Reduce Jekyll::Renderer instances during a build

[ashmaroli]

• This is an 🙋 enhancement.

Summary

This change reduces the number of Jekyll::Renderer instances by half

Jekyll::Renderer is initialized at following places in Jekyll Core:

jekyll/lib/jekyll/convertible.rb

Lines 245 to 247 in bdbf351

	def _renderer
	@_renderer ||= Jekyll::Renderer.new(site, self)
	end

jekyll/lib/jekyll/document.rb

Lines 99 to 101 in bdbf351

	def output_ext
	@output_ext ||= Jekyll::Renderer.new(site, self).output_ext
	end

jekyll/lib/jekyll/site.rb

Lines 516 to 521 in bdbf351

	def render_regenerated(document, payload)
	return unless regenerator.regenerate?(document)
	document.output = Jekyll::Renderer.new(self, document, payload).run
	document.trigger_hooks(:post_render)
	end

In other words, a Renderer instance is created twice for every Page or Document instance — Once instance to get the renderer's attributes and the other instance to render the document.

[DirtyF]

LGTM

[mattr-]

@jekyllbot: merge +minor