handle PoA block difficulty during block creation

- in vmState
- in txpool
- in sealing engine

fix #1105

nimbus/p2p/clique/clique_sealer.nim

@@ -12,8 +12,6 @@
 ## Mining Support for Clique PoA Consensus Protocol
 ## ================================================
 ##
-## Note that mining in currently unsupported by `NIMBUS`
-##
 ## For details see
 ## `EIP-225 <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-225.md>`_
 ## and
@@ -322,7 +320,7 @@ proc seal*(c: Clique; ethBlock: var EthBlock):
  ok()
 
 # clique/clique.go(673): func (c *Clique) CalcDifficulty(chain [..]
-proc calcDifficulty(c: Clique;
+proc calcDifficulty*(c: Clique;
  parent: BlockHeader): Result[DifficultyInt,CliqueError]
  {.gcsafe, raises: [Defect,CatchableError].} =
  ## For the Consensus Engine, `calcDifficulty()` is the difficulty adjustment

nimbus/sealer.nim

@@ -126,8 +126,6 @@ proc generateBlock(engine: SealingEngineRef,
  timestamp = getTime(),
  prevRandao = Hash256()): Result[void, string] =
  # deviation from standard block generator
- # - no local and remote transactions inclusion(need tx pool)
- # - no receipts from tx
  # - no DAO hard fork
  # - no local and remote uncles inclusion
 
@@ -188,6 +186,20 @@ proc sealingLoop(engine: SealingEngineRef): Future[void] {.async.} =
 
  clique.authorize(engine.signer, signerFunc)
 
+ proc diffCalculator(timeStamp: EthTime, parent: BlockHeader): DifficultyInt {.gcsafe, raises:[].} =
+ # pesky Nim effect system
+ try:
+ discard timestamp
+ let rc = clique.calcDifficulty(parent)
+ if rc.isErr:
+ return 0.u256
+ rc.get()
+ except:
+ 0.u256
+
+ # switch to PoA difficulty calculator
+ engine.txPool.calcDifficulty = diffCalculator
+
  # convert times.Duration to chronos.Duration
  let period = chronos.seconds(clique.cfg.period.inSeconds)
 

nimbus/utils/tx_pool.nim

@@ -772,6 +772,11 @@ proc `feeRecipient=`*(xp: TxPoolRef; beneficiary: EthAddress) =
  ## a.k.a miner in PoW chain or coinbase
  xp.chain.miner = beneficiary
 
+proc `calcDifficulty=`*(xp: TxPoolRef; val: DifficultyCalculator) =
+ ## Setter, either PoW or PoA difficulty calculator
+ ## PoS difficulty always zero
+ xp.chain.calcDifficulty = val
+
 # ------------------------------------------------------------------------------
 # Public functions, per-tx-item operations
 # ------------------------------------------------------------------------------

nimbus/utils/tx_pool/tx_chain.nim

@@ -20,6 +20,7 @@ import
  ../../forks,
  ../../p2p/executor,
  ../../utils,
+ ../../utils/difficulty,
  ../../vm_state,
  ../../vm_types,
  ./tx_chain/[tx_basefee, tx_gaslimits],
@@ -53,6 +54,8 @@ type
  txRoot: Hash256 ## `rootHash` after packing
  stateRoot: Hash256 ## `stateRoot` after packing
 
+ DifficultyCalculator* = proc(timeStamp: EthTime, parent: BlockHeader): DifficultyInt {.gcsafe, raises:[].}
+
  TxChainRef* = ref object ##\
  ## State cache of the transaction environment for creating a new\
  ## block. This state is typically synchrionised with the canonical\
@@ -69,6 +72,9 @@ type
  # EIP-4399 and EIP-3675
  prevRandao: Hash256 ## PoS block randomness
 
+ # overrideable difficulty calculator
+ calcDifficulty: DifficultyCalculator
+
 # ------------------------------------------------------------------------------
 # Private functions
 # ------------------------------------------------------------------------------
@@ -77,12 +83,16 @@ proc resetTxEnv(dh: TxChainRef; parent: BlockHeader; fee: Option[UInt256])
  {.gcsafe,raises: [Defect,CatchableError].} =
  dh.txEnv.reset
 
+ let timestamp = getTime().utc.toTime
+ # we don't consider PoS difficulty here
+ # because that is handled in vmState
  dh.txEnv.vmState = BaseVMState.new(
  parent = parent,
- timestamp = getTime().utc.toTime,
+ timestamp = timestamp,
  gasLimit = (if dh.maxMode: dh.limits.maxLimit else: dh.limits.trgLimit),
  fee = fee,
  prevRandao= dh.prevRandao,
+ difficulty= dh.calcDifficulty(timestamp, parent),
  miner = dh.miner,
  chainDB = dh.db)
 
@@ -118,6 +128,12 @@ proc new*(T: type TxChainRef; db: BaseChainDB; miner: EthAddress): T
  result.miner = miner
  result.lhwm.lwmTrg = TRG_THRESHOLD_PER_CENT
  result.lhwm.hwmMax = MAX_THRESHOLD_PER_CENT
+ result.calcDifficulty = proc(timeStamp: EthTime, parent: BlockHeader):
+ DifficultyInt {.gcsafe, raises:[].} =
+ try:
+ db.config.calcDifficulty(timestamp, parent)
+ except:
+ 0.u256
  result.update(db.getCanonicalHead)
 
 # ------------------------------------------------------------------------------
@@ -311,6 +327,10 @@ proc `prevRandao=`*(dh: TxChainRef; val: Hash256) =
  ## Setter
  dh.prevRandao = val
 
+proc `calcDifficulty=`*(dh: TxChainRef; val: DifficultyCalculator) =
+ ## Setter
+ dh.calcDifficulty = val
+
 # ------------------------------------------------------------------------------
 # End
 # ------------------------------------------------------------------------------

nimbus/vm/state.nim

@@ -67,6 +67,7 @@ proc init(
  gasLimit: GasInt;
  fee: Option[UInt256];
  prevRandao: Hash256;
+ difficulty: UInt256;
  miner: EthAddress;
  chainDB: BaseChainDB;
  ttdReached: bool;
@@ -80,6 +81,7 @@ proc init(
  self.gasLimit = gasLimit
  self.fee = fee
  self.prevRandao = prevRandao
+ self.blockDifficulty = difficulty
  self.chainDB = chainDB
  self.ttdReached = ttdReached
  self.tracer = tracer
@@ -96,6 +98,7 @@ proc init(
  gasLimit: GasInt;
  fee: Option[UInt256];
  prevRandao: Hash256;
+ difficulty: UInt256;
  miner: EthAddress;
  chainDB: BaseChainDB;
  tracerFlags: set[TracerFlags])
@@ -109,6 +112,7 @@ proc init(
  gasLimit = gasLimit,
  fee = fee,
  prevRandao= prevRandao,
+ difficulty= difficulty,
  miner = miner,
  chainDB = chainDB,
  ttdReached= chainDB.isTtdReached(parent.blockHash),
@@ -132,6 +136,7 @@ proc new*(
  gasLimit: GasInt; ## tx env: gas limit
  fee: Option[UInt256]; ## tx env: optional base fee
  prevRandao: Hash256; ## tx env: POS block randomness
+ difficulty: UInt256, ## tx env: difficulty
  miner: EthAddress; ## tx env: coinbase(PoW) or signer(PoA)
  chainDB: BaseChainDB; ## block chain database
  tracerFlags: set[TracerFlags] = {};
@@ -152,6 +157,7 @@ proc new*(
  gasLimit = gasLimit,
  fee = fee,
  prevRandao = prevRandao,
+ difficulty = difficulty,
  miner = miner,
  chainDB = chainDB,
  tracerFlags = tracerFlags)
@@ -162,6 +168,7 @@ proc reinit*(self: BaseVMState; ## Object descriptor
  gasLimit: GasInt; ## tx env: gas limit
  fee: Option[UInt256]; ## tx env: optional base fee
  prevRandao:Hash256; ## tx env: POS block randomness
+ difficulty:UInt256, ## tx env: difficulty
  miner: EthAddress; ## tx env: coinbase(PoW) or signer(PoA)
  pruneTrie: bool = true): bool
  {.gcsafe, raises: [Defect,CatchableError].} =
@@ -187,6 +194,7 @@ proc reinit*(self: BaseVMState; ## Object descriptor
  gasLimit = gasLimit,
  fee = fee,
  prevRandao = prevRandao,
+ difficulty = difficulty,
  miner = miner,
  chainDB = db,
  ttdReached = db.isTtdReached(parent.blockHash),
@@ -211,6 +219,7 @@ proc reinit*(self: BaseVMState; ## Object descriptor
  gasLimit = header.gasLimit,
  fee = header.fee,
  prevRandao= header.prevRandao,
+ difficulty= header.difficulty,
  miner = self.chainDB.getMinerAddress(header),
  pruneTrie = pruneTrie)
 
@@ -249,6 +258,7 @@ proc init*(
  gasLimit = header.gasLimit,
  fee = header.fee,
  prevRandao = header.prevRandao,
+ difficulty = header.difficulty,
  miner = chainDB.getMinerAddress(header),
  chainDB = chainDB,
  tracerFlags = tracerFlags)
@@ -305,12 +315,6 @@ proc setupTxContext*(vmState: BaseVMState, origin: EthAddress, gasPrice: GasInt,
  vmState.chainDB.config.toFork(vmState.parent.blockNumber + 1)
  vmState.gasCosts = vmState.fork.forkToSchedule
 
-proc consensusEnginePoA*(vmState: BaseVMState): bool =
- # PoA consensus engine have no reward for miner
- # TODO: this need to be fixed somehow
- # using `real` engine configuration
- vmState.chainDB.config.poaEngine
-
 method coinbase*(vmState: BaseVMState): EthAddress {.base, gcsafe.} =
  vmState.minerAddress
 
@@ -324,7 +328,7 @@ method difficulty*(vmState: BaseVMState): UInt256 {.base, gcsafe.} =
  # EIP-4399/EIP-3675
  UInt256.fromBytesBE(vmState.prevRandao.data, allowPadding = false)
  else:
- vmState.chainDB.config.calcDifficulty(vmState.timestamp, vmState.parent)
+ vmState.blockDifficulty
 
 method baseFee*(vmState: BaseVMState): UInt256 {.base, gcsafe.} =
  if vmState.fee.isSome:

nimbus/vm/types.nim

@@ -39,6 +39,7 @@ type
  gasLimit* : GasInt
  fee* : Option[UInt256]
  prevRandao* : Hash256
+ blockDifficulty*: UInt256
  ttdReached* : bool
  name* : string
  flags* : set[VMFlag]

nimbus/vm2/state.nim

@@ -65,6 +65,7 @@ proc init(
  gasLimit: GasInt;
  fee: Option[UInt256];
  prevRandao: Hash256;
+ difficulty: UInt256;
  miner: EthAddress;
  chainDB: BaseChainDB;
  ttdReached: bool;
@@ -78,6 +79,7 @@ proc init(
  self.gasLimit = gasLimit
  self.fee = fee
  self.prevRandao = prevRandao
+ self.blockDifficulty = difficulty
  self.chainDB = chainDB
  self.ttdReached = ttdReached
  self.tracer = tracer
@@ -94,6 +96,7 @@ proc init(
  gasLimit: GasInt;
  fee: Option[UInt256];
  prevRandao: Hash256;
+ difficulty: UInt256;
  miner: EthAddress;
  chainDB: BaseChainDB;
  tracerFlags: set[TracerFlags])
@@ -107,6 +110,7 @@ proc init(
  gasLimit = gasLimit,
  fee = fee,
  prevRandao= prevRandao,
+ difficulty= difficulty,
  miner = miner,
  chainDB = chainDB,
  ttdReached= chainDB.isTtdReached(parent.blockHash),
@@ -130,6 +134,7 @@ proc new*(
  gasLimit: GasInt; ## tx env: gas limit
  fee: Option[UInt256]; ## tx env: optional base fee
  prevRandao: Hash256; ## tx env: POS block randomness
+ difficulty: UInt256, ## tx env: difficulty
  miner: EthAddress; ## tx env: coinbase(PoW) or signer(PoA)
  chainDB: BaseChainDB; ## block chain database
  tracerFlags: set[TracerFlags] = {};
@@ -150,6 +155,7 @@ proc new*(
  gasLimit = gasLimit,
  fee = fee,
  prevRandao = prevRandao,
+ difficulty = difficulty,
  miner = miner,
  chainDB = chainDB,
  tracerFlags = tracerFlags)
@@ -160,6 +166,7 @@ proc reinit*(self: BaseVMState; ## Object descriptor
  gasLimit: GasInt; ## tx env: gas limit
  fee: Option[UInt256]; ## tx env: optional base fee
  prevRandao:Hash256; ## tx env: POS block randomness
+ difficulty:UInt256, ## tx env: difficulty
  miner: EthAddress; ## tx env: coinbase(PoW) or signer(PoA)
  pruneTrie: bool = true): bool
  {.gcsafe, raises: [Defect,CatchableError].} =
@@ -185,6 +192,7 @@ proc reinit*(self: BaseVMState; ## Object descriptor
  gasLimit = gasLimit,
  fee = fee,
  prevRandao = prevRandao,
+ difficulty = difficulty,
  miner = miner,
  chainDB = db,
  ttdReached = db.isTtdReached(parent.blockHash),
@@ -209,6 +217,7 @@ proc reinit*(self: BaseVMState; ## Object descriptor
  gasLimit = header.gasLimit,
  fee = header.fee,
  prevRandao= header.prevRandao,
+ difficulty= header.difficulty,
  miner = self.chainDB.getMinerAddress(header),
  pruneTrie = pruneTrie)
 
@@ -247,6 +256,7 @@ proc init*(
  gasLimit = header.gasLimit,
  fee = header.fee,
  prevRandao = header.prevRandao,
+ difficulty = header.difficulty,
  miner = chainDB.getMinerAddress(header),
  chainDB = chainDB,
  tracerFlags = tracerFlags)
@@ -290,13 +300,6 @@ proc new*(
  tracerFlags = tracerFlags,
  pruneTrie = pruneTrie)
 
-
-proc consensusEnginePoA*(vmState: BaseVMState): bool =
- # PoA consensus engine have no reward for miner
- # TODO: this need to be fixed somehow
- # using `real` engine configuration
- vmState.chainDB.config.poaEngine
-
 method coinbase*(vmState: BaseVMState): EthAddress {.base, gcsafe.} =
  vmState.minerAddress
 
@@ -310,7 +313,7 @@ method difficulty*(vmState: BaseVMState): UInt256 {.base, gcsafe.} =
  # EIP-4399/EIP-3675
  UInt256.fromBytesBE(vmState.prevRandao.data, allowPadding = false)
  else:
- vmState.chainDB.config.calcDifficulty(vmState.timestamp, vmState.parent)
+ vmState.blockDifficulty
 
 method baseFee*(vmState: BaseVMState): UInt256 {.base, gcsafe.} =
  if vmState.fee.isSome:

nimbus/vm2/types.nim

@@ -30,6 +30,7 @@ type
  gasLimit* : GasInt
  fee* : Option[UInt256]
  prevRandao* : Hash256
+ blockDifficulty*: UInt256
  ttdReached* : bool
  name* : string
  flags* : set[VMFlag]

nimbus/vm_state.nim

@@ -26,7 +26,6 @@ export
  vms.blockNumber,
  vms.buildWitness,
  vms.coinbase,
- vms.consensusEnginePoA,
  vms.difficulty,
  vms.disableTracing,
  vms.enableTracing,