TagSetPresenter: refactor humanized_essential_tag_string.

Move Post#humanized_essential_tag_string to TagSetPresenter#humanized_essential_tag_string.

This allows humanized_essential_tag_string to reuse the same set of tags
already fetched by the tag set presenter for the sidebar.

This avoids fetching the tag categories from memcache again (via
Post#typed_tags) when we're already fetched the tags once before.

This also means it's no longer necessary to cache humanized_essential_tag_string
itself in memcache, since it can be generated as quickly as the sidebar taglist.

app/logical/storage_manager.rb

@@ -115,7 +115,7 @@ class StorageManager
   def seo_tags(post)
     return "" if !tagged_filenames
 
-    tags = post.humanized_essential_tag_string.gsub(/[^a-z0-9]+/, "_").gsub(/(?:^_+)|(?:_+$)/, "").gsub(/_{2,}/, "_")
+    tags = post.presenter.humanized_essential_tag_string.gsub(/[^a-z0-9]+/, "_").gsub(/(?:^_+)|(?:_+$)/, "").gsub(/_{2,}/, "_")
     "__#{tags}__"
   end
 end

app/models/post.rb

@@ -36,7 +36,6 @@ class Post < ApplicationRecord
   after_save :create_version
   after_save :update_parent_on_save
   after_save :apply_post_metatags
-  after_save :expire_essential_tag_string_cache
   after_commit :delete_files, :on => :destroy
   after_commit :remove_iqdb_async, :on => :destroy
   after_commit :update_iqdb_async, :on => :create
@@ -936,36 +935,6 @@ class Post < ApplicationRecord
       end
     end
 
-    def expire_essential_tag_string_cache
-      Cache.delete("hets-#{id}")
-    end
-
-    def humanized_essential_tag_string
-      @humanized_essential_tag_string ||= Cache.get("hets-#{id}", 1.hour.to_i) do
-        string = []
-
-        TagCategory.humanized_list.each do |category|
-          typetags = typed_tags(category) - TagCategory.humanized_mapping[category]["exclusion"]
-          if TagCategory.humanized_mapping[category]["slice"] > 0
-            typetags = typetags.slice(0,TagCategory.humanized_mapping[category]["slice"]) + (typetags.length > TagCategory.humanized_mapping[category]["slice"] ? ["others"] : [])
-          end
-          if TagCategory.humanized_mapping[category]["regexmap"] != //
-            typetags = typetags.map do |tag|
-              tag.match(TagCategory.humanized_mapping[category]["regexmap"])[1]
-            end
-          end
-          if typetags.any?
-            if category != "copyright" || typed_tags("character").any?
-              string << TagCategory.humanized_mapping[category]["formatstr"] % typetags.to_sentence
-            else
-              string << typetags.to_sentence
-            end
-          end
-        end
-        string.empty? ? "##{id}" : string.join(" ").tr("_", " ")
-      end
-    end
-
     TagCategory.categories.each do |category|
       define_method("tag_string_#{category}") do
         typed_tags(category).join(" ")

app/presenters/post_presenter.rb

@@ -144,7 +144,7 @@ class PostPresenter < Presenter
   end
 
   def humanized_essential_tag_string
-    @post.humanized_essential_tag_string
+    @humanized_essential_tag_string ||= tag_set_presenter.humanized_essential_tag_string(default: "##{@post.id}")
   end
 
   def filename_for_download

app/presenters/tag_set_presenter.rb

@@ -61,6 +61,36 @@ class TagSetPresenter < Presenter
     end.join(" \n")
   end
 
+  def humanized_essential_tag_string(category_list: TagCategory.humanized_list, default: "")
+    strings = category_list.map do |category|
+      mapping = TagCategory.humanized_mapping[category]
+      max_tags = mapping["slice"]
+      regexmap = mapping["regexmap"]
+      formatstr = mapping["formatstr"]
+      excluded_tags = mapping["exclusion"]
+
+      type_tags = tags_for_category(category).map(&:name) - excluded_tags
+      next if type_tags.empty?
+
+      if max_tags > 0 && type_tags.length > max_tags
+        type_tags = type_tags.take(max_tags) + ["others"]
+      end
+
+      if regexmap != //
+        type_tags = type_tags.map { |tag| tag.match(regexmap)[1] }
+      end
+
+      if category == "copyright" && tags_for_category("character").blank?
+        type_tags.to_sentence
+      else
+        formatstr % type_tags.to_sentence
+      end
+    end
+
+    strings = strings.compact.join(" ").tr("_", " ")
+    strings.blank? ? default : strings
+  end
+
   private
 
   def tags
@@ -128,5 +158,5 @@ class TagSetPresenter < Presenter
     html
   end
 
-  memoize :tags, :tags_by_category, :ordered_tags
+  memoize :tags, :tags_by_category, :ordered_tags, :humanized_essential_tag_string
 end

app/views/comments/index.atom.builder

@@ -9,7 +9,7 @@ atom_feed(root_url: comments_url(host: Danbooru.config.hostname)) do |feed|
 
   @comments.each do |comment|
     feed.entry(comment, published: comment.created_at, updated: comment.updated_at) do |entry|
-      entry.title("@#{comment.creator_name} on post ##{comment.post_id} (#{comment.post.humanized_essential_tag_string})")
+      entry.title("@#{comment.creator_name} on post ##{comment.post_id} (#{comment.post.presenter.humanized_essential_tag_string})")
       entry.content(<<-EOS.strip_heredoc, type: "html")
         <img src="#{comment.post.preview_file_url}"/>