Class: Lookout::Rack::Utils::Log::LookoutFormatter

Inherits:
Log4r::Formatter
  • Object
show all
Defined in:
lib/lookout/rack/utils/log.rb

Overview

Formatter that include the filename and relative path, and line number in output of the caller.

Since all callers go through the methods defined in this class to log, we look at the second line of the tracer output, removing everything but the directories after the project directory.

Instance Method Summary collapse

Instance Method Details

#basedir ⇒ String

Return the project base directory for filtering to help with identifiying the filename and line number when formatting the log message

Returns:

  • (String) —

    Base directory for the project



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# File 'lib/lookout/rack/utils/log.rb', line 32

def basedir
  @basedir ||= File.expand_path(File.join(File.dirname(__FILE__), ".."))
end

#common_basedir(tracer) ⇒ String

Return the common base directory between this project and the given trace. If no common base directory is found, return basedir.

This memoizes the result, which can be bad if the first log comes from an unusual place. However, in all current uses this is running from an unpacked jar/war and its vastly faster to memoize the result.

Parameters:

  • tracer (String) —

    A line from the LogEvent#tracer Array

Returns:

  • (String) —

    Common base directory with the trace



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# File 'lib/lookout/rack/utils/log.rb', line 47

def common_basedir(tracer)
  return @common_basedir if @common_basedir

  basedir_pieces = basedir.split(File::SEPARATOR)
  trace_pieces = tracer.split(File::SEPARATOR)
  i = 0
  while basedir_pieces[i] == trace_pieces[i]
    i += 1
  end
  # If there were no common directories (besides /), return our basedir
  @common_basedir = (i <= 1) ? basedir : basedir_pieces[0...i].join(File::SEPARATOR)
end

#event_filename(tracer) ⇒ String

Return a trimmed version of the filename from where a LogEvent occurred

Parameters:

  • tracer (String) —

    A line from the LogEvent#tracer Array

Returns:

  • (String) —

    Trimmed and parsed version of the file ane line number



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# File 'lib/lookout/rack/utils/log.rb', line 63

def event_filename(tracer)
  base = common_basedir(tracer)
  parts = tracer.match(/#{base}\/(.*:[0-9]+).*:/)

  # If we get no matches back, we're probably in a jar file in which case
  # the format of the tracer is going to be abbreviated
  if parts.nil?
    parts = tracer.match(/(.*:[0-9]+).*:/)
  end
  return parts[-1] if parts
end

#format(event) ⇒ String

Receive the LogEvent and pull out the log message and format it for display in the logs

Parameters:

  • event (Log4r::LogEvent)

Returns:

  • (String) —

    Formatted log message



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# File 'lib/lookout/rack/utils/log.rb', line 80

def format(event)
  filename = event_filename(event.tracer[1])
  # CCYY-MM-DDThh:mm:ss.sssTZD
  time = Time.now.utc.iso8601 3
  return "#{Log4r::LNAMES[event.level]}: #{time}: #{filename}: #{event.data}\n"
end