models: Add recipient foreign key to Huddle.

This follows the already tested approach from
8acfa17fe6.

analytics/tests/test_counts.py

@@ -87,6 +87,8 @@ class AnalyticsTestCase(TestCase):
             kwargs[key] = kwargs.get(key, value)
         huddle = Huddle.objects.create(**kwargs)
         recipient = Recipient.objects.create(type_id=huddle.id, type=Recipient.HUDDLE)
+        huddle.recipient = recipient
+        huddle.save(update_fields=["recipient"])
         return huddle, recipient
 
     def create_message(self, sender: UserProfile, recipient: Recipient, **kwargs: Any) -> Message:

zerver/lib/import_realm.py

@@ -513,6 +513,10 @@ def remove_denormalized_recipient_column_from_data(data: TableData) -> None:
         if 'recipient' in user_profile_dict:
             del user_profile_dict['recipient']
 
+    for huddle_dict in data['zerver_huddle']:
+        if 'recipient' in huddle_dict:
+            del huddle_dict['recipient']
+
 def get_db_table(model_class: Any) -> str:
     """E.g. (RealmDomain -> 'zerver_realmdomain')"""
     return model_class._meta.db_table
@@ -914,6 +918,10 @@ def do_import_realm(import_dir: Path, subdomain: str, processes: int=1) -> Realm
     if 'zerver_huddle' in data:
         process_huddle_hash(data, 'zerver_huddle')
         bulk_import_model(data, Huddle)
+        for huddle in Huddle.objects.filter(recipient_id=None):
+            recipient = Recipient.objects.get(type=Recipient.HUDDLE, type_id=huddle.id)
+            huddle.recipient = recipient
+            huddle.save(update_fields=["recipient"])
 
     if 'zerver_userhotspot' in data:
         fix_datetime_fields(data, 'zerver_userhotspot')

zerver/migrations/0270_huddle_recipient.py

@@ -0,0 +1,19 @@
+# Generated by Django 2.2.10 on 2020-03-15 17:25
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('zerver', '0269_gitlab_auth'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='huddle',
+            name='recipient',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, to='zerver.Recipient'),
+        ),
+    ]

zerver/migrations/0271_huddle_set_recipient_column_values.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('zerver', '0270_huddle_recipient'),
+    ]
+
+    operations = [
+        migrations.RunSQL(
+            """
+            UPDATE zerver_huddle
+            SET recipient_id = zerver_recipient.id
+            FROM zerver_recipient
+            WHERE zerver_recipient.type_id = zerver_huddle.id AND zerver_recipient.type = 3;
+            """,
+            reverse_sql='UPDATE zerver_huddle SET recipient_id = NULL'),
+    ]

zerver/models.py

@@ -1547,13 +1547,9 @@ def bulk_get_streams(realm: Realm, stream_names: STREAM_NAMES) -> Dict[str, Any]
                                      [stream_name.lower() for stream_name in stream_names],
                                      id_fetcher=stream_to_lower_name)
 
-def get_recipient_cache_key(type: int, type_id: int) -> str:
+def get_recipient_cache_key(type: int, type_id: int) -> str:  # nocoverage
     return u"%s:get_recipient:%s:%s" % (cache.KEY_PREFIX, type, type_id,)
 
-@cache_with_key(get_recipient_cache_key, timeout=3600*24*7)
-def get_recipient(type: int, type_id: int) -> Recipient:
-    return Recipient.objects.get(type_id=type_id, type=type)
-
 def get_huddle_recipient(user_profile_ids: Set[int]) -> Recipient:
 
     # The caller should ensure that user_profile_ids includes
@@ -1561,7 +1557,7 @@ def get_huddle_recipient(user_profile_ids: Set[int]) -> Recipient:
     # we hit another cache to get the recipient.  We may want to
     # unify our caching strategy here.
     huddle = get_huddle(list(user_profile_ids))
-    return get_recipient(Recipient.HUDDLE, huddle.id)
+    return huddle.recipient
 
 def get_huddle_user_ids(recipient: Recipient) -> List[int]:
     assert(recipient.type == Recipient.HUDDLE)
@@ -2287,6 +2283,8 @@ class Huddle(models.Model):
     # TODO: We should consider whether using
     # CommaSeparatedIntegerField would be better.
     huddle_hash = models.CharField(max_length=40, db_index=True, unique=True)  # type: str
+    # Foreign key to the Recipient object for this Huddle.
+    recipient = models.ForeignKey(Recipient, null=True, on_delete=models.SET_NULL)
 
 def get_huddle_hash(id_list: List[int]) -> str:
     id_list = sorted(set(id_list))
@@ -2307,6 +2305,8 @@ def get_huddle_backend(huddle_hash: str, id_list: List[int]) -> Huddle:
         if created:
             recipient = Recipient.objects.create(type_id=huddle.id,
                                                  type=Recipient.HUDDLE)
+            huddle.recipient = recipient
+            huddle.save(update_fields=["recipient"])
             subs_to_create = [Subscription(recipient=recipient,
                                            user_profile_id=user_profile_id)
                               for user_profile_id in id_list]

zerver/tests/test_import_export.py

@@ -1013,6 +1013,11 @@ class ImportExportTest(ZulipTestCase):
             self.assertEqual(stream.recipient_id, Recipient.objects.get(type=Recipient.STREAM,
                                                                         type_id=stream.id).id)
 
+        for huddle_object in Huddle.objects.all():
+            # Huddles don't have a realm column, so we just test all Huddles for simplicity.
+            self.assertEqual(huddle_object.recipient_id, Recipient.objects.get(type=Recipient.HUDDLE,
+                                                                               type_id=huddle_object.id).id)
+
     def test_import_files_from_local(self) -> None:
 
         realm = Realm.objects.get(string_id='zulip')