Add compile-time flag for enabling UTxO-related logs during epoch val…

…idation

cardano-ledger.cabal

@@ -17,6 +17,10 @@ flag development
     default: False
     manual: True
 
+Flag debug-epoch-validation
+  description:         Enable debug log output for epoch validation.
+  default:             False
+
 library
   hs-source-dirs:      src
   exposed-modules:
@@ -154,6 +158,9 @@ library
   if (!flag(development))
     ghc-options:         -Werror
 
+  if flag(debug-epoch-validation)
+    cpp-options:         -DDEBUG_EPOCH_VALIDATION
+
 test-suite cardano-ledger-test
   hs-source-dirs:      test
   main-is:             test.hs

src/Cardano/Chain/Epoch/Validation.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP                 #-}
 {-# LANGUAGE FlexibleContexts    #-}
 {-# LANGUAGE LambdaCase          #-}
 {-# LANGUAGE OverloadedStrings   #-}
@@ -25,10 +26,7 @@ import Cardano.Chain.Block
   ( ABlockOrBoundary(..)
   , ChainValidationError
   , ChainValidationState(..)
-  , HeapSize
-  , UTxOSize
   , blockSlot
-  , calcUTxOSize
   , updateChainBlockOrBoundary
   )
 import Cardano.Chain.Epoch.File
@@ -40,7 +38,15 @@ import Cardano.Chain.Epoch.File
 import qualified Cardano.Chain.Genesis as Genesis
 import Cardano.Chain.Slotting
   (EpochIndex, SlotId, slotNumberEpoch, unflattenSlotId)
+
+#ifdef DEBUG_EPOCH_VALIDATION
+import Cardano.Chain.Block
+  ( HeapSize
+  , UTxOSize
+  , calcUTxOSize
+  )
 import Cardano.Chain.Txp (UTxO)
+#endif
 
 
 data EpochError
@@ -77,19 +83,30 @@ validateEpochFile config trace logconf cvs fp = do
     (sformat
       epochValidationFormat
       (slotNumberEpoch (Genesis.configEpochSlots config) (cvsLastSlot cvs))
+#ifdef DEBUG_EPOCH_VALIDATION
       utxoSize
       heapSize
+#endif
     )
+#ifdef DEBUG_EPOCH_VALIDATION
    where
     sizePair = calcUTxOSize (cvsUtxo cvs')
     utxoSize = snd sizePair
     heapSize = fst sizePair
+#endif
 
-  epochValidationFormat :: Format r (EpochIndex -> UTxOSize -> HeapSize UTxO -> r)
+  epochValidationFormat
+#ifdef DEBUG_EPOCH_VALIDATION
+    :: Format r (EpochIndex -> UTxOSize -> HeapSize UTxO -> r)
+#else
+    :: Format r (EpochIndex -> r)
+#endif
   epochValidationFormat =
-    "Succesfully validated epoch " . build . "\n" .
-    "Number of UTxO entries at the end of the epoch: " . build . "\n" .
-    "UTxO heap size in words at the end of the epoch: " . build . "\n"
+    "Succesfully validated epoch " . build . "\n"
+#ifdef DEBUG_EPOCH_VALIDATION
+    . "Number of UTxO entries at the end of the epoch: " . build . "\n"
+    . "UTxO heap size in words at the end of the epoch: " . build . "\n"
+#endif
 
 
 -- | Check that a list of epochs 'Block's are valid.