public BigInteger?EstimatePriorityFee(FeeHistoryResult feeHistory)
{
var rewards = feeHistory.Reward
?.Select((r) => r[0].Value)
.Where((r) => r != 0)
.ToList();
rewards.Sort();
if (rewards == null || rewards.Count == 0)
{
return(null);
}
var percentageIncreases = new List <BigInteger>();
for (var i = 0; i < rewards.Count - 1; i++)
{
var next = rewards[i + 1];
var p = ((next - rewards[i]) / rewards[i]) * 100;
percentageIncreases.Add(p);
}
var highestIncrease = percentageIncreases.Max();
var highestIncreaseIndex = percentageIncreases.IndexOf(highestIncrease);
//// If we have big increase in value, we could be considering "outliers" in our estimate
//// Skip the low elements and take a new median
var values =
(highestIncrease > PRIORITY_FEE_INCREASE_BOUNDARY &&
highestIncreaseIndex >= Math.Floor((double)(rewards.Count / 2))
? rewards.Skip(highestIncreaseIndex)
: rewards).ToArray();
var valuesIndex = (int)Math.Floor((double)(values.Length / 2));
return(values[valuesIndex]);
}
public Fee1559[] SuggestFees(FeeHistoryResult feeHistory, BigInteger tip)
{
var baseFee = feeHistory.BaseFeePerGas.Select(x => x == null? 0 : x.Value).ToArray();
var gasUsedRatio = feeHistory.GasUsedRatio;
// If a block is full then the baseFee of the next block is copied. The reason is that in full blocks the minimal tip might not be enough to get included.
// The last (pending) block is also assumed to end up being full in order to give some upwards bias for urgent suggestions.
baseFee[baseFee.Length - 1] *= 9 / 8;
for (var i = gasUsedRatio.Length - 1; i >= 0; i--)
{
if (gasUsedRatio[i] > (decimal)0.9)
{
baseFee[i] = baseFee[i + 1];
}
}
var order = new int[baseFee.Length];
for (var i = 0; i < baseFee.Length; i++)
{
order[i] = i;
}
#if DOTNET35
var comparer = Comparer.Create <int>
#else
var comparer = Comparer <int> .Create
#endif
((int x, int y) =>
{
var aa = baseFee[x];
var bb = baseFee[y];
if (aa < bb)
{
return(-1);
}
if (aa > bb)
{
return(1);
}
return(0);
});
Array.Sort(order, comparer);
var result = new List <Fee1559>();
BigDecimal maxBaseFee = 0;
for (var timeFactor = MaxTimeFactor; timeFactor >= 0; timeFactor--)
{
var bf = SuggestBaseFee(baseFee, order, timeFactor);
var t = new BigDecimal(tip, 0);
if (bf > maxBaseFee)
{
maxBaseFee = bf;
}
else
{
// If a narrower time window yields a lower base fee suggestion than a wider window then we are probably in a price dip.
// In this case getting included with a low tip is not guaranteed; instead we use the higher base fee suggestion
// and also offer extra tip to increase the chance of getting included in the base fee dip.
t += (maxBaseFee - bf) * ExtraTipRatio;
bf = maxBaseFee;
}
result.Add(new Fee1559()
{
BaseFee = bf.Floor().Mantissa,
MaxFeePerGas = (bf + t).Floor().Mantissa,
MaxPriorityFeePerGas = t.Floor().Mantissa
});
}
result.Reverse();
return(result.ToArray());
}