From b8e72b4cc73846e32bbaad93b54e7b901c300ccc Mon Sep 17 00:00:00 2001
From: Wang Gerui <wgr523@gmail.com>
Date: Sat, 23 Nov 2024 00:56:20 +0800
Subject: [PATCH] feat: Gasless

---
 cmd/utils/flags.go       |  4 ++++
 common/gas.go            | 13 ++++++++++++-
 core/tx_pool.go          |  4 +++-
 eth/gasprice/gasprice.go |  3 +++
 4 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 9880e8709..4c0444fdb 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -1144,6 +1144,10 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
 	}
 	if ctx.GlobalIsSet(GasPriceFlag.Name) {
 		cfg.GasPrice = GlobalBig(ctx, GasPriceFlag.Name)
+		if len(cfg.GasPrice.Bits()) == 0 { //IsUint64() && cfg.GasPrice.Uint64() == 0 {
+			common.Gasless = true
+			log.Info("Gasless enabled. You can run transactions with zero gas fee.")
+		}
 	}
 	if ctx.GlobalIsSet(VMEnableDebugFlag.Name) {
 		// TODO(fjl): force-enable this in --dev mode
diff --git a/common/gas.go b/common/gas.go
index 26783af02..632770e57 100644
--- a/common/gas.go
+++ b/common/gas.go
@@ -7,7 +7,12 @@ import (
 var MinGasPrice50x = big.NewInt(12500000000)
 var GasPrice50x = big.NewInt(12500000000)
 
+var Gasless = false
+
 func GetGasFee(blockNumber, gas uint64) *big.Int {
+	if Gasless {
+		return big.NewInt(0)
+	}
 	fee := new(big.Int).SetUint64(gas)
 	if blockNumber >= uint64(10) { //temp fix trc21issuer test fail
 		fee = fee.Mul(fee, GasPrice50x)
@@ -16,6 +21,9 @@ func GetGasFee(blockNumber, gas uint64) *big.Int {
 }
 
 func GetGasPrice(number *big.Int) *big.Int {
+	if Gasless {
+		return big.NewInt(0)
+	}
 	if number == nil {
 		return new(big.Int).Set(TRC21GasPrice)
 	}
@@ -23,8 +31,11 @@ func GetGasPrice(number *big.Int) *big.Int {
 }
 
 func GetMinGasPrice(number *big.Int) *big.Int {
+	if Gasless {
+		return big.NewInt(0)
+	}
 	if number == nil {
 		return new(big.Int).Set(MinGasPrice)
 	}
 	return new(big.Int).Set(MinGasPrice50x)
-}
\ No newline at end of file
+}
diff --git a/core/tx_pool.go b/core/tx_pool.go
index 16656f60b..f03dcadf1 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -664,7 +664,9 @@ func (pool *TxPool) validateTx(tx *types.Transaction, local bool) error {
 
 		// Check zero gas price.
 		if tx.GasPrice().Cmp(new(big.Int).SetInt64(0)) == 0 {
-			return ErrZeroGasPrice
+			if !common.Gasless {
+				return ErrZeroGasPrice
+			}
 		}
 
 		// under min gas price
diff --git a/eth/gasprice/gasprice.go b/eth/gasprice/gasprice.go
index 784f39145..96ccc845f 100644
--- a/eth/gasprice/gasprice.go
+++ b/eth/gasprice/gasprice.go
@@ -75,6 +75,9 @@ func NewOracle(backend ethapi.Backend, params Config) *Oracle {
 
 // SuggestPrice returns the recommended gas price.
 func (gpo *Oracle) SuggestPrice(ctx context.Context) (*big.Int, error) {
+	if common.Gasless {
+		return big.NewInt(0), nil
+	}
 	gpo.cacheLock.RLock()
 	lastHead := gpo.lastHead
 	lastPrice := gpo.lastPrice