public async Task Subscribe(CancellationToken cancellationToken)
{
// http://docs.nethereum.com/en/latest/nethereum-subscriptions-streaming/
using var streamingClient = new StreamingWebSocketClient(_batBotOptions.BlockchainEndpointWssUrl);
var subscription = new EthNewPendingTransactionObservableSubscription(streamingClient);
await _ethereumService.HandleSubscription(streamingClient, subscription, async() => await subscription.SubscribeAsync(), async th =>
{
await _messagingService.SendLogMessage($"Pending Transaction Hash: {th}");
// Don't process transactions (discard) when one is being processed for front running.
if (_backoffService.BackOff())
{
return;
}
await _backoffService.Protect(async() => await _transactionProcessorService.Process(await _ethereumService.GetSwap(th), cancellationToken));
}, null, cancellationToken);
}
public async Task Handle(JsonElement transaction, JsonElement contractCall, TransactionSource transactionSource, CancellationToken cancellationToken)
{
if (contractCall.GetProperty(Blocknative.Properties.MethodName).ValueEquals(Uniswap.SwapExactEthForTokens))
{
var transactionHash = transaction.GetProperty(Blocknative.Properties.Hash).GetString();
_logger.LogTrace($"Transaction {transactionHash} received");
var transactionStatus = EnumHelper.GetValueFromDescription <TransactionStatus>(transaction.GetProperty(Blocknative.Properties.Status).GetString());
switch (transactionStatus)
{
case TransactionStatus.Pending:
var @params = contractCall.GetProperty(Blocknative.Properties.Params);
await _transactionProcessorService.Process(new Swap
{
TransactionHash = transactionHash,
AmountIn = TryParseJsonString(transaction, Blocknative.Properties.Value),
Gas = transaction.GetProperty(Blocknative.Properties.Gas).GetUInt64(),
GasPrice = TryParseJsonString(transaction, Blocknative.Properties.GasPrice),
AmountOutMin = TryParseJsonString(@params, Blocknative.Properties.AmountOutMin),
Deadline = (long)TryParseJsonString(@params, Blocknative.Properties.Deadline),
Path = @params.GetProperty(Blocknative.Properties.Path).EnumerateArray().Select(e => e.GetString()).ToList(),
Source = transactionSource
}, cancellationToken);