Class: NodeTask

Inherits:
Object
  • Object
show all
Defined in:
lib/node_task/node_task.rb

Defined Under Namespace

Classes: Error

Constant Summary collapse

RESPONSE_TIMEOUT = 
9999
START_MAX_RETRIES = 
1

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(_task) ⇒ NodeTask

Returns a new instance of NodeTask.



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# File 'lib/node_task/node_task.rb', line 250

def initialize(_task)
  @task = _task
end

Class Attribute Details

.logger ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 31

def logger
  return @logger unless @logger.nil?
  @logger = Logger.new(STDERR)
  @logger.level = ENV["NODE_TASK_DEBUG"] ? Logger::DEBUG : Logger::INFO 
  @logger
end

.node_command ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 62

def node_command
  @node_command || ENV["NODE_COMMAND"] || 'node'
end

.working_dir ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 38

def working_dir
  @working_dir || Dir.pwd
end

Instance Attribute Details

#task ⇒ Object

Returns the value of attribute task.



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# File 'lib/node_task/node_task.rb', line 248

def task
  @task
end

Class Method Details

.check_error ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 112

def check_error
  if File.exist? error_log_file
    # TODO: raise error
    logger.error File.open(error_log_file).read
    File.unlink error_log_file
    true
  end
end

.clients_active ⇒ Object

number of connections active to the daemon



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# File 'lib/node_task/node_task.rb', line 159

def clients_active
  socket = _make_connection # might fail
  message = {status: true} # special message type
  result = request(socket, message)
  return 0 if result.nil?
  result[:clients]
end

.daemon_identifier ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 54

def daemon_identifier
  'ruby_node_task'
end

.daemon_start_script ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 66

def daemon_start_script
  File.join(gem_dir, 'index.js').to_s
end

.ensure_connection ⇒ Object

really try to successfully connect, starting the daemon if required



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# File 'lib/node_task/node_task.rb', line 85

def ensure_connection
  attempt = 0
  begin
    server # make sure daemon is running

    socket = server.connect do
      begin
        _make_connection
      rescue Errno::ENOENT => e 
        # daemon_controller doesn't understand ENOENT
        raise Errno::ECONNREFUSED, e.message
      end
    end
  rescue DaemonController::StartTimeout, DaemonController::StartError => e
    logger.error e.message
    if attempt < START_MAX_RETRIES
      attempt += 1
      logger.error "retrying attempt #{attempt}"
      retry
    else
      raise e
    end
  end

  socket
end

.error_log_file ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 42

def error_log_file
  File.join(working_dir, "#{daemon_identifier}-error.log")
end

.gem_dir ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 50

def gem_dir
  @gem_dir ||= File.dirname(File.expand_path(__FILE__))
end

.parse_response(socket) ⇒ Object

get a json response from socket



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# File 'lib/node_task/node_task.rb', line 122

def parse_response(socket)
  # only take one message - the result
  # response terminated by newline
  response_text = nil
  loop do
    response_text = socket.gets("\n")
    break if response_text
    break if check_error
  end
  if response_text
    JSON.parse(response_text, symbolize_names: true)
  else
    logger.error 'no response for message'
    nil
  end
end

.pid_file ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 46

def pid_file
  File.join(working_dir, "#{daemon_identifier}.pid")
end

.release ⇒ Object

stop the daemon if no one else is using it



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# File 'lib/node_task/node_task.rb', line 168

def release
  begin
    # this doesn't really work as intended right now
    # as no connections are maintained when tasks aren't running
    return if clients_active > 0
  rescue Errno::ENOENT => e
    # socket file probably doesn't exist
    # maybe we should just return here?
  end

  pid = nil
  begin
    pid = @controller.pid
  rescue Errno::ENOENT => e
    # presumably no pid file exists and the daemon is not running
    logger.debug "daemon already stopped"
    return
  end

  logger.debug "stopping daemon #{pid}"
  @controller.stop

  begin
    File.unlink socket_path
  rescue Errno::ENOENT => e
    # socket file's already gone
  end
end

.request(socket, message) ⇒ Object

make a single request, get a response and close the connection



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# File 'lib/node_task/node_task.rb', line 140

def request(socket, message)
  socket.write(message.to_json+"\n")

  result = nil
  begin
    Timeout::timeout(RESPONSE_TIMEOUT) do
      result = parse_response(socket)
    end
  rescue Timeout::Error, Exception => e
    logger.error e.message
  ensure
    # disconnect after receiving response
    socket.close
  end

  result
end

.server ⇒ Object

get configured daemon controller for daemon, and start it



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# File 'lib/node_task/node_task.rb', line 71

def server
  @controller ||= _make_daemon_controller

  begin
    @controller.start
    logger.debug "spawned server #{@controller.pid}"
  rescue DaemonController::AlreadyStarted => e
    logger.debug "server already running #{@controller.pid}"
  end

  @controller
end

.socket_path ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 58

def socket_path
  @socket_path ||= _make_sock_path(working_dir, daemon_identifier)
end

.windows? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/node_task/node_task.rb', line 27

def windows?
  (/cygwin|mswin|mingw|bccwin|wince|emx/ =~ RUBY_PLATFORM) != nil
end

Instance Method Details

#run(opts = nil) ⇒ Object 



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# File 'lib/node_task/node_task.rb', line 254

def run(opts = nil)
  socket = self.class.ensure_connection

  message = {
    task: task,
    opts: opts,
  }

  response = self.class.request(socket, message)
  if response
    if response[:error]
      raise NodeTask::Error, response[:error]
    else
      response[:result]
    end
  end
end