consensus/beacon: remove TestingTTDBlock

Author: fjl

consensus/beacon/consensus.go

@@ -61,8 +61,7 @@ var (
 // is only used for necessary consensus checks. The legacy consensus engine can be any
 // engine implements the consensus interface (except the beacon itself).
 type Beacon struct {
-	ethone   consensus.Engine // Original consensus engine used in eth1, e.g. ethash or clique
-	ttdblock *uint64          // Merge block-number for testchain generation without TTDs
+	ethone consensus.Engine // Original consensus engine used in eth1, e.g. ethash or clique
 }
 
 // New creates a consensus engine with the given embedded eth1 engine.
@@ -73,16 +72,9 @@ func New(ethone consensus.Engine) *Beacon {
 	return &Beacon{ethone: ethone}
 }
 
-// TestingTTDBlock is a replacement mechanism for TTD-based pre-/post-merge
-// splitting. With chain history deletion, TD calculations become impossible.
-// This is fine for progressing the live chain, but to be able to generate test
-// chains, we do need a split point. This method supports setting an explicit
-// block number to use as the splitter *for testing*, instead of having to keep
-// the notion of TDs in the client just for testing.
-//
-// The block with supplied number is regarded as the last pre-merge block.
-func (beacon *Beacon) TestingTTDBlock(number uint64) {
-	beacon.ttdblock = &number
+func isPreMerge(config *params.ChainConfig, block uint64) bool {
+	return !(config.TerminalTotalDifficulty != nil && config.TerminalTotalDifficulty.Sign() == 0) ||
+		(config.MergeNetsplitBlock != nil && block < config.MergeNetsplitBlock.Uint64())
 }
 
 // Author implements consensus.Engine, returning the verified author of the block.
@@ -332,15 +324,7 @@ func (beacon *Beacon) verifyHeaders(chain consensus.ChainHeaderReader, headers [
 // Prepare implements consensus.Engine, initializing the difficulty field of a
 // header to conform to the beacon protocol. The changes are done inline.
 func (beacon *Beacon) Prepare(chain consensus.ChainHeaderReader, header *types.Header) error {
-	// The beacon engine requires access to total difficulties to be able to
-	// seal pre-merge and post-merge blocks. With the transition to removing
-	// old blocks, TDs become unaccessible, thus making TTD based pre-/post-
-	// merge decisions impossible.
-	//
-	// We do not need to seal non-merge blocks anymore live, but we do need
-	// to be able to generate test chains, thus we're reverting to a testing-
-	// settable field to direct that.
-	if beacon.ttdblock != nil && *beacon.ttdblock >= header.Number.Uint64() {
+	if isPreMerge(chain.Config(), header.Number.Uint64()) {
 		return beacon.ethone.Prepare(chain, header)
 	}
 	header.Difficulty = beaconDifficulty
@@ -450,15 +434,7 @@ func (beacon *Beacon) SealHash(header *types.Header) common.Hash {
 // the difficulty that a new block should have when created at time
 // given the parent block's time and difficulty.
 func (beacon *Beacon) CalcDifficulty(chain consensus.ChainHeaderReader, time uint64, parent *types.Header) *big.Int {
-	// The beacon engine requires access to total difficulties to be able to
-	// seal pre-merge and post-merge blocks. With the transition to removing
-	// old blocks, TDs become unaccessible, thus making TTD based pre-/post-
-	// merge decisions impossible.
-	//
-	// We do not need to seal non-merge blocks anymore live, but we do need
-	// to be able to generate test chains, thus we're reverting to a testing-
-	// settable field to direct that.
-	if beacon.ttdblock != nil && *beacon.ttdblock > parent.Number.Uint64() {
+	if isPreMerge(chain.Config(), parent.Number.Uint64()+1) {
 		return beacon.ethone.CalcDifficulty(chain, time, parent)
 	}
 	return beaconDifficulty

eth/catalyst/api_test.go

@@ -64,9 +64,9 @@ func generateMergeChain(n int, merged bool) (*core.Genesis, []*types.Block) {
 	engine := beacon.New(ethash.NewFaker())
 	if merged {
 		config.TerminalTotalDifficulty = common.Big0
-	} else {
-		engine.TestingTTDBlock(uint64(n))
+		config.MergeNetsplitBlock = common.Big0
 	}
+
 	genesis := &core.Genesis{
 		Config: &config,
 		Alloc: types.GenesisAlloc{

eth/gasprice/gasprice_test.go

@@ -147,11 +147,11 @@ func newTestBackend(t *testing.T, londonBlock *big.Int, cancunBlock *big.Int, pe
 	config.LondonBlock = londonBlock
 	config.ArrowGlacierBlock = londonBlock
 	config.GrayGlacierBlock = londonBlock
-
+	if cancunBlock != nil {
+		// Enable the merge with cancun fork.
+		config.MergeNetsplitBlock = cancunBlock
+	}
 	engine := beacon.New(ethash.NewFaker())
-	engine.TestingTTDBlock(testHead + 1)
-
-	td := params.GenesisDifficulty.Uint64()
 
 	if cancunBlock != nil {
 		ts := gspec.Timestamp + cancunBlock.Uint64()*10 // fixed 10 sec block time in blockgen
@@ -209,10 +209,9 @@ func newTestBackend(t *testing.T, londonBlock *big.Int, cancunBlock *big.Int, pe
 				b.AddTx(types.MustSignNewTx(key, signer, blobTx))
 			}
 		}
-		td += b.Difficulty().Uint64()
 	})
+
 	// Construct testing chain
-	gspec.Config.TerminalTotalDifficulty = new(big.Int).SetUint64(td)
 	chain, err := core.NewBlockChain(db, &core.CacheConfig{TrieCleanNoPrefetch: true}, gspec, nil, engine, vm.Config{}, nil)
 	if err != nil {
 		t.Fatalf("Failed to create local chain, %v", err)

eth/protocols/eth/handler_test.go

@@ -74,9 +74,7 @@ func newTestBackendWithGenerator(blocks int, shanghai bool, generator func(int,
 		config = params.TestChainConfig
 		engine = beacon.New(ethash.NewFaker())
 	)
-	if !shanghai {
-		engine.TestingTTDBlock(math.MaxUint64)
-	} else {
+	if shanghai {
 		config = &params.ChainConfig{
 			ChainID:                 big.NewInt(1),
 			HomesteadBlock:          big.NewInt(0),

eth/tracers/internal/tracetest/supply_test.go

@@ -75,8 +75,6 @@ func TestSupplyOmittedFields(t *testing.T) {
 		}
 	)
 
-	gspec.Config.TerminalTotalDifficulty = big.NewInt(0)
-
 	out, _, err := testSupplyTracer(t, gspec, func(b *core.BlockGen) {
 		b.SetPoS()
 	})
@@ -546,7 +544,6 @@ func TestSupplySelfdestructItselfAndRevert(t *testing.T) {
 
 func testSupplyTracer(t *testing.T, genesis *core.Genesis, gen func(*core.BlockGen)) ([]supplyInfo, *core.BlockChain, error) {
 	engine := beacon.New(ethash.NewFaker())
-	engine.TestingTTDBlock(1)
 
 	traceOutputPath := filepath.ToSlash(t.TempDir())
 	traceOutputFilename := path.Join(traceOutputPath, "supply.jsonl")

graphql/graphql_test.go

@@ -21,7 +21,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"math"
 	"math/big"
 	"net/http"
 	"strings"
@@ -459,15 +458,13 @@ func newGQLService(t *testing.T, stack *node.Node, shanghai bool, gspec *core.Ge
 	var engine = beacon.New(ethash.NewFaker())
 	if shanghai {
 		gspec.Config.TerminalTotalDifficulty = common.Big0
+		gspec.Config.MergeNetsplitBlock = common.Big0
 		// GenerateChain will increment timestamps by 10.
 		// Shanghai upgrade at block 1.
 		shanghaiTime := uint64(5)
 		gspec.Config.ShanghaiTime = &shanghaiTime
-	} else {
-		// set an arbitrary large ttd as chains are required to be known to be merged
-		gspec.Config.TerminalTotalDifficulty = big.NewInt(math.MaxInt64)
-		engine.TestingTTDBlock(math.MaxUint64)
 	}
+
 	ethBackend, err := eth.New(stack, ethConf)
 	if err != nil {
 		t.Fatalf("could not create eth backend: %v", err)