eleks/oracle: demonstrate how expensive || can be!

Author: kk-hainq

eleks/oracle/src/Contracts/Oracle/OffChain.hs

@@ -102,7 +102,7 @@ updateOracle oracle operatorPrivateKey params = do
                                     , osmGameId = gameId
                                     , osmGameStatus = gameStatus
                                     }
-                        let oracleData' = oracleData{ ovSignedMessage = Just $ signMessage oracleSignMessage operatorPrivateKey }
+                        let oracleData' = oracleData{ ovSignedMessage = Nothing } -- This is not that hacky, the on-chain validation rule accepts it!
                         when (oracleData' /= oracleData) $ do
                             let requestTokenVal = assetClassValue (requestTokenClassFromOracle oracle) 1
                                 collateralVal = Ada.toValue $ oCollateral oracle 

eleks/oracle/src/Contracts/Oracle/OnChain.hs

@@ -132,11 +132,18 @@ mkOracleValidator oracle oracleData r ctx =
                                             >>= verifyOracleValueSigned (oOperatorKey oracle) 
                                             >>= (\(message, _) -> Just message)
 
-    isUpdateValid = (not isCurrentValueSigned) || 
-        (fromMaybe False $ validateGameStatusChanges <$> 
-        (osmGameStatus <$> extractSigendMessage (ovSignedMessage oracleData)) <*> 
+    -- if then else is way cheaper!
+    isUpdateValid = if not isCurrentValueSigned then True else
+        (fromMaybe False $ validateGameStatusChanges <$>
+        (osmGameStatus <$> extractSigendMessage (ovSignedMessage oracleData)) <*>
         (osmGameStatus <$> extractSigendMessage outputSignedMessage))
 
+    -- || is surprisingly way more expensive!
+    -- isUpdateValid = (not isCurrentValueSigned) ||
+    --     (fromMaybe False $ validateGameStatusChanges <$>
+    --     (osmGameStatus <$> extractSigendMessage (ovSignedMessage oracleData)) <*>
+    --     (osmGameStatus <$> extractSigendMessage outputSignedMessage))
+
 {-# INLINABLE verifyOracleValueSigned #-}
 verifyOracleValueSigned :: PubKey -> SignedMessage OracleSignedMessage -> Maybe (OracleSignedMessage, TxConstraints Void Void)
 verifyOracleValueSigned pubKey sm = case verifySignedMessageConstraints pubKey sm of

eleks/oracle/src/test/Spec.hs

@@ -6,8 +6,25 @@ import qualified Spec.Oracle
 import           Test.Tasty
 import           Test.Tasty.Hedgehog       (HedgehogTestLimit (..))
 
+import Data.Default
+import Ledger.Index
+import Plutus.Trace
+
+-- With `||`:
+-- ( Sum {getSum = 9539}
+-- , ExBudget {exBudgetCPU = ExCPU 1124168956, exBudgetMemory = ExMemory 3152700}
+-- )
+
+-- With `if then else`:
+-- ( Sum {getSum = 3531}
+-- , ExBudget {exBudgetCPU = ExCPU 698345767, exBudgetMemory = ExMemory 2069978}
+-- )
 main :: IO ()
-main = defaultMain tests
+main = print =<< writeScriptsTo
+        (ScriptsConfig "." (Scripts UnappliedValidators))
+        "updateOracleTrace"
+        Spec.Oracle.updateOracleTrace
+        def
 
 -- | Number of successful tests for each hedgehog property.
 --   The default is 100 but we use a smaller number here in order to speed up

eleks/oracle/src/test/Spec/Oracle.hs

@@ -11,6 +11,7 @@
 
 module Spec.Oracle
     ( tests
+    , updateOracleTrace
     ) where
 
 import           Control.Lens