feature_extractor.py: disable spectrum message handling for performance

gstlal-burst/python/snax/feature_extractor.py

@@ -204,15 +204,18 @@ class MultiChannelHandler(simplehandler.Handler):
 		# it should ignore it.  a return value of False means the
 		# parent class should do what it thinks should be done
 		#
-		if message.type == Gst.MessageType.ELEMENT:
-			if message.get_structure().get_name() == "spectrum":
-				# get the channel name & psd.
-				instrument, info = message.src.get_name().split("_", 1)
-				channel, _ = info.rsplit("_", 1)
-				psd = pipeio.parse_spectrum_message(message)
-				# save psd
-				self.psds[channel] = psd
-				return True		
+		# FIXME: disable PSD handling as it is a significant
+		# cost in parsing a large number of channels. reconsider
+		# re-enabling in the future
+		#if message.type == Gst.MessageType.ELEMENT:
+		#	if message.get_structure().get_name() == "spectrum":
+		#		# get the channel name & psd.
+		#		instrument, info = message.src.get_name().split("_", 1)
+		#		channel, _ = info.rsplit("_", 1)
+		#		psd = pipeio.parse_spectrum_message(message)
+		#		# save psd
+		#		self.psds[channel] = psd
+		#		return True
 		return False
 
 	def bufhandler(self, elem, sink_dict):