Optimized version of my super-fancy tree generator.

tree_generator_optimized.rb

module TreeGeneratorOptimized
  def self.generate_tree
    pages = all.select('id, name, depth, parent_id, sort_order').order('sort_order ASC')
    ordered_pages = ActiveSupport::OrderedHash.new

    parent_hash = Hash.new
    pages.each do |page|
      parent_hash[page.parent_id] = Array.new if parent_hash[page.parent_id].nil?
      parent_hash[page.parent_id].push(page) unless page.nil?
    end

    pages.each do |page|
      ordered_pages[page.id] = {page: page, children: generate_children_optimized(page, parent_hash)} if page.depth == 0
    end

    ordered_pages
  end
  
  protected
  
  def self.generate_children_optimized(page, page_hash)
    children = ActiveSupport::OrderedHash.new
    if page_hash.has_key?(page.id)
      page_hash[page.id].each {|p| children[p.id] = {page: p, children: generate_children_optimized(p, page_hash)} }
    end

    children
  end
end