Clarify comments in create_installer_archive.py.

chrome/tools/build/win/create_installer_archive.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Script to create Chrome Installer archive.
 
   This script is used to create an archive of all the files required for a
   Chrome install in appropriate directory structure. It reads chrome.release
   file as input, creates chrome.7z archive, compresses setup.exe and
@@ skipping 307 matching lines @@
 
   with open(resource_file_path, 'w') as f:
     f.write(resource_file)
 
 
 # Reads |manifest_name| from |build_dir| and writes |manifest_name| to
 # |output_dir| with the same content plus |inserted_string| added just before
 # |insert_before|.
 def CopyAndAugmentManifest(build_dir, output_dir, manifest_name,
                            inserted_string, insert_before):
-  with open(os.path.join(build_dir, manifest_name), 'r') as manifest_file:
-    manifest_lines = manifest_file.readlines()
+  with open(os.path.join(build_dir, manifest_name), 'r') as f:
+    manifest_lines = f.readlines()
 
   insert_line = -1
   insert_pos = -1
   for i in xrange(len(manifest_lines)):
     insert_pos = manifest_lines[i].find(insert_before)
     if insert_pos != -1:
       insert_line = i
       break
   if insert_line == -1:
     raise ValueError('Could not find {0} in the manifest:\n{1}'.format(
         insert_before, ''.join(manifest_lines)))
   old = manifest_lines[insert_line]
   manifest_lines[insert_line] = (old[:insert_pos] + '\n' + inserted_string +
                                  '\n' + old[insert_pos:])
 
-  with open(os.path.join(output_dir, manifest_name),
-            'w') as modified_manifest_file :
-    modified_manifest_file.write(''.join(manifest_lines))
+  with open(os.path.join(output_dir, manifest_name), 'w') as f :
+    f.write(''.join(manifest_lines))
 
 
 def CopyIfChanged(src, target_dir):
   """Copy specified |src| file to |target_dir|, but only write to target if
   the file has changed. This avoids a problem during packaging where parts of
   the build have not completed and have the runtime DLL locked when we try to
   copy over it. See http://crbug.com/305877 for details."""
   assert os.path.isdir(target_dir)
   dest = os.path.join(target_dir, os.path.basename(src))
   if os.path.exists(dest):
@@ skipping 83 matching lines @@
   # Copy the VS CRT DLLs to |build_dir|. This must be done before the general
   # copy step below to ensure the CRT DLLs are added to the archive and marked
   # as a dependency in the exe manifests generated below.
   CopyVisualStudioRuntimeDLLs(build_dir, target_arch)
 
   # Stage all the component DLLs found in |build_dir|. These are all the DLLs
   # which have not already been added to the staged |version_dir| by virtue of
   # chrome.release.
   build_dlls = glob.glob(os.path.join(build_dir, '*.dll'))
   staged_dll_basenames = [os.path.basename(staged_dll) for staged_dll in \
-                              glob.glob(os.path.join(version_dir, '*.dll'))]
+                          glob.glob(os.path.join(version_dir, '*.dll'))]
   component_dll_filenames = []
   for component_dll in [dll for dll in build_dlls if \
-                            os.path.basename(dll) not in staged_dll_basenames]:
+                        os.path.basename(dll) not in staged_dll_basenames]:
     # remoting_*.dll's don't belong in the archive (it doesn't depend on them
     # in gyp). Trying to copy them causes a build race when creating the
     # installer archive in component mode. See: crbug.com/180996
     if os.path.basename(component_dll).startswith('remoting_'):
       continue
     # Copy them to the version_dir (for the version assembly to be able to refer
-    # to them below and thus for chrome.exe to be able to load them at runtime).
+    # to them below and make sure chrome.exe can find them at runtime).
     shutil.copy(component_dll, version_dir)
     # Also copy them directly to the Installer directory for the installed
     # setup.exe to be able to run (as it doesn't statically link in component
     # DLLs).
-    # TODO(gab): This makes the archive ~278MB instead of ~185MB; consider
-    # copying the DLLs over from the installer.
+    # This makes the archive ~1.5X bigger (Release ~185MB => ~278MB;
+    # Debug ~520MB => ~875MB) this is however simpler than any other installer
+    # change and doesn't make archive generation itself slower so it only
+    # matters when copying the archive to other test machines. This approach
+    # can be revised if this is a problem.
     shutil.copy(component_dll, installer_dir)
     component_dll_filenames.append(os.path.basename(component_dll))
 
   # Copy chrome.exe.manifest as-is. It is required, among other things, to
   # declare a dependency on the version dir assembly.
   shutil.copy(os.path.join(build_dir, 'chrome.exe.manifest'), chrome_dir)
 
   # Also copy setup.exe.manifest as-is. It is required, among other things, to
   # let setup.exe UAC when it wants to, by specifying that it handles elevation
   # "asInvoker", rather than have Windows auto-elevate it when launched.
   shutil.copy(os.path.join(build_dir, 'setup.exe.manifest'), installer_dir)
 
   # Augment {version}.manifest to include all component DLLs as part of the
-  # assembly it constitutes which will allow dependents of this assembly to
+  # assembly it constitutes, which will allow dependents of this assembly to
   # find these DLLs.
   version_assembly_dll_additions = []
   for dll_filename in component_dll_filenames:
-    version_assembly_dll_additions.append(
-        "  <file name='{dll_filename}'/>".format(dll_filename=dll_filename))
+    version_assembly_dll_additions.append("  <file name='%s'/>" % dll_filename)
   CopyAndAugmentManifest(build_dir, version_dir,
-                         '{version}.manifest'.format(version=current_version),
+                         '%s.manifest' % current_version,
                          '\n'.join(version_assembly_dll_additions),
                          '</assembly>')
 
 
 def main(options):
   """Main method that reads input file, creates archive file and write
   resource input file.
   """
   current_version = BuildVersion(options.build_dir)
 
@@ skipping 104 matching lines @@
   if not options.resource_file_path:
     options.resource_file_path = os.path.join(options.build_dir,
                                               MINI_INSTALLER_INPUT_FILE)
 
   return options
 
 
 if '__main__' == __name__:
   print sys.argv
   sys.exit(main(_ParseOptions()))