Use cpp file map to unpack gzipped resources

We can get gzipped flag from gzipped_resource_map_source or
gzipped_resource_file_map_source and use it to unpack gzipped resources
with unpack.py.

Bug: 738243
Change-Id: I1bf56126f702fa6efbd2b3e8806ade9bdf904d1f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1518520
Commit-Queue: Dmitry Guketlev <yavanosta@yandex-team.ru>
Reviewed-by: Dan Beam <dbeam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#640738}

chrome/browser/resources/unpack_pak.py

@@ -4,6 +4,9 @@
 # found in the LICENSE file.
 
 import argparse
+import collections
+import cStringIO
+import gzip
 import os
 import re
 import sys
@@ -20,9 +23,16 @@ _SRC_PATH = os.path.normpath(os.path.join(_HERE_PATH, '..', '..', '..'))
 sys.path.insert(1, os.path.join(_SRC_PATH, 'tools', 'grit'))
 from grit.format import data_pack
 
+ResourceFile = collections.namedtuple('ResourceFile',
+                                      ['path', 'gzipped'])
+
+def UngzipString(data):
+  # Ungzipping using Python's built in gzip.
+  with gzip.GzipFile(fileobj=cStringIO.StringIO(data)) as gzip_file:
+    return gzip_file.read()
 
 def ParseLine(line):
-  return re.match('  {"([^"]+)", ([^},]+)', line)
+  return re.match('  {"([^"]+)", ([^},]+)(?:, ([^},]+))?', line)
 
 
 def Unpack(pak_path, out_path):
@@ -43,23 +53,29 @@ def Unpack(pak_path, out_path):
   assert resource_ids
 
   # Associate numerical string IDs to files.
-  resource_filenames = dict()
+  resource_files = dict()
   resources_map_path = os.path.join(pak_dir, 'grit', pak_id + '_map.cc')
   with open(resources_map_path) as resources_map:
     for line in resources_map:
       res = ParseLine(line)
       if res:
-        resource_filenames[res.group(2)] = res.group(1)
-  assert resource_filenames
+        resource_files[res.group(2)] = ResourceFile(
+          path=res.group(1),
+          gzipped=res.group(3) == 'true')
+  assert resource_files
 
   # Extract packed files, while preserving directory structure.
   for (resource_id, text) in data.resources.iteritems():
-    filename = resource_filenames[resource_ids[resource_id]]
-    dirname = os.path.join(out_path, os.path.dirname(filename))
-    if not os.path.exists(dirname):
-      os.makedirs(dirname)
-    with open(os.path.join(out_path, filename), 'w') as file:
-      file.write(text)
+    resource_file = resource_files[resource_ids[resource_id]]
+    file_path = resource_file.path
+    file_gzipped = resource_file.gzipped
+    file_dir = os.path.join(out_path, os.path.dirname(file_path))
+    if not os.path.exists(file_dir):
+      os.makedirs(file_dir)
+    if file_gzipped:
+      text = UngzipString(text)
+    with open(os.path.join(out_path, file_path), 'w') as f:
+      f.write(text)
 
 
 def main():

chrome/browser/resources/unpack_pak_test.py

@@ -15,6 +15,13 @@ class UnpackPakTest(unittest.TestCase):
     self.assertTrue(unpack_pak.ParseLine('  {"path.js", IDR_PATH, false}'))
     self.assertTrue(unpack_pak.ParseLine('  {"path.js", IDR_PATH, true}'))
 
+  def testUngzipString(self):
+    self.assertEqual(
+      unpack_pak.UngzipString(
+        '\x1f\x8b\x08\x00\x00\x00\x00\x00\x02\xff\xcbH\xcd\xc9\xc9W' +
+        '(\xcf/\xcaI\x01\x00\x85\x11J\r\x0b\x00\x00\x00'),
+      'hello world')
+
 
 if __name__ == '__main__':
   unittest.main()