Default genesis parameters yielding positive treasury

cardano-api/cardano-api.cabal

@@ -178,6 +178,7 @@ library internal
                       , cborg
                       , containers
                       , contra-tracer
+                      , data-default-class
                       , deepseq
                       , directory
                       , either

cardano-api/internal/Cardano/Api/Genesis.hs

@@ -1,10 +1,10 @@
 {-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE GeneralisedNewtypeDeriving #-}
-{-# LANGUAGE OverloadedStrings #-}
 
 module Cardano.Api.Genesis
   ( ShelleyGenesis(..)
   , shelleyGenesisDefaults
+  , conwayGenesisDefaults
 
   -- ** Configuration
   , ByronGenesisConfig
@@ -26,6 +26,7 @@ module Cardano.Api.Genesis
   ) where
 
 import           Cardano.Api.IO
+import           Cardano.Api.Utils (unsafeBoundedRational)
 
 import qualified Cardano.Chain.Genesis
 import qualified Cardano.Crypto.Hash.Blake2b
@@ -42,11 +43,14 @@ import qualified Cardano.Ledger.Shelley.Genesis as Ledger
 import qualified Ouroboros.Consensus.Shelley.Eras as Shelley
 
 import           Data.ByteString (ByteString)
+import qualified Data.Default.Class as DefaultClass
 import qualified Data.ListMap as ListMap
 import qualified Data.Map.Strict as Map
-import           Data.Maybe (fromMaybe)
+import           Data.Ratio
 import           Data.Text (Text)
 import qualified Data.Time as Time
+import           Data.Typeable
+import           GHC.Stack (HasCallStack)
 import           Lens.Micro
 
 data ShelleyConfig = ShelleyConfig
@@ -102,9 +106,7 @@ shelleyGenesisDefaults =
 
       -- consensus protocol parameters
     , sgSlotLength            = 1.0 :: NominalDiffTimeMicro -- 1s slots
-    , sgActiveSlotsCoeff      = fromMaybe
-                                  (error "shelleyGenesisDefaults: impossible")
-                                  (Ledger.boundRational (1/20))  -- 20s block times on average
+    , sgActiveSlotsCoeff      = unsafeBR (1 % 20)   -- f ; 1/f = 20s block times on average
     , sgSecurityParam         = k
     , sgEpochLength           = Ledger.EpochSize (k * 10 * 20) -- 10k/f
     , sgSlotsPerKESPeriod     = 60 * 60 * 36        -- 1.5 days with 1s slots
@@ -121,6 +123,9 @@ shelleyGenesisDefaults =
         & ppEMaxL      .~ EpochInterval 18
         & ppMinFeeAL   .~ Coin 1                -- The linear factor for the minimum fee calculation
         & ppMinFeeBL   .~ Coin 0                -- The constant factor for the minimum fee calculation
+                                                -- pot = tx_fees + ρ * remaining_reserves
+        & ppRhoL       .~ unsafeBR (1 % 10)     -- How much of reserves goes into pot
+        & ppTauL       .~ unsafeBR (1 % 10)     -- τ * remaining_reserves is sent to treasury every epoch
 
       -- genesis keys and initial funds
     , sgGenDelegs             = Map.empty
@@ -131,3 +136,10 @@ shelleyGenesisDefaults =
   where
     k = 2160
     zeroTime = Time.UTCTime (Time.fromGregorian 1970 1 1) 0 -- tradition
+    unsafeBR :: (HasCallStack, Typeable r, BoundedRational r) => Rational -> r
+    unsafeBR = unsafeBoundedRational
+
+
+conwayGenesisDefaults :: ConwayGenesis StandardCrypto
+conwayGenesisDefaults = DefaultClass.def
+

cardano-api/internal/Cardano/Api/Utils.hs

@@ -28,8 +28,10 @@ module Cardano.Api.Utils
 
     -- ** CLI option parsing
   , bounded
+  , unsafeBoundedRational
   ) where
 
+import           Cardano.Ledger.BaseTypes
 import           Cardano.Ledger.Shelley ()
 
 import           Control.Exception (bracket)
@@ -38,10 +40,12 @@ import qualified Data.Aeson.Types as Aeson
 import qualified Data.ByteString as BS
 import qualified Data.ByteString.Builder as Builder
 import qualified Data.ByteString.Lazy as LBS
-import           Data.Maybe.Strict
+import           Data.Maybe
 import           Data.Text (Text)
 import qualified Data.Text as Text
+import           Data.Typeable
 import           GHC.IO.Handle.FD (openFileBlocking)
+import           GHC.Stack
 import           Options.Applicative (ReadM)
 import qualified Options.Applicative as Opt
 import           Options.Applicative.Builder (eitherReader)
@@ -129,3 +133,12 @@ modifyWith :: ()
   -> (a -> a)
 modifyWith = id
 
+
+
+-- | Convert Rational to a bounded rational. Throw an exception when the rational is out of bounds.
+unsafeBoundedRational :: forall r. (HasCallStack, Typeable r, BoundedRational r)
+                      => Rational
+                      -> r
+unsafeBoundedRational x = fromMaybe (error errMessage) $ boundRational x
+  where
+    errMessage = show (typeRep (Proxy @r)) <> " is out of bounds: " <> show x

cardano-api/src/Cardano/Api.hs

@@ -988,6 +988,7 @@ module Cardano.Api (
 
     ResolvablePointers(..),
 
+    unsafeBoundedRational,
     -- ** Supporting modules
     module Cardano.Api.Monad.Error,
     module Cardano.Api.Pretty

cardano-api/src/Cardano/Api/Shelley.hs

@@ -9,6 +9,7 @@ module Cardano.Api.Shelley
     -- * Genesis
     ShelleyGenesis(..),
     shelleyGenesisDefaults,
+    conwayGenesisDefaults,
 
     -- * Cryptographic key interface
     -- $keys