Threads + Mutext

Thread_Mutext.rb

desc 'Video thumbnails'
task video_thumbnails_ping: :environment do
  p 'video_thumbnails_ping START'
  t1 = Time.now
 
  THREAD_COUNT = 8  # tweak this number for maximum performance.
  MAX_COUNT = 5000
 
  thumbnails = Thumbnail.last(MAX_COUNT).pluck(:id, :combined_url_2, :combined_url_1)
 
  tags = []
 
  mutex = Mutex.new
 
  threads = Array.new(THREAD_COUNT).map do
    Thread.new(thumbnails, tags) do |urls, tags|
 
      while thumbnail = mutex.synchronize { urls.pop }
        id          = thumbnail[0]
        _url_1      = thumbnail[1]
        _url_2      = thumbnail[2]
        length      = nil
        correct_url = nil
 
        conn = Faraday.head(_url_1)
 
        if conn.status == 200
          length      = conn.headers['content-length'].to_i
          correct_url = _url_1
        else
          conn = Faraday.head(_url_2)
 
          if conn.status == 200
            length      = conn.headers['content-length'].to_i
            correct_url = _url_2
          end
        end
 
        mutex.synchronize do
          tags << { id: id, length: length, url: correct_url }
        end
      end
 
    end
  end
 
  threads.each(&:join)
 
  t2 = Time.now
  p '---------------'
  p t2 - t1
  p '---------------'
 
 
  tags.each do |hash|
    thumbnail = Thumbnail.find_by(id: hash[:id])
 
    if thumbnail.blank?
      p "ERROR: #{ hash[:id] } NOT FOUND"
      next
    end
 
    thumbnail.update(length: hash[:length], file_name: hash[:url])
  end
end
 
 
# Thumbnail.where(file_name: nil)
# Thumbnail.where("length > 10_000_000") # 10 MB