Merge pull request #6 from binance-chain/disable_service

[R4R]disable service when network is congest

internal/ethapi/api.go

@@ -22,6 +22,7 @@ import (
 	"errors"
 	"fmt"
 	"math/big"
+	"sort"
 	"strings"
 	"time"
 
@@ -55,6 +56,9 @@ const (
 	UnHealthyTimeout    = 5 * time.Second
 	MaxBundleBlockDelay = 1200
 	MaxBundleTimeDelay  = 60 * 60 // second
+	MaxOracleBlocks     = 21
+	DropBlocks          = 3
+	MaxGasUsedRatio     = 90
 )
 
 // PublicEthereumAPI provides an API to access Ethereum related information.
@@ -2317,6 +2321,33 @@ func (s *PrivateTxBundleAPI) BundlePrice(ctx context.Context) (*big.Int, error)
 // SendBundle will add the signed transaction to the transaction pool.
 // The sender is responsible for signing the transaction and using the correct nonce and ensuring validity
 func (s *PrivateTxBundleAPI) SendBundle(ctx context.Context, args SendBundleArgs) (common.Hash, error) {
+	gasUsedRatio := make([]int, 0, MaxOracleBlocks)
+	block := s.b.CurrentBlock()
+	var err error
+	for i := 0; i < MaxOracleBlocks && block.NumberU64() > 1; i++ {
+		gasUsedRatio = append(gasUsedRatio, int(block.GasUsed()*100/block.GasLimit()))
+		block, err = s.b.BlockByHash(context.Background(), block.ParentHash())
+		if err != nil {
+			break
+		}
+	}
+	sort.Ints(gasUsedRatio)
+	validGasUsedRatio := gasUsedRatio
+	if len(gasUsedRatio) > DropBlocks {
+		validGasUsedRatio = gasUsedRatio[DropBlocks:]
+	}
+	if len(validGasUsedRatio) == 0 {
+		return common.Hash{}, errors.New("no enough example ratio")
+	}
+	var totalRatio int
+	for _, ratio := range validGasUsedRatio {
+		totalRatio += ratio
+	}
+	averageRatio := totalRatio / len(validGasUsedRatio)
+	if averageRatio >= MaxGasUsedRatio {
+		return common.Hash{}, errors.New("the network is congested, please try later")
+	}
+
 	var txs types.Transactions
 	if len(args.Txs) == 0 {
 		return common.Hash{}, errors.New("bundle missing txs")
@@ -2347,7 +2378,6 @@ func (s *PrivateTxBundleAPI) SendBundle(ctx context.Context, args SendBundleArgs
 		}
 		txs = append(txs, tx)
 	}
-
 	var minTimestamp, maxTimestamp uint64
 	if args.MinTimestamp != nil {
 		minTimestamp = *args.MinTimestamp