use cScaleFactor where I incorrectly used the variable zoom in the past. i was young and needed the money
{-# LANGUAGE BangPatterns #-}
module JoinsMonitor(
JoinsMonitor
, newJoinMonitor
, cleanup
, joinsSentry
) where
import qualified Data.Map as Map
import Data.Time
import Data.IORef
import qualified Data.ByteString as B
import Data.Maybe
import Control.Monad
newtype JoinsMonitor = JoinsMonitor (IORef (Map.Map B.ByteString [UTCTime]))
newJoinMonitor :: IO JoinsMonitor
newJoinMonitor = do
ioref <- newIORef Map.empty
return (JoinsMonitor ioref)
cleanup :: JoinsMonitor -> UTCTime -> IO ()
cleanup (JoinsMonitor ref) time = modifyIORef ref f
where
f = Map.mapMaybe (\v -> let v' = takeWhile (\t -> diffUTCTime time t < 60*60) v in if null v' then Nothing else Just v')
joinsSentry :: JoinsMonitor -> B.ByteString -> UTCTime -> IO Bool
joinsSentry (JoinsMonitor ref) host time = do
m <- readIORef ref
let lastJoins = map (diffUTCTime time) $ Map.findWithDefault [] host m
let last30sec = length $ takeWhile (< 30) lastJoins
let last2min = length $ takeWhile (< 120) lastJoins
let last10min = length $ takeWhile (< 600) lastJoins
let pass = last30sec < 2 && last2min < 3 && last10min < 5
when pass $ writeIORef ref $ Map.alter (Just . (:) time . fromMaybe []) host m
return pass