[ETCM-942] Muir Glacier (#1107)

* [ETCM-942] Add Muir Glacier block height to configs

* [ETCM-942] Implement Muir Glacier delay

* [ETCM-942] Make difficulty costants more readable

Author: lukasz-golebiewski

src/it/scala/io/iohk/ethereum/txExecTest/ECIP1017Test.scala

@@ -29,29 +29,12 @@ class ECIP1017Test extends AnyFlatSpec with Matchers {
       maxCodeSize = None,
       chainId = 0x3d.toByte,
       networkId = 1,
-      forkBlockNumbers = ForkBlockNumbers(
+      forkBlockNumbers = ForkBlockNumbers.Empty.copy(
         frontierBlockNumber = 0,
         homesteadBlockNumber = 1150000,
-        difficultyBombPauseBlockNumber = Long.MaxValue,
-        difficultyBombContinueBlockNumber = Long.MaxValue,
-        difficultyBombRemovalBlockNumber = Long.MaxValue,
-        eip106BlockNumber = Long.MaxValue,
         eip150BlockNumber = 2500000,
         eip160BlockNumber = 3000000,
-        eip155BlockNumber = 3000000,
-        eip161BlockNumber = Long.MaxValue,
-        byzantiumBlockNumber = Long.MaxValue,
-        constantinopleBlockNumber = Long.MaxValue,
-        istanbulBlockNumber = Long.MaxValue,
-        atlantisBlockNumber = Long.MaxValue,
-        aghartaBlockNumber = Long.MaxValue,
-        phoenixBlockNumber = Long.MaxValue,
-        petersburgBlockNumber = Long.MaxValue,
-        ecip1098BlockNumber = Long.MaxValue,
-        ecip1097BlockNumber = Long.MaxValue,
-        ecip1099BlockNumber = Long.MaxValue,
-        ecip1049BlockNumber = None,
-        magnetoBlockNumber = Long.MaxValue
+        eip155BlockNumber = 3000000
       ),
       customGenesisFileOpt = None,
       customGenesisJsonOpt = None,

src/main/resources/conf/chains/etc-chain.conf

@@ -101,6 +101,10 @@
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1099
   ecip1099-block-number = "11700000"
 
+  # Muir Glacier fork block number
+  # https://eips.ethereum.org/EIPS/eip-2387
+  muir-glacier-block-number = "1000000000000000000"
+
   # Magneto EVM and Protocol Upgrades
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1103
   magneto-block-number = "13189133"

src/main/resources/conf/chains/eth-chain.conf

@@ -98,6 +98,10 @@
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1099
   ecip1099-block-number = "1000000000000000000"
 
+  # Muir Glacier fork block number
+  # https://eips.ethereum.org/EIPS/eip-2387
+  muir-glacier-block-number = "9200000"
+
   # Magneto EVM and Protocol Upgrades
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1103
   magneto-block-number = "1000000000000000000"

src/main/resources/conf/chains/mordor-chain.conf

@@ -99,6 +99,10 @@
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1099
   ecip1099-block-number = "2520000"
 
+  # Muir Glacier fork block number
+  # https://eips.ethereum.org/EIPS/eip-2387
+  muir-glacier-block-number = "1000000000000000000"
+
   # Magneto EVM and Protocol Upgrades
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1103
   magneto-block-number = "3985893"

src/main/resources/conf/chains/ropsten-chain.conf

@@ -102,6 +102,10 @@
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1099
   ecip1099-block-number = "1000000000000000000"
 
+  # Muir Glacier fork block number
+  # https://eips.ethereum.org/EIPS/eip-2387
+  muir-glacier-block-number = "7117117"
+
   # Magneto EVM and Protocol Upgrades
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1103
   magneto-block-number = "1000000000000000000"

src/main/resources/conf/chains/test-chain.conf

@@ -99,6 +99,10 @@
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1099
   ecip1099-block-number = "1000000000000000000"
 
+  # Muir Glacier fork block number
+  # https://eips.ethereum.org/EIPS/eip-2387
+  muir-glacier-block-number = "1000000000000000000"
+
   # Magneto EVM and Protocol Upgrades
   # https://ecips.ethereumclassic.org/ECIPs/ecip-1103
   magneto-block-number = "1000000000000000000"

src/main/resources/conf/chains/testnet-internal-nomad-chain.conf

@@ -98,6 +98,10 @@
     # https://ecips.ethereumclassic.org/ECIPs/ecip-1099
     ecip1099-block-number = "1000000000000000000"
 
+    # Muir Glacier fork block number
+    # https://eips.ethereum.org/EIPS/eip-2387
+    muir-glacier-block-number = "1000000000000000000"
+
     # Magneto EVM and Protocol Upgrades
     # https://ecips.ethereumclassic.org/ECIPs/ecip-1103
     magneto-block-number = "1000000000000000000"

src/main/scala/io/iohk/ethereum/consensus/pow/difficulty/EthashDifficultyCalculator.scala

@@ -6,9 +6,10 @@ import io.iohk.ethereum.utils.BlockchainConfig
 
 object EthashDifficultyCalculator extends DifficultyCalculator {
   import DifficultyCalculator._
-  private val ExpDifficultyPeriod: Int = 100000
-  private val ByzantiumRelaxDifficulty: BigInt = 3000000
-  private val ConstantinopleRelaxDifficulty: BigInt = 5000000
+  private val ExpDifficultyPeriod: Int = 100_000
+  private val ByzantiumRelaxDifficulty: BigInt = 3_000_000
+  private val ConstantinopleRelaxDifficulty: BigInt = 5_000_000
+  private val MuirGlacierRelaxDifficulty: BigInt = 9_000_000
 
   def calculateDifficulty(blockNumber: BigInt, blockTimestamp: Long, parentHeader: BlockHeader)(implicit
       blockchainConfig: BlockchainConfig
@@ -32,8 +33,10 @@ object EthashDifficultyCalculator extends DifficultyCalculator {
       if (blockNumber < difficultyBombRemovalBlockNumber) {
         // calculate a fake block number for the ice-age delay
         val fakeBlockNumber: BigInt =
+          // https://eips.ethereum.org/EIPS/eip-2384
+          if (blockNumber >= muirGlacierBlockNumber) (blockNumber - MuirGlacierRelaxDifficulty).max(0)
           // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1234.md
-          if (blockNumber >= constantinopleBlockNumber) (blockNumber - ConstantinopleRelaxDifficulty).max(0)
+          else if (blockNumber >= constantinopleBlockNumber) (blockNumber - ConstantinopleRelaxDifficulty).max(0)
           // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-649.md
           else if (blockNumber >= byzantiumBlockNumber) (blockNumber - ByzantiumRelaxDifficulty).max(0)
           else blockNumber

src/main/scala/io/iohk/ethereum/utils/BlockchainConfig.scala

@@ -60,6 +60,7 @@ case class ForkBlockNumbers(
     ecip1097BlockNumber: BigInt,
     ecip1049BlockNumber: Option[BigInt],
     ecip1099BlockNumber: BigInt,
+    muirGlacierBlockNumber: BigInt,
     magnetoBlockNumber: BigInt
 ) {
   def all: List[BigInt] = this.productIterator.toList.flatMap {
@@ -96,6 +97,7 @@ object ForkBlockNumbers {
     ecip1097BlockNumber = Long.MaxValue,
     ecip1099BlockNumber = Long.MaxValue,
     ecip1049BlockNumber = None,
+    muirGlacierBlockNumber = Long.MaxValue,
     magnetoBlockNumber = Long.MaxValue
   )
 }
@@ -167,6 +169,7 @@ object BlockchainConfig {
     val allowedMinersPublicKeys = readPubKeySet(blockchainConfig, "allowed-miners")
 
     val ecip1099BlockNumber: BigInt = BigInt(blockchainConfig.getString("ecip1099-block-number"))
+    val muirGlacierBlockNumber: BigInt = BigInt(blockchainConfig.getString("muir-glacier-block-number"))
     val magnetoBlockNumber: BigInt = BigInt(blockchainConfig.getString("magneto-block-number"))
 
     val capabilities: List[Capability] =
@@ -196,6 +199,7 @@ object BlockchainConfig {
         ecip1097BlockNumber = ecip1097BlockNumber,
         ecip1049BlockNumber = ecip1049BlockNumber,
         ecip1099BlockNumber = ecip1099BlockNumber,
+        muirGlacierBlockNumber = muirGlacierBlockNumber,
         magnetoBlockNumber = magnetoBlockNumber
       ),
       treasuryAddress = treasuryAddress,

src/test/scala/io/iohk/ethereum/consensus/pow/validators/EthashBlockHeaderValidatorSpec.scala

@@ -254,6 +254,36 @@ class EthashBlockHeaderValidatorSpec
     difficulty shouldBe afterRewardReductionBlockHeader.difficulty
   }
 
+  it should "properly calculate the difficulty after muir glacier delay" in new EphemBlockchainTestSetup {
+    val blockchainConfigWithoutDifficultyBombRemoval: BlockchainConfig =
+      blockchainConfig.withUpdatedForkBlocks(
+        _.copy(
+          difficultyBombRemovalBlockNumber = BigInt("1000000000000"),
+          difficultyBombPauseBlockNumber = 0,
+          difficultyBombContinueBlockNumber = 0,
+          muirGlacierBlockNumber = 9200000
+        )
+      )
+
+    val parentHeader: BlockHeader =
+      validParentBlockHeader.copy(
+        number = 9200000 - 1,
+        unixTimestamp = 1525176000,
+        difficulty = BigInt("22627021745803")
+      )
+    val parent = Block(parentHeader, parentBody)
+
+    val blockNumber: BigInt = parentHeader.number + 1
+    val blockTimestamp: Long = parentHeader.unixTimestamp + 6
+
+    val difficulty: BigInt = EthashDifficultyCalculator.calculateDifficulty(blockNumber, blockTimestamp, parent.header)(
+      blockchainConfigWithoutDifficultyBombRemoval
+    )
+    val blockDifficultyWihtoutBomb = BigInt("22638070096265")
+
+    difficulty shouldBe blockDifficultyWihtoutBomb
+  }
+
   // FIXME: Replace with mocked miner validators once we have them
   object BlockValidatorWithPowMocked extends BlockHeaderValidatorSkeleton() {
 
@@ -388,6 +418,7 @@ class EthashBlockHeaderValidatorSpec
         byzantiumBlockNumber = 4370000,
         constantinopleBlockNumber = 7280000,
         istanbulBlockNumber = 9069000,
+        muirGlacierBlockNumber = 9200000,
         eip106BlockNumber = 0
       ),
       daoForkConfig = Some(new DaoForkConfig {