Making a list uniq with a Lua script?

[MeSF]

Hello everyone,

I was wondering if anyone already made a Lua script to make a list 'uniq', by removing all duplicates.

We have created this:

redis.call('del', KEYS[2])

local list = redis.call('lrange', KEYS[1] , 0, -1)

redis.log(redis.LOG_NOTICE, KEYS[1],  redis.call('llen', KEYS[1]))

local function table_count(tt, item)

  local count

  count = 0

  for ii,xx in pairs(tt) do

    if item == xx then count = count + 1 end

  end

  return count

end

local function table_unique(tt)

  local newtable

  newtable = {}

  for ii,xx in ipairs(tt) do

    if(table_count(newtable, xx) == 0) then

      newtable[#newtable+1] = xx

      redis.call('lpush', KEYS[2], xx)

    end

  end

  return newtable

end

table_unique(list)

redis.log(redis.LOG_NOTICE, KEYS[2],  redis.call('llen', KEYS[2]))

return redis.call('llen', KEYS[2])

But it's extremely slow. Anyone has a better idea?

Thanks

[Josiah Carlson]

Is your issue that you need the order to be in an order expected by adding to the left and right of the LIST?

If so, then you can use a Lua Script for insertion or removal from either end. Basically, you use a ZSET as a LIST, and use a bit of Lua to implement your LIST-like operations on ZSETs. About the only thing you can't do is "SORT" the "LIST" without performing a copy first - which can be done via:

 redis.call('rpush', key, unpack(redis.call('zrange', key2, 0, -1)))

 - Josiah

--
You received this message because you are subscribed to the Google Groups "Redis DB" group.
To unsubscribe from this group and stop receiving emails from it, send an email to redis-db+u...@googlegroups.com.
To post to this group, send email to redi...@googlegroups.com.
Visit this group at http://groups.google.com/group/redis-db?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.