re-added helios django app as part of the same git project

helios/README.txt

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+The Helios Django App
+=====================
+
+LICENSE: this code is released under the GPL v3 or later.
+
+NOTE: this used to be a separate git submodule, but now it's not.

helios/__init__.py

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+
+from django.conf import settings
+
+TEMPLATE_BASE = settings.HELIOS_TEMPLATE_BASE or "helios/templates/base.html"
+
+# a setting to ensure that only admins can create an election
+ADMIN_ONLY = settings.HELIOS_ADMIN_ONLY
+
+# allow upload of voters via CSV?
+VOTERS_UPLOAD = settings.HELIOS_VOTERS_UPLOAD
+
+# allow emailing of voters?
+VOTERS_EMAIL = settings.HELIOS_VOTERS_EMAIL
+
+from django.core.urlresolvers import reverse
+
+# get the short path for the URL
+def get_election_url(election):
+  from views import election_shortcut
+  return settings.URL_HOST + reverse(election_shortcut, args=[election.short_name])

helios/counters.py

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+# Copyright 2008 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+from google.appengine.api import memcache 
+from google.appengine.ext import db
+from google.appengine.api.datastore import _CurrentTransactionKey
+import random
+
+class GeneralCounterShardConfig(db.Model):
+  """Tracks the number of shards for each named counter."""
+  name = db.StringProperty(required=True)
+  num_shards = db.IntegerProperty(required=True, default=20)
+
+
+class GeneralCounterShard(db.Model):
+  """Shards for each named counter"""
+  name = db.StringProperty(required=True)
+  count = db.IntegerProperty(required=True, default=0)
+
+def get_config(name):
+  if _CurrentTransactionKey():
+    config = GeneralCounterShardConfig.get_by_key_name(name)
+    if not config:
+      config = GeneralCounterShardConfig(name=name)
+      config.put()
+    return config
+  else:
+    return GeneralCounterShardConfig.get_or_insert(name, name=name)
+
+def get_count(name):
+  """Retrieve the value for a given sharded counter.
+  
+  Parameters:
+    name - The name of the counter  
+  """
+  total = memcache.get(name)
+  if total is None:
+    total = 0
+    for counter in GeneralCounterShard.all().filter('name = ', name):
+      total += counter.count
+    memcache.add(name, str(total), 60)
+  return total
+
+
+def increment(name):
+  """Increment the value for a given sharded counter.
+  
+  Parameters:
+    name - The name of the counter  
+  """
+  config = get_config(name)
+  def txn():
+    index = random.randint(0, config.num_shards - 1)
+    shard_name = name + str(index)
+    counter = GeneralCounterShard.get_by_key_name(shard_name)
+    if counter is None:
+      counter = GeneralCounterShard(key_name=shard_name, name=name)
+    counter.count += 1
+    counter.put()
+
+  if _CurrentTransactionKey():
+    txn()
+  else:
+    db.run_in_transaction(txn)
+
+  memcache.incr(name)
+
+
+def increase_shards(name, num):  
+  """Increase the number of shards for a given sharded counter.
+  Will never decrease the number of shards.
+  
+  Parameters:
+    name - The name of the counter
+    num - How many shards to use
+    
+  """
+  config = get_config(name)
+  def txn():
+    if config.num_shards < num:
+      config.num_shards = num
+      config.put()
+
+  if _CurrentTransactionKey():
+    txn()
+  else:
+    db.run_in_transaction(txn)
+