Vulcanize MD History to improve page-load performance

chrome/browser/resources/vulcanize.py

 #!/usr/bin/env python
-# Copyright 2015 The Chromium Authors. All rights reserved.
+# Copyright 2016 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 os
 import subprocess
 import sys
 import tempfile
 
+# See //docs/vulcanize.md for instructions on installing prerequistes and
+# running the vulcanize build.
 
 _HERE_PATH = os.path.join(os.path.dirname(__file__))
-
-_HTML_IN_PATH = os.path.join(_HERE_PATH, 'downloads.html')
-_HTML_OUT_PATH = os.path.join(_HERE_PATH, 'vulcanized.html')
-_JS_OUT_PATH = os.path.join(_HERE_PATH, 'crisper.js')
-
-_SRC_PATH = os.path.normpath(os.path.join(_HERE_PATH, '..', '..', '..', '..'))
+_SRC_PATH = os.path.normpath(os.path.join(_HERE_PATH, '..', '..', '..'))
 
 _RESOURCES_PATH = os.path.join(_SRC_PATH, 'ui', 'webui', 'resources')
 
 _CR_ELEMENTS_PATH = os.path.join(_RESOURCES_PATH, 'cr_elements')
 _CSS_RESOURCES_PATH = os.path.join(_RESOURCES_PATH, 'css')
 _HTML_RESOURCES_PATH = os.path.join(_RESOURCES_PATH, 'html')
 _JS_RESOURCES_PATH = os.path.join(_RESOURCES_PATH, 'js')
-
 _POLYMER_PATH = os.path.join(
     _SRC_PATH, 'third_party', 'polymer', 'v1_0', 'components-chromium')
 
-_VULCANIZE_ARGS = [
+_VULCANIZE_BASE_ARGS = [
   '--exclude', 'crisper.js',
 
   # These files are already combined and minified.
   '--exclude', 'chrome://resources/html/polymer.html',
   '--exclude', 'web-animations-next-lite.min.js',
 
   # These files are dynamically created by C++.
   '--exclude', 'load_time_data.js',
   '--exclude', 'strings.js',
   '--exclude', 'text_defaults.css',
   '--exclude', 'text_defaults_md.css',
 
   '--inline-css',
   '--inline-scripts',
 
-  '--redirect', 'chrome://downloads/|%s' % _HERE_PATH,
   '--redirect', 'chrome://resources/cr_elements/|%s' % _CR_ELEMENTS_PATH,
   '--redirect', 'chrome://resources/css/|%s' % _CSS_RESOURCES_PATH,
   '--redirect', 'chrome://resources/html/|%s' % _HTML_RESOURCES_PATH,
   '--redirect', 'chrome://resources/js/|%s' % _JS_RESOURCES_PATH,
   '--redirect', 'chrome://resources/polymer/v1_0/|%s' % _POLYMER_PATH,
 
   '--strip-comments',
 ]
 
-def main():
+
+def _vulcanize(directory, host, html_in_file, html_out_file='vulcanized.html',
+               js_out_file='crisper.js', extra_args=None):

[Dan Beam, 2016/08/11 05:44:34]

can we me all of these keywords?  looking at the callsites of _vulcanize(),
nothing is particularly intuitive and they seem easy-ish to mess up

directory=directory, host=host, html_in_file=html_in_file

[tsergeant, 2016/08/15 05:54:18]

Done. I can just use them as keyword arguments from the callsites, there's no
need to change anything in the function signature (and no way to force them to
be used as keyword arguments).

   def _run_cmd(cmd_parts, stdout=None):
     cmd = "'" + "' '".join(cmd_parts) + "'"
     process = subprocess.Popen(
         cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
     stdout, stderr = process.communicate()
 
     if stderr:
       print >> sys.stderr, '%s failed: %s' % (cmd, stderr)
       raise
 
     return stdout
 
-  output = _run_cmd(['vulcanize'] + _VULCANIZE_ARGS + [_HTML_IN_PATH])
+  print 'Vulcanizing %s' % directory
+
+  target_path = os.path.join(_HERE_PATH, directory)
+  html_in_path = os.path.join(target_path, html_in_file)
+  html_out_path = os.path.join(target_path, html_out_file)
+  js_out_path = os.path.join(target_path, js_out_file)
+  extra_args = extra_args or []
+
+  output = _run_cmd(['vulcanize'] + _VULCANIZE_BASE_ARGS + extra_args +
+                    ['--redirect', 'chrome://%s/|%s' % (host, target_path),
+                     html_in_path])
 
   with tempfile.NamedTemporaryFile(mode='wt+', delete=False) as tmp:
+    # Grit includes are not supported, use HTML imports instead.
     tmp.write(output.replace(
-        '<include src="', '<include src="../../../../ui/webui/resources/js/'))
+        '<include src="', '<include src-disabled="'))
 
   try:
     _run_cmd(['crisper', '--source', tmp.name,
                          '--script-in-head', 'false',
-                         '--html', _HTML_OUT_PATH,
-                         '--js', _JS_OUT_PATH])
+                         '--html', html_out_path,
+                         '--js', js_out_path])
   finally:
     os.remove(tmp.name)
 
 
+def main():
+  _vulcanize('md_downloads', 'downloads', 'downloads.html')

[Dan Beam, 2016/08/11 05:44:34]

and then from each callsite use the keywords because it's way easier to read,
IMO

_vulcanize(directory='md_downloads', host='downloads',
           html_in_file='downloads.html')

etc.

[tsergeant, 2016/08/15 05:54:18]

Done.

+
+  # Already loaded by history.html:
+  history_extra_args = ['--exclude', 'chrome://resources/html/util.html',
+                        '--exclude', 'chrome://history/constants.html']
+  _vulcanize('md_history', 'history', 'app.html', 'app.vulcanized.html',
+             'app.crisper.js', history_extra_args)
+
+
 if __name__ == '__main__':
   main()