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

#app_name, #growl, #growl?, #growlcmd, #icon, #linux?, #mac?, #osx_foundation?, #windows?

Constructor Details

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

Returns a new instance of Runner.



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# File 'lib/rerun/runner.rb', line 15

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
end

Instance Method Details

#clear? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rerun/runner.rb', line 73

def clear?
  @options[:clear]
end

#clear_screen ⇒ Object 



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# File 'lib/rerun/runner.rb', line 259

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 161

def die
  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 65

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

#exit? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rerun/runner.rb', line 77

def exit?
  @options[:exit]
end

#git_head_changed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rerun/runner.rb', line 205

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

#join ⇒ Object 



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# File 'lib/rerun/runner.rb', line 166

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 229

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

#kill_keypress_thread ⇒ Object 



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# File 'lib/rerun/runner.rb', line 53

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

#notify(title, body) ⇒ Object 



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# File 'lib/rerun/runner.rb', line 216

def notify(title, body)
  growl title, body
  puts
  say "#{app_name} #{title}"
end

#pattern ⇒ Object 



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# File 'lib/rerun/runner.rb', line 69

def pattern
  @options[:pattern] || DEFAULT_PATTERN
end

#read_git_head ⇒ Object 



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

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 58

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

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rerun/runner.rb', line 170

def running?
  signal(0)
end

#say(msg) ⇒ Object 



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# File 'lib/rerun/runner.rb', line 222

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

#signal(signal) ⇒ Object 



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# File 'lib/rerun/runner.rb', line 174

def signal(signal)
  Process.kill(signal, @pid)
  true
rescue
  false
end

#start ⇒ Object 



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# File 'lib/rerun/runner.rb', line 81

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

  @pid = Kernel.fork do
    begin
      # Signal.trap("INT") { exit }
      exec(@run_command)
    rescue => e
      puts e
      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_class = osx_foundation? ? OSXWatcher : FSWatcher
    # watcher_class = FSWatcher

    watcher = watcher_class.new do
      restart unless @restarting
    end
    say "Watching #{dir}/#{pattern}"
    watcher.add_directory(dir, pattern)
    watcher.sleep_time = 1
    watcher.start
    @watcher = watcher
  end
end

#start_keypress_thread ⇒ Object 



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# File 'lib/rerun/runner.rb', line 20

def start_keypress_thread
  from = caller.first
  @keypress_thread = Thread.new do
    # puts "starting keypress thread #{Thread.current.object_id} from #{from}"
    while true
      if c = key_pressed
        puts "\n#{c.inspect} pressed inside rerun"
        case c.downcase
        when 'c'
          say "clearing screen"
          clear_screen
        when 'r'
          say "'r' pressed - restarting"
          restart
          break  # the break will stop this thread
        when 'x'
          die
          break  # the break will stop this thread, in case the 'die' doesn't
        else
          puts [["c", "clear screen"],
           ["r", "restart"],
           ["x", "stop and exit"]
          ].map{|key, description| "  #{key} -- #{description}"}.join("\n")
          puts
        end
      end
      sleep 1  # todo: use select instead of polling somehow?
    end
    # puts "keypress thread #{Thread.current.object_id} ending"
  end
  @keypress_thread.run
end

#stop ⇒ Object 



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# File 'lib/rerun/runner.rb', line 181

def stop
  if @pid && (@pid != 0)
    notify "stopping", "All good things must come to an end." unless @restarting
    begin
      timeout(2) do
        # start with a polite SIGTERM
        signal("TERM") && Process.wait(@pid)
      end
    rescue Timeout::Error
      begin
        timeout(2) 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