import { slidingWindowLimitScript } from "https://deno.land/x/upstash_ratelimit@v1.1.0-canary-1/src/lua-scripts/multi.ts";
type
`
local currentKey = KEYS[1] -- identifier including prefixes
local previousKey = KEYS[2] -- key of the previous bucket
local tokens = tonumber(ARGV[1]) -- tokens per window
local now = ARGV[2] -- current timestamp in milliseconds
local window = ARGV[3] -- interval in milliseconds
local requestId = ARGV[4] -- uuid for this request
local incrementBy = tonumber(ARGV[5]) -- custom rate, default is 1
local currentFields = redis.call("HGETALL", currentKey)
local requestsInCurrentWindow = 0
for i = 2, #currentFields, 2 do
requestsInCurrentWindow = requestsInCurrentWindow + tonumber(currentFields[i])
end
local previousFields = redis.call("HGETALL", previousKey)
local requestsInPreviousWindow = 0
for i = 2, #previousFields, 2 do
requestsInPreviousWindow = requestsInPreviousWindow + tonumber(previousFields[i])
end
local percentageInCurrent = ( now % window) / window
if requestsInPreviousWindow * (1 - percentageInCurrent ) + requestsInCurrentWindow >= tokens then
return {currentFields, previousFields, false}
end
redis.call("HSET", currentKey, requestId, incrementBy)
if requestsInCurrentWindow == 0 then
-- The first time this key is set, the value will be equal to incrementBy.
-- So we only need the expire command once
redis.call("PEXPIRE", currentKey, window * 2 + 1000) -- Enough time to overlap with a new window + 1 second
end
return {currentFields, previousFields, true}
`