catapipe: add support for COUNTER events

Differential Revision: https://phab.mercurial-scm.org/D6524

contrib/catapipe.py

@@ -1,98 +1,104
 #!/usr/bin/env python3
 #
 # Copyright 2018 Google LLC.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 """Tool read primitive events from a pipe to produce a catapult trace.
 
 Usage:
     Terminal 1: $ catapipe.py /tmp/mypipe /tmp/trace.json
     Terminal 2: $ HGCATAPULTSERVERPIPE=/tmp/mypipe hg root
     <ctrl-c catapipe.py in Terminal 1>
     $ catapult/tracing/bin/trace2html /tmp/trace.json  # produce /tmp/trace.html
     <open trace.html in your browser of choice; the WASD keys are very useful>
     (catapult is located at https://github.com/catapult-project/catapult)
 
 For now the event stream supports
 
   START $SESSIONID ...
 
 and
 
   END $SESSIONID ...
 
 events. Everything after the SESSIONID (which must not contain spaces)
 is used as a label for the event. Events are timestamped as of when
 they arrive in this process and are then used to produce catapult
 traces that can be loaded in Chrome's about:tracing utility. It's
 important that the event stream *into* this process stay simple,
 because we have to emit it from the shell scripts produced by
 run-tests.py.
 
 Typically you'll want to place the path to the named pipe in the
 HGCATAPULTSERVERPIPE environment variable, which both run-tests and hg
 understand. To trace *only* run-tests, use HGTESTCATAPULTSERVERPIPE instead.
 """
 from __future__ import absolute_import, print_function
 
 import argparse
 import json
 import os
 import timeit
 
 _TYPEMAP = {
     'START': 'B',
     'END': 'E',
+    'COUNTER': 'C',
 }
 
 _threadmap = {}
 
 # Timeit already contains the whole logic about which timer to use based on
 # Python version and OS
 timer = timeit.default_timer
 
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('pipe', type=str, nargs=1,
                         help='Path of named pipe to create and listen on.')
     parser.add_argument('output', default='trace.json', type=str, nargs='?',
                         help='Path of json file to create where the traces '
                              'will be stored.')
     parser.add_argument('--debug', default=False, action='store_true',
                         help='Print useful debug messages')
     args = parser.parse_args()
     fn = args.pipe[0]
     os.mkfifo(fn)
     try:
         with open(fn) as f, open(args.output, 'w') as out:
             out.write('[\n')
             start = timer()
             while True:
                 ev = f.readline().strip()
                 if not ev:
                     continue
                 now = timer()
                 if args.debug:
                     print(ev)
                 verb, session, label = ev.split(' ', 2)
                 if session not in _threadmap:
                     _threadmap[session] = len(_threadmap)
+                if verb == 'COUNTER':
+                    amount, label = label.split(' ', 1)
+                    payload_args = {'value': int(amount)}
+                else:
+                    payload_args = {}
                 pid = _threadmap[session]
                 ts_micros = (now - start) * 1000000
                 out.write(json.dumps(
                     {
                         "name": label,
                         "cat": "misc",
                         "ph": _TYPEMAP[verb],
                         "ts": ts_micros,
                         "pid": pid,
                         "tid": 1,
-                        "args": {}
+                        "args": payload_args,
                     }))
                 out.write(',\n')
     finally:
         os.unlink(fn)
 
 if __name__ == '__main__':
     main()