Ejemplo n.º 1
0
        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);
        }