Plot horizon distance from ranking statistics

This MR will change the horizon distance plotting program in the DAG: instead of creating one horizon distance plot from reference PSDs, the new program create the horizon distance from the ranking statistic for each template bank bin. The main changes that affect the DAG workflow are summarized below:

• gstlal_inspiral_pipe: change plotting program from gstlal_plot_psd_horizon to gstlal_inspiral_plot_rankingstats_horizon (previously called gstlal_inspiral_plot_psd_horizon which does not accurately describe what it actually does, also see miscellaneous changes below).
• inspiral.py: update the horizon_dist_layer for the new plotting program.
• gstlal_inspiral_summary_page: horizon distances plots are put inside a new UI component (report.ImagePagination) so that all the plots will not be fetched at the same time and can be paginated.
• make the above changes to new style DAG workflow as well.

Miscellaneous changes:

• add new plotting module called horizon.py
• update the gstlal_plot_psd_horizon to use horizon.py module,
• renamed gstlal_inspiral_plot_psd_horizon --> gstlal_inspiral_plot_rankingstats_horizon

Note: this MR depends on gstlal-visualisation/ligo-scald!36 (merged), it's better not to merged before that request has been merged.

gstlal/python/stream.py

@@ -31,6 +31,7 @@ from collections import namedtuple
 from collections.abc import Mapping
 import functools
 import io
+import os
 import sys
 import uuid
 
@@ -73,7 +74,7 @@ class Stream(object):
 	"""
 	thread_init = False
 
-	def __init__(self, mainloop=None, pipeline=None, handler=None, source=None, head=None):
+	def __init__(self, name=None, mainloop=None, pipeline=None, handler=None, source=None, head=None):
 		# initialize threads if not set
 		if not self.thread_init:
 			GObject.threads_init()
@@ -81,8 +82,9 @@ class Stream(object):
 			self.thread_init = True
 
 		# set up gstreamer pipeline
+		self.name = name if name else str(uuid.uuid1())
 		self.mainloop = mainloop if mainloop else GObject.MainLoop()
-		self.pipeline = pipeline if pipeline else Gst.Pipeline(str(uuid.uuid1()))
+		self.pipeline = pipeline if pipeline else Gst.Pipeline(self.name)
 		self.handler = handler if handler else StreamHandler(self.mainloop, self.pipeline)
 		self.head = head if head else None
 
@@ -98,6 +100,19 @@ class Stream(object):
 		if not self.source.is_live:
 			self._seek_gps()
 		self._set_state(Gst.State.PLAYING)
+
+		## Debugging output
+		if os.environ.get("GST_DEBUG_DUMP_DOT_DIR", False):
+			name = self.pipeline.get_name()
+			pipeparts.write_dump_dot(self.pipeline, f"{name}_PLAYING", verbose=True)
+
+			## Setup a signal handler to intercept SIGINT in order to write
+			## the pipeline graph at ctrl+C before cleanly shutting down
+			class SigHandler(simplehandler.OneTimeSignalHandler):
+				def do_on_call(self, signum, frame):
+					pipeparts.write_dump_dot(self.pipeline, f"{name}_SIGINT", verbose=True)
+			sighandler = SigHandler(self.pipeline)
+
 		self.mainloop.run()
 
 	@classmethod
@@ -112,6 +127,7 @@ class Stream(object):
 					for key, elem in head.items():
 						new_head = {
 							key: cls(
+								name=self.name,
 								mainloop=self.mainloop,
 								pipeline=self.pipeline,
 								handler=self.handler,
@@ -122,6 +138,7 @@ class Stream(object):
 					return new_head
 				else:
 					return cls(
+						name=self.name,
 						mainloop=self.mainloop,
 						pipeline=self.pipeline,
 						handler=self.handler,
@@ -143,6 +160,9 @@ class Stream(object):
 		)
 		return stream
 
+	def connect(self, *args, **kwargs):
+		self.head.connect(*args, **kwargs)
+
 	def sink(self, func):
 		def sample_handler(elem):
 			buf = self._pull_buffer(elem)