watchdog_reload.py

#!/usr/bin/env python
from __future__ import absolute_import, print_function, unicode_literals, division

import re
import logging
import threading
import time

import watchdog.events
import watchdog.observers
from IPython.lib.deepreload import reload as dreload

from . import utils, boot

log = logging.getLogger(__name__)


class ChangeDetector(watchdog.events.FileSystemEventHandler):
    def __init__(self, change_event):
        super(ChangeDetector, self).__init__()
        self._change_event = change_event

    def on_modified(self, event):
        if re.search(r'\.(py|ini|conf)$', event.src_path) is not None:
            log.info("Reloading because of file change: {}".format(event.src_path))
            self._change_event.set()


class ServerThread(threading.Thread):
    def __init__(self, change_event):
        super(ServerThread, self).__init__()
        self._change_event = change_event
        self.running = False

    def run(self):
        self.running = True
        while self.running:
            # Start server
            print('Starting...')
            server = boot.main(serve_forever=False)
            server.start()

            # Wait for change
            self._change_event.wait()
            self._change_event.clear()

            # Reload server
            print('Stopping...')
            server.stop(timeout=10)
            dreload(boot)


if __name__ == '__main__':
    change_event = threading.Event()
    change_detector = ChangeDetector(change_event)

    server_thread = ServerThread(change_event)
    server_thread.start()

    observer = watchdog.observers.Observer()
    observer.schedule(change_detector, utils.get_package_root_path(), recursive=True)
    observer.start()

    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        print('Terminated')
        observer.stop()
        server_thread.running = False
        change_event.set()

    observer.join()
    server_thread.join()

    raise SystemExit(0)
##