Introduce the P7 to P8 update.

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased changes
 
+- Add P7 -> P8 update.
 - Automatically suspend validators from the consensus that missed too many
   rounds in the previous payday.
 - Add support for suspend/resume to validator configuration updates.

concordium-consensus/src/Concordium/ProtocolUpdate/P7.hs

@@ -8,29 +8,33 @@ module Concordium.ProtocolUpdate.P7 (
     updateNextProtocolVersion,
 ) where
 
-import Control.Monad.State
+import Control.Monad.State hiding (get)
 import qualified Data.HashMap.Strict as HM
 import Data.Serialize
 
 import qualified Concordium.Crypto.SHA256 as SHA256
 import Concordium.Types
 import Concordium.Types.Updates
 
+import qualified Concordium.Genesis.Data.P8 as P8
 import Concordium.GlobalState.BlockState
 import qualified Concordium.GlobalState.Persistent.BlockState as PBS
 import Concordium.GlobalState.Types
 import qualified Concordium.GlobalState.Types as GSTypes
 import Concordium.KonsensusV1.TreeState.Implementation
 import Concordium.KonsensusV1.TreeState.Types
+import qualified Concordium.ProtocolUpdate.P7.ProtocolP8 as ProtocolP8
 import qualified Concordium.ProtocolUpdate.P7.Reboot as Reboot
 
 -- | Updates that are supported from protocol version P7.
-data Update = Reboot
+data Update
+    = Reboot
+    | ProtocolP8 P8.ProtocolUpdateData
     deriving (Show)
 
 -- | Hash map for resolving updates from their specification hash.
 updates :: HM.HashMap SHA256.Hash (Get Update)
-updates = HM.fromList [(Reboot.updateHash, return Reboot)]
+updates = HM.fromList [(Reboot.updateHash, return Reboot), (ProtocolP8.updateHash, ProtocolP8 <$> get)]
 
 -- | Determine if a 'ProtocolUpdate' corresponds to a supported update type.
 checkUpdate :: ProtocolUpdate -> Either String Update
@@ -53,9 +57,11 @@ updateRegenesis ::
     BlockPointer (MPV m) ->
     m (PVInit m)
 updateRegenesis Reboot = Reboot.updateRegenesis
+updateRegenesis (ProtocolP8 protocolUpdateData) = ProtocolP8.updateRegenesis protocolUpdateData
 
 -- | Determine the protocol version the update will update to.
 updateNextProtocolVersion ::
     Update ->
     SomeProtocolVersion
 updateNextProtocolVersion Reboot{} = SomeProtocolVersion SP7
+updateNextProtocolVersion ProtocolP8{} = SomeProtocolVersion SP8

concordium-consensus/src/Concordium/ProtocolUpdate/P7/ProtocolP8.hs

@@ -0,0 +1,120 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeFamilies #-}
+
+-- | This module implements the P7.ProtocolP8 protocol update.
+--  This protocol update is valid at protocol version P7, and updates
+--  to protocol version P8.
+--
+--  This produces a new 'RegenesisDataP8' using the 'GDP8RegenesisFromP7' constructor,
+--  as follows:
+--
+--  * 'genesisCore':
+--
+--      * 'genesisTime' is the timestamp of the last finalized block of the previous chain.
+--      * 'genesisEpochDuration' is taken from the previous genesis.
+--      * 'genesisSignatureThreshold' is taken from the previous genesis.
+--
+--  * 'genesisFirstGenesis' is either:
+--
+--      * the hash of the genesis block of the previous chain, if it is a 'GDP7Initial'; or
+--      * the 'genesisFirstGenesis' value of the genesis block of the previous chain, if it
+--        is a 'GDP7Regenesis'.
+--
+--  * 'genesisPreviousGenesis' is the hash of the previous genesis block.
+--
+--  * 'genesisTerminalBlock' is the hash of the last finalized block of the previous chain.
+--
+--  * 'genesisStateHash' is the state hash of the last finalized block of the previous chain.
+--
+--  * 'genesisMigration' is derived from the data provided to the protocol update, which is the
+--     validator score parameters
+--
+--  The block state is taken from the last finalized block of the previous chain. It is updated
+--  as part of the state migration, which makes the following changes:
+--
+--  * The seed state is migrated as follows:
+--
+--      * The current epoch is reset to zero.
+--      * The current and updated leadership election nonce are set to the hash of
+--        @"Regenesis" <> encode oldUpdatedNonce@.
+--      * The trigger block time is kept the same, meaning that the epoch will transition as soon
+--        as possible.
+--      * The epoch transition triggered flag is set.
+--      * The shutdown triggered flag is cleared.
+--
+--  * The old current epoch is subtracted from the next payday epoch.
+--
+--  * The protocol update queue is emptied during the migration.
+--
+--  Note that, the initial epoch of the new chain is not considered
+--  a new epoch for the purposes of block rewards and baker/finalization committee determination.
+--  In particular, the timing of the next payday will be the same as if the protocol update
+--  had not happened. (For instance, if it would have happened at the start of the next epoch
+--  prior to the protocol update, after the update it will happen at the start of epoch 1.
+--  The trigger block time in epoch 0 of the new consensus is the same as the trigger block
+--  time in the final epoch of the old consensus.)
+--  Furthermore, the bakers from the final epoch of the previous chain are also the bakers for the
+--  initial epoch of the new chain.
+module Concordium.ProtocolUpdate.P7.ProtocolP8 where
+
+import Control.Monad.State
+import Lens.Micro.Platform
+
+import qualified Concordium.Crypto.SHA256 as SHA256
+import qualified Concordium.Genesis.Data as GenesisData
+import qualified Concordium.Genesis.Data.BaseV1 as BaseV1
+import qualified Concordium.Genesis.Data.P8 as P8
+import Concordium.GlobalState.BlockState
+import qualified Concordium.GlobalState.Persistent.BlockState as PBS
+import Concordium.GlobalState.Types
+import qualified Concordium.GlobalState.Types as GSTypes
+import qualified Concordium.KonsensusV1.TreeState.Implementation as TreeState
+import Concordium.KonsensusV1.TreeState.Types
+import Concordium.KonsensusV1.Types
+import Concordium.Types.HashableTo (getHash)
+import Concordium.Types.ProtocolVersion
+
+-- | The hash that identifies a update from P7 to P8 protocol.
+--  This is the hash of the published specification document.
+updateHash :: SHA256.Hash
+updateHash = read "f12e20b6936a6b1b736e95715e1654b92adb4226ef7601b4183895bee563f9da"
+
+-- | Construct the genesis data for a P7.ProtocolP8 update.
+--  This takes the terminal block of the old chain which is used as the basis for constructing
+--  the new genesis block.
+updateRegenesis ::
+    ( MPV m ~ 'P7,
+      BlockStateStorage m,
+      MonadState (TreeState.SkovData (MPV m)) m,
+      GSTypes.BlockState m ~ PBS.HashedPersistentBlockState (MPV m)
+    ) =>
+    P8.ProtocolUpdateData ->
+    -- | The terminal block of the old chain.
+    BlockPointer 'P7 ->
+    m (PVInit m)
+updateRegenesis protocolUpdateData terminalBlock = do
+    -- Genesis time is the timestamp of the terminal block
+    let regenesisTime = blockTimestamp terminalBlock
+    -- Core parameters are derived from the old genesis, apart from genesis time which is set for
+    -- the time of the terminal block.
+    gMetadata <- use TreeState.genesisMetadata
+    BaseV1.CoreGenesisParametersV1{..} <- gmParameters <$> use TreeState.genesisMetadata
+    let core =
+            BaseV1.CoreGenesisParametersV1
+                { BaseV1.genesisTime = regenesisTime,
+                  ..
+                }
+    -- genesisFirstGenesis is the block hash of the previous genesis, if it is initial,
+    -- or the genesisFirstGenesis of the previous genesis otherwise.
+    let genesisFirstGenesis = gmFirstGenesisHash gMetadata
+        genesisPreviousGenesis = gmCurrentGenesisHash gMetadata
+        genesisTerminalBlock = getHash terminalBlock
+    let regenesisBlockState = bpState terminalBlock
+    genesisStateHash <- getStateHash regenesisBlockState
+    let genesisMigration =
+            P8.StateMigrationData
+                { migrationProtocolUpdateData = protocolUpdateData
+                }
+    let newGenesis = GenesisData.RGDP8 $ P8.GDP8RegenesisFromP7{genesisRegenesis = BaseV1.RegenesisDataV1{genesisCore = core, ..}, ..}
+    return (PVInit newGenesis (GenesisData.StateMigrationParametersP7ToP8 genesisMigration) (bmHeight $ bpInfo terminalBlock))