[tools/perf] Skip try job run if trybot config file does not change

tools/perf/core/trybot_command.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import argparse
 import os
 import logging
 import re
 import subprocess
 import urllib2
@@ skipping 226 matching lines @@
 
     Returns:
       (result, msg) where result is one of:
           SUCCESS if a tryjob was sent
           NO_CHANGES if there was nothing to try,
           ERROR if a tryjob was attempted but an error encountered
           and msg is an error message if an error was encountered, or rietveld
           url if success, otherwise throws TrybotError exception.
     """
     config = self._GetPerfConfig(bot_platform, arguments)
+    config_to_write = 'config = %s' % json.dumps(
+        config, sort_keys=True, indent=2, separators=(',', ': '))
+
     try:
-      config_file = open(cfg_file_path, 'w')
+      with open(cfg_file_path, 'r') as config_file:
+        if config_to_write == config_file.read():
+          return NO_CHANGES, ''
     except IOError:
       msg = 'Cannot find %s. Please run from src dir.' % cfg_file_path
       return (ERROR, msg)
-    config_file.write('config = %s' % json.dumps(
-        config, sort_keys=True, indent=2, separators=(',', ': ')))
-    config_file.close()
+
+    with open(cfg_file_path, 'w') as config_file:
+      config_file.write(config_to_write)
     # Commit the config changes locally.
     returncode, out, err = _RunProcess(
         ['git', 'commit', '-a', '-m', 'bisect config: %s' % bot_platform])
     if returncode:
       raise TrybotError('Could not commit bisect config change for %s,'
                         ' error %s' % (bot_platform, err))
     # Upload the CL to rietveld and run a try job.
     returncode, out, err = _RunProcess([
         'git', 'cl', 'upload', '-f', '--bypass-hooks', '-m',
         'CL for perf tryjob on %s' % bot_platform
@@ skipping 122 matching lines @@
       for bot_platform in self._builder_names:
         if not self._builder_names[bot_platform]:
           logging.warning('No builder is found for %s', bot_platform)
           continue
         try:
           results, output = self._UpdateConfigAndRunTryjob(
               bot_platform, cfg_file_path, arguments)
           if results == ERROR:
             logging.error(output)
             return ERROR
-          print ('Uploaded %s try job to rietveld for %s platform. '
-                 'View progress at %s' % (source_repo, bot_platform, output))
+          elif results == NO_CHANGES:
+            print ('Skip the try job run on %s because it has been tried in '
+                   'previous try job run. ' % bot_platform)
+          else:

[sullivan, 2016/03/03 06:31:59]

Shouldn't this use logging api?

[nednguyen, 2016/03/03 06:52:23]

I am unsure with logging to use, error, warning & debug don't seem right. I
think it's ok to surface this kind of info to the users, hence we use print
here.

+            print ('Uploaded %s try job to rietveld for %s platform. '
+                   'View progress at %s' % (source_repo, bot_platform, output))
         except TrybotError, err:
           print err
           logging.error(err)
     finally:
       # Checkout original branch and delete telemetry-tryjob branch.
       # TODO(prasadv): This finally block could be extracted out to be a
       # separate function called _CleanupBranch.
       returncode, out, err = _RunProcess(
           ['git', 'checkout', original_branchname])
       if returncode:
         logging.error('Could not check out %s. Please check it out and '
                       'manually delete the telemetry-tryjob branch. '
                       ': %s', original_branchname, err)
         return ERROR  # pylint: disable=lost-exception
       logging.info('Checked out original branch: %s', original_branchname)
       returncode, out, err = _RunProcess(
           ['git', 'branch', '-D', 'telemetry-tryjob'])
       if returncode:
         logging.error('Could not delete telemetry-tryjob branch. '
                       'Please delete it manually: %s', err)
         return ERROR  # pylint: disable=lost-exception
       logging.info('Deleted temp branch: telemetry-tryjob')
     return SUCCESS