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# Autoreloading launcher.
# Borrowed from Peter Hunt and the CherryPy project (http://www.cherrypy.org).
# Some taken from Ian Bicking's Paste (http://pythonpaste.org/).
#
# Portions copyright (c) 2004, CherryPy Team (team@cherrypy.org)
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
# * Neither the name of the CherryPy Team nor the names of its contributors
# may be used to endorse or promote products derived from this software
# without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
import os
import signal
import subprocess
import sys
import time
import traceback
import _thread
from django.apps import apps
from django.conf import settings
from django.core.signals import request_finished
# This import does nothing, but it's necessary to avoid some race conditions
# in the threading module. See http://code.djangoproject.com/ticket/2330 .
try:
import threading # NOQA
except ImportError:
pass
try:
import termios
except ImportError:
termios = None
USE_INOTIFY = False
try:
# Test whether inotify is enabled and likely to work
import pyinotify
fd = pyinotify.INotifyWrapper.create().inotify_init()
if fd >= 0:
USE_INOTIFY = True
os.close(fd)
except ImportError:
pass
RUN_RELOADER = True
FILE_MODIFIED = 1
I18N_MODIFIED = 2
_mtimes = {}
_win = (sys.platform == "win32")
_exception = None
_error_files = []
_cached_modules = set()
_cached_filenames = []
def gen_filenames(only_new=False):
"""
Return a list of filenames referenced in sys.modules and translation files.
"""
# N.B. ``list(...)`` is needed, because this runs in parallel with
# application code which might be mutating ``sys.modules``, and this will
# fail with RuntimeError: cannot mutate dictionary while iterating
global _cached_modules, _cached_filenames
module_values = set(sys.modules.values())
_cached_filenames = clean_files(_cached_filenames)
if _cached_modules == module_values:
# No changes in module list, short-circuit the function
if only_new:
return []
else:
return _cached_filenames + clean_files(_error_files)
new_modules = module_values - _cached_modules
new_filenames = clean_files(
[filename.__file__ for filename in new_modules
if hasattr(filename, '__file__')])
if not _cached_filenames and settings.USE_I18N:
# Add the names of the .mo files that can be generated
# by compilemessages management command to the list of files watched.
basedirs = [os.path.join(os.path.dirname(os.path.dirname(__file__)),
'conf', 'locale'),
'locale']
for app_config in reversed(list(apps.get_app_configs())):
basedirs.append(os.path.join(app_config.path, 'locale'))
basedirs.extend(settings.LOCALE_PATHS)
basedirs = [os.path.abspath(basedir) for basedir in basedirs
if os.path.isdir(basedir)]
for basedir in basedirs:
for dirpath, dirnames, locale_filenames in os.walk(basedir):
for filename in locale_filenames:
if filename.endswith('.mo'):
new_filenames.append(os.path.join(dirpath, filename))
_cached_modules = _cached_modules.union(new_modules)
_cached_filenames += new_filenames
if only_new:
return new_filenames + clean_files(_error_files)
else:
return _cached_filenames + clean_files(_error_files)
def clean_files(filelist):
filenames = []
for filename in filelist:
if not filename:
continue
if filename.endswith(".pyc") or filename.endswith(".pyo"):
filename = filename[:-1]
if filename.endswith("$py.class"):
filename = filename[:-9] + ".py"
if os.path.exists(filename):
filenames.append(filename)
return filenames
def reset_translations():
import gettext
from django.utils.translation import trans_real
gettext._translations = {}
trans_real._translations = {}
trans_real._default = None
trans_real._active = threading.local()
def inotify_code_changed():
"""
Check for changed code using inotify. After being called
it blocks until a change event has been fired.
"""
class EventHandler(pyinotify.ProcessEvent):
modified_code = None
def process_default(self, event):
if event.path.endswith('.mo'):
EventHandler.modified_code = I18N_MODIFIED
else:
EventHandler.modified_code = FILE_MODIFIED
wm = pyinotify.WatchManager()
notifier = pyinotify.Notifier(wm, EventHandler())
def update_watch(sender=None, **kwargs):
if sender and getattr(sender, 'handles_files', False):
# No need to update watches when request serves files.
# (sender is supposed to be a django.core.handlers.BaseHandler subclass)
return
mask = (
pyinotify.IN_MODIFY |
pyinotify.IN_DELETE |
pyinotify.IN_ATTRIB |
pyinotify.IN_MOVED_FROM |
pyinotify.IN_MOVED_TO |
pyinotify.IN_CREATE |
pyinotify.IN_DELETE_SELF |
pyinotify.IN_MOVE_SELF
)
for path in gen_filenames(only_new=True):
wm.add_watch(path, mask)
# New modules may get imported when a request is processed.
request_finished.connect(update_watch)
# Block until an event happens.
update_watch()
notifier.check_events(timeout=None)
notifier.read_events()
notifier.process_events()
notifier.stop()
# If we are here the code must have changed.
return EventHandler.modified_code
def code_changed():
global _mtimes, _win
for filename in gen_filenames():
stat = os.stat(filename)
mtime = stat.st_mtime
if _win:
mtime -= stat.st_ctime
if filename not in _mtimes:
_mtimes[filename] = mtime
continue
if mtime != _mtimes[filename]:
_mtimes = {}
try:
del _error_files[_error_files.index(filename)]
except ValueError:
pass
return I18N_MODIFIED if filename.endswith('.mo') else FILE_MODIFIED
return False
def check_errors(fn):
def wrapper(*args, **kwargs):
global _exception
try:
fn(*args, **kwargs)
except Exception:
_exception = sys.exc_info()
et, ev, tb = _exception
if getattr(ev, 'filename', None) is None:
# get the filename from the last item in the stack
filename = traceback.extract_tb(tb)[-1][0]
else:
filename = ev.filename
if filename not in _error_files:
_error_files.append(filename)
raise
return wrapper
def raise_last_exception():
global _exception
if _exception is not None:
raise _exception[0](_exception[1]).with_traceback(_exception[2])
def ensure_echo_on():
if termios:
fd = sys.stdin
if fd.isatty():
attr_list = termios.tcgetattr(fd)
if not attr_list[3] & termios.ECHO:
attr_list[3] |= termios.ECHO
if hasattr(signal, 'SIGTTOU'):
old_handler = signal.signal(signal.SIGTTOU, signal.SIG_IGN)
else:
old_handler = None
termios.tcsetattr(fd, termios.TCSANOW, attr_list)
if old_handler is not None:
signal.signal(signal.SIGTTOU, old_handler)
def reloader_thread():
ensure_echo_on()
if USE_INOTIFY:
fn = inotify_code_changed
else:
fn = code_changed
while RUN_RELOADER:
change = fn()
if change == FILE_MODIFIED:
sys.exit(3) # force reload
elif change == I18N_MODIFIED:
reset_translations()
time.sleep(1)
def restart_with_reloader():
while True:
args = [sys.executable] + ['-W%s' % o for o in sys.warnoptions] + sys.argv
new_environ = os.environ.copy()
new_environ["RUN_MAIN"] = 'true'
exit_code = subprocess.call(args, env=new_environ)
if exit_code != 3:
return exit_code
def python_reloader(main_func, args, kwargs):
if os.environ.get("RUN_MAIN") == "true":
_thread.start_new_thread(main_func, args, kwargs)
try:
reloader_thread()
except KeyboardInterrupt:
pass
else:
try:
exit_code = restart_with_reloader()
if exit_code < 0:
os.kill(os.getpid(), -exit_code)
else:
sys.exit(exit_code)
except KeyboardInterrupt:
pass
def jython_reloader(main_func, args, kwargs):
from _systemrestart import SystemRestart
_thread.start_new_thread(main_func, args)
while True:
if code_changed():
raise SystemRestart
time.sleep(1)
def main(main_func, args=None, kwargs=None):
if args is None:
args = ()
if kwargs is None:
kwargs = {}
if sys.platform.startswith('java'):
reloader = jython_reloader
else:
reloader = python_reloader
wrapped_main_func = check_errors(main_func)
reloader(wrapped_main_func, args, kwargs)