Update run_test_from_archive.py to handle 404

tools/isolate/run_test_from_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.
 
 """Reads a manifest, creates a tree of hardlinks and runs the test.
 
 Keeps a local cache.
 """
 
@@ skipping 99 matching lines @@
 def open_remote(file_or_url):
   """Reads a file or url."""
   if re.match(r'^https?://.+$', file_or_url):
     return urllib.urlopen(file_or_url)
   return open(file_or_url, 'rb')
 
 
 def download_or_copy(file_or_url, dest):
   """Copies a file or download an url."""
   if re.match(r'^https?://.+$', file_or_url):
-    urllib.urlretrieve(file_or_url, dest)
+    remote_file = urllib.urlopen(file_or_url)

[Marc-Antoine Ruel (Google), 2012/04/23 23:50:14]

I'd prefer to keep using urlretrieve(). Albeit it's a bit clunky to do;
http://stackoverflow.com/questions/1308542/how-to-catch-404-error-in-urllib-u...

The main issue I have is about keeping the whole data in memory, some files may
be over 1gb in size so buffering it all and then writing it may not be the most
efficient thing.

+    if remote_file.getcode() != 200:
+      logging.error('Failed to download ' + file_or_url)
+      return
+
+    f = open(dest, 'wb')
+    f.write(remote_file.read())
+    f.close()
   else:
     shutil.copy(file_or_url, dest)
 
 
 def get_free_space(path):
   """Returns the number of free bytes."""
   if sys.platform == 'win32':
     free_bytes = ctypes.c_ulonglong(0)
     ctypes.windll.kernel32.GetDiskFreeSpaceExW(
         ctypes.c_wchar_p(path), None, None, ctypes.pointer(free_bytes))
@@ skipping 172 matching lines @@
     parser.error('Unsupported args %s' % ' '.join(args))
 
   manifest = json.load(open_remote(options.manifest))
   return run_tha_test(
       manifest, os.path.abspath(options.cache), options.remote,
       options.max_cache_size, options.min_free_space)
 
 
 if __name__ == '__main__':
   sys.exit(main())