# 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, sys, time

try:

    import thread

except ImportError:

    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

except ImportError:

    pass

RUN_RELOADER = True

_mtimes = {}

_win = (sys.platform == "win32")

def code_changed():

    global _mtimes, _win

    for filename in filter(lambda v: v, map(lambda m: getattr(m, "__file__", None), sys.modules.values())):

        if filename.endswith(".pyc") or filename.endswith(".pyo"):

            filename = filename[:-1]

        if not os.path.exists(filename):

            continue # File might be in an egg, so it can't be reloaded.

        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 = {}

            return True

    return False

def reloader_thread():

    while RUN_RELOADER:

        if code_changed():

            sys.exit(3) # force reload

        time.sleep(1)

def restart_with_reloader():

    while True:

        args = [sys.executable] + 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:

            sys.exit(restart_with_reloader())

        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

    reloader(main_func, args, kwargs)