Script to populate the XML for the CSS property UseCounter.

tools/metrics/histograms/update_use_counter_css.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 """Scans the Chromium source of UseCounter, formats the Feature enum for
 histograms.xml and merges it. This script can also generate a python code
 snippet to put in uma.py of Chromium Dashboard. Make sure that you review the
 output for correctness.
 """
 
 import optparse
 import os
+import re
 import sys
 
 sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common'))
 from update_histogram_enum import ReadHistogramValues
-from update_histogram_enum import UpdateHistogramEnum
+from update_histogram_enum import UpdateHistogramFromDict
+
+
+USE_COUNTER_CPP_PATH = \
+    '../../../third_party/WebKit/Source/core/frame/UseCounter.cpp'
 
 
 def print_enum_for_dashboard(enum_dict):

[Mike Lawther (Google), 2014/05/08 07:29:50]

I wasn't sure where to factor this function to. Suggestions?

[Mike Lawther (Google), 2014/05/09 01:11:03]

I ended up just pulling it from the original location.

   """Prints enum_items formatted for use in uma.py of Chromium dashboard."""
   for key in sorted(enum_dict.iterkeys()):
     print '  %d: \'%s\',' % (key, enum_dict[key])
 

[tyoshino (SeeGerritForStatus), 2014/05/08 08:06:53]

two vertical spaces plz

http://google-styleguide.googlecode.com/svn/trunk/pyguide.html?showone=Blank_...

[Mike Lawther (Google), 2014/05/09 01:11:03]

Done. 

It looks like the presubmit picks up some double verts and not others.

+def enum_to_css(enum_name):

[tyoshino (SeeGerritForStatus), 2014/05/08 08:06:53]

enum_to_css_property

[Mike Lawther (Google), 2014/05/09 01:11:03]

Done.

+  """Converts a camel cased enum name to the lower case CSS property"""

[tyoshino (SeeGerritForStatus), 2014/05/08 08:06:53]

period plz

[Mike Lawther (Google), 2014/05/09 01:11:03]

Done.

+  return re.sub(r'([a-zA-Z])([A-Z])', r'\1-\2', enum_name).lower()
+

[tyoshino (SeeGerritForStatus), 2014/05/08 08:06:53]

ditto

[Mike Lawther (Google), 2014/05/09 01:11:03]

Done.

+def read_css_properties(filename):
+  # Read the file as a list of lines
+  with open(filename) as f:
+    content = f.readlines()
+
+  # Looking for a line like "case CSSPropertyGrid: return 453;"
+  bucket_finder = re.compile(r'.*CSSProperty(.*):\s*return\s*([0-9]+).*')
+
+  bucket_dict = {}
+  for line in content:
+    bucket_match = bucket_finder.match(line)
+    if bucket_match:
+      css_property = bucket_match.group(1)
+      bucket = int(bucket_match.group(2))
+      bucket_dict[bucket] = enum_to_css(css_property)

[tyoshino (SeeGerritForStatus), 2014/05/08 08:06:53]

this call looks weird.

how about s/css_property/enum_name/?

[Mike Lawther (Google), 2014/05/09 01:11:03]

Done.

+
+  return bucket_dict
 

[tyoshino (SeeGerritForStatus), 2014/05/08 08:06:53]

ditto

[Mike Lawther (Google), 2014/05/09 01:11:03]

Done.

 if __name__ == '__main__':
   parser = optparse.OptionParser()

[Mike Lawther (Google), 2014/05/08 07:29:50]

Is it worth factoring these lines out somewhere?

   parser.add_option('--for-dashboard', action='store_true', dest='dashboard',
                     default=False,
                     help='Print enum definition formatted for use in uma.py of '
                     'Chromium dashboard developed at '
                     'https://github.com/GoogleChrome/chromium-dashboard')
   options, args = parser.parse_args()
 
-  source_path = os.path.join(
-      '..', '..', '..',
-      'third_party', 'WebKit', 'Source', 'core', 'frame', 'UseCounter.h')
-
-  START_MARKER = '^enum Feature {'
-  END_MARKER = '^NumberOfFeatures'
-
   if options.dashboard:
-    enum_dict = ReadHistogramValues(source_path, START_MARKER, END_MARKER)
+    enum_dict = read_css_properties(USE_COUNTER_CPP_PATH)
     print_enum_for_dashboard(enum_dict)
   else:
-    UpdateHistogramEnum(
-        histogram_enum_name='FeatureObserver',
-        source_enum_path=source_path,
-        start_marker=START_MARKER,
-        end_marker=END_MARKER)
+    UpdateHistogramFromDict(
+      'MappedCSSProperties', read_css_properties(USE_COUNTER_CPP_PATH),

[tyoshino (SeeGerritForStatus), 2014/05/08 08:06:53]

4 space indentation

[Mike Lawther (Google), 2014/05/09 01:11:03]

Done.

+      USE_COUNTER_CPP_PATH)