port/file_watcher (#54)

migrate FileWatcher class from ovos_config for reuse

authored-by: jarbasai <[email protected]>

ovos_utils/file_utils.py

@@ -8,6 +8,11 @@
 from ovos_utils.bracket_expansion import expand_options
 from ovos_utils.log import LOG
 from ovos_utils.system import search_mycroft_core_location
+import time
+from os.path import dirname
+
+from watchdog.observers import Observer
+from watchdog.events import FileSystemEventHandler
 
 
 def get_temp_path(*args):
@@ -257,3 +262,40 @@ def read_translated_file(filename, data):
             return text.format(**data or {}).rstrip('\n').split('\n')
     else:
         return None
+
+
+class FileWatcher:
+    def __init__(self, files, callback, recursive=False, ignore_creation=False):
+        self.observer = Observer()
+        self.handlers = []
+        for file_path in files:
+            watch_dir = dirname(file_path)
+            self.observer.schedule(FileEventHandler(file_path, callback, ignore_creation),
+                                   watch_dir, recursive=recursive)
+        self.observer.start()
+
+    def shutdown(self):
+        self.observer.unschedule_all()
+        self.observer.stop()
+
+
+class FileEventHandler(FileSystemEventHandler):
+    def __init__(self, file_path, callback, ignore_creation=False):
+        super().__init__()
+        self._callback = callback
+        self._file_path = file_path
+        self._debounce = 1
+        self._last_update = 0
+        if ignore_creation:
+            self._events = ('modified')
+        else:
+            self._events = ('created', 'modified')
+
+    def on_any_event(self, event):
+        if event.is_directory:
+            return
+        elif event.event_type in self._events:
+            if event.src_path == self._file_path:
+                if time.time() - self._last_update >= self._debounce:
+                    self._callback(event.src_path)
+                    self._last_update = time.time()

requirements/requirements.txt

@@ -3,3 +3,4 @@ pexpect~=4.8
 requests~=2.26
 json_database~=0.7
 kthread~=0.2
+watchdog