Merge pull request #8 from avatao-content/watchdog

Watchdog

lib/tfw/components/directory_monitor.py

@@ -0,0 +1,35 @@
+from watchdog.observers import Observer
+from watchdog.events import FileSystemEventHandler
+
+from tfw.networking.event_handlers.server_connector import ServerUplinkConnector
+from tfw.util import RateLimiter
+
+from tfw.config.logs import logging
+log = logging.getLogger(__name__)
+
+
+
+class WebideReloadEventHandler(FileSystemEventHandler):
+    def __init__(self):
+        super().__init__()
+        self.uplink = ServerUplinkConnector()
+
+    @RateLimiter(rate_per_second=5)
+    def on_modified(self, event):
+        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.observer.schedule(WebideReloadEventHandler(), directory, recursive=True)
+
+    def watch(self):
+        self.observer.start()
+
+    def stop(self):
+        self.observer.stop()
+        self.observer.join()

lib/tfw/components/source_code_event_handler.py

@@ -3,6 +3,7 @@ from glob import glob
 
 from tfw.util import SupervisorMixin
 from tfw.event_handler_base import EventHandlerBase
+from tfw.components.directory_monitor import DirectoryMonitor
 
 from tfw.config.logs import logging
 log = logging.getLogger(__name__)
@@ -56,6 +57,9 @@ class SourceCodeEventHandler(EventHandlerBase, SupervisorMixin):
             'select': self.select
         }
 
+        self.monitor = DirectoryMonitor(directory)
+        self.monitor.watch()    # This runs on a separate thread
+
     def read(self, data):
         try: data['content'] = self.filemanager.file_contents
         except PermissionError: data['content'] = 'You have no permission to open that file :('
@@ -85,6 +89,9 @@ class SourceCodeEventHandler(EventHandlerBase, SupervisorMixin):
         self.attach_fileinfo(data)
         return data_json
 
+    def cleanup(self):
+        self.monitor.stop()
+
 
 def map_file_extension_to_language(filename):
     language_map = {

lib/tfw/event_handler_base.py

@@ -23,6 +23,9 @@ class EventHandlerBase:
     def handle_reset(self, data_json):
         return None
 
+    def cleanup(self):
+        pass
+
     def message_other(self, anchor, data):
         message = {
             'anchor': anchor,

lib/tfw/util.py

@@ -1,6 +1,8 @@
 import xmlrpc.client, zmq
 from contextlib import suppress
 from xmlrpc.client import Fault as SupervisorFault
+from time import time, sleep
+from functools import wraps
 
 from tfw.config import tfwenv
 
@@ -31,3 +33,23 @@ class SupervisorMixin:
 class ZMQConnectorBase:
     def __init__(self, zmq_context=None):
         self._zmq_context = zmq_context or zmq.Context.instance()
+
+
+class RateLimiter:
+    def __init__(self, rate_per_second):
+        self.min_interval = 1 / float(rate_per_second)
+        self.last_call = time()
+
+    def __call__(self, fun):
+        @wraps(fun)
+        def wrapper(*args, **kwargs):
+            self._limit_rate()
+            fun(*args, **kwargs)
+        return wrapper
+
+    def _limit_rate(self):
+        since_last_call = time() - self.last_call
+        to_next_call = self.min_interval - since_last_call
+        self.last_call = time()
+        if to_next_call > 0:
+            sleep(to_next_call)

requirements.txt

@@ -2,3 +2,4 @@ tornado==4.5.3
 pyzmq==16.0.4
 transitions==0.6.4
 terminado==0.8.1
+watchdog==0.8.3

src/demo/event_handler_main.py

@@ -6,6 +6,9 @@ from tfw.config import tfwenv
 
 
 if __name__ == '__main__':
-    anchor_webide = SourceCodeEventHandler('anchor_webide', tfwenv.WEBIDE_WD, 'login')
-    anchor_terminado = TerminadoEventHandler('anchor_terminado', 'terminado')
-    IOLoop.instance().start()
+    eventhandlers = {SourceCodeEventHandler('anchor_webide', tfwenv.WEBIDE_WD, 'login'),
+                     TerminadoEventHandler('anchor_terminado', 'terminado')}
+    try:
+        IOLoop.instance().start()
+    finally:
+        for eh in eventhandlers: eh.cleanup()