set max window_size to avoid out-of-memory

can't have infinite window size due to memory restrictions, only keep statistics for the last 10000 messages so as not to run out of memory

Signed-off-by: Chris Ye <[email protected]>

ros2topic/ros2topic/verb/hz.py

@@ -118,8 +118,8 @@ def __init__(self, node, window_size, filter_expr=None, use_wtime=False):
         self.use_wtime = use_wtime
 
         # can't have infinite window size due to memory restrictions
-        if window_size < 0:
-            window_size = 50000
+        if window_size < 0 or window_size > 10000:
+            window_size = 10000
         self.window_size = window_size
 
         # Clock that has support for ROS time.
@@ -175,7 +175,7 @@ def callback_hz(self, m, topic=None):
         :param m: Message instance
         :param topic: Topic name
         """
-        # #694: ignore messages that don't match filter
+        # ignore messages that don't match filter
         if self.filter_expr is not None and not self.filter_expr(m):
             return
         with self.lock:
@@ -200,7 +200,7 @@ def callback_hz(self, m, topic=None):
                 self.set_msg_tn(curr, topic=topic)
 
             # only keep statistics for the last 10000 messages so as not to run out of memory
-            if len(self.get_times(topic=topic)) > 10000:
+            if len(self.get_times(topic=topic)) > self.window_size - 1:
                 self.get_times(topic=topic).pop(0)
 
     def get_hz(self, topic=None):