Files
postgrest/src/PostgREST/Response/Performance.hs
T

37 lines
1.3 KiB
Haskell

module PostgREST.Response.Performance
( ServerTiming (..)
, serverTimingHeader
)
where
import qualified Data.ByteString.Char8 as BS
import qualified Network.HTTP.Types as HTTP
import Numeric (showFFloat)
import Protolude
data ServerTiming =
ServerTiming
{ jwt :: Maybe Double
, parse :: Maybe Double
, plan :: Maybe Double
, transaction :: Maybe Double
, response :: Maybe Double
}
deriving (Show)
-- | Render the Server-Timing header from a ServerTimingData
--
-- >>> serverTimingHeader ServerTiming { plan=Just 0.1, transaction=Just 0.2, response=Just 0.3, jwt=Just 0.4, parse=Just 0.5}
-- ("Server-Timing","jwt;dur=400000.0, parse;dur=500000.0, plan;dur=100000.0, transaction;dur=200000.0, response;dur=300000.0")
serverTimingHeader :: ServerTiming -> HTTP.Header
serverTimingHeader timing =
("Server-Timing", renderTiming)
where
renderMetric metric = maybe "" (\dur -> BS.concat [metric, BS.pack $ ";dur=" <> showFFloat (Just 1) (dur * 1000000) ""])
renderTiming = BS.intercalate ", " $ (\(k, v) -> renderMetric k (v timing)) <$>
[ ("jwt", jwt)
, ("parse", parse)
, ("plan", plan)
, ("transaction", transaction)
, ("response", response)
]