Bitwise logging

gistfile1.rb

require 'pp'

class LoggingLevel
	ONE		= 1
	TWO		= 2	
	DOCUMENTS	= 4
	ATTENDANCE	= 8
	DATABASE	= 16

	@@modification_time	= nil
	@@configuration_file	= "/tmp/logging.conf"

	def self.is?(level)
		return ( ( level & @@value ) != 0 ) 
	end

	def self.value=(val); @@value = val; end
	def self.value; @@value ; end

	def self.unused_from_file_is?(level)
		mod_time = File.stat(@@configuration_file).mtime
		if @@modification_time != mod_time
			@@value = File.open(@@configuration_file) { |f| f.read }.to_i
		end
		return ( ( level & @@value ) != 0 ) 
	end
end

def display_logging
	puts "The current log value is: #{LoggingLevel.value}"

	puts "I log for ONE"	if LoggingLevel.is?(LoggingLevel::ONE)
	puts "I log for TWO"	if LoggingLevel.is?(LoggingLevel::TWO)
	puts "I log for DOCUMENTS" if LoggingLevel.is?(LoggingLevel::DOCUMENTS)
	puts "I log for ATTENDANCE" if LoggingLevel.is?(LoggingLevel::ATTENDANCE)
	puts "I log for DATABASE" if LoggingLevel.is?(LoggingLevel::DATABASE)

	puts "-" * 72
end

# Logging only 'ONE'
LoggingLevel::value = 1

display_logging

# Logging only 'TWO'

LoggingLevel::value = 2

display_logging

# Logging both 'ONE' and 'TWO'

LoggingLevel::value = 3

display_logging

# Logging  'DATABASE' and  'DOCUMENTS'

LoggingLevel::value = 20

display_logging

# Logging 'DATABASE' only

LoggingLevel::value = 16

display_logging

# Logging 'TWO' and 'ATTENDANCE'
#

LoggingLevel::value = 10

display_logging

# Turn on all logging

LoggingLevel::value = 31

display_logging