eth/tracers: use non-threaded tracechain (ethereum#24283)

This makes non-JS tracers execute all block txs on a single goroutine.
In the previous implementation, we used to prepare every tx pre-state
on one goroutine, and then run the transactions again with tracing enabled.
Native tracers are usually faster, so it is faster overall to use their output as
the pre-state for tracing the next transaction.

Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>

core/vm/runtime/runtime_test.go

@@ -333,7 +333,7 @@ func benchmarkNonModifyingCode(gas uint64, code []byte, name string, tracerCode
 	cfg.State, _ = state.New(common.Hash{}, state.NewDatabase(rawdb.NewMemoryDatabase()), nil)
 	cfg.GasLimit = gas
 	if len(tracerCode) > 0 {
-		tracer, err := tracers.New(tracerCode, new(tracers.Context), nil)
+		tracer, err := tracers.DefaultDirectory.New(tracerCode, new(tracers.Context), nil)
 		if err != nil {
 			b.Fatal(err)
 		}
@@ -832,7 +832,7 @@ func TestRuntimeJSTracer(t *testing.T) {
 			statedb.SetCode(common.HexToAddress("0xee"), calleeCode)
 			statedb.SetCode(common.HexToAddress("0xff"), depressedCode)
 
-			tracer, err := tracers.New(jsTracer, new(tracers.Context), nil)
+			tracer, err := tracers.DefaultDirectory.New(jsTracer, new(tracers.Context), nil)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -868,7 +868,7 @@ func TestJSTracerCreateTx(t *testing.T) {
 	code := []byte{byte(vm.PUSH1), 0, byte(vm.PUSH1), 0, byte(vm.RETURN)}
 
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(rawdb.NewMemoryDatabase()), nil)
-	tracer, err := tracers.New(jsTracer, new(tracers.Context), nil)
+	tracer, err := tracers.DefaultDirectory.New(jsTracer, new(tracers.Context), nil)
 	if err != nil {
 		t.Fatal(err)
 	}

eth/tracers/api.go

@@ -593,6 +593,7 @@ func (api *API) traceBlock(ctx context.Context, block *types.Block, config *Trac
 	if block.NumberU64() == 0 {
 		return nil, errors.New("genesis is not traceable")
 	}
+	// Prepare base state
 	parent, err := api.blockByNumberAndHash(ctx, rpc.BlockNumber(block.NumberU64()-1), block.ParentHash())
 	if err != nil {
 		return nil, err
@@ -607,23 +608,64 @@ func (api *API) traceBlock(ctx context.Context, block *types.Block, config *Trac
 	}
 	defer release()
 
+	// JS tracers have high overhead. In this case run a parallel
+	// process that generates states in one thread and traces txes
+	// in separate worker threads.
+	if config != nil && config.Tracer != nil && *config.Tracer != "" {
+		if isJS := DefaultDirectory.IsJS(*config.Tracer); isJS {
+			return api.traceBlockParallel(ctx, block, statedb, config)
+		}
+	}
+	// Native tracers have low overhead
+	var (
+		txs       = block.Transactions()
+		blockHash = block.Hash()
+		is158     = api.backend.ChainConfig().IsEIP158(block.Number())
+		blockCtx  = core.NewEVMBlockContext(block.Header(), api.chainContext(ctx), nil)
+		signer    = types.MakeSigner(api.backend.ChainConfig(), block.Number())
+		results   = make([]*txTraceResult, len(txs))
+	)
+	for i, tx := range txs {
+		// Generate the next state snapshot fast without tracing
+		msg, _ := tx.AsMessage(signer, block.BaseFee())
+		txctx := &Context{
+			BlockHash: blockHash,
+			TxIndex:   i,
+			TxHash:    tx.Hash(),
+		}
+		res, err := api.traceTx(ctx, msg, txctx, blockCtx, statedb, config)
+		if err != nil {
+			return nil, err
+		}
+		results[i] = &txTraceResult{Result: res}
+		// Finalize the state so any modifications are written to the trie
+		// Only delete empty objects if EIP158/161 (a.k.a Spurious Dragon) is in effect
+		statedb.Finalise(is158)
+	}
+	return results, nil
+}
+
+// traceBlockParallel is for tracers that have a high overhead (read JS tracers). One thread
+// runs along and executes txes without tracing enabled to generate their prestate.
+// Worker threads take the tasks and the prestate and trace them.
+func (api *API) traceBlockParallel(ctx context.Context, block *types.Block, statedb *state.StateDB, config *TraceConfig) ([]*txTraceResult, error) {
 	// Execute all the transaction contained within the block concurrently
 	var (
-		signer  = types.MakeSigner(api.backend.ChainConfig(), block.Number())
-		txs     = block.Transactions()
-		results = make([]*txTraceResult, len(txs))
-		pend    sync.WaitGroup
+		txs       = block.Transactions()
+		blockHash = block.Hash()
+		blockCtx  = core.NewEVMBlockContext(block.Header(), api.chainContext(ctx), nil)
+		signer    = types.MakeSigner(api.backend.ChainConfig(), block.Number())
+		results   = make([]*txTraceResult, len(txs))
+		pend      sync.WaitGroup
 	)
 	threads := runtime.NumCPU()
 	if threads > len(txs) {
 		threads = len(txs)
 	}
 	jobs := make(chan *txTraceTask, threads)
-	blockHash := block.Hash()
 	for th := 0; th < threads; th++ {
 		pend.Add(1)
 		go func() {
-			blockCtx := core.NewEVMBlockContext(block.Header(), api.chainContext(ctx), nil)
 			defer pend.Done()
 			// Fetch and execute the next transaction trace tasks
 			for task := range jobs {
@@ -645,7 +687,6 @@ func (api *API) traceBlock(ctx context.Context, block *types.Block, config *Trac
 
 	// Feed the transactions into the tracers and return
 	var failed error
-	blockCtx := core.NewEVMBlockContext(block.Header(), api.chainContext(ctx), nil)
 txloop:
 	for i, tx := range txs {
 		// Send the trace task over for execution
@@ -923,7 +964,7 @@ func (api *API) traceTx(ctx context.Context, message core.Message, txctx *Contex
 	// Default tracer is the struct logger
 	tracer = logger.NewStructLogger(config.Config)
 	if config.Tracer != nil {
-		tracer, err = New(*config.Tracer, txctx, config.TracerConfig)
+		tracer, err = DefaultDirectory.New(*config.Tracer, txctx, config.TracerConfig)
 		if err != nil {
 			return nil, err
 		}

eth/tracers/internal/tracetest/calltrace_test.go

@@ -140,7 +140,7 @@ func testCallTracer(tracerName string, dirPath string, t *testing.T) {
 				}
 				_, statedb = tests.MakePreState(rawdb.NewMemoryDatabase(), test.Genesis.Alloc, false)
 			)
-			tracer, err := tracers.New(tracerName, new(tracers.Context), test.TracerConfig)
+			tracer, err := tracers.DefaultDirectory.New(tracerName, new(tracers.Context), test.TracerConfig)
 			if err != nil {
 				t.Fatalf("failed to create call tracer: %v", err)
 			}
@@ -243,7 +243,7 @@ func benchTracer(tracerName string, test *callTracerTest, b *testing.B) {
 	b.ReportAllocs()
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		tracer, err := tracers.New(tracerName, new(tracers.Context), nil)
+		tracer, err := tracers.DefaultDirectory.New(tracerName, new(tracers.Context), nil)
 		if err != nil {
 			b.Fatalf("failed to create call tracer: %v", err)
 		}
@@ -309,7 +309,7 @@ func TestZeroValueToNotExitCall(t *testing.T) {
 	}
 	_, statedb := tests.MakePreState(rawdb.NewMemoryDatabase(), alloc, false)
 	// Create the tracer, the EVM environment and run it
-	tracer, err := tracers.New("callTracer", nil, nil)
+	tracer, err := tracers.DefaultDirectory.New("callTracer", nil, nil)
 	if err != nil {
 		t.Fatalf("failed to create call tracer: %v", err)
 	}

eth/tracers/internal/tracetest/prestate_test.go

@@ -110,7 +110,7 @@ func testPrestateDiffTracer(tracerName string, dirPath string, t *testing.T) {
 				}
 				_, statedb = tests.MakePreState(rawdb.NewMemoryDatabase(), test.Genesis.Alloc, false)
 			)
-			tracer, err := tracers.New(tracerName, new(tracers.Context), test.TracerConfig)
+			tracer, err := tracers.DefaultDirectory.New(tracerName, new(tracers.Context), test.TracerConfig)
 			if err != nil {
 				t.Fatalf("failed to create call tracer: %v", err)
 			}

eth/tracers/js/goja.go

@@ -45,7 +45,16 @@ func init() {
 	if err != nil {
 		panic(err)
 	}
-	tracers.RegisterLookup(true, newJsTracer)
+	type ctorFn = func(*tracers.Context, json.RawMessage) (tracers.Tracer, error)
+	lookup := func(code string) ctorFn {
+		return func(ctx *tracers.Context, cfg json.RawMessage) (tracers.Tracer, error) {
+			return newJsTracer(code, ctx, cfg)
+		}
+	}
+	for name, code := range assetTracers {
+		tracers.DefaultDirectory.Register(name, lookup(code), true)
+	}
+	tracers.DefaultDirectory.RegisterJSEval(newJsTracer)
 }
 
 // bigIntProgram is compiled once and the exported function mostly invoked to convert
@@ -122,16 +131,14 @@ type jsTracer struct {
 	frameResultValue goja.Value
 }
 
-// newJsTracer instantiates a new JS tracer instance. code is either
-// the name of a built-in JS tracer or a Javascript snippet which
-// evaluates to an expression returning an object with certain methods.
+// newJsTracer instantiates a new JS tracer instance. code is a
+// Javascript snippet which evaluates to an expression returning
+// an object with certain methods:
+//
 // The methods `result` and `fault` are required to be present.
 // The methods `step`, `enter`, and `exit` are optional, but note that
 // `enter` and `exit` always go together.
 func newJsTracer(code string, ctx *tracers.Context, cfg json.RawMessage) (tracers.Tracer, error) {
-	if c, ok := assetTracers[code]; ok {
-		code = c
-	}
 	vm := goja.New()
 	// By default field names are exported to JS as is, i.e. capitalized.
 	vm.SetFieldNameMapper(goja.UncapFieldNameMapper())

eth/tracers/native/4byte.go

@@ -28,7 +28,7 @@ import (
 )
 
 func init() {
-	register("4byteTracer", newFourByteTracer)
+	tracers.DefaultDirectory.Register("4byteTracer", newFourByteTracer, false)
 }
 
 // fourByteTracer searches for 4byte-identifiers, and collects them for post-processing.

eth/tracers/native/call.go

@@ -32,7 +32,7 @@ import (
 //go:generate go run github.com/fjl/gencodec -type callFrame -field-override callFrameMarshaling -out gen_callframe_json.go
 
 func init() {
-	register("callTracer", newCallTracer)
+	tracers.DefaultDirectory.Register("callTracer", newCallTracer, false)
 }
 
 type callLog struct {

eth/tracers/native/mux.go

@@ -26,7 +26,7 @@ import (
 )
 
 func init() {
-	register("muxTracer", newMuxTracer)
+	tracers.DefaultDirectory.Register("muxTracer", newMuxTracer, false)
 }
 
 // muxTracer is a go implementation of the Tracer interface which
@@ -47,7 +47,7 @@ func newMuxTracer(ctx *tracers.Context, cfg json.RawMessage) (tracers.Tracer, er
 	objects := make([]tracers.Tracer, 0, len(config))
 	names := make([]string, 0, len(config))
 	for k, v := range config {
-		t, err := tracers.New(k, ctx, v)
+		t, err := tracers.DefaultDirectory.New(k, ctx, v)
 		if err != nil {
 			return nil, err
 		}

eth/tracers/native/noop.go

@@ -26,7 +26,7 @@ import (
 )
 
 func init() {
-	register("noopTracer", newNoopTracer)
+	tracers.DefaultDirectory.Register("noopTracer", newNoopTracer, false)
 }
 
 // noopTracer is a go implementation of the Tracer interface which

eth/tracers/native/prestate.go

@@ -32,7 +32,7 @@ import (
 //go:generate go run github.com/fjl/gencodec -type account -field-override accountMarshaling -out gen_account_json.go
 
 func init() {
-	register("prestateTracer", newPrestateTracer)
+	tracers.DefaultDirectory.Register("prestateTracer", newPrestateTracer, false)
 }
 
 type state = map[common.Address]*account