core, eth/gasestimator: introduce MaxGasUsed for estimation (#31735)

This PR improves gas estimation for data-heavy transactions which hit the floor data gas cost.

Author: rjl493456442

core/state_transition.go

@@ -34,10 +34,10 @@ import (
 // ExecutionResult includes all output after executing given evm
 // message no matter the execution itself is successful or not.
 type ExecutionResult struct {
-	UsedGas     uint64 // Total used gas, not including the refunded gas
-	RefundedGas uint64 // Total gas refunded after execution
-	Err         error  // Any error encountered during the execution(listed in core/vm/errors.go)
-	ReturnData  []byte // Returned data from evm(function result or data supplied with revert opcode)
+	UsedGas    uint64 // Total used gas, not including the refunded gas
+	MaxUsedGas uint64 // Maximum gas consumed during execution, excluding gas refunds.
+	Err        error  // Any error encountered during the execution(listed in core/vm/errors.go)
+	ReturnData []byte // Returned data from evm(function result or data supplied with revert opcode)
 }
 
 // Unwrap returns the internal evm error which allows us for further
@@ -509,9 +509,12 @@ func (st *stateTransition) execute() (*ExecutionResult, error) {
 		ret, st.gasRemaining, vmerr = st.evm.Call(msg.From, st.to(), msg.Data, st.gasRemaining, value)
 	}
 
+	// Record the gas used excluding gas refunds. This value represents the actual
+	// gas allowance required to complete execution.
+	peakGasUsed := st.gasUsed()
+
 	// Compute refund counter, capped to a refund quotient.
-	gasRefund := st.calcRefund()
-	st.gasRemaining += gasRefund
+	st.gasRemaining += st.calcRefund()
 	if rules.IsPrague {
 		// After EIP-7623: Data-heavy transactions pay the floor gas.
 		if st.gasUsed() < floorDataGas {
@@ -521,6 +524,9 @@ func (st *stateTransition) execute() (*ExecutionResult, error) {
 				t.OnGasChange(prev, st.gasRemaining, tracing.GasChangeTxDataFloor)
 			}
 		}
+		if peakGasUsed < floorDataGas {
+			peakGasUsed = floorDataGas
+		}
 	}
 	st.returnGas()
 
@@ -549,10 +555,10 @@ func (st *stateTransition) execute() (*ExecutionResult, error) {
 	}
 
 	return &ExecutionResult{
-		UsedGas:     st.gasUsed(),
-		RefundedGas: gasRefund,
-		Err:         vmerr,
-		ReturnData:  ret,
+		UsedGas:    st.gasUsed(),
+		MaxUsedGas: peakGasUsed,
+		Err:        vmerr,
+		ReturnData: ret,
 	}, nil
 }
 

eth/gasestimator/gasestimator.go

@@ -144,7 +144,7 @@ func Estimate(ctx context.Context, call *core.Message, opts *Options, gasCap uin
 	// There's a fairly high chance for the transaction to execute successfully
 	// with gasLimit set to the first execution's usedGas + gasRefund. Explicitly
 	// check that gas amount and use as a limit for the binary search.
-	optimisticGasLimit := (result.UsedGas + result.RefundedGas + params.CallStipend) * 64 / 63
+	optimisticGasLimit := (result.MaxUsedGas + params.CallStipend) * 64 / 63
 	if optimisticGasLimit < hi {
 		failed, _, err = execute(ctx, call, opts, optimisticGasLimit)
 		if err != nil {