[NOD-1589] Re-enable DisableDifficultyAdjustment (#1182)

* [NOD-1589] Re-enable DisableDifficultyAdjustment

* [NOD-1589] Remove simnet from TestDifficulty

* [NOD-1589] Update comment

domain/consensus/factory.go

@@ -126,6 +126,7 @@ func (f *factory) NewConsensus(dagParams *dagconfig.Params, db infrastructuredat
 		dagTraversalManager,
 		dagParams.PowMax,
 		dagParams.DifficultyAdjustmentWindowSize,
+		dagParams.DisableDifficultyAdjustment,
 		dagParams.TargetTimePerBlock,
 		dagParams.GenesisHash)
 	coinbaseManager := coinbasemanager.New(
@@ -148,8 +149,6 @@ func (f *factory) NewConsensus(dagParams *dagconfig.Params, db infrastructuredat
 		dagParams.SkipProofOfWork,
 		genesisHash,
 		dagParams.EnableNonNativeSubnetworks,
-		dagParams.DisableDifficultyAdjustment,
-		dagParams.DifficultyAdjustmentWindowSize,
 		dagParams.MaxBlockSize,
 		dagParams.MergeSetSizeLimit,
 		dagParams.MaxBlockParents,

domain/consensus/processes/blockvalidator/blockvalidator.go

@@ -11,16 +11,14 @@ import (
 // blockValidator exposes a set of validation classes, after which
 // it's possible to determine whether either a block is valid
 type blockValidator struct {
-	powMax                         *big.Int
-	skipPoW                        bool
-	genesisHash                    *externalapi.DomainHash
-	enableNonNativeSubnetworks     bool
-	disableDifficultyAdjustment    bool
-	powMaxBits                     uint32
-	difficultyAdjustmentWindowSize uint64
-	maxBlockSize                   uint64
-	mergeSetSizeLimit              uint64
-	maxBlockParents                model.KType
+	powMax                     *big.Int
+	skipPoW                    bool
+	genesisHash                *externalapi.DomainHash
+	enableNonNativeSubnetworks bool
+	powMaxBits                 uint32
+	maxBlockSize               uint64
+	mergeSetSizeLimit          uint64
+	maxBlockParents            model.KType
 
 	databaseContext       model.DBReader
 	difficultyManager     model.DifficultyManager
@@ -44,8 +42,6 @@ func New(powMax *big.Int,
 	skipPoW bool,
 	genesisHash *externalapi.DomainHash,
 	enableNonNativeSubnetworks bool,
-	disableDifficultyAdjustment bool,
-	difficultyAdjustmentWindowSize uint64,
 	maxBlockSize uint64,
 	mergeSetSizeLimit uint64,
 	maxBlockParents model.KType,
@@ -68,16 +64,14 @@ func New(powMax *big.Int,
 	blockStatusStore model.BlockStatusStore) model.BlockValidator {
 
 	return &blockValidator{
-		powMax:                         powMax,
-		skipPoW:                        skipPoW,
-		genesisHash:                    genesisHash,
-		enableNonNativeSubnetworks:     enableNonNativeSubnetworks,
-		disableDifficultyAdjustment:    disableDifficultyAdjustment,
-		powMaxBits:                     util.BigToCompact(powMax),
-		difficultyAdjustmentWindowSize: difficultyAdjustmentWindowSize,
-		maxBlockSize:                   maxBlockSize,
-		mergeSetSizeLimit:              mergeSetSizeLimit,
-		maxBlockParents:                maxBlockParents,
+		powMax:                     powMax,
+		skipPoW:                    skipPoW,
+		genesisHash:                genesisHash,
+		enableNonNativeSubnetworks: enableNonNativeSubnetworks,
+		powMaxBits:                 util.BigToCompact(powMax),
+		maxBlockSize:               maxBlockSize,
+		mergeSetSizeLimit:          mergeSetSizeLimit,
+		maxBlockParents:            maxBlockParents,
 
 		databaseContext:       databaseContext,
 		difficultyManager:     difficultyManager,

domain/consensus/processes/difficultymanager/difficultymanager.go

@@ -22,12 +22,12 @@ type difficultyManager struct {
 	genesisHash                    *externalapi.DomainHash
 	powMax                         *big.Int
 	difficultyAdjustmentWindowSize uint64
+	disableDifficultyAdjustment    bool
 	targetTimePerBlock             time.Duration
 }
 
 // New instantiates a new DifficultyManager
-func New(
-	databaseContext model.DBReader,
+func New(databaseContext model.DBReader,
 	ghostdagManager model.GHOSTDAGManager,
 	ghostdagStore model.GHOSTDAGDataStore,
 	headerStore model.BlockHeaderStore,
@@ -35,9 +35,9 @@ func New(
 	dagTraversalManager model.DAGTraversalManager,
 	powMax *big.Int,
 	difficultyAdjustmentWindowSize uint64,
+	disableDifficultyAdjustment bool,
 	targetTimePerBlock time.Duration,
-	genesisHash *externalapi.DomainHash,
-) model.DifficultyManager {
+	genesisHash *externalapi.DomainHash) model.DifficultyManager {
 	return &difficultyManager{
 		databaseContext:                databaseContext,
 		ghostdagManager:                ghostdagManager,
@@ -47,6 +47,7 @@ func New(
 		dagTraversalManager:            dagTraversalManager,
 		powMax:                         powMax,
 		difficultyAdjustmentWindowSize: difficultyAdjustmentWindowSize,
+		disableDifficultyAdjustment:    disableDifficultyAdjustment,
 		targetTimePerBlock:             targetTimePerBlock,
 		genesisHash:                    genesisHash,
 	}
@@ -63,13 +64,12 @@ func (dm *difficultyManager) genesisBits() (uint32, error) {
 
 // RequiredDifficulty returns the difficulty required for some block
 func (dm *difficultyManager) RequiredDifficulty(blockHash *externalapi.DomainHash) (uint32, error) {
-
 	parents, err := dm.dagTopologyManager.Parents(blockHash)
 	if err != nil {
 		return 0, err
 	}
-	// Genesis block
-	if len(parents) == 0 {
+	// Genesis block or network that doesn't have difficulty adjustment (such as simnet)
+	if len(parents) == 0 || dm.disableDifficultyAdjustment {
 		return dm.genesisBits()
 	}
 

domain/consensus/processes/difficultymanager/difficultymanager_test.go

@@ -15,6 +15,9 @@ import (
 
 func TestDifficulty(t *testing.T) {
 	testutils.ForAllNets(t, true, func(t *testing.T, params *dagconfig.Params) {
+		if params.DisableDifficultyAdjustment {
+			return
+		}
 		params.K = 1
 		params.DifficultyAdjustmentWindowSize = 264
 
@@ -118,7 +121,7 @@ func TestDifficulty(t *testing.T) {
 		switch params.Name {
 		case "kaspa-testnet", "kaspa-devnet":
 			expectedBits = uint32(0x1e7f83df)
-		case "kaspa-mainnet", "kaspa-simnet":
+		case "kaspa-mainnet":
 			expectedBits = uint32(0x207f83df)
 		}