Unzipping a file to parse and save dat from each file using nokogiri is time consuming as there are 739 files and each of 1.2-1.5 mb which comes down to total as 1.2 GB.This operation runs as a background job using redis-resque.

journey_planner

require 'open-uri'  #Open-uri is a part of ruby standard library. It just need to be required when used.
require 'zip/zip'
require 'active_support/core_ext'
require 'nokogiri'

class JourneyPlanner
  @queue = :journey_planner
  
  class << self
    def perform
      
      zipfilename = download_file_from_url
      Zip::ZipFile.open(zipfilename) do |zipfile|
        zipfile.each do |entry|
          
          xml = zipfile.read(entry) 
          xml_to_hash = get_the_hash_from_xml(xml)
          
          journey_status_details_hash = xml_to_hash[:TransXChange]
          AnnotatedStopPointRef.create_stop_points(journey_status_details_hash[:StopPoints])
          JourneyPatternSection.create_journey_pattern_sections(journey_status_details_hash[:JourneyPatternSections])
          Operator.create_operators(journey_status_details_hash[:Operators])
          Route.create_routes(journey_status_details_hash[:Routes])
          RouteSection.create_route_sections(journey_status_details_hash[:RouteSections])
          Service.create_services(journey_status_details_hash[:Services])
          VehicleJourney.create_vehicle_journeys(journey_status_details_hash[:VehicleJourneys])
      
        end
      end
        
    end
  
    def get_the_hash_from_xml(xml_io) 
      begin
        result = Nokogiri::XML(xml_io)
        return { result.root.name.to_sym => xml_node_to_hash(result.root)} 
      rescue Exception => e
        # raise the custom exception here
      end
    end
    
    def download_file_from_url
      begin
        zip_file_from_url = open('http://www.tfl.gov.uk/tfl/businessandpartners/syndication/feed.aspx?email=rajashekaran@sourcebits.com&feedId=15')
        return zip_file_from_url  
      rescue Exception => e
        #raise the custom exception here 
    end   
    
    def xml_node_to_hash(node) 
        # If we are at the root of the document, start the hash 
      if node.element?
        result_hash = {} 
       
        if node.children.size > 0
          node.children.each do |child| 
            result = xml_node_to_hash(child) 
  
            if child.name == "text"
              unless child.next_sibling || child.previous_sibling
                return prepare(result)
              end
            elsif result_hash[child.name.to_sym]
              if result_hash[child.name.to_sym].is_a?(Object::Array)
                result_hash[child.name.to_sym] << prepare(result)
              else
                result_hash[child.name.to_sym] = [result_hash[child.name.to_sym]] << prepare(result)
              end
            else 
              result_hash[child.name.to_sym] = prepare(result)
            end
          end
  
          return result_hash 
        else 
          return result_hash
        end 
      else 
        return prepare(node.content.to_s) 
      end 
    end          

    def prepare(data)
      (data.class == String && data.to_i.to_s == data) ? data.to_i : data
    end
    
  end
end