perf scripts python: Add trace end processing and PRODUCT and CATEGORIES information

The final output will now be presented in JSON format following the Gecko
profile structure. Additionally, the inclusion of PRODUCT allows easy retrieval
of header information for UI.

Furthermore, CATEGORIES have been introduced to enable customization of
kernel and user colors using input arguments. To facilitate this functionality,
an argparse-based parser has been implemented.

Note: The implementation of threads will be addressed in subsequent commits
for now I have commented it out.
Signed-off-by: Anup Sharma <anupnewsmail@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/fa6d027e4134c48e8a2ea45dd8f6b21e6a3418e4.1689961706.git.anupnewsmail@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/scripts/python/gecko.py

@@ -11,6 +11,8 @@
 
 import os
 import sys
+import json
+import argparse
 from dataclasses import dataclass, field
 from typing import List, Dict, Optional, NamedTuple, Set, Tuple, Any
 
@@ -30,6 +32,13 @@ Milliseconds = float
 # start_time is intialiazed only once for the all event traces.
 start_time = None
 
+# https://github.com/firefox-devtools/profiler/blob/53970305b51b9b472e26d7457fee1d66cd4e2737/src/types/profile.js#L425
+# Follow Brendan Gregg's Flamegraph convention: orange for kernel and yellow for user space by default.
+CATEGORIES = None
+
+# The product name is used by the profiler UI to show the Operating system and Processor.
+PRODUCT = os.popen('uname -op').read().strip()
+
 # https://github.com/firefox-devtools/profiler/blob/53970305b51b9b472e26d7457fee1d66cd4e2737/src/types/gecko-profile.js#L156
 class Frame(NamedTuple):
 	string_id: StringID
@@ -171,4 +180,58 @@ def process_event(param_dict: Dict) -> None:
 # Trace_end runs at the end and will be used to aggregate
 # the data into the final json object and print it out to stdout.
 def trace_end() -> None:
-	pass
+	# Schema: https://github.com/firefox-devtools/profiler/blob/53970305b51b9b472e26d7457fee1d66cd4e2737/src/types/gecko-profile.js#L305
+	gecko_profile_with_meta = {
+		"meta": {
+			"interval": 1,
+			"processType": 0,
+			"product": PRODUCT,
+			"stackwalk": 1,
+			"debug": 0,
+			"gcpoison": 0,
+			"asyncstack": 1,
+			"startTime": start_time,
+			"shutdownTime": None,
+			"version": 24,
+			"presymbolicated": True,
+			"categories": CATEGORIES,
+			"markerSchema": [],
+			},
+		"libs": [],
+		# threads will be implemented in later commits.
+		# "threads": threads,
+		"processes": [],
+		"pausedRanges": [],
+	}
+	json.dump(gecko_profile_with_meta, sys.stdout, indent=2)
+
+def main() -> None:
+	global CATEGORIES
+	parser = argparse.ArgumentParser(description="Convert perf.data to Firefox\'s Gecko Profile format")
+
+	# Add the command-line options
+	# Colors must be defined according to this:
+	# https://github.com/firefox-devtools/profiler/blob/50124adbfa488adba6e2674a8f2618cf34b59cd2/res/css/categories.css
+	parser.add_argument('--user-color', default='yellow', help='Color for the User category')
+	parser.add_argument('--kernel-color', default='orange', help='Color for the Kernel category')
+	# Parse the command-line arguments
+	args = parser.parse_args()
+	# Access the values provided by the user
+	user_color = args.user_color
+	kernel_color = args.kernel_color
+
+	CATEGORIES = [
+		{
+			"name": 'User',
+			"color": user_color,
+			"subcategories": ['Other']
+		},
+		{
+			"name": 'Kernel',
+			"color": kernel_color,
+			"subcategories": ['Other']
+		},
+	]
+
+if __name__ == '__main__':
+    main()