django1/django/utils/autoreload.py

360 lines
12 KiB
Python

# 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 sys
import tempfile
import time
import traceback
from django.conf import settings
from django.core.signals import request_finished
try:
from django.utils.six.moves import _thread as thread
except ImportError:
from django.utils.six.moves import _dummy_thread as thread
# 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
try:
import select
select.kevent, select.kqueue
USE_KQUEUE = True
import resource
NOFILES_SOFT, NOFILES_HARD = resource.getrlimit(resource.RLIMIT_NOFILE)
import subprocess
command = ["sysctl", "-n", "kern.maxfilesperproc"]
NOFILES_KERN = int(subprocess.check_output(command).strip())
except (AttributeError, OSError):
USE_KQUEUE = False
RUN_RELOADER = True
_mtimes = {}
_win = (sys.platform == "win32")
_error_files = []
def gen_filenames():
"""
Yields a generator over filenames referenced in sys.modules and translation
files.
"""
filenames = [filename.__file__ for filename in sys.modules.values()
if hasattr(filename, '__file__')]
# 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']
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'):
filenames.append(os.path.join(dirpath, filename))
for filename in filenames + _error_files:
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):
yield filename
def inotify_code_changed():
"""
Checks for changed code using inotify. After being called
it blocks until a change event has been fired.
"""
wm = pyinotify.WatchManager()
notifier = pyinotify.Notifier(wm)
def update_watch(sender=None, **kwargs):
mask = (
pyinotify.IN_MODIFY |
pyinotify.IN_DELETE |
pyinotify.IN_ATTRIB |
pyinotify.IN_MOVED_FROM |
pyinotify.IN_MOVED_TO |
pyinotify.IN_CREATE
)
for path in gen_filenames():
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.stop()
# If we are here the code must have changed.
return True
def kqueue_code_changed():
"""
Checks for changed code using kqueue. After being called
it blocks until a change event has been fired.
"""
kqueue = select.kqueue()
# Utility function to create kevents.
_filter = select.KQ_FILTER_VNODE
flags = select.KQ_EV_ADD
fflags = select.KQ_NOTE_DELETE | select.KQ_NOTE_WRITE | select.KQ_NOTE_RENAME
def make_kevent(descriptor):
return select.kevent(descriptor, _filter, flags, fflags)
# New modules may get imported when a request is processed. We add a file
# descriptor to the kqueue to exit the kqueue.control after each request.
watcher = tempfile.TemporaryFile(bufsize=0)
kqueue.control([make_kevent(watcher)], 0)
def update_watch(sender=None, **kwargs):
watcher.write('.')
request_finished.connect(update_watch)
# We have to manage a set of descriptors to avoid the overhead of opening
# and closing every files whenever we reload the set of files to watch.
filenames = set()
descriptors = set()
while True:
old_filenames = filenames
filenames = set(gen_filenames())
new_filenames = filenames - old_filenames
# If new files were added since the last time we went through the loop,
# add them to the kqueue.
if new_filenames:
# We must increase the maximum number of open file descriptors
# because each kevent uses one file descriptor and resource limits
# are too low by default.
#
# In fact there are two limits:
# - kernel limit: `sysctl kern.maxfilesperproc` -> 10240 on OS X.9
# - resource limit: `launchctl limit maxfiles` -> 256 on OS X.9
#
# The latter can be changed with Python's resource module, but it
# can never exceed the former. Unfortunately, getrlimit(3) -- used
# by both launchctl and the resource module -- reports no "hard
# limit", even though the kernel sets one.
# If project is too large or kernel limits are too tight, use polling.
if len(filenames) >= NOFILES_KERN:
return code_changed()
# Add the number of file descriptors we're going to use to the current
# resource limit, while staying within the kernel limit.
nofiles_target = min(len(filenames) + NOFILES_SOFT, NOFILES_KERN)
resource.setrlimit(resource.RLIMIT_NOFILE, (nofiles_target, NOFILES_HARD))
new_descriptors = set(open(filename) for filename in new_filenames)
descriptors |= new_descriptors
kqueue.control([make_kevent(descriptor) for descriptor in new_descriptors], 0)
events = kqueue.control([], 1)
# After a request, reload the set of watched files.
if len(events) == 1 and events[0].ident == watcher.fileno():
continue
# If the change affected another file, clean up and exit.
for descriptor in descriptors:
descriptor.close()
watcher.close()
kqueue.close()
return True
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 True
return False
def check_errors(fn):
def wrapper(*args, **kwargs):
try:
fn(*args, **kwargs)
except (ImportError, IndentationError, NameError, SyntaxError,
TypeError, AttributeError):
et, ev, tb = sys.exc_info()
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 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
elif USE_KQUEUE:
fn = kqueue_code_changed
else:
fn = code_changed
while RUN_RELOADER:
if fn():
sys.exit(3) # force reload
time.sleep(1)
def restart_with_reloader():
while True:
args = [sys.executable] + ['-W%s' % o for o in sys.warnoptions] + sys.argv
if sys.platform == "win32":
args = ['"%s"' % arg for arg in args]
new_environ = os.environ.copy()
new_environ["RUN_MAIN"] = 'true'
exit_code = os.spawnve(os.P_WAIT, sys.executable, args, 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)