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From Allen He <>
Subject If a user has millions of followers, is there millions of iterate? (ref Twissandra)
Date Thu, 15 Apr 2010 07:56:38 GMT
Hello folks,

When Twissandra <> (Twitter clone example for
Cassandra) post a tweet, it iterate all of the followers to insert a
tweet_id to their time lines(see highlight):

def save_tweet(tweet_id, user_id, tweet):
    Saves the tweet record.
    # Generate a timestamp, and put it in the tweet record
    raw_ts = int(time.time() * 1e6)
    tweet['_ts'] = raw_ts
    ts = _long(raw_ts)
    encoded = dict(((k, json.dumps(v)) for k, v in tweet.iteritems()))
    # Insert the tweet, then into the user's timeline, then into the public one
    TWEET.insert(str(tweet_id), encoded)
    USERLINE.insert(str(user_id), {ts: str(tweet_id)})
    USERLINE.insert(PUBLIC_USERLINE_KEY, {ts: str(tweet_id)})
    # Get the user's followers, and insert the tweet into all of their streams
    follower_ids = [user_id] + get_follower_ids(user_id)
*    **for** **follower_id** **in** **follower_ids**:*
*        **TIMELINE**.**insert**(**str**(**follower_id**),**
**{**ts**:** **str**(**tweet_id**)})*
*My question is, If a user has millions of followers, is there
millions of iterate?*

Sorry for my English :)


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