Limit the number of extra/missing files that get printed.

win_toolchain/get_toolchain_if_necessary.py

 #!/usr/bin/env python
 # Copyright 2013 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.
 
 """Downloads and unpacks a toolchain for building on Windows. The contents are
 matched by sha1 which will be updated when the toolchain is updated.
 
 Having a toolchain script in depot_tools means that it's not versioned
 directly with the source code. That is, if the toolchain is upgraded, but
@@ skipping 121 matching lines @@
         matches = False
         break
   elif os.path.exists(timestamps_file):
     # Print some information about the extra/missing files. Don't do this if we
     # don't have a timestamp file, as all the files will be considered as
     # missing.
     timestamps_data_files = []
     for f in timestamps_data['files']:
       timestamps_data_files.append(f[0])
     missing_files = [f for f in timestamps_data_files if f not in file_list]
     if len(missing_files):

[scottmg, 2016/06/23 16:45:24]

These two duplicated blocks almost look like they could be a function? But I
guess the strings make it borderline.

[Sébastien Marchand, 2016/06/23 17:41:45]

Yeah, I thought about this but it seemed a little bit overkill, not sure it's
worth it.

-      print ('Some files are missing from the %s version of the toolchain:' %
-             expected_hash)
-      for f in missing_files:
+      print ('%d files missing from the %s version of the toolchain:' %
+             (len(missing_files), expected_hash))
+      for f in missing_files[:10]:
         print '\t%s' % f
+      if len(missing_files) > 10:
+        print '\t...'
     extra_files = [f for f in file_list if f not in timestamps_data_files]
     if len(extra_files):
-      print ('There\'s some extra files in the %s version of the toolchain:' %
-             expected_hash)
-      for f in extra_files:
+      print ('%d extra files in the %s version of the toolchain:' %
+             (len(extra_files), expected_hash))
+      for f in extra_files[:10]:
         print '\t%s' % f
+      if len(extra_files) > 10:
+        print '\t...'
   if matches:
     return timestamps_data['sha1']
 
   # Make long hangs when updating the toolchain less mysterious.
   print 'Calculating hash of toolchain in %s. Please wait...' % full_root_path
   sys.stdout.flush()
   digest = hashlib.sha1()
   for path in file_list:
     path_without_hash = str(path).replace('/', '\\')
     if expected_hash:
@@ skipping 377 matching lines @@
   if os.environ.get('GYP_MSVS_VERSION') == '2015':
     InstallUniversalCRTIfNeeded(abs_toolchain_target_dir)
 
   RemoveUnusedToolchains(target_dir)
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())