Class: Copland::LogFactory

Inherits:
Object
  • Object
show all
Defined in:
lib/copland/log-factory.rb

Overview

A factory class that returns Logger instances. The LogFactory is not a singleton for the same reason that Copland::Registry is not a singleton–the allow multiple registries to exist simultaneously. Since each registry has its own logger factory, the logger factory must be separately instantiable.

Constant Summary collapse

DEFAULT_CONFIG_FILE =

The default name of the logger configuration file. This file will be used to read default properties for initializing logger objects.

"./logger.yml"
DEFAULT_LOG_FILENAME =

The default name of the log file to write to.

"./copland.log"
LEVEL_TRANSLATOR =

Translate names of levels to their actual values.

{
  "DEBUG" => Logger::DEBUG,
  "INFO" => Logger::INFO,
  "WARN" => Logger::WARN,
  "ERROR" => Logger::ERROR,
  "FATAL" => Logger::FATAL,
  "UNKNOWN" => Logger::UNKNOWN
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ LogFactory

Create a new LogFactory using the given initialization parameters. The valid options are:

  • :config_file: the configuration file from which to read logger configuration options.

  • :device: the device (pseudo-IO object) to write log messages to. Either this, or :filename must be specified.

  • :filename: the filename of the log to write to.

  • :roll_age: the number of days before the log should be rolled.

  • :roll_frequency: either ‘daily’, ‘weekly’, or ‘monthly’.

  • :roll_size: the maximum size of a log file.

  • :default_format: the default date format string for the log.

  • :default_level: the default log level for the log.

  • :levels: a hash of patterns that map to a hash of ‘level’ and ‘format’ keys, specifying the log level and date format for any log whose name matches the key.



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# File 'lib/copland/log-factory.rb', line 90

def initialize( opts={} )
  opts[ :config_file ] ||= DEFAULT_CONFIG_FILE
  read_config opts

  if opts[ :device ]
    @device = opts[ :device ]
  else
    filename = opts[ :filename ] || DEFAULT_LOG_FILENAME
    roll_age = opts[ :roll_age ] || opts[ :roll_frequency ] || 0
    roll_size = opts[ :roll_size ]
    @device = Logger::LogDevice.new( filename,
                  :shift_age => roll_age,
                  :shift_size => roll_size )
  end

  @default_format = opts[ :default_format ]
  @default_level = opts[ :default_level ]

  @levels = Hash.new "level" => nil, "format" => nil 

  ( opts[ :levels ] || Hash.new ).each_pair do |key, value|
    key = Regexp.new( "^" + key.gsub( /\./, "\\." ).gsub( /\*/, ".*" ) )
    value = { "level" => value } if value.is_a? String
    @levels[ key ] = value
  end

  @loggers = Hash.new

  @mutex = Mutex.new
end

Instance Attribute Details

#default_format ⇒ Object (readonly)

The default (date) format string to use when logging.



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# File 'lib/copland/log-factory.rb', line 65

def default_format
  @default_format
end

#default_level ⇒ Object (readonly)

The default log level to use for logs that are created.



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# File 'lib/copland/log-factory.rb', line 68

def default_level
  @default_level
end

#device ⇒ Object (readonly)

The device that logs will write to.



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# File 'lib/copland/log-factory.rb', line 71

def device
  @device
end

Instance Method Details

#close ⇒ Object

Closes the logging device and makes this factory invalid for future accesses.



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# File 'lib/copland/log-factory.rb', line 188

def close
  @mutex.synchronize do
    return if @closed

    @device.close unless [ $stdout, $stderr ].include?( @device )

    @loggers = nil
    @closed = true
  end
end

#closed? ⇒ Boolean

Returns true if the factory has been closed.

Returns:

  • (Boolean) 


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# File 'lib/copland/log-factory.rb', line 200

def closed?
  @closed
end

#get(name) ⇒ Object

Retrieves the logger with the given name. If no such log has been created, the log will be created and initialized. Otherwise, the log with the given name is returned.



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# File 'lib/copland/log-factory.rb', line 161

def get( name )
  # the common case first, outside the synchronize, for speed
  return @loggers[ name ] if @loggers[ name ]

  @mutex.synchronize do
    # check again, inside the synchronize, to avoid race conditions
    return @loggers[ name ] if @loggers[ name ]

    definition = find_definition( name )

    level = definition[ "level" ] || @default_level
    format = definition[ "format" ] || @default_format

    level = LEVEL_TRANSLATOR[ level ] || level

    logger = Logger.new( @device )
    logger.level = level if level
    logger.datetime_format = format if format
    logger.progname = name

    @loggers[ name ] = logger
    return logger
  end
end