FIXUP: merge micro-bench

Author: jorisdral

bench/micro/Bench/Database/LSMTree/Internal/Merge.hs

@@ -28,6 +28,7 @@ import qualified Database.LSMTree.Internal.RunAcc as RunAcc
 import qualified Database.LSMTree.Internal.RunBuilder as RunBuilder
 import           Database.LSMTree.Internal.RunNumber
 import           Database.LSMTree.Internal.Serialise
+import           Database.LSMTree.Internal.Types (Salt)
 import           Database.LSMTree.Internal.UniqCounter
 import           Prelude hiding (getContents)
 import           System.Directory (removeDirectoryRecursive)
@@ -221,8 +222,11 @@ benchmarks = bgroup "Bench.Database.LSMTree.Internal.Merge" [
          | w <- weights
          ]
 
+benchSalt :: Salt
+benchSalt = 4
+
 sessionSalt :: SessionSalt
-sessionSalt = SessionSalt 4
+sessionSalt = SessionSalt benchSalt
 
 runParams :: RunBuilder.RunParams
 runParams =
@@ -450,5 +454,5 @@ randomRunData Config {..} runentries g0 =
 -- Each run entry needs a distinct key.
 randomWord64OutOf :: Int -> Rnd SerialisedKey
 randomWord64OutOf possibleKeys =
-      first (serialiseKey . Hash.hashSalt64 0)
+      first (serialiseKey . Hash.hashSalt64 benchSalt)
     . uniformR (0, fromIntegral possibleKeys :: Word64)