Class: CrawlJob

Inherits:
Object
  • Object
show all
Defined in:
lib/crawl_job.rb

Class Method Summary collapse

Class Method Details

.finished(content_request) ⇒ Object 



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# File 'lib/crawl_job.rb', line 83

def self.finished(content_request)
  # finished
  @stats.end_crawl(content_request)
  Resque.enqueue(const_get(content_request[:crawl_finished_queue]), Stats.get_statistics.merge({:redis_options => content_request[:redis_options], :crawl_id => content_request[:crawl_id], :source_id => content_request[:source_id]}))                
end

.perform(content_request) ⇒ Object 



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# File 'lib/crawl_job.rb', line 10

def self.perform(content_request)
  
  # change all hash keys to symbols
  content_request = self.deep_symbolize_keys(content_request)
  
  content_request[:redis_options] = {} unless content_request.has_key? :redis_options
  @redis = NamespacedRedis.new(content_request[:redis_options], "cobweb-#{Cobweb.version}-#{content_request[:crawl_id]}")
  @stats = Stats.new(content_request)
  
  @debug = content_request[:debug]
  
  refresh_counters
  
  # check we haven't crawled this url before
  unless @redis.sismember "crawled", content_request[:url]
    @redis.srem "queued", content_request[:url]
    decrement_queue_counter
    @redis.sadd "crawled", content_request[:url]
    increment_crawl_counter
    
    # if there is no limit or we're still under it lets get the url
    if within_crawl_limits?(content_request[:crawl_limit])

      content = Cobweb.new(content_request).get(content_request[:url], content_request)
      
      ## update statistics
      @stats.update_statistics(content)
      
      # set the base url if this is the first page
      set_base_url @redis, content, content_request
      
      if within_queue_limits?(content_request[:crawl_limit])
        internal_links = all_links_from_content(content).map{|link| link.to_s}
      
        # reject the link if we've crawled it or queued it
        internal_links.reject!{|link| @redis.sismember("crawled", link)}
        internal_links.reject!{|link| @redis.sismember("queued", link)}
      
        # select the link if its internal
        internal_links.select!{|link| internal_link?(link)}

        internal_links.each do |link|
          enqueue_content(content_request, link) if within_queue_limits?(content_request[:crawl_limit])
        end
      end
      
      # enqueue to processing queue
      send_to_processing_queue(content, content_request)
      
      #if the enqueue counter has been requested update that
      if content_request.has_key? :enqueue_counter_key                                                                                  
        enqueue_redis = NamespacedRedis.new(content_request[:redis_options], content_request[:enqueue_counter_namespace].to_s)
        current_count = enqueue_redis.hget(content_request[:enqueue_counter_key], content_request[:enqueue_counter_field]).to_i
        enqueue_redis.hset(content_request[:enqueue_counter_key], content_request[:enqueue_counter_field], current_count+1)
      end

      # if there's nothing left queued or the crawled limit has been reached
      if content_request[:crawl_limit].nil? || content_request[:crawl_limit] == 0
        if @redis.scard("queued") == 0
          finished(content_request)
        end
      elsif @queue_counter == 0 || @crawl_counter >= content_request[:crawl_limit].to_i
        finished(content_request)
      end
    end
  else
    @redis.srem "queued", content_request[:url]
    decrement_queue_counter
    puts "Already crawled #{content_request[:url]}" if content_request[:debug]
  end

end

.send_to_processing_queue(content, content_request) ⇒ Object 



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# File 'lib/crawl_job.rb', line 89

def self.send_to_processing_queue(content, content_request)
  content_to_send = content.merge({:internal_urls => internal_patterns, :redis_options => content_request[:redis_options], :source_id => content_request[:source_id], :crawl_id => content_request[:crawl_id]})
  if content_request[:use_encoding_safe_process_job]
    content_to_send[:body] = Base64.encode64(content[:body])
    content_to_send[:processing_queue] = content_request[:processing_queue]
    Resque.enqueue(EncodingSafeProcessJob, content_to_send)
  else
    Resque.enqueue(const_get(content_request[:processing_queue]), content_to_send)
  end
  puts "#{content_request[:url]} has been sent for processing. use_encoding_safe_process_job: #{content_request[:use_encoding_safe_process_job]}" if content_request[:debug]
  puts "Crawled: #{@crawl_counter} Limit: #{content_request[:crawl_limit]} Queued: #{@queue_counter}" if content_request[:debug]
end