Load non-locale .pak files directly from the .apk on Android (rather than extracting on start-up).

build/android/gyp/locale_pak_resources.py

 #!/usr/bin/env python
 #
 # 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.
 """Creates a resources.zip for locale .pak files.
 
 Places the locale.pak files into appropriate resource configs
-(e.g. en-GB.pak -> res/raw-en/en_gb.pak). Also generates a locale_paks
+(e.g. en-GB.pak -> res/raw-en/en_gb.lpak). Also generates a locale_paks
 TypedArray so that resource files can be enumerated at runtime.
 """
 
 import collections
 import optparse
 import os
 import sys
 import zipfile
 
 from util import build_utils
 
 
 # This should stay in sync with:
 # base/android/java/src/org/chromium/base/LocaleUtils.java
 _CHROME_TO_ANDROID_LOCALE_MAP = {
     'he': 'iw',
     'id': 'in',
     'fil': 'tl',
 }
 
 
+def ToResourceFileName(name):
+  """Returns the resource-compatible file name for the given file."""
+  # Resources file names must consist of [a-z0-9_.].
+  # Changes extension to .lpak so that compression can be toggled separately for
+  # locale pak files vs other pak files.
+  return name.replace('-', '_').replace('.pak', '.lpak').lower()

[cjhopman, 2015/06/17 21:47:50]

What do you think of changing it so that we just use a special extension for
things (these pak files, icudtl, maybe the v8 snapshots) that we want
uncompressed (like .uncompressed, or something shorter)?

Could maybe just handle it in the thing that opens apk assets, too.

[agrieve, 2015/06/18 15:50:41]

I went down this path for a little while, but abandoned it:
- The build rules for assets are quite copy & pasted, and to rename the assets
for every target would be a lot of work.
- For locale paks, we want to store them uncompressed in splits, but compressed
in non-splits. Would complicate the code if they had different names.
- The aapt command for marking files as do-not-store actually does suffix
matches instead of just extension matches (so we do have the ability to be more
specific about which files to not compress if we wanted to)

+
+
 def CreateLocalePaksXml(names):
   """Creates the contents for the locale-paks.xml files."""
   VALUES_FILE_TEMPLATE = '''<?xml version="1.0" encoding="utf-8"?>
 <resources>
   <array name="locale_paks">%s
   </array>
 </resources>
 '''
   VALUES_ITEM_TEMPLATE = '''
     <item>@raw/%s</item>'''
@@ skipping 13 matching lines @@
   build_utils.CheckOptions(options, parser,
                            required=['locale_paks', 'resources_zip'])
 
   sources = build_utils.ParseGypList(options.locale_paks)
 
   if options.depfile:
     deps = sources + build_utils.GetPythonDependencies()
     build_utils.WriteDepfile(options.depfile, deps)
 
   with zipfile.ZipFile(options.resources_zip, 'w', zipfile.ZIP_STORED) as out:
-    # e.g. "en" -> ["en_gb.pak"]
+    # e.g. "en" -> ["en_gb.lpak"]
     lang_to_locale_map = collections.defaultdict(list)
     for src_path in sources:
       basename = os.path.basename(src_path)
       name = os.path.splitext(basename)[0]
-      # Resources file names must consist of [a-z0-9_.].
-      res_compatible_name = basename.replace('-', '_').lower()
+      res_name = ToResourceFileName(basename)
       if name == 'en-US':
         dest_dir = 'raw'
       else:
         # Chrome uses different region mapping logic from Android, so include
         # all regions for each language.
         android_locale = _CHROME_TO_ANDROID_LOCALE_MAP.get(name, name)
         lang = android_locale[0:2]
         dest_dir = 'raw-' + lang
-        lang_to_locale_map[lang].append(res_compatible_name)
-      out.write(src_path, os.path.join(dest_dir, res_compatible_name))
+        lang_to_locale_map[lang].append(res_name)
+      out.write(src_path, os.path.join(dest_dir, res_name))
 
     # Create a String Arrays resource so ResourceExtractor can enumerate files.
     def WriteValuesFile(lang, names):
       dest_dir = 'values'
       if lang:
         dest_dir += '-' + lang
-      # Always extract en-US.pak since it's the fallback.
-      xml = CreateLocalePaksXml(names + ['en_us.pak'])
+      # Always extract en-US.lpak since it's the fallback.
+      xml = CreateLocalePaksXml(names + ['en_us.lpak'])
       out.writestr(os.path.join(dest_dir, 'locale-paks.xml'), xml)
 
     for lang, names in lang_to_locale_map.iteritems():
       WriteValuesFile(lang, names)
     WriteValuesFile(None, [])
 
 
 if __name__ == '__main__':
   sys.exit(main())