") },
-            "categories"   => post_attr_hash('categories'),
-            "tags"         => post_attr_hash('tags'),
-            "collections"  => collections.values.map(&:to_liquid),
-            "documents"    => documents,
-            "data"         => site_data
-        }))
-      }
     end
 
     # Get the implementation class for the given Converter.

lib/jekyll/url.rb

@@ -59,6 +59,14 @@ module Jekyll
     #
     # Returns the unsanitized String URL
     def generate_url(template)
+      if @placeholders.is_a? Drops::UrlDrop
+        generate_url_from_drop(template)
+      else
+        generate_url_from_hash(template)
+      end
+    end
+
+    def generate_url_from_hash(template)
       @placeholders.inject(template) do |result, token|
         break result if result.index(':').nil?
         if token.last.nil?
@@ -70,6 +78,12 @@ module Jekyll
       end
     end
 
+    def generate_url_from_drop(template)
+      template.gsub(/(:[a-z_]+)/) do |match|
+        @placeholders.public_send(match.sub(':', ''))
+      end.gsub(/\/\//, '/')
+    end
+
     # Returns a sanitized String URL, stripping "../../" and multiples of "/",
     # as well as the beginning "/" so we can enforce and ensure it.