class TaskJuggler::Log

The Log class implements a filter for segmented execution traces. The trace messages are filtered based on their segment name and the nesting level of the segments. The class is a Singleton, so there is only one instance in the program.

Public Class Methods

activity() click to toggle source

This function may only be called when Log#startProgressMeter has been called before. It updates the progress indicator to the next symbol to visualize ongoing activity.

# File lib/taskjuggler/Log.rb, line 143
def Log.activity
  return if @@silent

  indicator = %w( - \\ | / )
  @@progress = (@@progress.to_i + 1) % indicator.length
  $stdout.print("#{@@progressMeter} [#{indicator[@@progress]}]\r")
enter(segment, message) click to toggle source

This function is used to open a new segment. segment is the name of the segment and message is a description of it.

# File lib/taskjuggler/Log.rb, line 60
def Log.enter(segment, message)
  return if @@level == 0

  @@stack << segment
  Log.msg { ">> [#{segment}] #{message}" }
exit(segment, message = nil) click to toggle source

This function is used to close an open segment. To make this mechanism a bit more robust, it will search the stack of open segments for a segment with that name and will close all nested segments as well.

# File lib/taskjuggler/Log.rb, line 70
def Log.exit(segment, message = nil)
  return if @@level == 0

  Log.msg { "<< [#{segment}] #{message}" } if message
  if @@stack.include?(segment)
    loop do
      m = @@stack.pop
      break if m == segment
level=(l) click to toggle source

Set the maximum nesting level that should be shown. Segments with a nesting level greater than l will be silently dropped.

# File lib/taskjuggler/Log.rb, line 36
def Log.level=(l)
  @@level = l
msg() { |block| ... } click to toggle source

Use this function to show a log message within the currently active segment. The message is the result of the passed block. The block will only be evaluated if the message will actually be shown.

# File lib/taskjuggler/Log.rb, line 85
def Log.msg(&block)
  return if @@level == 0

  offset = 0
  unless @@segments.empty?
    showMessage = false
    @@stack.each do |segment|
      # If a segment list is used to filter the output, we look for the
      # first listed segments on the stack. This and all nested segments
      # will be shown.
      if @@segments.include?(segment)
        offset = @@stack.index(segment)
        showMessage = true
    return unless showMessage
  if @@stack.length - offset < @@level
    $stderr.puts ' ' * (@@stack.length - offset) + yield(block)
progress(percent) click to toggle source

This function may only be called when Log#startProgressMeter has been called before. It updates the progress bar to the given percent completion value. The value should be between 0.0 and 1.0.

# File lib/taskjuggler/Log.rb, line 154
def Log.progress(percent)
  return if @@silent

  percent = 0.0 if percent < 0.0
  percent = 1.0 if percent > 1.0
  @@progress = percent

  length = 16
  full = (length * percent).to_i
  bar = '=' * full + ' ' * (length - full)
  label = (percent * 100.0).to_i.to_s + '%'
  bar[length / 2 - label.length / 2, label.length] = label
  $stdout.print("#{@@progressMeter} [" +
      "#{bar}") + "]\r")
segments=(s) click to toggle source

The trace output can be limited to a list of segments. Messages not in these segments will be ignored. Messages from segments that are nested into the shown segments will be shown for the next @@level nested segments.

# File lib/taskjuggler/Log.rb, line 44
def Log.segments=(s)
  @@segments = s
silent() click to toggle source

Return the @@silent value.

# File lib/taskjuggler/Log.rb, line 54
def Log.silent
silent=(s) click to toggle source

if s is true, progress information will not be shown.

# File lib/taskjuggler/Log.rb, line 49
def Log.silent=(s)
  @@silent = s
startProgressMeter(text) click to toggle source

The progress meter can be a textual progress bar or some animated character sequence that informs the user about ongoing activities. Call this function to start the progress meter display or to change the info text. The the meter is active the text cursor is always returned to the start of the same line. Consequent output will overwrite the last meter text.

# File lib/taskjuggler/Log.rb, line 121
def Log.startProgressMeter(text)
  return if @@silent

  maxlen = 60
  text = text.ljust(maxlen)
  text = text[0..maxlen - 1] if text.length_utf8 > maxlen
  @@progressMeter = text
  $stdout.print("#{@@progressMeter} ...\r")
status(message) click to toggle source

Print out a status message unless we are in silent mode.

# File lib/taskjuggler/Log.rb, line 109
def Log.status(message)
  return if @@silent

  $stdout.puts message
stopProgressMeter() click to toggle source

This sets the progress meter status to “done” and puts the cursor into the next line again.

# File lib/taskjuggler/Log.rb, line 133
def Log.stopProgressMeter
  return if @@silent

  $stdout.print("#{@@progressMeter} [      " +
      "Done") + "      ]\n")