Have pretty_print.py find histograms.xml.

tools/metrics/histograms/pretty_print.py

 #!/usr/bin/env python
 # Copyright 2013 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.
 
 """Pretty-prints the histograms.xml file, alphabetizing tags, wrapping text
 at 80 chars, enforcing standard attribute ordering, and standardizing
 indentation.
 
 This is quite a bit more complicated than just calling tree.toprettyxml();
 we need additional customization, like special attribute ordering in tags
 and wrapping text nodes, so we implement our own full custom XML pretty-printer.
 """
 
 from __future__ import with_statement
 
 import diffutil
 import json
 import logging
+import os
 import shutil
 import sys
 import textwrap
 import xml.dom.minidom
 
+sys.path.insert(1, os.path.join(sys.path[0], '..', '..', 'python'))

[Ilya Sherman, 2013/12/27 21:48:05]

Hmm, I hadn't noticed that this was needed to support path_utils... that's
pretty silly.  Still, though, I think the resulting code is cleaner this way
than as it was before, and also matches extract_actions.py, which is nice. 
Thanks!

+from google import path_utils
 
 WRAP_COLUMN = 80
 
 # Desired order for tag attributes; attributes listed here will appear first,
 # and in the same order as in these lists.
 # { tag_name: [attribute_name, ...] }
 ATTRIBUTE_ORDER = {
   'enum': ['name', 'type'],
   'histogram': ['name', 'enum', 'units'],
   'int': ['value', 'label'],
@@ skipping 274 matching lines @@
   tree = xml.dom.minidom.parseString(raw_xml)
   tree = TransformByAlphabetizing(tree)
   return PrettyPrintNode(tree)
 
 
 def main():
   logging.basicConfig(level=logging.INFO)
 
   presubmit = ('--presubmit' in sys.argv)
 
+  script_dir = path_utils.ScriptDir()
+
   logging.info('Loading histograms.xml...')
-  with open('histograms.xml', 'rb') as f:
+  with open(os.path.join(script_dir, 'histograms.xml'), 'rb') as f:
     xml = f.read()
 
   # Check there are no CR ('\r') characters in the file.
   if '\r' in xml:
     logging.info('DOS-style line endings (CR characters) detected - these are '
                  'not allowed. Please run dos2unix histograms.xml')
     sys.exit(1)
 
   logging.info('Pretty-printing...')
   try:
     pretty = PrettyPrint(xml)
   except Error:
     logging.error('Aborting parsing due to fatal errors.')
     sys.exit(1)
 
   if xml == pretty:
     logging.info('histograms.xml is correctly pretty-printed.')
     sys.exit(0)
   if presubmit:
     logging.info('histograms.xml is not formatted correctly; run '
                  'pretty_print.py to fix.')
     sys.exit(1)
   if not diffutil.PromptUserToAcceptDiff(
       xml, pretty,
       'Is the prettified version acceptable?'):
     logging.error('Aborting')
     return
 
   logging.info('Creating backup file histograms.before.pretty-print.xml')
-  shutil.move('histograms.xml', 'histograms.before.pretty-print.xml')
+  shutil.move(os.path.join(script_dir, 'histograms.xml'),
+              os.path.join(script_dir, 'histograms.before.pretty-print.xml'))

[Ilya Sherman, 2013/12/27 21:48:05]

nit: Please declare named constants for the file names, especially so that you
don't need to repeat "os.path.join(script_dir, 'histograms.xml')" throughout.

[gavinp, 2014/01/06 17:36:07]

Done. I did this with automatic variables though in the function scope (like
script_dir), to maintain locality of reference, which I think enhances
readability. Let me know if you want me to change these.

[Ilya Sherman, 2014/01/06 23:22:36]

This is fine, thanks.

 
   logging.info('Writing new histograms.xml file')
-  with open('histograms.xml', 'wb') as f:
+  with open(os.path.join(script_dir, 'histograms.xml'), 'wb') as f:
     f.write(pretty)
 
 
 if __name__ == '__main__':
   main()