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ruby--ruby/lib/logger.rb
nahi c40f4227f5 * lib/logger.rb: Comment fix. I don't like inline documentation... Hard to
maintain, doesn't go together with refactoring.  [defensively]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4570 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2003-09-18 07:58:09 +00:00

574 lines
14 KiB
Ruby

# Logger -- Logging utility.
#
# $Id$
#
# This module is copyrighted free software by NAKAMURA, Hiroshi.
# You can redistribute it and/or modify it under the same term as Ruby.
#
# See Logger at first.
# DESCRIPTION
# Logger -- Logging utility.
#
# How to create a logger.
# 1. Create logger which logs messages to STDERR/STDOUT.
# logger = Logger.new(STDERR)
# logger = Logger.new(STDOUT)
#
# 2. Create logger for the file which has the specified name.
# logger = Logger.new('logfile.log')
#
# 3. Create logger for the specified file.
# file = open('foo.log', File::WRONLY | File::APPEND)
# # To create new (and to remove old) logfile, add File::CREAT like;
# # file = open('foo.log', File::WRONLY | File::APPEND | File::CREAT)
# logger = Logger.new(file)
#
# 4. Create logger which ages logfile automatically. Leave 10 ages and each
# file is about 102400 bytes.
# logger = Logger.new('foo.log', 10, 102400)
#
# 5. Create logger which ages logfile daily/weekly/monthly automatically.
# logger = Logger.new('foo.log', 'daily')
# logger = Logger.new('foo.log', 'weekly')
# logger = Logger.new('foo.log', 'monthly')
#
# How to log a message.
#
# 1. Message in block.
# logger.fatal { "Argument 'foo' not given." }
#
# 2. Message as a string.
# logger.error "Argument #{ @foo } mismatch."
#
# 3. With progname.
# logger.info('initialize') { "Initializing..." }
#
# 4. With severity.
# logger.add(Logger::FATAL) { 'Fatal error!' }
#
# How to close a logger.
#
# logger.close
#
# Setting severity threshold.
#
# 1. Original interface.
# logger.level = Logger::WARN
#
# 2. Log4r (somewhat) compatible interface.
# logger.level = Logger::INFO
#
# DEBUG < INFO < WARN < ERROR < FATAL < UNKNOWN
#
# Format.
#
# Log format:
# SeverityID, [Date Time mSec #pid] SeverityLabel -- ProgName: message
#
# Log sample:
# I, [Wed Mar 03 02:34:24 JST 1999 895701 #19074] INFO -- Main: info.
#
class Logger
/: (\S+),v (\S+)/ =~ %q$Id$
ProgName = "#{$1}/#{$2}"
class Error < RuntimeError; end
class ShiftingError < Error; end
# Logging severity.
module Severity
DEBUG = 0
INFO = 1
WARN = 2
ERROR = 3
FATAL = 4
UNKNOWN = 5
end
include Severity
# Logging severity threshold.
attr_accessor :level
# Logging program name.
attr_accessor :progname
# Logging date-time format (string passed to strftime)
attr_accessor :datetime_format
alias sev_threshold level
alias sev_threshold= level=
def debug?; @level <= DEBUG; end
def info?; @level <= INFO; end
def warn?; @level <= WARN; end
def error?; @level <= ERROR; end
def fatail?; @level <= FATAL; end
# SYNOPSIS
# Logger.new(name, shift_age = 7, shift_size = 1048576)
#
# ARGS
# log String as filename of logging.
# or
# IO as logging device(i.e. STDERR).
# shift_age An Integer Num of files you want to keep aged logs.
# 'daily' Daily shifting.
# 'weekly' Weekly shifting (Every monday.)
# 'monthly' Monthly shifting (Every 1th day.)
# shift_size Shift size threshold when shift_age is an integer.
# Otherwise (like 'daily'), shift_size will be ignored.
#
# DESCRIPTION
# Create an instance.
#
def initialize(logdev, shift_age = 0, shift_size = 1048576)
@logdev = nil
@progname = nil
@level = DEBUG
@datetime_format = nil
@logdev = LogDevice.new(logdev, :shift_age => shift_age, :shift_size => shift_size) if logdev
end
# SYNOPSIS
# Logger#add(severity, msg = nil, progname = nil) { ... } = nil
#
# ARGS
# severity Severity. Constants are defined in Logger namespace.
# DEBUG, INFO, WARN, ERROR, FATAL, or UNKNOWN.
# msg Message. A string, exception, or something. Can be omitted.
# progname Program name string. Can be omitted.
# Logged as a msg if no msg and block are given.
# block Can be omitted.
# Called to get a message string if msg is nil.
#
# RETURN
# true if succeed, false if failed.
# When the given severity is not enough severe,
# Log no message, and returns true.
#
# DESCRIPTION
# Log a log if the given severity is enough severe.
#
# BUGS
# Logfile is not locked.
# Append open does not need to lock file.
# But on the OS which supports multi I/O, records possibly be mixed.
#
def add(severity, msg = nil, progname = nil, &block)
severity ||= UNKNOWN
if @logdev.nil? or severity < @level
return true
end
progname ||= @progname
if msg.nil?
if block_given?
msg = yield
else
msg = progname
progname = @progname
end
end
@logdev.write(
format_message(
format_severity(severity),
format_datetime(Time.now),
msg2str(msg),
progname
)
)
true
end
alias log add
# SYNOPSIS
# Logger#debug(progname = nil) { ... } = nil
# Logger#info(progname = nil) { ... } = nil
# Logger#warn(progname = nil) { ... } = nil
# Logger#error(progname = nil) { ... } = nil
# Logger#fatal(progname = nil) { ... } = nil
# Logger#unknown(progname = nil) { ... } = nil
#
# ARGS
# progname Program name string. Can be omitted.
# Logged as a msg if no block are given.
# block Can be omitted.
# Called to get a message string if msg is nil.
#
# RETURN
# See Logger#add .
#
# DESCRIPTION
# Log a log.
#
def debug(progname = nil, &block)
add(DEBUG, nil, progname, &block)
end
def info(progname = nil, &block)
add(INFO, nil, progname, &block)
end
def warn(progname = nil, &block)
add(WARN, nil, progname, &block)
end
def error(progname = nil, &block)
add(ERROR, nil, progname, &block)
end
def fatal(progname = nil, &block)
add(FATAL, nil, progname, &block)
end
def unknown(progname = nil, &block)
add(UNKNOWN, nil, progname, &block)
end
# SYNOPSIS
# Logger#close
#
# DESCRIPTION
# Close the logging device.
#
def close
@logdev.close if @logdev
end
private
# Severity label for logging. (max 5 char)
SEV_LABEL = %w(DEBUG INFO WARN ERROR FATAL ANY);
def format_severity(severity)
SEV_LABEL[severity] || 'UNKNOWN'
end
def format_datetime(datetime)
if @datetime_format.nil?
datetime.strftime("%Y-%m-%dT%H:%M:%S.") << "%6d " % datetime.usec
else
datetime.strftime(@datetime_format)
end
end
def format_message(severity, timestamp, msg, progname)
line = '%s, [%s#%d] %5s -- %s: %s' << "\n"
line % [severity[0..0], timestamp, $$, severity, progname, msg]
end
def msg2str(msg)
if msg.is_a?(::String)
msg
elsif msg.is_a?(::Exception)
"#{ msg.message } (#{ msg.class })\n" << (msg.backtrace || []).join("\n")
elsif msg.respond_to?(:to_str)
msg.to_str
else
msg.inspect
end
end
# LogDevice -- Logging device.
class LogDevice
attr_reader :dev
attr_reader :filename
# SYNOPSIS
# Logger::LogDev.new(name, opt = {})
#
# ARGS
# log String as filename of logging.
# or
# IO as logging device(i.e. STDERR).
# opt Hash of options.
#
# DESCRIPTION
# Log device class. Output and shifting of log.
# When a String was given, LogDevice opens the file and set sync = true.
#
# OPTIONS
# :shift_age
# An Integer Num of files you want to keep aged logs.
# 'daily' Daily shifting.
# 'weekly' Weekly shifting (Shift every monday.)
# 'monthly' Monthly shifting (Shift every 1th day.)
#
# :shift_size Shift size threshold when :shift_age is an integer.
# Otherwise (like 'daily'), it is ignored.
#
def initialize(log = nil, opt = {})
@dev = @filename = @shift_age = @shift_size = nil
if log.is_a?(IO)
@dev = log
elsif log.is_a?(String)
@dev = open_logfile(log)
@dev.sync = true
@filename = log
@shift_age = opt[:shift_age] || 7
@shift_size = opt[:shift_size] || 1048576
else
raise ArgumentError.new("Wrong argument: #{ log } for log.")
end
end
# SYNOPSIS
# Logger::LogDev#write(message)
#
# ARGS
# message Message to be logged.
#
# DESCRIPTION
# Log a message. If needed, the log device is aged and the new device
# is prepared. Log device is not locked. Append open does not need to
# lock file but on the OS which supports multi I/O, records possibly be
# mixed.
#
def write(message)
if shift_log?
begin
shift_log
rescue
raise Logger::ShiftingError.new("Shifting failed. #{$!}")
end
end
@dev.write(message)
end
# SYNOPSIS
# Logger::LogDev#close
#
# DESCRIPTION
# Close the logging device.
#
def close
@dev.close
end
private
def open_logfile(filename)
if (FileTest.exist?(filename))
open(filename, (File::WRONLY | File::APPEND))
else
create_logfile(filename)
end
end
def create_logfile(filename)
logdev = open(filename, (File::WRONLY | File::APPEND | File::CREAT))
add_log_header(logdev)
logdev
end
def add_log_header(file)
file.write(
"# Logfile created on %s by %s\n" % [Time.now.to_s, Logger::ProgName]
)
end
SiD = 24 * 60 * 60
def shift_log?
if !@shift_age or !@dev.respond_to?(:stat)
return false
end
if (@shift_age.is_a?(Integer))
# Note: always returns false if '0'.
return (@filename && (@shift_age > 0) && (@dev.stat.size > @shift_size))
else
now = Time.now
limit_time = case @shift_age
when /^daily$/
eod(now - 1 * SiD)
when /^weekly$/
eod(now - ((now.wday + 1) * SiD))
when /^monthly$/
eod(now - now.mday * SiD)
else
now
end
return (@dev.stat.mtime <= limit_time)
end
end
def shift_log
# At first, close the device if opened.
if @dev
@dev.close
@dev = nil
end
if (@shift_age.is_a?(Integer))
(@shift_age-3).downto(0) do |i|
if (FileTest.exist?("#{@filename}.#{i}"))
File.rename("#{@filename}.#{i}", "#{@filename}.#{i+1}")
end
end
File.rename("#{@filename}", "#{@filename}.0")
else
now = Time.now
postfix_time = case @shift_age
when /^daily$/
eod(now - 1 * SiD)
when /^weekly$/
eod(now - ((now.wday + 1) * SiD))
when /^monthly$/
eod(now - now.mday * SiD)
else
now
end
postfix = postfix_time.strftime("%Y%m%d") # YYYYMMDD
age_file = "#{@filename}.#{postfix}"
if (FileTest.exist?(age_file))
raise RuntimeError.new("'#{ age_file }' already exists.")
end
File.rename("#{@filename}", age_file)
end
@dev = create_logfile(@filename)
return true
end
def eod(t)
Time.mktime(t.year, t.month, t.mday, 23, 59, 59)
end
end
# DESCRIPTION
# Application -- Add logging support to your application.
#
# USAGE
# 1. Define your application class as a sub-class of this class.
# 2. Override 'run' method in your class to do many things.
# 3. Instanciate it and invoke 'start'.
#
# EXAMPLE
# class FooApp < Application
# def initialize(foo_app, application_specific, arguments)
# super('FooApp') # Name of the application.
# end
#
# def run
# ...
# log(WARN, 'warning', 'my_method1')
# ...
# @log.error('my_method2') { 'Error!' }
# ...
# end
# end
#
# status = FooApp.new(....).start
#
class Application
include Logger::Severity
attr_reader :appname
attr_reader :logdev
# SYNOPSIS
# Application.new(appname = '')
#
# ARGS
# appname Name String of the application.
#
# DESCRIPTION
# Create an instance. Log device is STDERR by default.
#
def initialize(appname = nil)
@appname = appname
@log = Logger.new(STDERR)
@log.progname = @appname
@level = @log.level
end
# SYNOPSIS
# Application#start
#
# DESCRIPTION
# Start the application.
#
# RETURN
# Status code.
#
def start
status = -1
begin
log(INFO, "Start of #{ @appname }.")
status = run
rescue
log(FATAL, "Detected an exception. Stopping ... #{$!} (#{$!.class})\n" << $@.join("\n"))
ensure
log(INFO, "End of #{ @appname }. (status: #{ status.to_s })")
end
status
end
# SYNOPSIS
# Application#set_log(log, shift_age, shift_size)
#
# ARGS
# (Args are explained in the class Logger)
#
# DESCRIPTION
# Set the log device for this application.
#
def set_log(logdev, shift_age = 0, shift_size = 102400)
@log = Logger.new(logdev, shift_age, shift_size)
@log.progname = @appname
@log.level = @level
end
def log=(logdev)
set_log(logdev)
end
# SYNOPSIS
# Application#level=(severity)
#
# ARGS
# level Severity threshold.
#
# DESCRIPTION
# Set severity threshold.
#
def level=(level)
@level = level
@log.level = @level
end
protected
# SYNOPSIS
# Application#log(severity, comment = nil) { ... }
#
# ARGS
# severity Severity. See above to give this.
# comment Message String.
# block Can be omitted. Called to get a message String if
# comment is nil or omitted.
#
# DESCRIPTION
# Log a log if the given severity is enough severe.
# For more detail, see Log.add.
#
# RETURN
# true if succeed, false if failed.
# When the given severity is not enough severe,
# Log no message, and returns true.
#
def log(severity, message = nil, &block)
@log.add(severity, message, @appname, &block) if @log
end
private
def run
raise RuntimeError.new('Method run must be defined in the derived class.')
end
end
end