Repository: bitcoin/bitcoin
File: src/txorphanage.cpp (C++)

Code before:
// Copyright (c) 2021-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <txorphanage.h>

#include <consensus/validation.h>
#include <logging.h>
#include <policy/policy.h>
#include <primitives/transaction.h>

#include <cassert>

/** Expiration time for orphan transactions in seconds */
static constexpr int64_t ORPHAN_TX_EXPIRE_TIME = 20 * 60;
/** Minimum time between orphan transactions expire time checks in seconds */
static constexpr int64_t ORPHAN_TX_EXPIRE_INTERVAL = 5 * 60;


bool TxOrphanage::AddTx(const CTransactionRef& tx, NodeId peer)
{
    LOCK(m_mutex);

    const Txid& hash = tx->GetHash();
    const Wtxid& wtxid = tx->GetWitnessHash();
    if (m_orphans.count(hash))
        return false;

    // Ignore big transactions, to avoid a
    // send-big-orphans memory exhaustion attack. If a peer has a legitimate
    // large transaction with a missing parent then we assume
    // it will rebroadcast it later, after the parent transaction(s)
    // have been mined or received.
    // 100 orphans, each of which is at most 100,000 bytes big is
    // at most 10 megabytes of orphans and somewhat more byprev index (in the worst case):
    unsigned int sz = GetTransactionWeight(*tx);
    if (sz > MAX_STANDARD_TX_WEIGHT)
    {
        LogPrint(BCLog::TXPACKAGES, "ignoring large orphan tx (size: %u, txid: %s, wtxid: %s)\n", sz, hash.ToString(), wtxid.ToString());
        return false;
    }

    auto ret = m_orphans.emplace(hash, OrphanTx{tx, peer, GetTime() + ORPHAN_TX_EXPIRE_TIME, m_orphan_list.size()});
    assert(ret.second);
    m_orphan_list.push_back(ret.first);
    // Allow for lookups in the orphan pool by wtxid, as well as txid
    m_wtxid_to_orphan_it.emplace(tx->GetWitnessHash(), ret.first);
    for (const CTxIn& txin : tx->vin) {
        m_outpoint_to_orphan_it[txin.prevout].insert(ret.first);
    }


Review comment (suggestion):
c++-20 nit:
```suggestion
    if (m_orphans.contains(wtxid))
```

Code after:
// Copyright (c) 2021-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <txorphanage.h>

#include <consensus/validation.h>
#include <logging.h>
#include <policy/policy.h>
#include <primitives/transaction.h>

#include <cassert>

/** Expiration time for orphan transactions in seconds */
static constexpr int64_t ORPHAN_TX_EXPIRE_TIME = 20 * 60;
/** Minimum time between orphan transactions expire time checks in seconds */
static constexpr int64_t ORPHAN_TX_EXPIRE_INTERVAL = 5 * 60;


bool TxOrphanage::AddTx(const CTransactionRef& tx, NodeId peer)
{
    LOCK(m_mutex);

    const Txid& hash = tx->GetHash();
    const Wtxid& wtxid = tx->GetWitnessHash();
    if (m_orphans.count(wtxid))
        return false;

    // Ignore big transactions, to avoid a
    // send-big-orphans memory exhaustion attack. If a peer has a legitimate
    // large transaction with a missing parent then we assume
    // it will rebroadcast it later, after the parent transaction(s)
    // have been mined or received.
    // 100 orphans, each of which is at most 100,000 bytes big is
    // at most 10 megabytes of orphans and somewhat more byprev index (in the worst case):
    unsigned int sz = GetTransactionWeight(*tx);
    if (sz > MAX_STANDARD_TX_WEIGHT)
    {
        LogPrint(BCLog::TXPACKAGES, "ignoring large orphan tx (size: %u, txid: %s, wtxid: %s)\n", sz, hash.ToString(), wtxid.ToString());
        return false;
    }

    auto ret = m_orphans.emplace(wtxid, OrphanTx{tx, peer, GetTime() + ORPHAN_TX_EXPIRE_TIME, m_orphan_list.size()});
    assert(ret.second);
    m_orphan_list.push_back(ret.first);
    for (const CTxIn& txin : tx->vin) {
        m_outpoint_to_orphan_it[txin.prevout].insert(ret.first);
    }

    LogPrint(BCLog::TXPACKAGES, "stored orphan tx %s (wtxid=%s), weight: %u (mapsz %u outsz %u)\n", hash.ToString(), wtxid.ToString(), sz,
             m_orphans.size(), m_outpoint_to_orphan_it.size());