Retry fetching patch from rietveld on a 404

rietveld.py

 # coding: utf-8
 # 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.
 """Defines class Rietveld to easily access a rietveld instance.
 
 Security implications:
 
 The following hypothesis are made:
 - Rietveld enforces:
@@ skipping 79 matching lines @@
 
     Converts any CRLF into LF and strip extraneous whitespace.
     """
     return '\n'.join(self.get('/%d/description' % issue).strip().splitlines())
 
   def get_issue_properties(self, issue, messages):
     """Returns all the issue's metadata as a dictionary."""
     url = '/api/%d' % issue
     if messages:
       url += '?messages=true'
-    data = json.loads(self.get(url))
+    NUM_RETRIES = 5
+    for tries in xrange(NUM_RETRIES):
+      try:
+        data = json.loads(self.get(url))

[M-A Ruel, 2014/07/28 21:11:38]

It'd be more sane to add a retry_404=True flag to _send() function instead of
two loops of retries on over the other.

[hinoka, 2014/08/27 13:42:47]

Done.

+      except urllib2.HTTPError as e:
+        if e.code == 404:
+          # 404 might indicate datastore lag.  Wait and try again.
+          if tries < NUM_RETRIES - 1:
+            time.sleep(2 ** tries)
+            continue
+        raise
+      else:
+        break
+
     data['description'] = '\n'.join(data['description'].strip().splitlines())
     return data
 
   def get_patchset_properties(self, issue, patchset):
     """Returns the patchset properties."""
     url = '/api/%d/%d' % (issue, patchset)
     return json.loads(self.get(url))
 
   def get_file_content(self, issue, patchset, item):
     """Returns the content of a new file.
@@ skipping 606 matching lines @@
   def trigger_try_jobs(  # pylint:disable=R0201
       self, issue, patchset, reason, clobber, revision, builders_and_tests,
       master=None):
     logging.info('ReadOnlyRietveld: triggering try jobs %r for issue %d' %
         (builders_and_tests, issue))
 
   def trigger_distributed_try_jobs(  # pylint:disable=R0201
       self, issue, patchset, reason, clobber, revision, masters):
     logging.info('ReadOnlyRietveld: triggering try jobs %r for issue %d' %
         (masters, issue))