redis luaスクリプトトークンバケツストリーム制限実装

redis.replicate_commands()

local key = KEYS[1] --      
local capacity = tonumber(ARGV[1]) --     
local quota = tonumber(ARGV[2]) --         
local period = tonumber(ARGV[3]) --       （ ）
local quantity = tonumber(ARGV[4]) or 1 --        ，   1
local timestamp = tonumber(redis.call('time')[1]) --      

--            
if (redis.call('exists', key) == 0) then
    redis.call('hmset', key, 'remain', capacity, 'timestamp', timestamp)
else
    --                       
    local remain = tonumber(redis.call('hget', key, 'remain'))
    local last_reset = tonumber(redis.call('hget', key, 'timestamp'))
    local delta_quota = math.floor(((timestamp - last_reset) / period) * quota)
    if (delta_quota > 0) then
        remain = remain + delta_quota
        if (remain > capacity) then
            remain = capacity
        end
        redis.call('hmset', key, 'remain', remain, 'timestamp', timestamp)
    end
end

--                
redis.call('hmset', key, 'capacity', capacity, 'quota', quota, 'period', period);

local result = {} --       
local remain = tonumber(redis.call('hget', key, 'remain'))
if (remain < quantity) then
    result = {1, capacity, remain}
else
    result = {0, capacity, remain - quantity}
    redis.call('hincrby', key, 'remain', -quantity)
end

return result