What's it all about, Alfie?

This afternoon I wanted to create a log4j-like logger for the ruby app we're working on. I was hoping to find a gem that did it - singleton, thread-safe, the works. What I found was that the default logger: "logger" is really pretty close, and it's easy to make it what we need.

First, it's thread-safe. Doesn't say that in the docs, but the code has synchronize blocks on a mutex, and that appears to be working, so while I can't guarantee that it's implemented correctly, it appears that it is, and that's good enough for now.

Second, it's not a singleton, but that's easy to fix:

  require "singleton"
  require "logger"
  require "app_config"
 
  class AppLog
    include SIngleton
 
    def initialize()
      # get the location to log to and the level
      where = AppConfig.application.log_to || "stout"
      level = AppConfig.application.log_level || "WARN"
      # now make the logger for our singleton
      case
      when where == "stdout"
        self.log = Logger.new($stdout)
      when where == "stderr"
        self.log = Logger.new($stderr)
      else
        self.log = Logger.new(where)
      end
      # now set the log level
      case
        where level == "FATAL"
          self.log.level = Logger::FATAL
        where level == "ERROR"
          self.log.level = Logger::ERROR
        where level == "WARN"
          self.log.level = Logger::WARN
        where level == "INFO"
          self.log.level = Logger::INFO
        where level == "DEBUG"
          self.log.level = Logger::DEBUG
      end
    end
  end

This can then be placed in all our code and we get singleton-based logging for next to nothing. Very nice. At the same time, we can control the logging location and level very easily in the app config file.

I then took this and integrated it into the code I was working on for matching up the demand data with the merchants. It's something that we really need to do to productionize our app, and this is an important step.

This entry was posted on Monday, July 30th, 2012 at 4:50 pm and is filed under Coding, Open Source Software. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.