baseimage-tutorial-framework/lib/tfw/components/directory_monitor.py

from watchdog.observers import Observer
from watchdog.events import FileSystemEventHandler

from tfw.networking.event_handlers.server_connector import ServerUplinkConnector
from tfw.components.decorators import RateLimiter

from tfw.config.logs import logging
log = logging.getLogger(__name__)


class WebideReloadEventHandler(FileSystemEventHandler):
    def __init__(self):
        super().__init__()
        self.uplink = ServerUplinkConnector()
        self._paused = False

    def pause(self):
        self._paused = True

    def resume(self):
        self._paused = False

    @RateLimiter(rate_per_second=5)
    def on_modified(self, event):
        if self._paused: return
        log.debug(event)
        anchor = 'anchor_webide'
        self.uplink.send(anchor, {'anchor': anchor,
                                  'data': {'command': 'reload'}})


class DirectoryMonitor:
    def __init__(self, directory):
        self.observer = Observer()
        self.eventhandler = WebideReloadEventHandler()
        self.observer.schedule(self.eventhandler, directory, recursive=True)
        self.pause, self.resume = self.eventhandler.pause, self.eventhandler.resume

    def watch(self):
        self.observer.start()

    def stop(self):
        self.observer.stop()
        self.observer.join()