Source Code for Module node_manager_fkie.supervised_popen

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  3  # Copyright (c) 2012, Fraunhofer FKIE/US, Alexander Tiderko 
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 32   
 33  from python_qt_binding.QtCore import QObject, Signal 
 34  import subprocess 
 35  import threading 
 36   
 37  from .detailed_msg_box import MessageBox 
 38   
 39   
 40 -class SupervisedPopen(QObject): 
 41      ''' 
 42      The class overrides the subprocess.Popen and waits in a thread for its finish. 
 43      If an error is printed out, it will be shown in a message dialog. 
 44      ''' 
 45      error = Signal(str, str, str) 
 46      '''@ivar: the signal is emitted if error output was detected (id, decription, message)''' 
 47   
 48      finished = Signal(str) 
 49      '''@ivar: the signal is emitted on exit (id)''' 
 50   
 51 -    def __init__(self, args, bufsize=0, executable=None, stdin=None, stdout=None, 
 52                   stderr=subprocess.PIPE, preexec_fn=None, close_fds=False, 
 53                   shell=False, cwd=None, env=None, universal_newlines=False, 
 54                   startupinfo=None, creationflags=0, object_id='', description=''): 
 55          ''' 
 56          For arguments see https://docs.python.org/2/library/subprocess.html 
 57          Additional arguments: 
 58          :param object_id: the identification string of this object and title of the 
 59          error message dialog 
 60          :type object_id: str 
 61          :param description: the description string used as addiotional information 
 62          in dialog if an error was occured 
 63          :type description: str 
 64          ''' 
 65          try: 
 66              QObject.__init__(self) 
 67              self._args = args 
 68              self._object_id = object_id 
 69              self._description = description 
 70              self.error.connect(self.on_error) 
 71              # wait for process to avoid 'defunct' processes 
 72              self.popen = subprocess.Popen(args=args, bufsize=bufsize, executable=executable, stdin=stdin, stdout=stdout, 
 73                                            stderr=stderr, preexec_fn=preexec_fn, close_fds=close_fds, shell=shell, cwd=cwd, env=env, 
 74                                            universal_newlines=universal_newlines, startupinfo=startupinfo, creationflags=creationflags) 
 75              thread = threading.Thread(target=self._supervise) 
 76              thread.setDaemon(True) 
 77              thread.start() 
 78          except Exception as _: 
 79              raise 
 80   
 81  #   def __del__(self): 
 82  #     print "Deleted:", self._description 
 83   
 84      @property 
 85 -    def stdout(self): 
 86          return self.popen.stdout 
 87   
 88      @property 
 89 -    def stderr(self): 
 90          return self.popen.stderr 
 91   
 92      @property 
 93 -    def stdin(self): 
 94          return self.popen.stdin 
 95   
 96 -    def _supervise(self): 
 97          ''' 
 98          Wait for process to avoid 'defunct' processes 
 99          ''' 
100          self.popen.wait() 
101          result_err = '' 
102          if self.stderr is not None: 
103              result_err = self.stderr.read() 
104          if result_err: 
105              self.error.emit(self._object_id, self._description, result_err) 
106          self.finished.emit(self._object_id) 
107   
108 -    def on_error(self, object_id, descr, msg): 
109          MessageBox.warning(None, object_id, '%s\n\n' 
110                             '%s' % (descr, msg), ' '.join(self._args)) 
111