PDF Concatenation with Prawn - Slow Example

prawn-concatenate-example.rb

require 'rubygems'
require 'benchmark'
require 'bundler'
Bundler.setup
require 'prawn'
require 'ruby-debug'

sources = ['ML091590492.pdf', 'file1.pdf', 'file2.pdf']

document = Prawn::Document.new(:template => sources.first)

sources[1..(sources.length - 1)].each do |file|
  document.go_to_page(document.page_count)
  object_store = Prawn::Core::ObjectStore.new(:template => file)
  num_pages = object_store.page_count
  (1..num_pages).each do |page_number|
    document.start_new_page(:template => file, :template_page => page_number)
  end
end

document.render_file('out.pdf')

it's a bit faster if you load the first document as a template