/// <summary>
/// Tries to perform mempool cleanup with the help of the backend.
/// </summary>
public async Task <bool> TryPerformMempoolCleanupAsync(Func <Uri> destAction, IPEndPoint torSocks)
{
// If already cleaning, then no need to run it that often.
if (Interlocked.CompareExchange(ref _cleanupInProcess, 1, 0) == 1)
{
return(false);
}
// This function is designed to prevent forever growing mempool.
try
{
if (!TransactionHashes.Any())
{
return(true); // There's nothing to cleanup.
}
Logger.LogInfo <MempoolService>("Start cleaning out mempool...");
using (var client = new WasabiClient(destAction, torSocks))
{
var compactness = 10;
var allMempoolHashes = await client.GetMempoolHashesAsync(compactness);
var toRemove = TransactionHashes.Where(x => !allMempoolHashes.Contains(x.ToString().Substring(0, compactness)));
int removedTxCount = 0;
foreach (uint256 tx in toRemove)
{
if (TransactionHashes.TryRemove(tx))
{
removedTxCount++;
}
}
Logger.LogInfo <MempoolService>($"{removedTxCount} transactions were cleaned from mempool.");
}
return(true);
}
catch (Exception ex)
{
Logger.LogWarning <MempoolService>(ex);
}
finally
{
Interlocked.Exchange(ref _cleanupInProcess, 0);
}
return(false);
}
/// <summary>
/// Tries to perform mempool cleanup with the help of the connected nodes.
/// NOTE: This results in heavy network activity! https://github.com/zkSNACKs/WalletWasabi/issues/1273
/// </summary>
public async Task <bool> TryPerformMempoolCleanupAsync(NodesGroup nodes, CancellationToken cancel)
{
// If already cleaning, then no need to run it that often.
if (Interlocked.CompareExchange(ref _cleanupInProcess, 1, 0) == 1)
{
return(false);
}
// This function is designed to prevent forever growing mempool.
try
{
if (!TransactionHashes.Any())
{
return(true); // There's nothing to cleanup.
}
var delay = TimeSpan.FromMinutes(1);
if (nodes?.ConnectedNodes is null)
{
return(false);
}
while (nodes.ConnectedNodes.Count != nodes.MaximumNodeConnection && nodes.ConnectedNodes.All(x => x.IsConnected))
{
if (cancel.IsCancellationRequested)
{
return(false);
}
Logger.LogInfo <MemPoolService>($"Not all nodes were in a connected state. Delaying mempool cleanup for {delay.TotalSeconds} seconds...");
await Task.Delay(delay, cancel);
}
Logger.LogInfo <MemPoolService>("Start cleaning out mempool...");
var allTxs = new HashSet <uint256>();
foreach (Node node in nodes.ConnectedNodes)
{
try
{
if (!node.IsConnected)
{
continue;
}
if (cancel.IsCancellationRequested)
{
return(false);
}
uint256[] txs = node.GetMempool(cancel);
if (cancel.IsCancellationRequested)
{
return(false);
}
allTxs.UnionWith(txs);
if (cancel.IsCancellationRequested)
{
return(false);
}
}
catch (Exception ex) when((ex is InvalidOperationException && ex.Message.StartsWith("The node is not in a connected state", StringComparison.InvariantCultureIgnoreCase)) ||
ex is OperationCanceledException ||
ex is TaskCanceledException ||
ex is TimeoutException)
{
Logger.LogTrace <MemPoolService>(ex);
}
catch (Exception ex)
{
Logger.LogDebug <MemPoolService>(ex);
}
}
uint256[] toRemove = TransactionHashes.Except(allTxs).ToArray();
foreach (uint256 tx in toRemove)
{
TransactionHashes.TryRemove(tx);
}
Logger.LogInfo <MemPoolService>($"{toRemove.Count()} transactions were cleaned from mempool.");
return(true);
}
catch (Exception ex) when(ex is OperationCanceledException ||
ex is TaskCanceledException ||
ex is TimeoutException)
{
Logger.LogTrace <MemPoolService>(ex);
}
catch (Exception ex)
{
Logger.LogDebug <MemPoolService>(ex);
}
finally
{
Interlocked.Exchange(ref _cleanupInProcess, 0);
}
return(false);
}
public bool Process(SmartTransaction tx)
{
uint256 txId = tx.GetHash();
var walletRelevant = false;
bool justUpdate = false;
if (tx.Confirmed)
{
TransactionHashes.TryRemove(txId); // If we have in mempool, remove.
if (!tx.Transaction.PossiblyP2WPKHInvolved())
{
return(false); // We do not care about non-witness transactions for other than mempool cleanup.
}
bool isFoundTx = TransactionCache.Contains(tx); // If we have in cache, update height.
if (isFoundTx)
{
SmartTransaction foundTx = TransactionCache.FirstOrDefault(x => x == tx);
if (foundTx != default(SmartTransaction)) // Must check again, because it's a concurrent collection!
{
foundTx.SetHeight(tx.Height, tx.BlockHash, tx.BlockIndex);
walletRelevant = true;
justUpdate = true; // No need to check for double spend, we already processed this transaction, just update it.
}
}
}
else if (!tx.Transaction.PossiblyP2WPKHInvolved())
{
return(false); // We do not care about non-witness transactions for other than mempool cleanup.
}
if (!justUpdate && !tx.Transaction.IsCoinBase) // Transactions we already have and processed would be "double spends" but they shouldn't.
{
var doubleSpends = new List <SmartCoin>();
foreach (SmartCoin coin in Coins)
{
var spent = false;
foreach (TxoRef spentOutput in coin.SpentOutputs)
{
foreach (TxIn txIn in tx.Transaction.Inputs)
{
if (spentOutput.TransactionId == txIn.PrevOut.Hash && spentOutput.Index == txIn.PrevOut.N) // Do not do (spentOutput == txIn.PrevOut), it's faster this way, because it won't check for null.
{
doubleSpends.Add(coin);
spent = true;
walletRelevant = true;
break;
}
}
if (spent)
{
break;
}
}
}
if (doubleSpends.Any())
{
if (tx.Height == Height.Mempool)
{
// if the received transaction is spending at least one input already
// spent by a previous unconfirmed transaction signaling RBF then it is not a double
// spanding transaction but a replacement transaction.
if (doubleSpends.Any(x => x.IsReplaceable))
{
// remove double spent coins (if other coin spends it, remove that too and so on)
// will add later if they came to our keys
foreach (SmartCoin doubleSpentCoin in doubleSpends.Where(x => !x.Confirmed))
{
Coins.TryRemove(doubleSpentCoin);
}
tx.SetReplacement();
walletRelevant = true;
}
else
{
return(false);
}
}
else // new confirmation always enjoys priority
{
// remove double spent coins recursively (if other coin spends it, remove that too and so on), will add later if they came to our keys
foreach (SmartCoin doubleSpentCoin in doubleSpends)
{
Coins.TryRemove(doubleSpentCoin);
}
walletRelevant = true;
}
}
}
var isLikelyCoinJoinOutput = false;
bool hasEqualOutputs = tx.Transaction.GetIndistinguishableOutputs(includeSingle: false).FirstOrDefault() != default;
if (hasEqualOutputs)
{
var receiveKeys = KeyManager.GetKeys(x => tx.Transaction.Outputs.Any(y => y.ScriptPubKey == x.P2wpkhScript));
bool allReceivedInternal = receiveKeys.All(x => x.IsInternal);
if (allReceivedInternal)
{
// It is likely a coinjoin if the diff between receive and sent amount is small and have at least 2 equal outputs.
Money spentAmount = Coins.Where(x => tx.Transaction.Inputs.Any(y => y.PrevOut.Hash == x.TransactionId && y.PrevOut.N == x.Index)).Sum(x => x.Amount);
Money receivedAmount = tx.Transaction.Outputs.Where(x => receiveKeys.Any(y => y.P2wpkhScript == x.ScriptPubKey)).Sum(x => x.Value);
bool receivedAlmostAsMuchAsSpent = spentAmount.Almost(receivedAmount, Money.Coins(0.005m));
if (receivedAlmostAsMuchAsSpent)
{
isLikelyCoinJoinOutput = true;
}
}
}
List <SmartCoin> spentOwnCoins = null;
for (var i = 0U; i < tx.Transaction.Outputs.Count; i++)
{
// If transaction received to any of the wallet keys:
var output = tx.Transaction.Outputs[i];
HdPubKey foundKey = KeyManager.GetKeyForScriptPubKey(output.ScriptPubKey);
if (foundKey != default)
{
walletRelevant = true;
if (output.Value <= DustThreshold)
{
continue;
}
foundKey.SetKeyState(KeyState.Used, KeyManager);
spentOwnCoins = spentOwnCoins ?? Coins.Where(x => tx.Transaction.Inputs.Any(y => y.PrevOut.Hash == x.TransactionId && y.PrevOut.N == x.Index)).ToList();
var anonset = tx.Transaction.GetAnonymitySet(i);
if (spentOwnCoins.Count != 0)
{
anonset += spentOwnCoins.Min(x => x.AnonymitySet) - 1; // Minus 1, because do not count own.
}
SmartCoin newCoin = new SmartCoin(txId, i, output.ScriptPubKey, output.Value, tx.Transaction.Inputs.ToTxoRefs().ToArray(), tx.Height, tx.IsRBF, anonset, isLikelyCoinJoinOutput, foundKey.Label, spenderTransactionId: null, false, pubKey: foundKey); // Do not inherit locked status from key, that's different.
// If we did not have it.
if (Coins.TryAdd(newCoin))
{
TransactionCache.TryAdd(tx);
CoinReceived?.Invoke(this, newCoin);
// Make sure there's always 21 clean keys generated and indexed.
KeyManager.AssertCleanKeysIndexed(isInternal: foundKey.IsInternal);
if (foundKey.IsInternal)
{
// Make sure there's always 14 internal locked keys generated and indexed.
KeyManager.AssertLockedInternalKeysIndexed(14);
}
}
else // If we had this coin already.
{
if (newCoin.Height != Height.Mempool) // Update the height of this old coin we already had.
{
SmartCoin oldCoin = Coins.FirstOrDefault(x => x.TransactionId == txId && x.Index == i);
if (oldCoin != null) // Just to be sure, it is a concurrent collection.
{
oldCoin.Height = newCoin.Height;
}
}
}
}
}
// If spends any of our coin
for (var i = 0; i < tx.Transaction.Inputs.Count; i++)
{
var input = tx.Transaction.Inputs[i];
var foundCoin = Coins.FirstOrDefault(x => x.TransactionId == input.PrevOut.Hash && x.Index == input.PrevOut.N);
if (foundCoin != null)
{
walletRelevant = true;
var alreadyKnown = foundCoin.SpenderTransactionId == txId;
foundCoin.SpenderTransactionId = txId;
TransactionCache.TryAdd(tx);
if (!alreadyKnown)
{
CoinSpent?.Invoke(this, foundCoin);
}
if (tx.Confirmed)
{
SpenderConfirmed?.Invoke(this, foundCoin);
}
}
}
return(walletRelevant);
}
