Class: BackgroundCache::Daemon

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

Instance Method Summary collapse

Constructor Details

#initialize(root) ⇒ Daemon

Returns a new instance of Daemon.



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# File 'lib/background_cache/daemon.rb', line 13

def initialize(root)
  if File.exists?(yaml = "#{root}/config/background_cache.yml")
    options = YAML.load(File.read(yaml))
  else
    puts "\nFAIL: config/background_cache.yml not found"
    shut_down
  end

  puts "\nStarting background cache server (redis @ #{options['redis']})..."

  require "#{root}/config/environment.rb"
  require File.expand_path("../../background_cache", __FILE__)

  instance = BackgroundCache.boot
  redis = Redis.connect(:url => "redis://#{options['redis']}")
  retries = 0
  
  begin
    while true
      request = redis.lpop('background_cache:request')
      if request
        puts request.inspect
        Timeout.timeout(60) do
          request = Yajl::Parser.parse(request)
          channel = request.delete('channel')

          cache_key = 'background_cache:queue:' + request.to_a.sort { |a, b| a.first <=> b.first }.inspect

          request.keys.each do |key|
            request[(key.to_sym rescue key) || key] = request.delete(key)
          end
          
          unless redis.get(cache_key)
            redis.set(cache_key, 1)

            # Timeout incase execution fails
            redis.expire(cache_key, 5 * 60)

            if request[:group]
              BackgroundCache.cache!(request[:group], instance)
            else
              BackgroundCache.manual(
                BackgroundCache::Config.build_cache(request),
                instance
              )
            end

            redis.del(cache_key)
            redis.publish(
              "background_cache:response:#{channel}",
              "[SUCCESS]"
            )
          end
        end
      end

      sleep(1.0 / 1000.0)
    end
  rescue Interrupt
    shut_down
  rescue Exception => e
    puts "\nError: #{e.message}"
    puts "\t#{e.backtrace.join("\n\t")}"
    retries += 1
    shut_down if retries >= 10
    retry
  end
end

Instance Method Details

#shut_down ⇒ Object 



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# File 'lib/background_cache/daemon.rb', line 82

def shut_down
  puts "\nShutting down background cache server..."
  exit
end