def unfollow(cls, from_user_id, to_user_id):
if from_user_id == to_user_id:
return 0
# Queryset 的 delete 操作返回两个值，一个是删了多少数据，一个是具体每种类型删了多少
# 为什么会出现多种类型数据的删掉？因为可能因为 foreign key 设置了 cascade 出现级联
# 删除，也就是比如 A model 的某个属性是 B model 的 foreign key，并且设置了
# on_delete = models.CASCADE，那么当 B 的某个数据被删除的时候，A 中的关联也会被删除。
# 所以 CASCADE 是很危险的，一般最好不要用，而是用 on_delete = models.SET_NULL
# 取而代之，这样至少可以避免误删除操作带来的多米诺效应
if not GateKeeper.is_switch_on('switch_friendship_to_hbase'):
deleted, _ = Friendship.objects.filter(
from_user_id=from_user_id,
to_user_id=to_user_id,
).delete()
return deleted
instance = cls.get_follow_instance(from_user_id, to_user_id)
if instance is None:
return 0
HBaseFollowing.delete(from_user_id=from_user_id,
created_at=instance.created_at)
HBaseFollower.delete(to_user_id=to_user_id,
created_at=instance.created_at)
return 1
def test_create_and_get(self):
# missing column data, can not store in hbase
try:
HBaseFollower.create(to_user_id=1, created_at=self.ts_now)
exception_raised = False
except EmptyColumnError:
exception_raised = True
self.assertEqual(exception_raised, True)
# invalid row_key
try:
HBaseFollower.create(from_user_id=1, to_user_id=2)
exception_raised = False
except BadRowKeyError as e:
exception_raised = True
self.assertEqual(str(e), 'created_at is missing in row key')
self.assertEqual(exception_raised, True)
ts = self.ts_now
HBaseFollower.create(from_user_id=1, to_user_id=2, created_at=ts)
instance = HBaseFollower.get(to_user_id=2, created_at=ts)
self.assertEqual(instance.from_user_id, 1)
self.assertEqual(instance.to_user_id, 2)
self.assertEqual(instance.created_at, ts)
# can not get if row key missing
try:
HBaseFollower.get(to_user_id=2)
exception_raised = False
except BadRowKeyError as e:
exception_raised = True
self.assertEqual(str(e), 'created_at is missing in row key')
self.assertEqual(exception_raised, True)
def unfollow(cls, from_user_id, to_user_id):
if from_user_id == to_user_id:
return 0
if not GateKeeper.is_switch_on('switch_friendship_to_hbase'):
deleted, _ = Friendship.objects.filter(
from_user_id=from_user_id,
to_user_id=to_user_id,
).delete()
return deleted
instance = cls.get_follow_instance(from_user_id, to_user_id)
if instance is None:
return 0
HBaseFollowing.delete(from_user_id=from_user_id,
created_at=instance.created_at)
HBaseFollower.delete(to_user_id=to_user_id,
created_at=instance.created_at)
return 1
def follow(cls, from_user_id, to_user_id):
if from_user_id == to_user_id:
return None
if not GateKeeper.is_switch_on('switch_friendship_to_hbase'):
return Friendship.objects.create(
from_user_id=from_user_id,
to_user_id=to_user_id,
)
now = ts_now_as_int()
HBaseFollower.create(
from_user_id=from_user_id,
created_at=now,
to_user_id=to_user_id,
)
return HBaseFollowing.create(
from_user_id=from_user_id,
created_at=now,
to_user_id=to_user_id,
)
def follow(cls, from_user_id, to_user_id):
if from_user_id == to_user_id:
return None
if not GateKeeper.is_switch_on('switch_friendship_to_hbase'):
# create data in mysql
return Friendship.objects.create(
from_user_id=from_user_id,
to_user_id=to_user_id,
)
# create data in hbase
now = int(time.time() * 1000000)
HBaseFollower.create(
from_user_id=from_user_id,
to_user_id=to_user_id,
created_at=now,
)
return HBaseFollowing.create(
from_user_id=from_user_id,
to_user_id=to_user_id,
created_at=now,
)
def unfollow(cls, from_user_id, to_user_id):
if from_user_id == to_user_id:
return 0
if not GateKeeper.is_switch_on('switch_friendship_to_hbase'):
delete, _ = Friendship.objects.filter(
from_user_id=from_user_id,
to_user_id=to_user_id,
).delete()
return delete
following = cls.get_following_instance(from_user_id=from_user_id,
to_user_id=to_user_id)
# fs = HBaseFollowing.filter(prefix=(from_user_id, None))
# for f in fs:
# print(f.from_user_id, f.created_at, '->', f.to_user_id)
# print(following)
if following is None:
return 0
HBaseFollowing.delete(from_user_id=from_user_id,
created_at=following.created_at)
HBaseFollower.delete(to_user_id=to_user_id,
created_at=following.created_at)
return 1
def get_follower_count(cls, to_user_id):
if not GateKeeper.is_switch_on('switch_friendship_to_hbase'):
return Friendship.objects.filter(to_user_id=to_user_id).count()
followers = HBaseFollower.filter(prefix=(to_user_id, None))
return len(followers)
def get_follower_ids(cls, to_user_id):
if not GateKeeper.is_switch_on('switch_friendship_to_hbase'):
friendships = Friendship.objects.filter(to_user_id=to_user_id)
else:
friendships = HBaseFollower.filter(prefix=(to_user_id, None))
return [friendship.from_user_id for friendship in friendships]
def test_create_and_get(self):
now = self.ts_now()
HBaseFollower.create(
created_at=now,
to_user_id=456,
from_user_id=123,
)
follower = HBaseFollower.get(to_user_id=456, created_at=now)
self.assertEqual(follower.from_user_id, 123)
self.assertEqual(follower.to_user_id, 456)
self.assertEqual(follower.created_at, now)
# invalid row_key get
try:
HBaseFollower.get(to_user_id=456, from_user_id=123)
exception_raised = False
except BadRowKeyException as e:
exception_raised = True
self.assertEqual(str(e), "created_at not defined")
self.assertEqual(exception_raised, True)
# invalid row_keys creation
try:
HBaseFollower.create(from_user_id=123, create_at=now)
exception_raised = False
except BadRowKeyException as e:
exception_raised = True
self.assertEqual(str(e), 'to_user_id not defined')
self.assertEqual(exception_raised, True)
# no column_key value
try:
HBaseFollower.create(to_user_id=123, created_at=now)
exception_raised = False
except EmptyColumnException as e:
exception_raised = True
self.assertEqual(exception_raised, True)
# wrong order input
try:
HBaseFollower.create(from_user_id=0,
to_user_id=123,
created_at=now)
exception_raised = False
except EmptyColumnException as e:
exception_raised = True
self.assertEqual(exception_raised, True)
# row_key should not have ':'
try:
HBaseFollower.create(
from_user_id=123,
created_at=now,
to_user_id='456:',
)
exception_raised = False
except BadRowKeyException as e:
exception_raised = True
self.assertEqual(str(e),
"to_user_id must not have ':' in value 456:")
self.assertEqual(exception_raised, True)