def load_tweets_through_cache(cls, user_id):
# Django query is lazy loading
# it is triggered by iterations inside the load_object()
queryset = Tweet.objects.filter(
user_id=user_id).order_by('-created_at')
name = USER_TWEET_PATTERN.format(user_id=user_id)
return RedisHelper.load_objects(name, queryset)
def get_cached_newsfeeds(cls, user_id):
key = USER_NEWSFEEDS_PATTERN.format(user_id=user_id)
if GateKeeper.is_switch_on('switch_newsfeed_to_hbase'):
serializer = HBaseModelSerializer
else:
serializer = DjangoModelSerializer
return RedisHelper.load_objects(key,
lazy_load_newsfeeds(user_id),
serializer=serializer)
def get_cached_tweet(cls, user_id):
# queryset is lazy loading, here is not get data from db yet
queryset = Tweet.objects.filter(
user_id=user_id).order_by('-created_at')
key = USER_TWEETS_PATTERN.format(user_id=user_id)
return RedisHelper.load_objects(key, queryset)
def get_cached_newsfeeds(cls, user_id):
queryset = NewsFeed.objects.filter(user_id=user_id).order_by('-created_at')
key = USER_NEWSFEEDS_PATTERN.format(user_id=user_id)
return RedisHelper.load_objects(key, queryset)
def get_cached_tweets(cls, user_id):
queryset = Tweet.objects.filter(
user_id=user_id).order_by('-created_at')
key = USER_TWEETS_PATTERN.format(user_id=user_id)
return RedisHelper.load_objects(key, queryset)
def get_cached_tweets(cls, user_id):
key = USER_TWEETS_PATTERN.format(user_id=user_id)
return RedisHelper.load_objects(key, lazy_load_tweets(user_id))
def load_newsfeeds_through_cache(cls, user_id):
# queryset lazy loading
queryset = NewsFeed.objects.filter(user_id=user_id)
name = USER_NEWSFEED_PATTERN.format(user_id=user_id)
return RedisHelper.load_objects(name, queryset)
def get_cached_tweets(cls, user_id):
# Queryset is lazy loading
# 此时并没有进行数据库的访问，只有需要进行iteration的时候才会真正查询数据库
queryset = Tweet.objects.filter(user_id=user_id).order_by('-created_at')
key = USER_TWEETS_PATTERN.format(user_id=user_id)
return RedisHelper.load_objects(key, queryset)
def get_cached_tweets(cls, user_id):
# queryset is lazy loading, it will loaded when it's needed. eg, for loop queryset, list(queryset)
queryset = Tweet.objects.filter(
user_id=user_id).order_by('-created_at')
key = USER_TWEETS_PATTERN.format(user_id=user_id)
return RedisHelper.load_objects(key, queryset)
def get_cached_tweets(cls, user_id):
# Queryset is lazy loading, this statement doesn't incur real database query
queryset = Tweet.objects.filter(
user_id=user_id).order_by('-created_at')
key = USER_TWEETS_PATTERN.format(user_id=user_id)
return RedisHelper.load_objects(key, queryset)