Cut string allocations in content_tag_string

content_tag's first argument is will generate a string with an html tag so `:a` will generate: `<a></a>`. When this happens, the symbol is implicitly `to_s`-d so a new string is allocated. We can get around that by using a frozen string instead which

This change buys us 74,236 bytes of memory and 1,855 fewer objects per request.

6 files changed, 20 insertions, 20 deletions

diff --git a/actionview/lib/action_view/helpers/asset_tag_helper.rb b/actionview/lib/action_view/helpers/asset_tag_helper.rb
index 3041ad3ef7..e506c782d6 100644
--- a/actionview/lib/action_view/helpers/asset_tag_helper.rb
+++ b/actionview/lib/action_view/helpers/asset_tag_helper.rb
@@ -60,7 +60,7 @@ module ActionView
           tag_options = {
             "src" => path_to_javascript(source, path_options)
           }.merge!(options)
-          content_tag(:script, "", tag_options)
+          content_tag("script".freeze, "", tag_options)
         }.join("\n").html_safe
       end
 
diff --git a/actionview/lib/action_view/helpers/date_helper.rb b/actionview/lib/action_view/helpers/date_helper.rb
index fbd7261477..94fbaa2dca 100644
--- a/actionview/lib/action_view/helpers/date_helper.rb
+++ b/actionview/lib/action_view/helpers/date_helper.rb
@@ -681,7 +681,7 @@ module ActionView
         content  = args.first || I18n.l(date_or_time, :format => format)
         datetime = date_or_time.acts_like?(:time) ? date_or_time.xmlschema : date_or_time.iso8601
 
-        content_tag(:time, content, options.reverse_merge(:datetime => datetime), &block)
+        content_tag("time".freeze, content, options.reverse_merge(:datetime => datetime), &block)
       end
     end
 
@@ -809,7 +809,7 @@ module ActionView
           1.upto(12) do |month_number|
             options = { :value => month_number }
             options[:selected] = "selected" if month == month_number
-            month_options << content_tag(:option, month_name(month_number), options) + "\n"
+            month_options << content_tag("option".freeze, month_name(month_number), options) + "\n"
           end
           build_select(:month, month_options.join)
         end
@@ -971,7 +971,7 @@ module ActionView
             tag_options[:selected] = "selected" if selected == i
             text = options[:use_two_digit_numbers] ? sprintf("%02d", i) : value
             text = options[:ampm] ? AMPM_TRANSLATION[i] : text
-            select_options << content_tag(:option, text, tag_options)
+            select_options << content_tag("option".freeze, text, tag_options)
           end
 
           (select_options.join("\n") + "\n").html_safe
@@ -991,11 +991,11 @@ module ActionView
           select_options[:class] = [select_options[:class], type].compact.join(' ') if @options[:with_css_classes]
 
           select_html = "\n"
-          select_html << content_tag(:option, '', :value => '') + "\n" if @options[:include_blank]
+          select_html << content_tag("option".freeze, '', :value => '') + "\n" if @options[:include_blank]
           select_html << prompt_option_tag(type, @options[:prompt]) + "\n" if @options[:prompt]
           select_html << select_options_as_html
 
-          (content_tag(:select, select_html.html_safe, select_options) + "\n").html_safe
+          (content_tag("select".freeze, select_html.html_safe, select_options) + "\n").html_safe
         end
 
         # Builds a prompt option tag with supplied options or from default options.
@@ -1012,7 +1012,7 @@ module ActionView
               I18n.translate(:"datetime.prompts.#{type}", :locale => @options[:locale])
           end
 
-          prompt ? content_tag(:option, prompt, :value => '') : ''
+          prompt ? content_tag("option".freeze, prompt, :value => '') : ''
         end
 
         # Builds hidden input tag for date part and value.
diff --git a/actionview/lib/action_view/helpers/form_options_helper.rb b/actionview/lib/action_view/helpers/form_options_helper.rb
index 8e729b3c39..728e633bbf 100644
--- a/actionview/lib/action_view/helpers/form_options_helper.rb
+++ b/actionview/lib/action_view/helpers/form_options_helper.rb
@@ -456,7 +456,7 @@ module ActionView
           option_tags = options_from_collection_for_select(
             group.send(group_method), option_key_method, option_value_method, selected_key)
 
-          content_tag(:optgroup, option_tags, label: group.send(group_label_method))
+          content_tag("optgroup".freeze, option_tags, label: group.send(group_label_method))
         end.join.html_safe
       end
 
@@ -528,7 +528,7 @@ module ActionView
         body = "".html_safe
 
         if prompt
-          body.safe_concat content_tag(:option, prompt_text(prompt), value: "")
+          body.safe_concat content_tag("option".freeze, prompt_text(prompt), value: "")
         end
 
         grouped_options.each do |container|
@@ -541,7 +541,7 @@ module ActionView
           end
 
           html_attributes = { label: label }.merge!(html_attributes)
-          body.safe_concat content_tag(:optgroup, options_for_select(container, selected_key), html_attributes)
+          body.safe_concat content_tag("optgroup".freeze, options_for_select(container, selected_key), html_attributes)
         end
 
         body
@@ -577,7 +577,7 @@ module ActionView
           end
 
           zone_options.safe_concat options_for_select(convert_zones[priority_zones], selected)
-          zone_options.safe_concat content_tag(:option, '-------------', value: '', disabled: true)
+          zone_options.safe_concat content_tag("option".freeze, '-------------', value: '', disabled: true)
           zone_options.safe_concat "\n"
 
           zones = zones - priority_zones
diff --git a/actionview/lib/action_view/helpers/form_tag_helper.rb b/actionview/lib/action_view/helpers/form_tag_helper.rb
index 896020bc15..d36701955a 100644
--- a/actionview/lib/action_view/helpers/form_tag_helper.rb
+++ b/actionview/lib/action_view/helpers/form_tag_helper.rb
@@ -140,15 +140,15 @@ module ActionView
           end
 
           if include_blank
-            option_tags = content_tag(:option, include_blank, value: '').safe_concat(option_tags)
+            option_tags = content_tag("option".freeze, include_blank, value: '').safe_concat(option_tags)
           end
         end
 
         if prompt = options.delete(:prompt)
-          option_tags = content_tag(:option, prompt, value: '').safe_concat(option_tags)
+          option_tags = content_tag("option".freeze, prompt, value: '').safe_concat(option_tags)
         end
 
-        content_tag :select, option_tags, { "name" => html_name, "id" => sanitize_to_id(name) }.update(options.stringify_keys)
+        content_tag "select".freeze, option_tags, { "name" => html_name, "id" => sanitize_to_id(name) }.update(options.stringify_keys)
       end
 
       # Creates a standard text field; use these text fields to input smaller chunks of text like a username
@@ -568,7 +568,7 @@ module ActionView
       #   # => <fieldset class="format"><p><input id="name" name="name" type="text" /></p></fieldset>
       def field_set_tag(legend = nil, options = nil, &block)
         output = tag(:fieldset, options, true)
-        output.safe_concat(content_tag(:legend, legend)) unless legend.blank?
+        output.safe_concat(content_tag("legend".freeze, legend)) unless legend.blank?
         output.concat(capture(&block)) if block_given?
         output.safe_concat("</fieldset>")
       end
diff --git a/actionview/lib/action_view/helpers/javascript_helper.rb b/actionview/lib/action_view/helpers/javascript_helper.rb
index e237a32cb7..ed7e882c94 100644
--- a/actionview/lib/action_view/helpers/javascript_helper.rb
+++ b/actionview/lib/action_view/helpers/javascript_helper.rb
@@ -47,8 +47,8 @@ module ActionView
       # tag.
       #
       #   javascript_tag "alert('All is good')", defer: 'defer'
-      # 
-      # Returns: 
+      #
+      # Returns:
       #   <script defer="defer">
       #   //<![CDATA[
       #   alert('All is good')
@@ -70,7 +70,7 @@ module ActionView
             content_or_options_with_block
           end
 
-        content_tag(:script, javascript_cdata_section(content), html_options)
+        content_tag("script".freeze, javascript_cdata_section(content), html_options)
       end
 
       def javascript_cdata_section(content) #:nodoc:
diff --git a/actionview/lib/action_view/helpers/url_helper.rb b/actionview/lib/action_view/helpers/url_helper.rb
index 5eb1377d38..d676a0a931 100644
--- a/actionview/lib/action_view/helpers/url_helper.rb
+++ b/actionview/lib/action_view/helpers/url_helper.rb
@@ -186,7 +186,7 @@ module ActionView
         url = url_for(options)
         html_options["href".freeze] ||= url
 
-        content_tag(:a, name || url, html_options, &block)
+        content_tag("a".freeze, name || url, html_options, &block)
       end
 
       # Generates a form containing a single button that submits to the URL created
@@ -471,7 +471,7 @@ module ActionView
         encoded_email_address = ERB::Util.url_encode(email_address).gsub("%40", "@")
         html_options["href"] = "mailto:#{encoded_email_address}#{extras}"
 
-        content_tag(:a, name || email_address, html_options, &block)
+        content_tag("a".freeze, name || email_address, html_options, &block)
       end
 
       # True if the current request URI was generated by the given +options+.