1. Fixed an compiler error caused by declaring non-static variables in header file and included by external .c files more than once~
2. Fix a typo in assert()

/usr/bin/ld: CMakeFiles/tairzset_module.dir/__/dep/skiplist.c.o:/data/alibaba/TairZset/dep/skiplist.h:59: multiple definition of `shared_maxstring'; CMakeFiles/tairzset_module.dir/tairzset.c.o:/data/alibaba/TairZset/dep/skiplist.h:59: first defined here
/usr/bin/ld: CMakeFiles/tairzset_module.dir/__/dep/skiplist.c.o:/data/alibaba/TairZset/dep/skiplist.h:58: multiple definition of `shared_minstring'; CMakeFiles/tairzset_module.dir/tairzset.c.o:/data/alibaba/TairZset/dep/skiplist.h:58: first defined here
collect2: error: ld returned 1 exit status

Signed-off-by: RinChanNOWWW [email protected]

Summary

related issues: https://github.com/alibaba/TairZset/issues/12

Implementation reference: Redis 7.0

• https://redis.io/commands/zintercard/

Description of the feature

The new command ZINTERCARD was introduced in Redis 7.0. We can implement this command, too.

Additional information

https://redis.io/commands/zintercard/

Signed-off-by: RinChanNOWWW [email protected]

Summary

related issues: #4

Implementation reference: Redis 6.2 https://redis.io/commands/zrandmember/

Command Description

EXZRANDMEMBER

EXZRANDMEMBER key [ count [WITHSCORES]] time complexity：O(N) where N is the number of elements returned.

Command Description:

When called with just the key argument, return a random element from the sorted set value stored at key.

If the provided count argument is positive, return an array of distinct elements. The array's length is either count or the sorted set's cardinality (EXZCARD), whichever is lower.

If called with a negative count, the behavior changes and the command is allowed to return the same element multiple times. In this case, the number of returned elements is the absolute value of the specified count.

The optional WITHSCORES modifier changes the reply so it includes the respective scores of the randomly selected elements from the sorted set.

Return value

Bulk string reply: without the additional count argument, the command returns a Bulk Reply with the randomly selected element, or nil when key does not exist.

Array reply: when the additional count argument is passed, the command returns an array of elements, or an empty array when key does not exist. If the WITHSCORES modifier is used, the reply is a list elements and their scores from the sorted set.

TODO

• [x] Fixing the compatibility problems with Redis 5.0 and 6.0.

Signed-off-by: RinChanNOWWW [email protected]

Summary

related issues: #4

EXZMSCORE

EXZMSCORE key member [member ...] time complexity：O(N) where N is the number of members being requested.

Command Description:

Returns the scores associated with the specified members in the sorted set stored at key. For every member that does not exist in the sorted set, a nil value is returned.

Return value

Array reply: list of scores or nil associated with the specified member values (a double precision floating point number), represented as strings.

活动官网

https://asoc2022.opensource.alibaba.com/

题目描述

TairZset作为redis原生zset的一个多增增强结构，前期只实现了一些基本的命令， 还有部分命令（使用频率相对较低）没有支持， 为了更好的对齐redis原生zset语义，需要补全这些命令的实现和对应的测试。

任务目标

1、开发支持EXZUNIONSTORE、EXZUNION、EXZSCAN、EXZDIFF、EXZDIFFSTORE、EXZINTER、EXZINTERSTORE、EXZRANDMEMBER、EXZMSCORE等确实命令（对齐到redis 5.0版本即可） 2、添加对应的tcl测试

项目技术要求

熟悉c、tcl，了解redis zset实现原理

题目难度

中

导师信息

Qu Dong ，@chenyang8094，ASoC Mentor, redis contributor. [email protected]（联系导师请附上个人简历）

Signed-off-by: RinChanNOWWW [email protected]

Summary

related issues: https://github.com/alibaba/TairZset/issues/4

Implementation reference: Redis 6.2

• https://redis.io/commands/zdiffstore/
• https://redis.io/commands/zdiff/

Signed-off-by: RinChanNOWWW [email protected]

Summary

related issues: https://github.com/alibaba/TairZset/issues/4

Implementation reference: Redis 6.2

• https://redis.io/commands/zinterstore/
• https://redis.io/commands/zinter/

Summary

related issues: https://github.com/alibaba/TairZset/issues/4

Implementation reference: Redis 6.2

• https://redis.io/commands/zunionstore/
• https://redis.io/commands/zunion/

TBD

The behavior when a field in the multi score become NaN.

Signed-off-by: RinChanNOWWW [email protected]

Summary

related issues: https://github.com/alibaba/TairZset/issues/4

Implementation reference: Redis 5.0 https://redis.io/commands/scan/

Command Description

EXZSCAN

EXZSCAN key cursor [MATCH pattern] [COUNT count] time complexity: O(1) for every call. O(N) for a complete iteration, including enough command calls for the cursor to return back to 0. N is the number of elements inside the collection.

Command Description:

Iterates elements of TairZset types and their associated scores.

EXSCAN is a cursor based iterator. This means that at every call of the command, the server returns an updated cursor that the user needs to use as the cursor argument in the next call. An iteration starts when the cursor is set to 0, and terminates when the cursor returned by the server is 0.

While EXSCAN does not provide guarantees about the number of elements returned at every iteration, it is possible to empirically adjust the behavior of EXZSCAN using the COUNT option. Basically with COUNT the user specified the amount of work that should be done at every call in order to retrieve elements from the collection. This is just a hint for the implementation, however generally speaking this is what you could expect most of the times from the implementation.

It is possible to only iterate elements matching a given glob-style pattern, similarly to the behavior of the KEYS command that takes a pattern as only argument. To do so, just append the MATCH arguments at the end of the EXZSCAN command. It is important to note that the MATCH filter is applied after elements are retrieved from the collection, just before returning data to the client. This means that if the pattern matches very little elements inside the collection, EXZSCAN will likely return no elements in most iterations.

More detail information: https://redis.io/commands/scan/

Return value

A two elements multi-bulk reply, where the first element is a string representing an unsigned 64 bit number (the cursor), and the second element is a multi-bulk with an array of elements.

Others

• Fix the compile warnings.
• Add a new data structure list (double linked list) from Redis source codes.

Hi, Thanks for your nice work!

I think there might be a use case for having different scores being compared in independent orders. Let's say I want to create a leaderboard for my game and I have a highscore with an ascending score (meaning the higher the score, the higher the rank) and for the same scores I would compare the time of the score (which the lower the time the higher the rank). From what I see with your module, we have to accomplish this with saving either the time or the highscore with some math function to reverse it's meaning and then use the module. But because I think this feature would be used alot, It would be worth implementation. Can this be implemented?

Thanks