[PATCH v5 04/14] perf jevents: Sort json files entries

[Ian Rogers <irogers@google.com>]

Sort the json files entries on conversion to C. The sort order tries to
replicated cmp_sevent from pmu.c so that the input there is already
sorted except for sysfs events. Specifically, the sort order is given by
the tuple:
(not j.desc is None, fix_none(j.topic), fix_none(j.name),
fix_none(j.pmu), fix_none(j.metric_name))
which is putting events with descriptions and topics before those
without, then sorting by name, then pmu and finally metric_name

Add the topic to JsonEvent on reading to simplify. Remove an unnecessary
lambda in the json reading.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/pmu-events/jevents.py | 48 +++++++++++++++++++++++---------
 1 file changed, 35 insertions(+), 13 deletions(-)

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index 31936eafa9ff..84fbb0f384cc 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -18,6 +18,8 @@ _sys_event_tables = []
 _arch_std_events = {}
 # Track whether an events table is currently being defined and needs closing.
 _close_table = False
+# Events to write out when the table is closed
+_pending_events = []
 
 
 def removesuffix(s: str, suffix: str) -> str:
@@ -128,6 +130,7 @@ class JsonEvent:
       eventcode |= int(jd['ExtSel']) << 8
     configcode = int(jd['ConfigCode'], 0) if 'ConfigCode' in jd else None
     self.name = jd['EventName'].lower() if 'EventName' in jd else None
+    self.topic = ''
     self.compat = jd.get('Compat')
     self.desc = fixdesc(jd.get('BriefDescription'))
     self.long_desc = fixdesc(jd.get('PublicDescription'))
@@ -200,7 +203,7 @@ class JsonEvent:
         s += f'\t{attr} = {value},\n'
     return s + '}'
 
-  def to_c_string(self, topic_local: str) -> str:
+  def to_c_string(self) -> str:
     """Representation of the event as a C struct initializer."""
 
     def attr_string(attr: str, value: str) -> str:
@@ -212,25 +215,27 @@ class JsonEvent:
       return attr_string(attr, getattr(self, attr))
 
     s = '{\n'
-    s += f'\t.topic = "{topic_local}",\n'
     for attr in [
         'aggr_mode', 'compat', 'deprecated', 'desc', 'event', 'long_desc',
         'metric_constraint', 'metric_expr', 'metric_group', 'metric_name',
-        'name', 'perpkg', 'pmu', 'unit'
+        'name', 'perpkg', 'pmu', 'topic', 'unit'
     ]:
       s += str_if_present(self, attr)
     s += '},\n'
     return s
 
 
-def read_json_events(path: str) -> Sequence[JsonEvent]:
+def read_json_events(path: str, topic: str) -> Sequence[JsonEvent]:
   """Read json events from the specified file."""
 
   try:
-    return json.load(open(path), object_hook=lambda d: JsonEvent(d))
+    result = json.load(open(path), object_hook=JsonEvent)
   except BaseException as err:
     print(f"Exception processing {path}")
     raise
+  for event in result:
+    event.topic = topic
+  return result
 
 
 def preprocess_arch_std_files(archpath: str) -> None:
@@ -238,7 +243,7 @@ def preprocess_arch_std_files(archpath: str) -> None:
   global _arch_std_events
   for item in os.scandir(archpath):
     if item.is_file() and item.name.endswith('.json'):
-      for event in read_json_events(item.path):
+      for event in read_json_events(item.path, topic=''):
         if event.name:
           _arch_std_events[event.name.lower()] = event
 
@@ -252,19 +257,36 @@ def print_events_table_prefix(tblname: str) -> None:
   _close_table = True
 
 
-def print_events_table_entries(item: os.DirEntry, topic: str) -> None:
-  """Create contents of an events table."""
+def add_events_table_entries(item: os.DirEntry, topic: str) -> None:
+  """Add contents of file to _pending_events table."""
   if not _close_table:
     raise IOError('Table entries missing prefix')
-  for event in read_json_events(item.path):
-    _args.output_file.write(event.to_c_string(topic))
+  for e in read_json_events(item.path, topic):
+    _pending_events.append(e)
 
 
 def print_events_table_suffix() -> None:
   """Optionally close events table."""
+
+  def event_cmp_key(j: JsonEvent):
+    def fix_none(s: str):
+      if s is None:
+        return ''
+      return s
+
+    return (not j.desc is None, fix_none(j.topic), fix_none(j.name), fix_none(j.pmu),
+            fix_none(j.metric_name))
+
   global _close_table
-  if _close_table:
-    _args.output_file.write("""{
+  if not _close_table:
+    return
+
+  global _pending_events
+  for event in sorted(_pending_events, key=event_cmp_key):
+    _args.output_file.write(event.to_c_string())
+    _pending_events = []
+
+  _args.output_file.write("""{
 \t.name = 0,
 \t.event = 0,
 \t.desc = 0,
@@ -307,7 +329,7 @@ def process_one_file(parents: Sequence[str], item: os.DirEntry) -> None:
   if not item.is_file() or not item.name.endswith('.json'):
     return
 
-  print_events_table_entries(item, get_topic(item.name))
+  add_events_table_entries(item, get_topic(item.name))
 
 
 def print_mapping_table(archs: Sequence[str]) -> None:
-- 
2.37.1.595.g718a3a8f04-goog