redis里使用lua脚本对hash里的数据进行排序

注意：本脚本只适用于数据量较少的集合进行排序，数据量太大会严重影响redis的性能。

local t = redis.call('hgetall', KEYS[1]);
local arr = {};
for i, v in pairs(t) do
    if i % 2 == 0 then
        local j = cjson.decode(v)
        if j.language == ARGV[1] then j.languageEquals = 1 else j.languageEquals = 0 end;
        if j.country == ARGV[2] then j.countryEquals = 1 else j.countryEquals = 0 end;
        table.insert(arr, j)
    end    
end 
table.sort(arr, function (a, b) 
    if a.languageEquals - b.languageEquals == 0 then
        if a.countryEquals - b.countryEquals == 0 then 
            return a.createTime < b.createTime
        else return a.countryEquals > b.countryEquals end;
    end;
    return a.languageEquals > b.languageEquals;
end)
return cjson.encode(arr);