[PATCH v3 4/6] scripts: python: Add trace end processing and JSON output

[Anup Sharma]

Inside the trace end function the final output will be dumped
to standard output in JSON gecko format. Additionally, constants
such as USER_CATEGORY_INDEX, KERNEL_CATEGORY_INDEX, CATEGORIES, and
PRODUCT are defined to provide contextual information.

Signed-off-by: Anup Sharma <anupnewsmail@xxxxxxxxx>
---
 .../scripts/python/firefox-gecko-converter.py | 34 ++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/tools/perf/scripts/python/firefox-gecko-converter.py b/tools/perf/scripts/python/firefox-gecko-converter.py
index 0b8a86bdcab1..39818a603265 100644
--- a/tools/perf/scripts/python/firefox-gecko-converter.py
+++ b/tools/perf/scripts/python/firefox-gecko-converter.py
@@ -24,8 +24,40 @@ from Core import *
 thread_map = {}
 start_time = None
 
+# Follow Brendan Gregg's Flamegraph convention: orange for kernel and yellow for user
+CATEGORIES = [
+    {'name': 'User', 'color': 'yellow', 'subcategories': ['Other']},
+    {'name': 'Kernel', 'color': 'orange', 'subcategories': ['Other']}
+]
+
+# The product name is used by the profiler UI to show the Operating system and Processor.
+PRODUCT = os.popen('uname -op').read().strip()
+
 def trace_end():
-	pass
+    thread_array = thread_map.values()))
+
+    result = {
+        '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': thread_array,
+        'processes': [],
+        'pausedRanges': []
+    }
+    json.dump(result, sys.stdout, indent=2)
 
 def process_event(param_dict):
 	global start_time
-- 
2.34.1