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, 7 insertions, 6 deletions

diff --git a/core/chain_makers.go b/core/chain_makers.go
index 5bf1ece25..c47c719f6 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -21,13 +21,14 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus/ethash"
+	"github.com/ethereum/go-ethereum/consensus/misc"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/params"
-	"github.com/ethereum/go-ethereum/pow"
 )
 
 // So we can deterministically seed different blockchains
@@ -141,7 +142,7 @@ func (b *BlockGen) OffsetTime(seconds int64) {
 	if b.header.Time.Cmp(b.parent.Header().Time) <= 0 {
 		panic("block time out of range")
 	}
-	b.header.Difficulty = CalcDifficulty(b.config, b.header.Time.Uint64(), b.parent.Time().Uint64(), b.parent.Number(), b.parent.Difficulty())
+	b.header.Difficulty = ethash.CalcDifficulty(b.config, b.header.Time.Uint64(), b.parent.Time().Uint64(), b.parent.Number(), b.parent.Difficulty())
 }
 
 // GenerateChain creates a chain of n blocks. The first block's
@@ -173,13 +174,13 @@ func GenerateChain(config *params.ChainConfig, parent *types.Block, db ethdb.Dat
 			}
 		}
 		if config.DAOForkSupport && config.DAOForkBlock != nil && config.DAOForkBlock.Cmp(h.Number) == 0 {
-			ApplyDAOHardFork(statedb)
+			misc.ApplyDAOHardFork(statedb)
 		}
 		// Execute any user modifications to the block and finalize it
 		if gen != nil {
 			gen(i, b)
 		}
-		AccumulateRewards(statedb, h, b.uncles)
+		ethash.AccumulateRewards(statedb, h, b.uncles)
 		root, err := statedb.Commit(config.IsEIP158(h.Number))
 		if err != nil {
 			panic(fmt.Sprintf("state write error: %v", err))
@@ -212,7 +213,7 @@ func makeHeader(config *params.ChainConfig, parent *types.Block, state *state.St
 		Root:       state.IntermediateRoot(config.IsEIP158(parent.Number())),
 		ParentHash: parent.Hash(),
 		Coinbase:   parent.Coinbase(),
-		Difficulty: CalcDifficulty(config, time.Uint64(), new(big.Int).Sub(time, big.NewInt(10)).Uint64(), parent.Number(), parent.Difficulty()),
+		Difficulty: ethash.CalcDifficulty(config, time.Uint64(), new(big.Int).Sub(time, big.NewInt(10)).Uint64(), parent.Number(), parent.Difficulty()),
 		GasLimit:   CalcGasLimit(parent),
 		GasUsed:    new(big.Int),
 		Number:     new(big.Int).Add(parent.Number(), common.Big1),
@@ -229,7 +230,7 @@ func newCanonical(n int, full bool) (ethdb.Database, *BlockChain, error) {
 	db, _ := ethdb.NewMemDatabase()
 	genesis := gspec.MustCommit(db)
 
-	blockchain, _ := NewBlockChain(db, params.AllProtocolChanges, pow.FakePow{}, new(event.TypeMux), vm.Config{})
+	blockchain, _ := NewBlockChain(db, params.AllProtocolChanges, ethash.NewFaker(), new(event.TypeMux), vm.Config{})
 	// Create and inject the requested chain
 	if n == 0 {
 		return db, blockchain, nil