core: refactor StateProcessor to accept ChainContext interface

core/evm.go

@@ -25,21 +25,16 @@ import (
 	"github.com/ethereum/go-ethereum/core/tracing"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
-	"github.com/ethereum/go-ethereum/params"
 	"github.com/holiman/uint256"
 )
 
 // ChainContext supports retrieving headers and consensus parameters from the
 // current blockchain to be used during transaction processing.
 type ChainContext interface {
+	consensus.ChainHeaderReader
+
 	// Engine retrieves the chain's consensus engine.
 	Engine() consensus.Engine
-
-	// GetHeader returns the header corresponding to the hash/number argument pair.
-	GetHeader(common.Hash, uint64) *types.Header
-
-	// Config returns the chain's configuration.
-	Config() *params.ChainConfig
 }
 
 // NewEVMBlockContext creates a new context for use in the EVM.

core/state_processor.go

@@ -36,11 +36,11 @@ import (
 // StateProcessor implements Processor.
 type StateProcessor struct {
 	config *params.ChainConfig // Chain configuration options
-	chain  *HeaderChain        // Canonical header chain
+	chain  ChainContext        // Chain context interface
 }
 
 // NewStateProcessor initialises a new StateProcessor.
-func NewStateProcessor(config *params.ChainConfig, chain *HeaderChain) *StateProcessor {
+func NewStateProcessor(config *params.ChainConfig, chain ChainContext) *StateProcessor {
 	return &StateProcessor{
 		config: config,
 		chain:  chain,
@@ -123,7 +123,7 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
 	}
 
 	// Finalize the block, applying any consensus engine specific extras (e.g. block rewards)
-	p.chain.engine.Finalize(p.chain, header, tracingStateDB, block.Body())
+	p.chain.Engine().Finalize(p.chain, header, tracingStateDB, block.Body())
 
 	return &ProcessResult{
 		Receipts: receipts,

core/vm/runtime/runtime_test.go

@@ -312,6 +312,18 @@ func (d *dummyChain) Config() *params.ChainConfig {
 	return nil
 }
 
+func (d *dummyChain) CurrentHeader() *types.Header {
+	return nil
+}
+
+func (d *dummyChain) GetHeaderByNumber(n uint64) *types.Header {
+	return d.GetHeader(common.Hash{}, n)
+}
+
+func (d *dummyChain) GetHeaderByHash(h common.Hash) *types.Header {
+	return nil
+}
+
 // TestBlockhash tests the blockhash operation. It's a bit special, since it internally
 // requires access to a chain reader.
 func TestBlockhash(t *testing.T) {

eth/tracers/api.go

@@ -80,6 +80,7 @@ type StateReleaseFunc func()
 type Backend interface {
 	HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error)
 	HeaderByNumber(ctx context.Context, number rpc.BlockNumber) (*types.Header, error)
+	CurrentHeader() *types.Header
 	BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error)
 	BlockByNumber(ctx context.Context, number rpc.BlockNumber) (*types.Block, error)
 	GetCanonicalTransaction(txHash common.Hash) (bool, *types.Transaction, common.Hash, uint64, uint64)

eth/tracers/api_test.go

@@ -142,6 +142,10 @@ func (b *testBackend) ChainDb() ethdb.Database {
 	return b.chaindb
 }
 
+func (b *testBackend) CurrentHeader() *types.Header {
+	return b.chain.CurrentHeader()
+}
+
 // teardown releases the associated resources.
 func (b *testBackend) teardown() {
 	b.chain.Stop()

internal/ethapi/api.go

@@ -636,6 +636,8 @@ func (api *BlockChainAPI) GetBlockReceipts(ctx context.Context, blockNrOrHash rp
 type ChainContextBackend interface {
 	Engine() consensus.Engine
 	HeaderByNumber(context.Context, rpc.BlockNumber) (*types.Header, error)
+	HeaderByHash(context.Context, common.Hash) (*types.Header, error)
+	CurrentHeader() *types.Header
 	ChainConfig() *params.ChainConfig
 }
 
@@ -669,6 +671,20 @@ func (context *ChainContext) Config() *params.ChainConfig {
 	return context.b.ChainConfig()
 }
 
+func (context *ChainContext) CurrentHeader() *types.Header {
+	return context.b.CurrentHeader()
+}
+
+func (context *ChainContext) GetHeaderByNumber(number uint64) *types.Header {
+	header, _ := context.b.HeaderByNumber(context.ctx, rpc.BlockNumber(number))
+	return header
+}
+
+func (context *ChainContext) GetHeaderByHash(hash common.Hash) *types.Header {
+	header, _ := context.b.HeaderByHash(context.ctx, hash)
+	return header
+}
+
 func doCall(ctx context.Context, b Backend, args TransactionArgs, state *state.StateDB, header *types.Header, overrides *override.StateOverride, blockOverrides *override.BlockOverrides, timeout time.Duration, globalGasCap uint64) (*core.ExecutionResult, error) {
 	blockCtx := core.NewEVMBlockContext(header, NewChainContext(ctx, b), nil)
 	if blockOverrides != nil {

internal/ethapi/simulate.go

@@ -541,3 +541,23 @@ func (b *simBackend) HeaderByNumber(ctx context.Context, number rpc.BlockNumber)
 func (b *simBackend) ChainConfig() *params.ChainConfig {
 	return b.b.ChainConfig()
 }
+
+func (b *simBackend) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error) {
+	if b.base.Hash() == hash {
+		return b.base, nil
+	}
+	if header, err := b.b.HeaderByHash(ctx, hash); err == nil {
+		return header, nil
+	}
+	// Check simulated headers
+	for _, header := range b.headers {
+		if header.Hash() == hash {
+			return header, nil
+		}
+	}
+	return nil, errors.New("header not found")
+}
+
+func (b *simBackend) CurrentHeader() *types.Header {
+	return b.b.CurrentHeader()
+}

tests/state_test_util.go

@@ -559,3 +559,6 @@ type dummyChain struct {
 func (d *dummyChain) Engine() consensus.Engine                        { return nil }
 func (d *dummyChain) GetHeader(h common.Hash, n uint64) *types.Header { return nil }
 func (d *dummyChain) Config() *params.ChainConfig                     { return d.config }
+func (d *dummyChain) CurrentHeader() *types.Header                    { return nil }
+func (d *dummyChain) GetHeaderByNumber(n uint64) *types.Header        { return nil }
+func (d *dummyChain) GetHeaderByHash(h common.Hash) *types.Header     { return nil }