internal, accounts, eth: utilize vm failed flag to help gas estimation

3 files changed, 33 insertions, 28 deletions

diff --git a/accounts/abi/bind/backends/simulated.go b/accounts/abi/bind/backends/simulated.go
index d6d16eb3f..0621e81c2 100644
--- a/accounts/abi/bind/backends/simulated.go
+++ b/accounts/abi/bind/backends/simulated.go
@@ -168,7 +168,7 @@ func (b *SimulatedBackend) CallContract(ctx context.Context, call ethereum.CallM
 	if err != nil {
 		return nil, err
 	}
-	rval, _, err := b.callContract(ctx, call, b.blockchain.CurrentBlock(), state)
+	rval, _, _, err := b.callContract(ctx, call, b.blockchain.CurrentBlock(), state)
 	return rval, err
 }
 
@@ -178,7 +178,7 @@ func (b *SimulatedBackend) PendingCallContract(ctx context.Context, call ethereu
 	defer b.mu.Unlock()
 	defer b.pendingState.RevertToSnapshot(b.pendingState.Snapshot())
 
-	rval, _, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
+	rval, _, _, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
 	return rval, err
 }
 
@@ -204,8 +204,11 @@ func (b *SimulatedBackend) EstimateGas(ctx context.Context, call ethereum.CallMs
 	defer b.mu.Unlock()
 
 	// Binary search the gas requirement, as it may be higher than the amount used
-	var lo, hi uint64
-	if call.Gas != nil {
+	var (
+		lo uint64 = params.TxGas - 1
+		hi uint64
+	)
+	if call.Gas != nil && call.Gas.Uint64() >= params.TxGas {
 		hi = call.Gas.Uint64()
 	} else {
 		hi = b.pendingBlock.GasLimit().Uint64()
@@ -216,11 +219,11 @@ func (b *SimulatedBackend) EstimateGas(ctx context.Context, call ethereum.CallMs
 		call.Gas = new(big.Int).SetUint64(mid)
 
 		snapshot := b.pendingState.Snapshot()
-		_, gas, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
+		_, _, failed, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
 		b.pendingState.RevertToSnapshot(snapshot)
 
-		// If the transaction became invalid or used all the gas (failed), raise the gas limit
-		if err != nil || gas.Cmp(call.Gas) == 0 {
+		// If the transaction became invalid or execution failed, raise the gas limit
+		if err != nil || failed {
 			lo = mid
 			continue
 		}
@@ -232,7 +235,7 @@ func (b *SimulatedBackend) EstimateGas(ctx context.Context, call ethereum.CallMs
 
 // callContract implemens common code between normal and pending contract calls.
 // state is modified during execution, make sure to copy it if necessary.
-func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallMsg, block *types.Block, statedb *state.StateDB) ([]byte, *big.Int, error) {
+func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallMsg, block *types.Block, statedb *state.StateDB) ([]byte, *big.Int, bool, error) {
 	// Ensure message is initialized properly.
 	if call.GasPrice == nil {
 		call.GasPrice = big.NewInt(1)
@@ -254,9 +257,8 @@ func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallM
 	// about the transaction and calling mechanisms.
 	vmenv := vm.NewEVM(evmContext, statedb, b.config, vm.Config{})
 	gaspool := new(core.GasPool).AddGas(math.MaxBig256)
-	// TODO utilize returned failed flag to help gas estimation.
-	ret, gasUsed, _, _, err := core.NewStateTransition(vmenv, msg, gaspool).TransitionDb()
-	return ret, gasUsed, err
+	ret, gasUsed, _, failed, err := core.NewStateTransition(vmenv, msg, gaspool).TransitionDb()
+	return ret, gasUsed, failed, err
 }
 
 // SendTransaction updates the pending block to include the given transaction.
diff --git a/eth/api.go b/eth/api.go
index d64e4e6c7..e91f51bb9 100644
--- a/eth/api.go
+++ b/eth/api.go
@@ -523,8 +523,7 @@ func (api *PrivateDebugAPI) TraceTransaction(ctx context.Context, txHash common.
 
 	// Run the transaction with tracing enabled.
 	vmenv := vm.NewEVM(context, statedb, api.config, vm.Config{Debug: true, Tracer: tracer})
-	// TODO utilize failed flag
-	ret, gas, _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
+	ret, gas, failed, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
 	if err != nil {
 		return nil, fmt.Errorf("tracing failed: %v", err)
 	}
@@ -532,6 +531,7 @@ func (api *PrivateDebugAPI) TraceTransaction(ctx context.Context, txHash common.
 	case *vm.StructLogger:
 		return &ethapi.ExecutionResult{
 			Gas:         gas,
+			Failed:      failed,
 			ReturnValue: fmt.Sprintf("%x", ret),
 			StructLogs:  ethapi.FormatLogs(tracer.StructLogs()),
 		}, nil
diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index ab8478929..1ffb5a180 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -580,12 +580,12 @@ type CallArgs struct {
 	Data     hexutil.Bytes   `json:"data"`
 }
 
-func (s *PublicBlockChainAPI) doCall(ctx context.Context, args CallArgs, blockNr rpc.BlockNumber, vmCfg vm.Config) ([]byte, *big.Int, error) {
+func (s *PublicBlockChainAPI) doCall(ctx context.Context, args CallArgs, blockNr rpc.BlockNumber, vmCfg vm.Config) ([]byte, *big.Int, bool, error) {
 	defer func(start time.Time) { log.Debug("Executing EVM call finished", "runtime", time.Since(start)) }(time.Now())
 
 	state, header, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
-		return nil, common.Big0, err
+		return nil, common.Big0, false, err
 	}
 	// Set sender address or use a default if none specified
 	addr := args.From
@@ -623,7 +623,7 @@ func (s *PublicBlockChainAPI) doCall(ctx context.Context, args CallArgs, blockNr
 	// Get a new instance of the EVM.
 	evm, vmError, err := s.b.GetEVM(ctx, msg, state, header, vmCfg)
 	if err != nil {
-		return nil, common.Big0, err
+		return nil, common.Big0, false, err
 	}
 	// Wait for the context to be done and cancel the evm. Even if the
 	// EVM has finished, cancelling may be done (repeatedly)
@@ -635,26 +635,28 @@ func (s *PublicBlockChainAPI) doCall(ctx context.Context, args CallArgs, blockNr
 	// Setup the gas pool (also for unmetered requests)
 	// and apply the message.
 	gp := new(core.GasPool).AddGas(math.MaxBig256)
-	// TODO utilize failed flag to help gas estimation
-	res, gas, _, err := core.ApplyMessage(evm, msg, gp)
+	res, gas, failed, err := core.ApplyMessage(evm, msg, gp)
 	if err := vmError(); err != nil {
-		return nil, common.Big0, err
+		return nil, common.Big0, false, err
 	}
-	return res, gas, err
+	return res, gas, failed, err
 }
 
 // Call executes the given transaction on the state for the given block number.
 // It doesn't make and changes in the state/blockchain and is useful to execute and retrieve values.
 func (s *PublicBlockChainAPI) Call(ctx context.Context, args CallArgs, blockNr rpc.BlockNumber) (hexutil.Bytes, error) {
-	result, _, err := s.doCall(ctx, args, blockNr, vm.Config{DisableGasMetering: true})
+	result, _, _, err := s.doCall(ctx, args, blockNr, vm.Config{DisableGasMetering: true})
 	return (hexutil.Bytes)(result), err
 }
 
 // EstimateGas returns an estimate of the amount of gas needed to execute the given transaction.
 func (s *PublicBlockChainAPI) EstimateGas(ctx context.Context, args CallArgs) (*hexutil.Big, error) {
 	// Binary search the gas requirement, as it may be higher than the amount used
-	var lo, hi uint64
-	if (*big.Int)(&args.Gas).Sign() != 0 {
+	var (
+		lo uint64 = params.TxGas - 1
+		hi uint64
+	)
+	if (*big.Int)(&args.Gas).Uint64() >= params.TxGas {
 		hi = (*big.Int)(&args.Gas).Uint64()
 	} else {
 		// Retrieve the current pending block to act as the gas ceiling
@@ -669,10 +671,10 @@ func (s *PublicBlockChainAPI) EstimateGas(ctx context.Context, args CallArgs) (*
 		mid := (hi + lo) / 2
 		(*big.Int)(&args.Gas).SetUint64(mid)
 
-		_, gas, err := s.doCall(ctx, args, rpc.PendingBlockNumber, vm.Config{})
+		_, _, failed, err := s.doCall(ctx, args, rpc.PendingBlockNumber, vm.Config{})
 
-		// If the transaction became invalid or used all the gas (failed), raise the gas limit
-		if err != nil || gas.Cmp((*big.Int)(&args.Gas)) == 0 {
+		// If the transaction became invalid or execution failed, raise the gas limit
+		if err != nil || failed {
 			lo = mid
 			continue
 		}
@@ -683,10 +685,11 @@ func (s *PublicBlockChainAPI) EstimateGas(ctx context.Context, args CallArgs) (*
 }
 
 // ExecutionResult groups all structured logs emitted by the EVM
-// while replaying a transaction in debug mode as well as the amount of
-// gas used and the return value
+// while replaying a transaction in debug mode as well as transaction
+// execution status, the amount of gas used and the return value
 type ExecutionResult struct {
 	Gas         *big.Int       `json:"gas"`
+	Failed      bool           `json:"failed"`
 	ReturnValue string         `json:"returnValue"`
 	StructLogs  []StructLogRes `json:"structLogs"`
 }