Support streaming in juggle.py (#20982)

* add --stream to juggle.py

* better

* rm old code

* for loopify

* clean up

* easier to pick out

* start by default

* don't exit

* Update tools/plotjuggler/juggle.py

Co-authored-by: Adeeb Shihadeh <adeebshihadeh@gmail.com>

* Revert "start by default"

This reverts commit 6cb481a6fdc2b401693a46be8d17553c1c00cc0f.

* Revert "don't exit"

This reverts commit 861b423eb8e259c8353586f3314ea8bad871f15a.

* rm

* move out of juggle_route

* Update PJ README.md

* Update tools/plotjuggler/README.md

* this is in the readme

* Updates

Co-authored-by: Adeeb Shihadeh <adeebshihadeh@gmail.com>
old-commit-hash: 63e521935e

tools/plotjuggler/juggle.py

@@ -24,21 +24,25 @@ def load_segment(segment_name):
     print(f"Error parsing {segment_name}: {e}")
     return []
 
-def juggle_file(fn, dbc=None, layout=None):
+def start_juggler(fn=None, dbc=None, layout=None):
   env = os.environ.copy()
   env["BASEDIR"] = BASEDIR
+  pj = os.getenv("PLOTJUGGLER_PATH", "plotjuggler")
 
   if dbc:
     env["DBC_NAME"] = dbc
 
-  pj = os.getenv("PLOTJUGGLER_PATH", "plotjuggler")
-  extra_args = ""
+  extra_args = []
+  if fn is not None:
+    extra_args.append(f'-d {fn}')
+
   if layout is not None:
-    extra_args += f'-l {layout}'
-  subprocess.call(f'{pj} --plugin_folders {os.path.join(juggle_dir, "bin")} -d {fn} {extra_args}', shell=True, env=env, cwd=juggle_dir)
+    extra_args.append(f'-l {layout}')
+
+  extra_args = " ".join(extra_args)
+  subprocess.call(f'{pj} --plugin_folders {os.path.join(juggle_dir, "bin")} {extra_args}', shell=True, env=env, cwd=juggle_dir)
 
 def juggle_route(route_name, segment_number, qlog, can, layout):
-
   if route_name.startswith("http://") or route_name.startswith("https://") or os.path.isfile(route_name):
     logs = [route_name]
   else:
@@ -80,7 +84,7 @@ def juggle_route(route_name, segment_number, qlog, can, layout):
   save_log(tempfile.name, all_data, compress=False)
   del all_data
 
-  juggle_file(tempfile.name, dbc, layout)
+  start_juggler(tempfile.name, dbc, layout)
 
 def get_arg_parser():
   parser = argparse.ArgumentParser(description="PlotJuggler plugin for reading rlogs",
@@ -88,6 +92,7 @@ def get_arg_parser():
 
   parser.add_argument("--qlog", action="store_true", help="Use qlogs")
   parser.add_argument("--can", action="store_true", help="Parse CAN data")
+  parser.add_argument("--stream", action="store_true", help="Start PlotJuggler without a route to stream data using Cereal")
   parser.add_argument("--layout", nargs='?', help="Run PlotJuggler with a pre-defined layout")
   parser.add_argument("route_name", nargs='?', help="The name of the route that will be plotted.")
   parser.add_argument("segment_number", type=int, nargs='?', help="The index of the segment that will be plotted")
@@ -99,4 +104,8 @@ if __name__ == "__main__":
     arg_parser.print_help()
     sys.exit()
   args = arg_parser.parse_args(sys.argv[1:])
-  juggle_route(args.route_name, args.segment_number, args.qlog, args.can, args.layout)
+
+  if args.stream:
+    start_juggler()
+  else:
+    juggle_route(args.route_name, args.segment_number, args.qlog, args.can, args.layout)