bicycle_statistics: Transformed to file system event driven service

Signed-off-by: Thomas Klaehn <thomas.klaehn@u-blox.com>

input_observer/__init__.py

@@ -0,0 +1,31 @@
+from watchdog.events import PatternMatchingEventHandler
+
+import threading
+
+class InputObserver(PatternMatchingEventHandler):
+    def __init__(self, patterns=None, ignore_patterns=None,
+                 ignore_directories=False, case_sensitive=False):
+        super(InputObserver, self).__init__(patterns, ignore_patterns,
+                                            ignore_directories, case_sensitive)
+
+        self.lock = threading.Lock()
+        self.lock.acquire()
+        self.new_filename = None
+        self.run_condition = True
+
+
+    def on_created(self, event):
+        self.new_filename = event.src_path
+        self.lock.release()
+
+
+    def get_new_file(self):
+        self.lock.acquire() # don't release - will be released with next on_created
+        if self.run_condition == True:
+            return self.new_filename
+        else:
+            return None
+
+    def stop(self):
+        self.run_condition = False
+        self.lock.release()