Reapply "refactor: reduce number of heap allocations in tracing (#952)…

…" (#959)

This reverts commit 2ba5ea3.

core/types/l2trace.go

@@ -70,7 +70,7 @@ type ExecutionResult struct {
 	// currently they are just `from` and `to` account
 	AccountsAfter []*AccountWrapper `json:"accountAfter"`
 
-	StructLogs []*StructLogRes `json:"structLogs"`
+	StructLogs []StructLogRes  `json:"structLogs"`
 	CallTrace  json.RawMessage `json:"callTrace"`
 }
 
@@ -91,8 +91,8 @@ type StructLogRes struct {
 
 // NewStructLogResBasic Basic StructLogRes skeleton, Stack&Memory&Storage&ExtraData are separated from it for GC optimization;
 // still need to fill in with Stack&Memory&Storage&ExtraData
-func NewStructLogResBasic(pc uint64, op string, gas, gasCost uint64, depth int, refundCounter uint64, err error) *StructLogRes {
-	logRes := &StructLogRes{
+func NewStructLogResBasic(pc uint64, op string, gas, gasCost uint64, depth int, refundCounter uint64, err error) StructLogRes {
+	logRes := StructLogRes{
 		Pc:            pc,
 		Op:            op,
 		Gas:           gas,

core/vm/logger.go

@@ -23,6 +23,7 @@ import (
 	"io"
 	"math/big"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/holiman/uint256"
@@ -79,8 +80,8 @@ type StructLog struct {
 	Err           error                       `json:"-"`
 }
 
-func NewStructlog(pc uint64, op OpCode, gas, cost uint64, depth int, err error) *StructLog {
-	return &StructLog{
+func NewStructlog(pc uint64, op OpCode, gas, cost uint64, depth int, err error) StructLog {
+	return StructLog{
 		Pc:      pc,
 		Op:      op,
 		Gas:     gas,
@@ -90,14 +91,6 @@ func NewStructlog(pc uint64, op OpCode, gas, cost uint64, depth int, err error)
 	}
 }
 
-func (s *StructLog) clean() {
-	s.Memory.Reset()
-	s.Stack = s.Stack[:0]
-	s.ReturnData.Reset()
-	s.Storage = nil
-	s.Err = nil
-}
-
 // overrides for gencodec
 type structLogMarshaling struct {
 	Gas         math.HexOrDecimal64
@@ -158,10 +151,11 @@ type StructLogger struct {
 	storage        map[common.Address]Storage
 	createdAccount *types.AccountWrapper
 
-	callStackLogInd []int
-	logs            []*StructLog
-	output          []byte
-	err             error
+	callStackLogInd      []int
+	pooledLogSliceHeader *[]StructLog
+	logs                 []StructLog
+	output               []byte
+	err                  error
 }
 
 // NewStructLogger returns a new logger
@@ -178,16 +172,26 @@ func NewStructLogger(cfg *LogConfig) *StructLogger {
 	return logger
 }
 
-// Reset clears the data held by the logger.
-func (l *StructLogger) Reset() {
-	l.bytecodes = make(map[common.Hash]CodeInfo)
-	l.storage = make(map[common.Address]Storage)
-	l.statesAffected = make(map[common.Address]struct{})
-	l.output = make([]byte, 0)
-	l.logs = l.logs[:0]
-	l.callStackLogInd = nil
-	l.err = nil
-	l.createdAccount = nil
+var logsPool = sync.Pool{
+	New: func() any {
+		return new([]StructLog)
+	},
+}
+
+// InitLogsFromPool initiliazes logs buffer from a pool instead of unconditionally allocating
+// a new buffer every time
+func (l *StructLogger) InitLogsFromPool() {
+	l.pooledLogSliceHeader = logsPool.Get().(*[]StructLog)
+	l.logs = *l.pooledLogSliceHeader
+}
+
+// ReleaseLogsToPool releases the logs back to the pool
+// Keep in mind after calling this any copies of the internal StructLog buffer that you may
+// have acquired by calling StructLogs() is invalid. Do not interact with it in any way.
+func (l *StructLogger) ReleaseLogsToPool() {
+	*l.pooledLogSliceHeader = l.logs[:0]
+	l.logs = nil
+	logsPool.Put(l.pooledLogSliceHeader)
 }
 
 // CaptureStart implements the EVMLogger interface to initialize the tracing operation.
@@ -359,7 +363,7 @@ func (l *StructLogger) TracedBytecodes() map[common.Hash]CodeInfo {
 func (l *StructLogger) CreatedAccount() *types.AccountWrapper { return l.createdAccount }
 
 // StructLogs returns the captured log entries.
-func (l *StructLogger) StructLogs() []*StructLog { return l.logs }
+func (l *StructLogger) StructLogs() []StructLog { return l.logs }
 
 // Error returns the VM error captured by the trace.
 func (l *StructLogger) Error() error { return l.err }
@@ -368,7 +372,7 @@ func (l *StructLogger) Error() error { return l.err }
 func (l *StructLogger) Output() []byte { return l.output }
 
 // WriteTrace writes a formatted trace to the given writer
-func WriteTrace(writer io.Writer, logs []*StructLog) {
+func WriteTrace(writer io.Writer, logs []StructLog) {
 	for _, log := range logs {
 		fmt.Fprintf(writer, "%-16spc=%08d gas=%v cost=%v", log.Op, log.Pc, log.Gas, log.GasCost)
 		if log.Err != nil {
@@ -488,9 +492,11 @@ func (t *mdLogger) CaptureEnter(typ OpCode, from common.Address, to common.Addre
 func (t *mdLogger) CaptureExit(output []byte, gasUsed uint64, err error) {}
 
 // FormatLogs formats EVM returned structured logs for json output
-func FormatLogs(logs []*StructLog) []*types.StructLogRes {
-	formatted := make([]*types.StructLogRes, 0, len(logs))
+func FormatLogs(logs []StructLog) []types.StructLogRes {
+	formatted := make([]types.StructLogRes, 0, len(logs))
 
+	// note: make sure you don't retain a reference to any memory that originally belongs to `logs` as they might be pooled and
+	// reused
 	for _, trace := range logs {
 		logRes := types.NewStructLogResBasic(trace.Pc, trace.Op.String(), trace.Gas, trace.GasCost, trace.Depth, trace.RefundCounter, trace.Err)
 		for _, stackValue := range trace.Stack {

eth/tracers/api_test.go

@@ -227,7 +227,7 @@ func TestTraceCall(t *testing.T) {
 				Gas:         params.TxGas,
 				Failed:      false,
 				ReturnValue: "",
-				StructLogs:  []*types.StructLogRes{},
+				StructLogs:  []types.StructLogRes{},
 			},
 		},
 		// Standard JSON trace upon the head, plain transfer.
@@ -245,7 +245,7 @@ func TestTraceCall(t *testing.T) {
 				Gas:         params.TxGas,
 				Failed:      false,
 				ReturnValue: "",
-				StructLogs:  []*types.StructLogRes{},
+				StructLogs:  []types.StructLogRes{},
 			},
 		},
 		// Standard JSON trace upon the non-existent block, error expects
@@ -275,7 +275,7 @@ func TestTraceCall(t *testing.T) {
 				Gas:         params.TxGas,
 				Failed:      false,
 				ReturnValue: "",
-				StructLogs:  []*types.StructLogRes{},
+				StructLogs:  []types.StructLogRes{},
 			},
 		},
 		// Standard JSON trace upon the pending block
@@ -293,7 +293,7 @@ func TestTraceCall(t *testing.T) {
 				Gas:         params.TxGas,
 				Failed:      false,
 				ReturnValue: "",
-				StructLogs:  []*types.StructLogRes{},
+				StructLogs:  []types.StructLogRes{},
 			},
 		},
 	}
@@ -347,7 +347,7 @@ func TestTraceTransaction(t *testing.T) {
 		Gas:         params.TxGas,
 		Failed:      false,
 		ReturnValue: "",
-		StructLogs:  []*types.StructLogRes{},
+		StructLogs:  []types.StructLogRes{},
 	}) {
 		t.Error("Transaction tracing result is different")
 	}

go.mod

@@ -51,7 +51,7 @@ require (
 	github.com/rjeczalik/notify v0.9.1
 	github.com/rs/cors v1.7.0
 	github.com/scroll-tech/da-codec v0.1.1-0.20240718144756-1875fd490923
-	github.com/scroll-tech/zktrie v0.8.4
+	github.com/scroll-tech/zktrie v0.8.5-0.20240821080004-fe110072a0a1
 	github.com/shirou/gopsutil v3.21.11+incompatible
 	github.com/sourcegraph/conc v0.3.0
 	github.com/status-im/keycard-go v0.0.0-20190316090335-8537d3370df4

go.sum

@@ -394,8 +394,8 @@ github.com/rs/cors v1.7.0/go.mod h1:gFx+x8UowdsKA9AchylcLynDq+nNFfI8FkUZdN/jGCU=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/scroll-tech/da-codec v0.1.1-0.20240718144756-1875fd490923 h1:A1ItzpnFDCHMh4g6cpeBZf7/fPf2lfwHbhjr/FSpk2w=
 github.com/scroll-tech/da-codec v0.1.1-0.20240718144756-1875fd490923/go.mod h1:D6XEESeNVJkQJlv3eK+FyR+ufPkgVQbJzERylQi53Bs=
-github.com/scroll-tech/zktrie v0.8.4 h1:UagmnZ4Z3ITCk+aUq9NQZJNAwnWl4gSxsLb2Nl7IgRE=
-github.com/scroll-tech/zktrie v0.8.4/go.mod h1:XvNo7vAk8yxNyTjBDj5WIiFzYW4bx/gJ78+NK6Zn6Uk=
+github.com/scroll-tech/zktrie v0.8.5-0.20240821080004-fe110072a0a1 h1:1WofmDyxxynpzfWkguUp2qAW4Dxaa0nYOrQ1tdYPYZU=
+github.com/scroll-tech/zktrie v0.8.5-0.20240821080004-fe110072a0a1/go.mod h1:F5gbEGfKRMpjdTfaAnUHD51wfCmLnoSYokiJJpUtfBw=
 github.com/segmentio/kafka-go v0.1.0/go.mod h1:X6itGqS9L4jDletMsxZ7Dz+JFWxM6JHfPOCvTvk+EJo=
 github.com/segmentio/kafka-go v0.2.0/go.mod h1:X6itGqS9L4jDletMsxZ7Dz+JFWxM6JHfPOCvTvk+EJo=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=

rollup/tracing/tracing.go

@@ -69,7 +69,7 @@ type TraceEnv struct {
 	// The following Mutexes are used to protect against parallel read/write,
 	// since txs are executed in parallel.
 	pMu sync.Mutex // for `TraceEnv.StorageTrace.Proofs`
-	sMu sync.Mutex // for `TraceEnv.state``
+	sMu sync.Mutex // for `TraceEnv.state`
 	cMu sync.Mutex // for `TraceEnv.Codes`
 
 	*types.StorageTrace
@@ -325,6 +325,8 @@ func (env *TraceEnv) getTxResult(state *state.StateDB, index int, block *types.B
 
 	applyMessageStart := time.Now()
 	structLogger := vm.NewStructLogger(env.logConfig)
+	structLogger.InitLogsFromPool()
+	defer structLogger.ReleaseLogsToPool()
 	tracer := NewMuxTracer(structLogger, callTracer)
 	// Run the transaction with tracing enabled.
 	vmenv := vm.NewEVM(env.blockCtx, txContext, state, env.chainConfig, vm.Config{Debug: true, Tracer: tracer, NoBaseFee: true})