Initial Vexta Core v0.1.0 release

src/node/transaction.cpp

@@ -0,0 +1,139 @@
+// Copyright (c) 2010 Satoshi Nakamoto
+// Copyright (c) 2009-2020 The DigiByte Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <consensus/validation.h>
+#include <net.h>
+#include <net_processing.h>
+#include <node/context.h>
+#include <validation.h>
+#include <validationinterface.h>
+#include <node/transaction.h>
+
+#include <future>
+
+static TransactionError HandleATMPError(const TxValidationState& state, std::string& err_string_out)
+{
+    err_string_out = state.ToString();
+    if (state.IsInvalid()) {
+        if (state.GetResult() == TxValidationResult::TX_MISSING_INPUTS) {
+            return TransactionError::MISSING_INPUTS;
+        }
+        return TransactionError::MEMPOOL_REJECTED;
+    } else {
+        return TransactionError::MEMPOOL_ERROR;
+    }
+}
+
+TransactionError BroadcastTransaction(NodeContext& node, const CTransactionRef tx, std::string& err_string, const CAmount& max_tx_fee, bool relay, bool wait_callback)
+{
+    // BroadcastTransaction can be called by either sendrawtransaction RPC or the wallet.
+    // chainman, mempool and peerman are initialized before the RPC server and wallet are started
+    // and reset after the RPC sever and wallet are stopped.
+    assert(node.chainman);
+    assert(node.mempool);
+    assert(node.peerman);
+
+    std::promise<void> promise;
+    uint256 txid = tx->GetHash();
+    uint256 wtxid = tx->GetWitnessHash();
+    bool callback_set = false;
+
+    {
+        LOCK(cs_main);
+
+        // If the transaction is already confirmed in the chain, don't do anything
+        // and return early.
+        CCoinsViewCache &view = node.chainman->ActiveChainstate().CoinsTip();
+        for (size_t o = 0; o < tx->vout.size(); o++) {
+            const Coin& existingCoin = view.AccessCoin(COutPoint(txid, o));
+            // IsSpent doesn't mean the coin is spent, it means the output doesn't exist.
+            // So if the output does exist, then this transaction exists in the chain.
+            if (!existingCoin.IsSpent()) return TransactionError::ALREADY_IN_CHAIN;
+        }
+
+        if (auto mempool_tx = node.mempool->get(txid); mempool_tx) {
+            // There's already a transaction in the mempool with this txid. Don't
+            // try to submit this transaction to the mempool (since it'll be
+            // rejected as a TX_CONFLICT), but do attempt to reannounce the mempool
+            // transaction if relay=true.
+            //
+            // The mempool transaction may have the same or different witness (and
+            // wtxid) as this transaction. Use the mempool's wtxid for reannouncement.
+            wtxid = mempool_tx->GetWitnessHash();
+        } else {
+            // Transaction is not already in the mempool.
+            if (max_tx_fee > 0) {
+                // First, call ATMP with test_accept and check the fee. If ATMP
+                // fails here, return error immediately.
+                const MempoolAcceptResult result = AcceptToMemoryPool(node.chainman->ActiveChainstate(), *node.mempool, tx, false, true);
+                if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) {
+                    return HandleATMPError(result.m_state, err_string);
+                } else if (result.m_base_fees.value() > max_tx_fee) {
+                    return TransactionError::MAX_FEE_EXCEEDED;
+                } else {
+                    // This doesnt really matter, as its just a test; but may as well be consistent
+                    AcceptToMemoryPool(node.chainman->ActiveChainstate(), *node.stempool, tx, false, true);
+                }
+            }
+            // Try to submit the transaction to the stempool only (if dandelion is enabled);
+            if (gArgs.GetBoolArg("-dandelion", DEFAULT_DANDELION)) {
+                const MempoolAcceptResult result = AcceptToMemoryPool(node.chainman->ActiveChainstate(), *node.stempool, tx, false, false);
+                if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) {
+                    return HandleATMPError(result.m_state, err_string);
+                }
+            } else {
+                const MempoolAcceptResult result = AcceptToMemoryPool(node.chainman->ActiveChainstate(), *node.mempool, tx, false, false);
+                if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) {
+                    return HandleATMPError(result.m_state, err_string);
+                }
+            }
+
+            // Transaction was accepted to the mempool.
+
+            if (relay) {
+                // the mempool tracks locally submitted transactions to make a
+                // best-effort of initial broadcast
+                node.mempool->AddUnbroadcastTx(txid);
+            }
+
+            if (wait_callback) {
+                // For transactions broadcast from outside the wallet, make sure
+                // that the wallet has been notified of the transaction before
+                // continuing.
+                //
+                // This prevents a race where a user might call sendrawtransaction
+                // with a transaction to/from their wallet, immediately call some
+                // wallet RPC, and get a stale result because callbacks have not
+                // yet been processed.
+                CallFunctionInValidationInterfaceQueue([&promise] {
+                    promise.set_value();
+                });
+                callback_set = true;
+            }
+        }
+    } // cs_main
+
+    if (callback_set) {
+        // Wait until Validation Interface clients have been notified of the
+        // transaction entering the mempool.
+        promise.get_future().wait();
+    }
+
+    if (relay) {
+        if (gArgs.GetBoolArg("-dandelion", DEFAULT_DANDELION)) {
+            auto current_time = GetTime<std::chrono::milliseconds>();
+            std::chrono::microseconds nEmbargo = DANDELION_EMBARGO_MINIMUM + PoissonNextSend(current_time, DANDELION_EMBARGO_AVG_ADD);
+            node.connman->insertDandelionEmbargo(txid, nEmbargo);
+            auto embargo_timeout = std::chrono::duration_cast<std::chrono::seconds>(nEmbargo - current_time).count();
+            LogPrint(BCLog::DANDELION, "dandeliontx %s embargoed for %d seconds\n", txid.ToString(), embargo_timeout);
+            CInv embargoTx(MSG_DANDELION_TX, txid);
+            node.connman->localDandelionDestinationPushInventory(embargoTx);
+            return TransactionError::OK;
+        }
+        node.peerman->RelayTransaction(txid, wtxid);
+    }
+
+    return TransactionError::OK;
+}