consensus,core,miner: avoid overhead of creating a new block (#19301)

* consensus,core,miner: avoid overhead of creating a new block

* consensus: nitpick dot

* consensus: fix some comment formatting nits

3 files changed, 30 insertions, 5 deletions

diff --git a/consensus/clique/clique.go b/consensus/clique/clique.go
index 6bdee6dd5..4caa9dc74 100644
--- a/consensus/clique/clique.go
+++ b/consensus/clique/clique.go
@@ -548,8 +548,16 @@ func (c *Clique) Prepare(chain consensus.ChainReader, header *types.Header) erro
 }
 
 // Finalize implements consensus.Engine, ensuring no uncles are set, nor block
-// rewards given, and returns the final block.
-func (c *Clique) Finalize(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) {
+// rewards given.
+func (c *Clique) Finalize(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header) {
+	// No block rewards in PoA, so the state remains as is and uncles are dropped
+	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
+	header.UncleHash = types.CalcUncleHash(nil)
+}
+
+// FinalizeAndAssemble implements consensus.Engine, ensuring no uncles are set,
+// nor block rewards given, and returns the final block.
+func (c *Clique) FinalizeAndAssemble(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) {
 	// No block rewards in PoA, so the state remains as is and uncles are dropped
 	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
 	header.UncleHash = types.CalcUncleHash(nil)
diff --git a/consensus/consensus.go b/consensus/consensus.go
index 487b07be7..f753af550 100644
--- a/consensus/consensus.go
+++ b/consensus/consensus.go
@@ -80,10 +80,19 @@ type Engine interface {
 	Prepare(chain ChainReader, header *types.Header) error
 
 	// Finalize runs any post-transaction state modifications (e.g. block rewards)
-	// and assembles the final block.
+	// but does not assemble the block.
+	//
 	// Note: The block header and state database might be updated to reflect any
 	// consensus rules that happen at finalization (e.g. block rewards).
 	Finalize(chain ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
+		uncles []*types.Header)
+
+	// FinalizeAndAssemble runs any post-transaction state modifications (e.g. block
+	// rewards) and assembles the final block.
+	//
+	// Note: The block header and state database might be updated to reflect any
+	// consensus rules that happen at finalization (e.g. block rewards).
+	FinalizeAndAssemble(chain ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction,
 		uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error)
 
 	// Seal generates a new sealing request for the given input block and pushes
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
index 4d909146f..d271518f4 100644
--- a/consensus/ethash/consensus.go
+++ b/consensus/ethash/consensus.go
@@ -561,8 +561,16 @@ func (ethash *Ethash) Prepare(chain consensus.ChainReader, header *types.Header)
 }
 
 // Finalize implements consensus.Engine, accumulating the block and uncle rewards,
-// setting the final state and assembling the block.
-func (ethash *Ethash) Finalize(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) {
+// setting the final state on the header
+func (ethash *Ethash) Finalize(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header) {
+	// Accumulate any block and uncle rewards and commit the final state root
+	accumulateRewards(chain.Config(), state, header, uncles)
+	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
+}
+
+// FinalizeAndAssemble implements consensus.Engine, accumulating the block and
+// uncle rewards, setting the final state and assembling the block.
+func (ethash *Ethash) FinalizeAndAssemble(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) {
 	// Accumulate any block and uncle rewards and commit the final state root
 	accumulateRewards(chain.Config(), state, header, uncles)
 	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))