module Network.Metric.Sink.Statsd (
Sink(..)
, open
, Group
, Bucket
, AnySink(..)
) where
import Control.Monad (liftM)
import Network.Socket (SocketType(..))
import System.Random (randomRIO)
import Network.Metric.Internal
import qualified Data.ByteString.Char8 as BS
import qualified Data.ByteString.Lazy.Char8 as BL
data Sampled = Sampled | Exact | Ignore
data Statsd = Statsd Host Handle deriving (Show)
instance Sink Statsd where
push (Statsd host hd) m = mapM enc (measure m) >>= mapM_ (hPush hd)
where
enc (Counter g b v) = put host g b v "c" 1.0
enc (Gauge g b v) = put host g b v "g" 1.0
enc (Timer g b v) = put host g b v "ms" 1.0
close (Statsd _ hd) = hClose hd
open :: Host -> HostName -> PortNumber -> IO AnySink
open host = fOpen (Statsd host) Datagram
put :: Encodable a
=> Host
-> Group
-> Bucket
-> a
-> BS.ByteString
-> Double
-> IO BL.ByteString
put host group bucket value typ rate =
liftM bstr (randomRIO (0.0, 1.0))
where
base = [key host group bucket, ":", encode value, "|", typ]
bstr n = BL.fromChunks $ case sample rate n of
Sampled -> base ++ ["@", BS.pack $ show rate]
Exact -> base
Ignore -> []
sample :: Double -> Double -> Sampled
sample rate rand | rate < 1.0 && rand <= rate = Sampled
| rate == 1.0 = Exact
| otherwise = Ignore