Class: Rerun::Runner

Inherits:
Object
  • Object
show all
Includes:
System
Defined in:
lib/rerun/runner.rb

Class Method Summary collapse

Instance Method Summary collapse

Methods included from System

#growl, #growl_available?, #growlcmd, #icon, #linux?, #mac?, #windows?

Constructor Details

#initialize(run_command, options = {}) ⇒ Runner

Returns a new instance of Runner.



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# File 'lib/rerun/runner.rb', line 17

def initialize(run_command, options = {})
  @run_command, @options = run_command, options
  @run_command = "ruby #{@run_command}" if @run_command.split(' ').first =~ /\.rb$/
end

Class Method Details

.keep_running(cmd, options) ⇒ Object 



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# File 'lib/rerun/runner.rb', line 7

def self.keep_running(cmd, options)
  runner = new(cmd, options)
  runner.start
  runner.join
  # apparently runner doesn't keep running anymore (as of Listen 2) so we have to sleep forever :-(
  sleep 10000 while true  # :-(
end

Instance Method Details

#app_name ⇒ Object 



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# File 'lib/rerun/runner.rb', line 112

def app_name
  @options[:name]
end

#clear? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rerun/runner.rb', line 104

def clear?
  @options[:clear]
end

#clear_screen ⇒ Object 



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# File 'lib/rerun/runner.rb', line 303

def clear_screen
  # see http://ascii-table.com/ansi-escape-sequences-vt-100.php
  $stdout.print "\033[H\033[2J"
end

#die ⇒ Object 



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# File 'lib/rerun/runner.rb', line 201

def die
  #stop_keypress_thread   # don't do this since we're probably *in* the keypress thread
  stop # stop the child process if it exists
  exit 0  # todo: status code param
end

#dir ⇒ Object 



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# File 'lib/rerun/runner.rb', line 88

def dir
  @options[:dir]
end

#dirs ⇒ Object 



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# File 'lib/rerun/runner.rb', line 92

def dirs
  @options[:dir] || "."
end

#exit? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rerun/runner.rb', line 108

def exit?
  @options[:exit]
end

#git_head_changed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rerun/runner.rb', line 249

def git_head_changed?
  old_git_head = @git_head
  read_git_head
  @git_head and old_git_head and @git_head != old_git_head
end

#ignore ⇒ Object 



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# File 'lib/rerun/runner.rb', line 100

def ignore
  @options[:ignore] || []
end

#join ⇒ Object 



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# File 'lib/rerun/runner.rb', line 207

def join
  @watcher.join
end

#key_pressed ⇒ Object

non-blocking stdin reader. returns a 1-char string if a key was pressed; otherwise nil



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# File 'lib/rerun/runner.rb', line 273

def key_pressed
  begin
    # this "raw input" nonsense is because unix likes waiting for linefeeds before sending stdin

    # 'raw' means turn raw input on

    # restore proper output newline handling -- see stty.rb and "man stty" and /usr/include/sys/termios.h
    # looks like "raw" flips off the OPOST bit 0x00000001 /* enable following output processing */
    # which disables #define ONLCR    0x00000002  /* map NL to CR-NL (ala CRMOD) */
    # so this sets it back on again since all we care about is raw input, not raw output
    system("stty raw opost")

    c = nil
    if $stdin.ready?
      c = $stdin.getc
    end
    c.chr if c
  ensure
    system "stty -raw" # turn raw input off
  end

  # note: according to 'man tty' the proper way restore the settings is
  # tty_state=`stty -g`
  # ensure
  #   system 'stty "#{tty_state}'
  # end
  # but this way seems fine and less confusing

end

#notify(title, body) ⇒ Object 



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# File 'lib/rerun/runner.rb', line 260

def notify(title, body)
  growl title, body if @options[:growl]
  puts
  say "#{app_name} #{title}"
end

#pattern ⇒ Object 



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# File 'lib/rerun/runner.rb', line 96

def pattern
  @options[:pattern]
end

#read_git_head ⇒ Object 



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# File 'lib/rerun/runner.rb', line 255

def read_git_head
  git_head_file = File.join(dir, '.git', 'HEAD')
  @git_head = File.exists?(git_head_file) && File.read(git_head_file)
end

#restart ⇒ Object 



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# File 'lib/rerun/runner.rb', line 61

def restart
  @restarting = true
  stop
  start
  @restarting = false
end

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rerun/runner.rb', line 211

def running?
  signal(0)
end

#say(msg) ⇒ Object 



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# File 'lib/rerun/runner.rb', line 266

def say msg
  puts "#{Time.now.strftime("%T")} [rerun] #{msg}"
end

#signal(signal) ⇒ Object 



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# File 'lib/rerun/runner.rb', line 215

def signal(signal)
  say "Sending signal #{signal} to #{@pid}" unless signal == 0
  Process.kill(signal, @pid)
  true
rescue
  false
end

#start ⇒ Object 



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# File 'lib/rerun/runner.rb', line 116

def start
  if windows?
    raise "Sorry, Rerun does not work on Windows."
  end

  if (!@already_running)
    taglines = [
      "To infinity... and beyond!",
      "Charge!",
    ]
    notify "launched", taglines[rand(taglines.size)]
    @already_running = true
  else
    taglines = [
      "Here we go again!",
      "Keep on trucking.",
      "Once more unto the breach, dear friends, once more!",
      "The road goes ever on and on, down from the door where it began.",
    ]
    notify "restarted", taglines[rand(taglines.size)]
  end

  clear_screen if clear?
  start_keypress_thread unless @keypress_thread

  @pid = Kernel.fork do
    begin
      exec(@run_command)
    rescue => e
      puts "#{e.class}: #{e.message}"
      exit
    end
  end
  status_thread = Process.detach(@pid) # so if the child exits, it dies

  Signal.trap("INT") do # INT = control-C -- allows user to stop the top-level rerun process
    die
  end

  Signal.trap("TERM") do  # TERM is the polite way of terminating a process
    die
  end

  begin
    sleep 2
  rescue Interrupt => e
    # in case someone hits control-C immediately ("oops!")
    die
  end

  if exit?
    status = status_thread.value
    if status.success?
      notify "succeeded", ""
    else
      notify "failed", "Exit status #{status.exitstatus}"
    end
  else
    if !running?
      notify "Launch Failed", "See console for error output"
      @already_running = false
    end
  end

  unless @watcher

    watcher = Watcher.new(:directory => dirs, :pattern => pattern, :ignore => ignore) do |changes|

      message = [:modified, :added, :removed].map do |change|
        count = changes[change].size
        if count and count > 0
          "#{count} #{change}"
        end
      end.compact.join(", ")
      say "Change detected: #{message}"
      restart unless @restarting
    end
    watcher.start
    @watcher = watcher
    say "Watching #{dir.join(', ')} for #{pattern}" +
            (ignore.empty? ? "" : " (ignoring #{ignore.join(',')})") +
            " using #{watcher.adapter.class.name.split('::').last} adapter"
  end
end

#start_keypress_thread ⇒ Object 



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# File 'lib/rerun/runner.rb', line 22

def start_keypress_thread
  return if @options[:background]

  @keypress_thread = Thread.new do
    while true
      if c = key_pressed
        case c.downcase
        when 'c'
          say "Clearing screen"
          clear_screen
        when 'r'
          say "Restarting"
          restart
        when 'p'
          toggle_pause if watcher_running?
        when 'x', 'q'
          die
          break  # the break will stop this thread, in case the 'die' doesn't
        else
          puts "\n#{c.inspect} pressed inside rerun"
          puts [["c", "clear screen"],
           ["r", "restart"],
           ["p", "toggle pause"],
           ["x or q", "stop and exit"]
          ].map{|key, description| "  #{key} -- #{description}"}.join("\n")
          puts
        end
      end
      sleep 1  # todo: use select instead of polling somehow?
    end
  end
  @keypress_thread.run
end

#stop ⇒ Object

todo: test escalation



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# File 'lib/rerun/runner.rb', line 224

def stop
  default_signal = @options[:signal] || "TERM"
  if @pid && (@pid != 0)
    notify "stopping", "All good things must come to an end." unless @restarting
    begin
      timeout(5) do  # todo: escalation timeout setting
        # start with a polite SIGTERM
        signal(default_signal) && Process.wait(@pid)
      end
    rescue Timeout::Error
      begin
        timeout(5) do
          # escalate to SIGINT aka control-C since some foolish process may be ignoring SIGTERM
          signal("INT") && Process.wait(@pid)
        end
      rescue Timeout::Error
        # escalate to SIGKILL aka "kill -9" which cannot be ignored
        signal("KILL") && Process.wait(@pid)
      end
    end
  end
rescue => e
  false
end

#stop_keypress_thread ⇒ Object 



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# File 'lib/rerun/runner.rb', line 56

def stop_keypress_thread
  @keypress_thread.kill if @keypress_thread
  @keypress_thread = nil
end

#toggle_pause ⇒ Object 



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# File 'lib/rerun/runner.rb', line 72

def toggle_pause
  unless @pausing
    say "Pausing.  Press 'p' again to resume."
    @watcher.pause
    @pausing = true
  else
    say "Resuming"
    @watcher.unpause
    @pausing = false
  end
end

#unpause ⇒ Object 



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# File 'lib/rerun/runner.rb', line 84

def unpause
  @watcher.unpause
end

#watcher_running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rerun/runner.rb', line 68

def watcher_running?
  @watcher && @watcher.running?
end