eth/gasestimator: allow slight estimation error in favor of less iterations (#28618)

* eth/gasestimator: early exit for plain transfer and error allowance

* core, eth/gasestimator: hard guess at a possible required gas

* internal/ethapi: update estimation tests with the error ratio

* eth/gasestimator: I hate you linter

* graphql: fix gas estimation test

---------

Co-authored-by: Oren <orenyomtov@users.noreply.github.com>

core/state_transition.go

@@ -32,9 +32,10 @@ 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 but include the refunded gas
-	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
+	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)
 }
 
 // Unwrap returns the internal evm error which allows us for further
@@ -419,12 +420,13 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 		ret, st.gasRemaining, vmerr = st.evm.Call(sender, st.to(), msg.Data, st.gasRemaining, msg.Value)
 	}
 
+	var gasRefund uint64
 	if !rules.IsLondon {
 		// Before EIP-3529: refunds were capped to gasUsed / 2
-		st.refundGas(params.RefundQuotient)
+		gasRefund = st.refundGas(params.RefundQuotient)
 	} else {
 		// After EIP-3529: refunds are capped to gasUsed / 5
-		st.refundGas(params.RefundQuotientEIP3529)
+		gasRefund = st.refundGas(params.RefundQuotientEIP3529)
 	}
 	effectiveTip := msg.GasPrice
 	if rules.IsLondon {
@@ -442,13 +444,14 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 	}
 
 	return &ExecutionResult{
-		UsedGas:    st.gasUsed(),
-		Err:        vmerr,
-		ReturnData: ret,
+		UsedGas:     st.gasUsed(),
+		RefundedGas: gasRefund,
+		Err:         vmerr,
+		ReturnData:  ret,
 	}, nil
 }
 
-func (st *StateTransition) refundGas(refundQuotient uint64) {
+func (st *StateTransition) refundGas(refundQuotient uint64) uint64 {
 	// Apply refund counter, capped to a refund quotient
 	refund := st.gasUsed() / refundQuotient
 	if refund > st.state.GetRefund() {
@@ -463,6 +466,8 @@ func (st *StateTransition) refundGas(refundQuotient uint64) {
 	// Also return remaining gas to the block gas counter so it is
 	// available for the next transaction.
 	st.gp.AddGas(st.gasRemaining)
+
+	return refund
 }
 
 // gasUsed returns the amount of gas used up by the state transition.