如何使用redis编写SO帖子?

时间:2012-08-31 20:08:38

标签: redis

我在想如何使用redis实现stackoverflow。最困难的部分是我应该如何做评论,并以一种我不循环的方式让每个评论upvotes。我决定修改二进制块。 UVComment有点复杂。

每当我想要使用哈希时,我最终都会使用集合或列表。我对redis很新,所以如果我犯了错误,我不会感到惊讶。这个设计得好吗?

CreatePost / Question(除了标志之外设置相同的东西,答案中的标签为空

postId=incr postCount
MULTI
rpush p:postId bin[IsQuestion,authorId,title,body,tags,datetimestamp]
foreach tag in tags
    sadd tags:tag postId
EXEC

UpdatePost /问题

WATCH p:postId  //dont want a new revision in the meantime
old=lrange p:postId -1 -1 //current but now old
MULTI
rpush p:postId bin[IsQuestion,authorId,title,body,tags,datetimestamp] //new revision
foreach tag in old.tags
    srem tags:tag postId
foreach tag in tags
    sadd tags:tag postId
EXEC

Upvote / Downvote Post

//up
sadd pUV:postId user
srem pDV:postId user
//down
sadd pDV:postId user
srem pUV:postId user
//undo up/down
srem pUV:postId user
srem pDV:postId user

注释:

commentId=incr commentCount
multi
SET comment_post:commentId postId //for later use when we flag comments. We'll need to know where in the db it is
RPUSH post_comment:postId bin[authorId,text,HasBeenEdited,datetimestamp,commentId, UVCount]
exec

UVComment

watch commentUV:commentId
res=SISMEMBER commentUV:commentId userId
if res>0 //already upvoted
    unwatch
    return
watch post_comment:postId
lrange post_comment:postId 0 -1 //then we find which index matches our commentId
//modify UVCount
MULTI
lset post_comment:postId targetIndex modifiedData
sadd commentUV:commentId userId
EXEC

GetPostLogic

lrange p:postId -1 -1 //current revision
scard pUV:postId
scard pDV:postId
comments=lrange post_comment:postId 0 -1 //get all comments

0 个答案:

没有答案