Source Code for Module trac.util.autoreload

  1  # -*- coding: utf-8 -*- 
  2  # 
  3  # Copyright (C) 2006-2020 Edgewall Software 
  4  # All rights reserved. 
  5  # 
  6  # This software is licensed as described in the file COPYING, which 
  7  # you should have received as part of this distribution. The terms 
  8  # are also available at https://trac.edgewall.org/wiki/TracLicense. 
  9  # 
 10  # This software consists of voluntary contributions made by many 
 11  # individuals. For the exact contribution history, see the revision 
 12  # history and logs, available at https://trac.edgewall.org/log/. 
 13   
 14  import os 
 15  import sys 
 16  import threading 
 17  import time 
 18  import traceback 
 19   
 20  _SLEEP_TIME = 1 
 21   
 22 -def _reloader_thread(modification_callback, loop_callback): 
 23      """When this function is run from the main thread, it will force other 
 24      threads to exit when any modules currently loaded change. 
 25   
 26      :param modification_callback: a function taking a single argument, 
 27                                    the modified file, which is called 
 28                                    every time a modification is 
 29                                    detected 
 30   
 31      :param loop_callback: a function taking no arguments, which is 
 32                            called after every modification check 
 33   
 34      """ 
 35      mtimes = {} 
 36      while True: 
 37          for filename in filter(None, [getattr(module, '__file__', None) 
 38                                        for module in sys.modules.values()]): 
 39              while not os.path.isfile(filename): # Probably in an egg or zip file 
 40                  filename = os.path.dirname(filename) 
 41                  if not filename: 
 42                      break 
 43              if not filename: # Couldn't map to physical file, so just ignore 
 44                  continue 
 45   
 46              if filename.endswith(('.pyc', '.pyo')): 
 47                  filename = filename[:-1] 
 48   
 49              if not os.path.isfile(filename): 
 50                  # Compiled file for non-existant source 
 51                  continue 
 52   
 53              mtime = os.stat(filename).st_mtime 
 54              if filename not in mtimes: 
 55                  mtimes[filename] = mtime 
 56                  continue 
 57              if mtime != mtimes[filename]: 
 58                  modification_callback(filename) 
 59                  sys.exit(3) 
 60          loop_callback() 
 61          time.sleep(_SLEEP_TIME) 
 62   
 63 -def _restart_with_reloader(): 
 64      is_win32 = sys.platform == 'win32' 
 65      if is_win32: 
 66          can_exec = lambda path: os.path.isfile(path) and \ 
 67                                  os.path.normpath(path).endswith('.exe') 
 68      else: 
 69          can_exec = lambda path: os.access(path, os.X_OK) 
 70   
 71      if os.path.isfile(sys.argv[0]): 
 72          args = sys.argv if can_exec(sys.argv[0]) else \ 
 73                 [sys.executable] + sys.argv 
 74      elif is_win32 and can_exec(sys.argv[0] + '.exe'): 
 75          args = [sys.argv[0] + '.exe'] + sys.argv[1:] 
 76      elif os.path.isfile(sys.argv[0] + '-script.py'): 
 77          args = [sys.executable, sys.argv[0] + '-script.py'] + sys.argv[1:] 
 78      else: 
 79          args = [sys.executable] + sys.argv 
 80      path = args[0] 
 81      if is_win32: 
 82          args = ['"%s"' % arg for arg in args] 
 83      new_environ = os.environ.copy() 
 84      new_environ['RUN_MAIN'] = 'true' 
 85   
 86      while True: 
 87          # This call reinvokes ourself and goes into the other branch of main as 
 88          # a new process. 
 89          exit_code = os.spawnve(os.P_WAIT, path, args, new_environ) 
 90          if exit_code != 3: 
 91              return exit_code 
 92   
 93 -def main(func, modification_callback, *args, **kwargs): 
 94      """Run the given function and restart any time modules are changed.""" 
 95      if os.environ.get('RUN_MAIN'): 
 96          exit_code = [] 
 97          def main_thread(): 
 98              try: 
 99                  func(*args, **kwargs) 
100                  exit_code.append(None) 
101              except SystemExit as e: 
102                  exit_code.append(e.code) 
103              except: 
104                  traceback.print_exception(*sys.exc_info()) 
105                  exit_code.append(1) 
106          def check_exit(): 
107              if exit_code: 
108                  sys.exit(exit_code[0]) 
109          # Lanch the actual program as a child thread 
110          thread = threading.Thread(target=main_thread, name='Main thread') 
111          thread.setDaemon(True) 
112          thread.start() 
113          try: 
114              # Now wait for a file modification and quit 
115              _reloader_thread(modification_callback, check_exit) 
116          except KeyboardInterrupt: 
117              pass 
118      else: 
119          # Initial invocation just waits around restarting this executable 
120          try: 
121              sys.exit(_restart_with_reloader()) 
122          except KeyboardInterrupt: 
123              pass 
124