feat: estimate time for a transaction (#2744)

services/wallet/api.go

@@ -318,6 +318,11 @@ func (api *API) GetSuggestedFees(ctx context.Context, chainID uint64) (*Suggeste
 	return api.s.feesManager.suggestedFees(ctx, chainID)
 }
 
+func (api *API) GetTransactionEstimatedTime(ctx context.Context, chainID uint64, maxFeePerGas float64) (TransactionEstimation, error) {
+	log.Debug("call to getTransactionEstimatedTime")
+	return api.s.feesManager.transactionEstimatedTime(ctx, chainID, maxFeePerGas), nil
+}
+
 func (api *API) GetSuggestedRoutes(ctx context.Context, account common.Address, amount float64, tokenSymbol string) (*SuggestedRoutes, error) {
 	log.Debug("call to GetSuggestedRoutes")
 	return api.router.suggestedRoutes(ctx, account, amount, tokenSymbol)

services/wallet/fees.go

@@ -2,6 +2,7 @@ package wallet
 
 import (
 	"context"
+	"math"
 	"math/big"
 	"sort"
 	"strings"
@@ -21,6 +22,18 @@ type SuggestedFees struct {
 	EIP1559Enabled       bool       `json:"eip1559Enabled"`
 }
 
+const inclusionThreshold = 0.95
+
+type TransactionEstimation int
+
+const (
+	Unknown TransactionEstimation = iota
+	LessThanOneMinute
+	LessThanThreeMinutes
+	LessThanFiveMinutes
+	MoreThanFiveMinutes
+)
+
 type FeeHistory struct {
 	BaseFeePerGas []string `json:"baseFeePerGas"`
 }
@@ -39,6 +52,12 @@ func weiToGwei(val *big.Int) *big.Float {
 	return result.Quo(result, new(big.Float).SetInt(unit))
 }
 
+func gweiToWei(val float64) *big.Int {
+	res := new(big.Int)
+	res.SetUint64(uint64(val * 1000000000))
+	return res
+}
+
 func (f *FeeManager) suggestedFees(ctx context.Context, chainID uint64) (*SuggestedFees, error) {
 	backend, err := f.RPCClient.EthClient(chainID)
 	if err != nil {
@@ -70,21 +89,11 @@ func (f *FeeManager) suggestedFees(ctx context.Context, chainID uint64) (*Sugges
 	config := params.MainnetChainConfig
 	baseFee := misc.CalcBaseFee(config, block.Header())
 
-	var feeHistory FeeHistory
-
-	err = f.RPCClient.Call(&feeHistory, chainID, "eth_feeHistory", 101, "latest", nil)
+	fees, err := f.getFeeHistorySorted(chainID)
 	if err != nil {
 		return nil, err
 	}
 
-	fees := []*big.Int{}
-	for _, fee := range feeHistory.BaseFeePerGas {
-		i := new(big.Int)
-		i.SetString(strings.Replace(fee, "0x", "", 1), 16)
-		fees = append(fees, i)
-	}
-	sort.Slice(fees, func(i, j int) bool { return fees[i].Cmp(fees[j]) < 0 })
-
 	perc10 := fees[int64(0.1*float64(len(fees)))-1]
 	perc20 := fees[int64(0.2*float64(len(fees)))-1]
 
@@ -115,3 +124,96 @@ func (f *FeeManager) suggestedFees(ctx context.Context, chainID uint64) (*Sugges
 		EIP1559Enabled:       true,
 	}, nil
 }
+
+func (f *FeeManager) transactionEstimatedTime(ctx context.Context, chainID uint64, maxFeePerGas float64) TransactionEstimation {
+	fees, err := f.getFeeHistorySorted(chainID)
+	if err != nil {
+		return Unknown
+	}
+
+	maxFeePerGasWei := gweiToWei(maxFeePerGas)
+	// pEvent represents the probability of the transaction being included in a block,
+	// we assume this one is static over time, in reality it is not.
+	pEvent := 0.0
+	for idx, fee := range fees {
+		if fee.Cmp(maxFeePerGasWei) == 1 || idx == len(fees)-1 {
+			pEvent = float64(idx) / float64(len(fees))
+			break
+		}
+	}
+
+	// Probability of next 4 blocks including the transaction (less than 1 minute)
+	// Generalising the formula: P(AUB) = P(A) + P(B) - P(A∩B) for 4 events and in our context P(A) == P(B) == pEvent
+	// The factors are calculated using the combinations formula
+	probability := pEvent*4 - 6*(math.Pow(pEvent, 2)) + 4*(math.Pow(pEvent, 3)) - (math.Pow(pEvent, 4))
+	if probability >= inclusionThreshold {
+		return LessThanOneMinute
+	}
+
+	// Probability of next 12 blocks including the transaction (less than 5 minutes)
+	// Generalising the formula: P(AUB) = P(A) + P(B) - P(A∩B) for 20 events and in our context P(A) == P(B) == pEvent
+	// The factors are calculated using the combinations formula
+	probability = pEvent*12 -
+		66*(math.Pow(pEvent, 2)) +
+		220*(math.Pow(pEvent, 3)) -
+		495*(math.Pow(pEvent, 4)) +
+		792*(math.Pow(pEvent, 5)) -
+		924*(math.Pow(pEvent, 6)) +
+		792*(math.Pow(pEvent, 7)) -
+		495*(math.Pow(pEvent, 8)) +
+		220*(math.Pow(pEvent, 9)) -
+		66*(math.Pow(pEvent, 10)) +
+		12*(math.Pow(pEvent, 11)) -
+		math.Pow(pEvent, 12)
+	if probability >= inclusionThreshold {
+		return LessThanThreeMinutes
+	}
+
+	// Probability of next 20 blocks including the transaction (less than 5 minutes)
+	// Generalising the formula: P(AUB) = P(A) + P(B) - P(A∩B) for 20 events and in our context P(A) == P(B) == pEvent
+	// The factors are calculated using the combinations formula
+	probability = pEvent*20 -
+		190*(math.Pow(pEvent, 2)) +
+		1140*(math.Pow(pEvent, 3)) -
+		4845*(math.Pow(pEvent, 4)) +
+		15504*(math.Pow(pEvent, 5)) -
+		38760*(math.Pow(pEvent, 6)) +
+		77520*(math.Pow(pEvent, 7)) -
+		125970*(math.Pow(pEvent, 8)) +
+		167960*(math.Pow(pEvent, 9)) -
+		184756*(math.Pow(pEvent, 10)) +
+		167960*(math.Pow(pEvent, 11)) -
+		125970*(math.Pow(pEvent, 12)) +
+		77520*(math.Pow(pEvent, 13)) -
+		38760*(math.Pow(pEvent, 14)) +
+		15504*(math.Pow(pEvent, 15)) -
+		4845*(math.Pow(pEvent, 16)) +
+		1140*(math.Pow(pEvent, 17)) -
+		190*(math.Pow(pEvent, 18)) +
+		20*(math.Pow(pEvent, 19)) -
+		math.Pow(pEvent, 20)
+	if probability >= inclusionThreshold {
+		return LessThanFiveMinutes
+	}
+
+	return MoreThanFiveMinutes
+}
+
+func (f *FeeManager) getFeeHistorySorted(chainID uint64) ([]*big.Int, error) {
+	var feeHistory FeeHistory
+
+	err := f.RPCClient.Call(&feeHistory, chainID, "eth_feeHistory", 101, "latest", nil)
+	if err != nil {
+		return nil, err
+	}
+
+	fees := []*big.Int{}
+	for _, fee := range feeHistory.BaseFeePerGas {
+		i := new(big.Int)
+		i.SetString(strings.Replace(fee, "0x", "", 1), 16)
+		fees = append(fees, i)
+	}
+
+	sort.Slice(fees, func(i, j int) bool { return fees[i].Cmp(fees[j]) < 0 })
+	return fees, nil
+}