restruct difficulty modules

consensus/consensus.go

@@ -1,6 +1,8 @@
 package consensus
 
 import (
+	"sync"
+
 	"github.com/Qitmeer/qng/common/hash"
 	"github.com/Qitmeer/qng/config"
 	"github.com/Qitmeer/qng/consensus/model"
@@ -13,7 +15,6 @@ import (
 	"github.com/Qitmeer/qng/node/service"
 	"github.com/Qitmeer/qng/params"
 	"github.com/Qitmeer/qng/services/index"
-	"sync"
 )
 
 type consensus struct {

consensus/model/block.go

@@ -9,4 +9,5 @@ type Block interface {
 	GetOrder() uint
 	HasParents() bool
 	GetMainParent() uint
+	GetHeight() uint
 }

consensus/model/block_chain.go

@@ -26,4 +26,6 @@ type BlockChain interface {
 	GetBlockOrderByHash(hash *hash.Hash) (uint, error)
 	GetBlockHeader(block Block) *types.BlockHeader
 	ForeachBlueBlocks(start Block, depth uint, powType pow.PowType, fn func(block Block, header *types.BlockHeader) error) error
+	ChainRLock()
+	ChainRUnlock()
 }

consensus/model/meer_dag.go

@@ -0,0 +1,11 @@
+package model
+
+import (
+	"github.com/Qitmeer/qng/common/hash"
+	"github.com/Qitmeer/qng/rpc/api"
+)
+
+type MeerDag interface {
+	RegisterAPIs(apis []api.API)
+	GetBlockIDByTxHash(txhash *hash.Hash) uint64
+}

core/blockchain/process.go

@@ -8,16 +8,18 @@ package blockchain
 import (
 	"container/list"
 	"fmt"
+	"time"
+
 	"github.com/Qitmeer/qng/common/hash"
 	"github.com/Qitmeer/qng/consensus/model"
 	"github.com/Qitmeer/qng/core/blockchain/utxo"
 	"github.com/Qitmeer/qng/core/state"
 	"github.com/Qitmeer/qng/core/types"
 	"github.com/Qitmeer/qng/core/types/pow"
+	"github.com/Qitmeer/qng/core/types/pow/difficultymanager"
 	"github.com/Qitmeer/qng/engine/txscript"
 	l "github.com/Qitmeer/qng/log"
 	"github.com/Qitmeer/qng/meerdag"
-	"time"
 )
 
 // ProcessBlock is the main workhorse for handling insertion of new blocks into
@@ -153,7 +155,7 @@ func (b *BlockChain) preProcessBlock(block *types.SerializedBlock, flags Behavio
 			// expected based on elapsed time since the last checkpoint and
 			// maximum adjustment allowed by the retarget rules.
 			duration := blockHeader.Timestamp.Sub(checkpointTime)
-			requiredTarget := pow.CompactToBig(b.calcEasiestDifficulty(
+			requiredTarget := pow.CompactToBig(difficultymanager.NewDiffManager(b.consensus.BlockChain(), b.params).CalcEasiestDifficulty(
 				checkpointNode.Difficulty, duration, block.Block().Header.Pow))
 			currentTarget := pow.CompactToBig(blockHeader.Difficulty)
 			if !block.Block().Header.Pow.CompareDiff(currentTarget, requiredTarget) {

core/blockchain/validate.go

@@ -10,6 +10,9 @@ import (
 	"encoding/binary"
 	"encoding/hex"
 	"fmt"
+	"math"
+	"time"
+
 	"github.com/Qitmeer/qng/common/hash"
 	"github.com/Qitmeer/qng/consensus/forks"
 	"github.com/Qitmeer/qng/consensus/model"
@@ -22,11 +25,10 @@ import (
 	"github.com/Qitmeer/qng/core/state"
 	"github.com/Qitmeer/qng/core/types"
 	"github.com/Qitmeer/qng/core/types/pow"
+	"github.com/Qitmeer/qng/core/types/pow/difficultymanager"
 	"github.com/Qitmeer/qng/engine/txscript"
 	"github.com/Qitmeer/qng/meerdag"
 	"github.com/Qitmeer/qng/params"
-	"math"
-	"time"
 )
 
 const (
@@ -758,7 +760,8 @@ func (b *BlockChain) checkBlockHeaderContext(block *types.SerializedBlock, prevN
 		// Ensure the difficulty specified in the block header matches
 		// the calculated difficulty based on the previous block and
 		// difficulty retarget rules.
-		expDiff, err := b.calcNextRequiredDifficulty(prevNode,
+
+		expDiff, err := difficultymanager.NewDiffManager(b.consensus.BlockChain(), b.params).RequiredDifficulty(prevNode,
 			header.Timestamp, instance)
 		if err != nil {
 			return err

core/types/common.go

@@ -18,4 +18,9 @@ const (
 	// MaxAmount is the maximum transaction amount allowed in atoms.
 	// TODO, relocate the coin related item to chain's params
 	MaxAmount = 21e6 * AtomsPerCoin
+
+	// MEER difficulty adjustment
+	DIFFICULTY_MODE_MEER = 0
+	// KASPAD difficulty adjustment
+	DIFFICULTY_MODE_KASPAD
 )

core/types/pow/config.go

@@ -48,9 +48,11 @@ type PowConfig struct {
 
 	//is init
 	init bool
+
+	DifficultyMode int
 }
 
-//global cache
+// global cache
 func GetPowConfig() *PowConfig {
 	if PowConfigInstance != nil {
 		return PowConfigInstance

core/types/pow/difficultymanager/interface_difficultymanager.go

@@ -0,0 +1,39 @@
+package difficultymanager
+
+import (
+	"math/big"
+	"time"
+
+	"github.com/Qitmeer/qng/consensus/model"
+	"github.com/Qitmeer/qng/core/types"
+	"github.com/Qitmeer/qng/core/types/pow"
+	"github.com/Qitmeer/qng/params"
+)
+
+// DifficultyManager provides a method to resolve the
+// difficulty value of a block
+type DifficultyManager interface {
+	CalcNextRequiredDifficulty(timestamp time.Time, powType pow.PowType) (uint32, error)
+	RequiredDifficulty(block model.Block, newBlockTime time.Time, powInstance pow.IPow) (uint32, error)
+	CalcEasiestDifficulty(bits uint32, duration time.Duration, powInstance pow.IPow) uint32
+	GetCurrentPowDiff(ib model.Block, powType pow.PowType) *big.Int
+}
+
+func NewDiffManager(b model.BlockChain, cfg *params.Params) DifficultyManager {
+	switch cfg.PowConfig.DifficultyMode {
+	case types.DIFFICULTY_MODE_KASPAD:
+		return &kaspadDiff{
+			b:                              b,
+			powMax:                         cfg.PowConfig.MeerXKeccakV1PowLimit,
+			difficultyAdjustmentWindowSize: int(cfg.WorkDiffWindowSize),
+			disableDifficultyAdjustment:    false,
+			targetTimePerBlock:             cfg.TargetTimePerBlock,
+			genesisBits:                    cfg.PowConfig.MeerXKeccakV1PowLimitBits,
+			cfg:                            cfg,
+		}
+	}
+	return &meerDiff{
+		b:   b,
+		cfg: cfg,
+	}
+}