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

build/android/gyp/locale_pak_resources.py

Index: build/android/gyp/locale_pak_resources.py
diff --git a/build/android/gyp/locale_pak_resources.py b/build/android/gyp/locale_pak_resources.py
index 8bf92185c1db8735205c18f1705667bede0b065c..a2bf09f8a437e4e2b14188496f576a823efc8734 100755
--- a/build/android/gyp/locale_pak_resources.py
+++ b/build/android/gyp/locale_pak_resources.py
@@ -6,7 +6,7 @@
 """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.
 """
 
@@ -28,6 +28,14 @@ _CHROME_TO_ANDROID_LOCALE_MAP = {
 }
 
 
+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"?>
@@ -61,13 +69,12 @@ def main():
     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:
@@ -76,16 +83,16 @@ def main():
         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():