Improved user-facing messages

async_push.py

 # 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.
 """Out of band HTTP push."""
 
 import Queue
 import json
 import logging
 import os
 import threading
@@ skipping 41 matching lines @@
     with self.lock:
       with open(os.path.join('workdir', 'events.json'), 'w') as f:
         json.dump(self.queue, f, indent=2)
 
   def send(self, pending, packet):
     with self.lock:
       self.queue.append(self._package(pending, packet))
 
 
 class AsyncPush(AsyncPushNoop):
-  """Sends HTTP Post in a background worker thread.
+  """Sends HTTP Post asynchronously to the tree status application.
 
-  Thread-safe.
+  This object uses a background worker thread, and is thread-safe.
   """
   _TERMINATE = object()
 
   def __init__(self, url, password):
     super(AsyncPush, self).__init__()
     assert url
     assert password
     self.url = url
     self.password = password
     self.queue = Queue.Queue()
@@ skipping 29 matching lines @@
         'Accept': 'text/plain'
     }
     done = False
     try:
       while not done:
         items = self._get_items()
         if self._TERMINATE in items:
           done = True
           logging.debug('Worker thread exiting')
           items.remove(self._TERMINATE)
-        url = self.url + '/receiver'
+        url = self.url + '/receiver'   # application-specific

[Paweł Hajdan Jr., 2014/01/06 11:23:26]

nit: It's not obvious what this comment adds.

I'd rather make this /receiver path part also part of the ctor, so that the
class itself is not application specific.

         logging.debug('Sending %d items to %s' % (len(items), url))
         try:
           data = [('p', json.dumps(item)) for item in items]
           data.append(('password', self.password))
           urllib.urlopen(url, urllib.urlencode(data), params).read()
         except IOError as e:
           logging.error(e)
           for item in items:
             self.queue.put(item)
           if not done:
             time.sleep(1)
           # Don't retry if done.
     except Exception as e:
       traceback.print_exc()
       errors.send_stack(e)