Class: Helpers::BufferedLogger

Inherits:
Logger
  • Object
show all
Defined in:
lib/helpers/buffered_logger.rb

Instance Method Summary collapse

Constructor Details

#initialize(logdev, shift_age = 0, shift_size = 1048576) ⇒ BufferedLogger

:call-seq:

Logger.new(name, shift_age = 7, shift_size = 1048576)
Logger.new(name, shift_age = 'weekly')

Args

logdev

The log device. This is a filename (String) or IO object (typically STDOUT, STDERR, or an open file).

shift_age

Number of old log files to keep, or frequency of rotation (daily, weekly or monthly).

shift_size

Maximum logfile size (only applies when shift_age is a number).

Description

Create an instance.



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# File 'lib/helpers/buffered_logger.rb', line 28

def initialize(logdev, shift_age = 0, shift_size = 1048576)
  super
  if logdev == STDOUT
    @stdout = STDOUT
  end

  @last_messages = RingBuffer.new(200)
end

Instance Method Details

#add(severity, message = nil, progname = nil, &block) ⇒ Object

:call-seq:

Logger#add(severity, message = nil, progname = nil) { ... }

Args

severity

Severity. Constants are defined in Logger namespace: DEBUG, INFO, WARN, ERROR, FATAL, or UNKNOWN.

message

The log message. A String or Exception.

progname

Program name string. Can be omitted. Treated as a message if no message and block are given.

block

Can be omitted. Called to get a message string if message is nil.

Return

When the given severity is not high enough (for this particular logger), log no message, and return true. Even if the severity is not high enough we save each message in a ring buffer.

Description

Log a message if the given severity is high enough. This is the generic logging method. Users will be more inclined to use #debug, #info, #warn, #error, and #fatal.

Message format: message can be any object, but it has to be converted to a String in order to log it. Generally, inspect is used if the given object is not a String. A special case is an Exception object, which will be printed in detail, including message, class, and backtrace. See #msg2str for the implementation if required.

Bugs

  • Logfile is not locked.

  • Append open does not need to lock file.

  • If the OS supports multi I/O, records possibly may be mixed.



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# File 'lib/helpers/buffered_logger.rb', line 79

def add(severity, message = nil, progname = nil, &block)
  super
  severity ||= UNKNOWN
  progname ||= @progname
  if message.nil?
    if block_given?
      message = yield
    else
      message = progname
      progname = @progname
    end
  end
  @last_messages.push(format_message(format_severity(severity), Time.now, progname, message))
  @stdout.flush if @stdout
  true
end

#last_messages ⇒ Object

Return

Get array of last log messages. Even log messages with low severity are included. The number of returned messages is limited by the size of the underlying ring buffer.

Description

After calling this method the underling ring buffer is empty.



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# File 'lib/helpers/buffered_logger.rb', line 106

def last_messages
  @last_messages.flush
end