From 6002967886a2564fd6b7e11e1a106166b7957b54 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Thu, 16 Nov 2017 18:32:46 +0200
Subject: [PATCH] core/vm, internal/ethapi: omit disabled trace fields

---
 core/vm/logger.go      | 11 +++------
 internal/ethapi/api.go | 55 ++++++++++++++++++++++++------------------
 2 files changed, 35 insertions(+), 31 deletions(-)

diff --git a/core/vm/logger.go b/core/vm/logger.go
index 2790cbe05e..75309da921 100644
--- a/core/vm/logger.go
+++ b/core/vm/logger.go
@@ -135,14 +135,13 @@ func (l *StructLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost ui
 		)
 		l.changedValues[contract.Address()][address] = value
 	}
-	// copy a snapstot of the current memory state to a new buffer
+	// Copy a snapstot of the current memory state to a new buffer
 	var mem []byte
 	if !l.cfg.DisableMemory {
 		mem = make([]byte, len(memory.Data()))
 		copy(mem, memory.Data())
 	}
-
-	// copy a snapshot of the current stack state to a new buffer
+	// Copy a snapshot of the current stack state to a new buffer
 	var stck []*big.Int
 	if !l.cfg.DisableStack {
 		stck = make([]*big.Int, len(stack.Data()))
@@ -150,13 +149,9 @@ func (l *StructLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost ui
 			stck[i] = new(big.Int).Set(item)
 		}
 	}
-
-	// Copy the storage based on the settings specified in the log config. If full storage
-	// is disabled (default) we can use the simple Storage.Copy method, otherwise we use
-	// the state object to query for all values (slow process).
+	// Copy a snapshot of the current storage to a new container
 	var storage Storage
 	if !l.cfg.DisableStorage {
-		// Copy a snapshot of the current storage to a new container.
 		storage = l.changedValues[contract.Address()].Copy()
 	}
 	// create a new snaptshot of the EVM.
diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index 8ee28b23cf..cf15d1c71e 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -710,43 +710,52 @@ type ExecutionResult struct {
 // StructLogRes stores a structured log emitted by the EVM while replaying a
 // transaction in debug mode
 type StructLogRes struct {
-	Pc      uint64            `json:"pc"`
-	Op      string            `json:"op"`
-	Gas     uint64            `json:"gas"`
-	GasCost uint64            `json:"gasCost"`
-	Depth   int               `json:"depth"`
-	Error   error             `json:"error,omitempty"`
-	Stack   []string          `json:"stack"`
-	Memory  []string          `json:"memory"`
-	Storage map[string]string `json:"storage"`
+	Pc      uint64             `json:"pc"`
+	Op      string             `json:"op"`
+	Gas     uint64             `json:"gas"`
+	GasCost uint64             `json:"gasCost"`
+	Depth   int                `json:"depth"`
+	Error   error              `json:"error,omitempty"`
+	Stack   *[]string          `json:"stack,omitempty"`
+	Memory  *[]string          `json:"memory,omitempty"`
+	Storage *map[string]string `json:"storage,omitempty"`
 }
 
 // formatLogs formats EVM returned structured logs for json output
-func FormatLogs(structLogs []vm.StructLog) []StructLogRes {
-	formattedStructLogs := make([]StructLogRes, len(structLogs))
-	for index, trace := range structLogs {
-		formattedStructLogs[index] = StructLogRes{
+func FormatLogs(logs []vm.StructLog) []StructLogRes {
+	formatted := make([]StructLogRes, len(logs))
+	for index, trace := range logs {
+		formatted[index] = StructLogRes{
 			Pc:      trace.Pc,
 			Op:      trace.Op.String(),
 			Gas:     trace.Gas,
 			GasCost: trace.GasCost,
 			Depth:   trace.Depth,
 			Error:   trace.Err,
-			Stack:   make([]string, len(trace.Stack)),
-			Memory:  make([]string, 0, (len(trace.Memory)+31)/32),
-			Storage: make(map[string]string),
 		}
-		for i, stackValue := range trace.Stack {
-			formattedStructLogs[index].Stack[i] = fmt.Sprintf("%x", math.PaddedBigBytes(stackValue, 32))
+		if trace.Stack != nil {
+			stack := make([]string, len(trace.Stack))
+			for i, stackValue := range trace.Stack {
+				stack[i] = fmt.Sprintf("%x", math.PaddedBigBytes(stackValue, 32))
+			}
+			formatted[index].Stack = &stack
 		}
-		for i := 0; i+32 <= len(trace.Memory); i += 32 {
-			formattedStructLogs[index].Memory = append(formattedStructLogs[index].Memory, fmt.Sprintf("%x", trace.Memory[i:i+32]))
+		if trace.Memory != nil {
+			memory := make([]string, 0, (len(trace.Memory)+31)/32)
+			for i := 0; i+32 <= len(trace.Memory); i += 32 {
+				memory = append(memory, fmt.Sprintf("%x", trace.Memory[i:i+32]))
+			}
+			formatted[index].Memory = &memory
 		}
-		for i, storageValue := range trace.Storage {
-			formattedStructLogs[index].Storage[fmt.Sprintf("%x", i)] = fmt.Sprintf("%x", storageValue)
+		if trace.Storage != nil {
+			storage := make(map[string]string)
+			for i, storageValue := range trace.Storage {
+				storage[fmt.Sprintf("%x", i)] = fmt.Sprintf("%x", storageValue)
+			}
+			formatted[index].Storage = &storage
 		}
 	}
-	return formattedStructLogs
+	return formatted
 }
 
 // rpcOutputBlock converts the given block to the RPC output which depends on fullTx. If inclTx is true transactions are