Initial snapshot.

lib/models.py

@@ -0,0 +1,111 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014, Ian Gulliver
+#
+# 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.
+
+import json
+import logging
+
+from google.appengine.api import channel
+from google.appengine.ext import db
+
+
+# Profile
+# ↳ Client
+# ↳ StateEntry
+#
+# Subject
+# ↳ Subscription (⤴︎ Client)
+
+
+class Profile(db.Model):
+  google_user = db.UserProperty()
+
+  @classmethod
+  def FromGoogleUser(cls, google_user):
+    if not google_user:
+      profile = Profile()
+      profile.put()
+      return profile
+
+    profiles = Profile.all().filter('google_user =', google_user).fetch(1)
+    if profiles:
+      return profiles[0]
+    else:
+      # TODO(flamingcow): Fetch-then-store uniqueness is a race.
+      profile = Profile(google_user=google_user)
+      profile.put()
+      return profile
+
+  @db.transactional(xg=True)
+  def MergeFrom(self, source_profile):
+    # Merge from another profile into this one, using last_set time as the
+    # arbiter.
+    my_states = {}
+    for state_entry in (StateEntry.all()
+                        .ancestor(self)
+                        .run()):
+      my_states[state_entry.entry_key] = state_entry
+
+    for state_entry in (StateEntry.all()
+                        .ancestor(source_profile)
+                        .run()):
+      my_state_entry = my_states.get(state_entry.entry_key, None)
+      if my_state_entry:
+        if state_entry.last_set > my_state_entry.last_set:
+          # newer, merge in
+          my_state_entry.entry_value = state_entry.entry_value
+          my_state_entry.put()
+      else:
+        # entirely new, add
+        StateEntry(parent=self,
+            entry_key=state_entry.entry_key,
+            entry_value=state_entry.entry_value
+            ).put()
+
+
+class Client(db.Model):
+  first_seen = db.DateTimeProperty(required=True, auto_now_add=True)
+  channel_active = db.BooleanProperty(required=True, default=False)
+
+  @classmethod
+  def FromProfile(cls, profile):
+    client = cls(parent=profile)
+    client.put()
+    return client
+
+  @classmethod
+  def FromGoogleUser(cls, google_user):
+    profile = Profile.FromGoogleUser(google_user)
+    return cls.FromProfile(profile)
+
+
+class StateEntry(db.Model):
+  last_set = db.DateTimeProperty(required=True, auto_now=True)
+  entry_key = db.StringProperty(required=True)
+  entry_value = db.StringProperty(required=True)
+
+  def SendToClient(self, client_id):
+    channel.send_message(str(client_id), json.dumps({
+        'message_type': 'state',
+        'key': self.entry_key,
+        'value': self.entry_value,
+    }))
+
+
+class Subject(db.Model):
+  name = db.StringProperty(required=True)
+
+
+class Subscription(db.Model):
+  client = db.ReferenceProperty(reference_class=Client)