core, consensus: pluggable consensus engines (#3817)

This commit adds pluggable consensus engines to go-ethereum. In short, it
introduces a generic consensus interface, and refactors the entire codebase to
use this interface.

1 files changed, 6 insertions, 5 deletions

diff --git a/eth/handler.go b/eth/handler.go
index ade8f7719..445272060 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -27,6 +27,8 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus"
+	"github.com/ethereum/go-ethereum/consensus/misc"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth/downloader"
@@ -37,7 +39,6 @@ import (
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/params"
-	"github.com/ethereum/go-ethereum/pow"
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
@@ -97,7 +98,7 @@ type ProtocolManager struct {
 
 // NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
 // with the ethereum network.
-func NewProtocolManager(config *params.ChainConfig, fastSync bool, networkId int, maxPeers int, mux *event.TypeMux, txpool txPool, pow pow.PoW, blockchain *core.BlockChain, chaindb ethdb.Database) (*ProtocolManager, error) {
+func NewProtocolManager(config *params.ChainConfig, fastSync bool, networkId int, maxPeers int, mux *event.TypeMux, txpool txPool, engine consensus.Engine, blockchain *core.BlockChain, chaindb ethdb.Database) (*ProtocolManager, error) {
 	// Create the protocol manager with the base fields
 	manager := &ProtocolManager{
 		networkId:   networkId,
@@ -165,8 +166,8 @@ func NewProtocolManager(config *params.ChainConfig, fastSync bool, networkId int
 		blockchain.GetTdByHash, blockchain.InsertHeaderChain, manager.insertChain, blockchain.InsertReceiptChain, blockchain.Rollback,
 		manager.removePeer)
 
-	validator := func(block *types.Block, parent *types.Block) error {
-		return core.ValidateHeader(config, pow, block.Header(), parent.Header(), true, false)
+	validator := func(header *types.Header) error {
+		return engine.VerifyHeader(blockchain, header, true)
 	}
 	heighter := func() uint64 {
 		return blockchain.CurrentBlock().NumberU64()
@@ -448,7 +449,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 				p.forkDrop = nil
 
 				// Validate the header and either drop the peer or continue
-				if err := core.ValidateDAOHeaderExtraData(pm.chainconfig, headers[0]); err != nil {
+				if err := misc.VerifyDAOHeaderExtraData(pm.chainconfig, headers[0]); err != nil {
 					p.Log().Debug("Verified to be on the other side of the DAO fork, dropping")
 					return err
 				}