#lua #redis

scan.lua

-- scan whole keys in redis by key_pattern and filter
-- key_pattern: key regexp
-- count: match count for once scan
-- filter: one function that accepts the value of key as param.
local scan=function(key_pattern, count, filter)
    local start = "-1"
    local lst = {}

    while (start ~= "0") do
        if (start == "-1") then
            start = "0"
        end

        local res = redis.call("scan", start, "match", key_pattern, "count", count)
        start = res[1]
        local keys = res[2]
        if (filter ~= nil) then
            for i, key in ipairs(keys) do
                local value = redis.call("get", key)
                if (filter(value)) then
                    table.insert(lst, key)
                end
            end
        end
    end

    return lst
end

-- filter example
local filter=function(val)
    return tonumber(val) > 0
end

-- example: scan all keys in redis that key pattern matchs "sns-*com*" and the value is bigger than 0.
return scan("sns-*com*", 100, filter)

删除 redis 内 state

EVAL "for i=0,8 do redis.call('del', 'filex:state:fbaidu-upmov-y-'..i) end" 0