Class: TinyLog

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

Overview

This class provides a simple logging utility with some metadata attached:

  • timestamp to the microsecond

  • the process ID

  • logger level

  • the log message

Ex:

l = Log.new
l.erro('hi there')
l.erro('hi there')
2022-11-18T01:26:37.086295Z  92967 ERRO hi there
^timestamp to microsecond    ^pid  ^lvl ^log message

Instance Method Summary collapse

Constructor Details

#initialize(filename: nil, buffering: true, background_thread: true) ⇒ TinyLog

filename: the I/O stream to send log messages to

if unspecified, will default to $stdout
if specified, attempts to open a file with the specified name to append to

buffering: whether or not to buffer log output

true, or not specified: log buffering is enabled
false: log buffering is disabled - most useful for dev/test environments
  where you want to watch output in realtime

background_thread: whether logging should be done in a background Thread

true, or not specified, use a Thread to write to the log every 5 seconds
false, write to the log immediately



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# File 'lib/tiny_log.rb', line 26

def initialize(filename: nil, buffering: true, background_thread: true)
  @buffering = !!buffering
  @io = filename.is_a?(String) ? File.open(filename, 'a') : $stdout

  if background_thread
    @msg_queue = Queue.new
    @background_thread = Thread.new do |t|
      loop do
        @msg_queue
          .length
          .times{ @io.puts @msg_queue.shift }
        sleep 5
      end
    end
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(prefix, *msgs) ⇒ Object

the clever bit that annotates the log message with a log level and UTC timestamp



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# File 'lib/tiny_log.rb', line 45

def method_missing(prefix, *msgs)
  msgs.each{|m| _build_lines(m).each{|l| @background_thread ? @msg_queue << l : @io.puts(l) } }
  @io.flush unless @buffering

  nil
end

Instance Method Details

#_build_lines(m) ⇒ Object 



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# File 'lib/tiny_log.rb', line 52

def _build_lines(m)
  m.to_s.lines.map do |l|
    "#{Time.now.utc.iso8601(6)} #{Process.pid.to_s.rjust(6)} #{prefix.to_s.upcase} #{l}"
  end
end