From af03289998673b9d7b11046187dd429a81170ac3 Mon Sep 17 00:00:00 2001
From: weiihann <weihan774237@gmail.com>
Date: Fri, 24 Nov 2023 13:19:00 +0800
Subject: [PATCH] legacypool: use uint256 instead of big

---
 common/big.go                             | 10 +++++++++
 core/txpool/legacypool/legacypool.go      | 19 ++++++++--------
 core/txpool/legacypool/legacypool_test.go |  5 +----
 core/txpool/legacypool/list.go            | 27 ++++++++++++++---------
 core/txpool/legacypool/list_test.go       |  4 ++--
 5 files changed, 39 insertions(+), 26 deletions(-)

diff --git a/common/big.go b/common/big.go
index cbb562a28ef8..eed30048bef0 100644
--- a/common/big.go
+++ b/common/big.go
@@ -34,3 +34,13 @@ var (
 
 	U2560 = uint256.NewInt(0)
 )
+
+var (
+	Uint1   = uint256.NewInt(1)
+	Uint2   = uint256.NewInt(2)
+	Uint3   = uint256.NewInt(3)
+	Uint0   = uint256.NewInt(0)
+	Uint32  = uint256.NewInt(32)
+	Uint256 = uint256.NewInt(256)
+	Uint257 = uint256.NewInt(257)
+)
diff --git a/core/txpool/legacypool/legacypool.go b/core/txpool/legacypool/legacypool.go
index 624dafc60d03..949515cac858 100644
--- a/core/txpool/legacypool/legacypool.go
+++ b/core/txpool/legacypool/legacypool.go
@@ -37,6 +37,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/params"
+	"github.com/holiman/uint256"
 )
 
 const (
@@ -202,7 +203,7 @@ type LegacyPool struct {
 	config      Config
 	chainconfig *params.ChainConfig
 	chain       BlockChain
-	gasTip      atomic.Pointer[big.Int]
+	gasTip      atomic.Pointer[uint256.Int]
 	txFeed      event.Feed
 	signer      types.Signer
 	mu          sync.RWMutex
@@ -292,7 +293,7 @@ func (pool *LegacyPool) Init(gasTip *big.Int, head *types.Header, reserve txpool
 	pool.reserve = reserve
 
 	// Set the basic pool parameters
-	pool.gasTip.Store(gasTip)
+	pool.gasTip.Store(uint256.MustFromBig(gasTip))
 
 	// Initialize the state with head block, or fallback to empty one in
 	// case the head state is not available(might occur when node is not
@@ -434,10 +435,10 @@ func (pool *LegacyPool) SetGasTip(tip *big.Int) {
 	defer pool.mu.Unlock()
 
 	old := pool.gasTip.Load()
-	pool.gasTip.Store(new(big.Int).Set(tip))
+	pool.gasTip.Store(uint256.MustFromBig(tip))
 
 	// If the min miner fee increased, remove transactions below the new threshold
-	if tip.Cmp(old) > 0 {
+	if uint256.MustFromBig(tip).Cmp(old) > 0 {
 		// pool.priced is sorted by GasFeeCap, so we have to iterate through pool.all instead
 		drop := pool.all.RemotesBelowTip(tip)
 		for _, tx := range drop {
@@ -532,7 +533,7 @@ func (pool *LegacyPool) Pending(enforceTips bool) map[common.Address][]*txpool.L
 		// If the miner requests tip enforcement, cap the lists now
 		if enforceTips && !pool.locals.contains(addr) {
 			for i, tx := range txs {
-				if tx.EffectiveGasTipIntCmp(pool.gasTip.Load(), pool.priced.urgent.baseFee) < 0 {
+				if tx.EffectiveGasTipIntCmp(pool.gasTip.Load().ToBig(), pool.priced.urgent.baseFee) < 0 {
 					txs = txs[:i]
 					break
 				}
@@ -594,7 +595,7 @@ func (pool *LegacyPool) validateTxBasics(tx *types.Transaction, local bool) erro
 			1<<types.AccessListTxType |
 			1<<types.DynamicFeeTxType,
 		MaxSize: txMaxSize,
-		MinTip:  pool.gasTip.Load(),
+		MinTip:  pool.gasTip.Load().ToBig(),
 	}
 	if local {
 		opts.MinTip = new(big.Int)
@@ -624,7 +625,7 @@ func (pool *LegacyPool) validateTx(tx *types.Transaction, local bool) error {
 		},
 		ExistingExpenditure: func(addr common.Address) *big.Int {
 			if list := pool.pending[addr]; list != nil {
-				return list.totalcost
+				return list.totalcost.ToBig()
 			}
 			return new(big.Int)
 		},
@@ -1441,7 +1442,7 @@ func (pool *LegacyPool) promoteExecutables(accounts []common.Address) []*types.T
 		}
 		log.Trace("Removed old queued transactions", "count", len(forwards))
 		// Drop all transactions that are too costly (low balance or out of gas)
-		drops, _ := list.Filter(pool.currentState.GetBalance(addr).ToBig(), gasLimit)
+		drops, _ := list.Filter(pool.currentState.GetBalance(addr), gasLimit)
 		for _, tx := range drops {
 			hash := tx.Hash()
 			pool.all.Remove(hash)
@@ -1642,7 +1643,7 @@ func (pool *LegacyPool) demoteUnexecutables() {
 			log.Trace("Removed old pending transaction", "hash", hash)
 		}
 		// Drop all transactions that are too costly (low balance or out of gas), and queue any invalids back for later
-		drops, invalids := list.Filter(pool.currentState.GetBalance(addr).ToBig(), gasLimit)
+		drops, invalids := list.Filter(pool.currentState.GetBalance(addr), gasLimit)
 		for _, tx := range drops {
 			hash := tx.Hash()
 			log.Trace("Removed unpayable pending transaction", "hash", hash)
diff --git a/core/txpool/legacypool/legacypool_test.go b/core/txpool/legacypool/legacypool_test.go
index cd2cfb92e492..ec2a12bd9b55 100644
--- a/core/txpool/legacypool/legacypool_test.go
+++ b/core/txpool/legacypool/legacypool_test.go
@@ -199,9 +199,6 @@ func validatePoolInternals(pool *LegacyPool) error {
 		if nonce := pool.pendingNonces.get(addr); nonce != last+1 {
 			return fmt.Errorf("pending nonce mismatch: have %v, want %v", nonce, last+1)
 		}
-		if txs.totalcost.Cmp(common.Big0) < 0 {
-			return fmt.Errorf("totalcost went negative: %v", txs.totalcost)
-		}
 	}
 	return nil
 }
@@ -349,7 +346,7 @@ func TestInvalidTransactions(t *testing.T) {
 	}
 
 	tx = transaction(1, 100000, key)
-	pool.gasTip.Store(big.NewInt(1000))
+	pool.gasTip.Store(uint256.NewInt(1000))
 	if err, want := pool.addRemote(tx), txpool.ErrUnderpriced; !errors.Is(err, want) {
 		t.Errorf("want %v have %v", want, err)
 	}
diff --git a/core/txpool/legacypool/list.go b/core/txpool/legacypool/list.go
index 05ae0b58cd59..010f2dafe0cc 100644
--- a/core/txpool/legacypool/list.go
+++ b/core/txpool/legacypool/list.go
@@ -27,6 +27,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/holiman/uint256"
 )
 
 // nonceHeap is a heap.Interface implementation over 64bit unsigned integers for
@@ -271,9 +272,9 @@ type list struct {
 	strict bool       // Whether nonces are strictly continuous or not
 	txs    *sortedMap // Heap indexed sorted hash map of the transactions
 
-	costcap   *big.Int // Price of the highest costing transaction (reset only if exceeds balance)
-	gascap    uint64   // Gas limit of the highest spending transaction (reset only if exceeds block limit)
-	totalcost *big.Int // Total cost of all transactions in the list
+	costcap   *uint256.Int // Price of the highest costing transaction (reset only if exceeds balance)
+	gascap    uint64       // Gas limit of the highest spending transaction (reset only if exceeds block limit)
+	totalcost *uint256.Int // Total cost of all transactions in the list
 }
 
 // newList create a new transaction list for maintaining nonce-indexable fast,
@@ -282,8 +283,8 @@ func newList(strict bool) *list {
 	return &list{
 		strict:    strict,
 		txs:       newSortedMap(),
-		costcap:   new(big.Int),
-		totalcost: new(big.Int),
+		costcap:   new(uint256.Int),
+		totalcost: new(uint256.Int),
 	}
 }
 
@@ -325,10 +326,11 @@ func (l *list) Add(tx *types.Transaction, priceBump uint64) (bool, *types.Transa
 		l.subTotalCost([]*types.Transaction{old})
 	}
 	// Add new tx cost to totalcost
-	l.totalcost.Add(l.totalcost, tx.Cost())
+	l.totalcost.Add(l.totalcost, uint256.MustFromBig(tx.Cost()))
+
 	// Otherwise overwrite the old transaction with the current one
 	l.txs.Put(tx)
-	if cost := tx.Cost(); l.costcap.Cmp(cost) < 0 {
+	if cost := uint256.MustFromBig(tx.Cost()); l.costcap.Cmp(cost) < 0 {
 		l.costcap = cost
 	}
 	if gas := tx.Gas(); l.gascap < gas {
@@ -355,17 +357,17 @@ func (l *list) Forward(threshold uint64) types.Transactions {
 // a point in calculating all the costs or if the balance covers all. If the threshold
 // is lower than the costgas cap, the caps will be reset to a new high after removing
 // the newly invalidated transactions.
-func (l *list) Filter(costLimit *big.Int, gasLimit uint64) (types.Transactions, types.Transactions) {
+func (l *list) Filter(costLimit *uint256.Int, gasLimit uint64) (types.Transactions, types.Transactions) {
 	// If all transactions are below the threshold, short circuit
 	if l.costcap.Cmp(costLimit) <= 0 && l.gascap <= gasLimit {
 		return nil, nil
 	}
-	l.costcap = new(big.Int).Set(costLimit) // Lower the caps to the thresholds
+	l.costcap = new(uint256.Int).Set(costLimit) // Lower the caps to the thresholds
 	l.gascap = gasLimit
 
 	// Filter out all the transactions above the account's funds
 	removed := l.txs.Filter(func(tx *types.Transaction) bool {
-		return tx.Gas() > gasLimit || tx.Cost().Cmp(costLimit) > 0
+		return tx.Gas() > gasLimit || tx.Cost().Cmp(costLimit.ToBig()) > 0
 	})
 
 	if len(removed) == 0 {
@@ -456,7 +458,10 @@ func (l *list) LastElement() *types.Transaction {
 // total cost of all transactions.
 func (l *list) subTotalCost(txs []*types.Transaction) {
 	for _, tx := range txs {
-		l.totalcost.Sub(l.totalcost, tx.Cost())
+		_, underflow := l.totalcost.SubOverflow(l.totalcost, uint256.MustFromBig(tx.Cost()))
+		if underflow {
+			panic("totalcost underflow")
+		}
 	}
 }
 
diff --git a/core/txpool/legacypool/list_test.go b/core/txpool/legacypool/list_test.go
index b5cd34b23b62..b96bf9b45a71 100644
--- a/core/txpool/legacypool/list_test.go
+++ b/core/txpool/legacypool/list_test.go
@@ -17,12 +17,12 @@
 package legacypool
 
 import (
-	"math/big"
 	"math/rand"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/holiman/uint256"
 )
 
 // Tests that transactions can be added to strict lists and list contents and
@@ -60,7 +60,7 @@ func BenchmarkListAdd(b *testing.B) {
 		txs[i] = transaction(uint64(i), 0, key)
 	}
 	// Insert the transactions in a random order
-	priceLimit := big.NewInt(int64(DefaultConfig.PriceLimit))
+	priceLimit := uint256.NewInt(DefaultConfig.PriceLimit)
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		list := newList(true)