Method UpdateTransactionsFromBlock

src/txmempool.cpp:181–234

}

void CTxMemPool::UpdateTransactionsFromBlock(const std::vector<uint256> &vHashesToUpdate, uint64_t ancestor_size_limit, uint64_t ancestor_count_limit)
{
    AssertLockHeld(cs);
    // For each entry in vHashesToUpdate, store the set of in-mempool, but not
    // in-vHashesToUpdate transactions, so that we don't have to recalculate
    // descendants when we come across a previously seen entry.
    cacheMap mapMemPoolDescendantsToUpdate;

    // Use a set for lookups into vHashesToUpdate (these entries are already
    // accounted for in the state of their ancestors)
    std::set<uint256> setAlreadyIncluded(vHashesToUpdate.begin(), vHashesToUpdate.end());

    std::set<uint256> descendants_to_remove;

    // Iterate in reverse, so that whenever we are looking at a transaction
    // we are sure that all in-mempool descendants have already been processed.
    // This maximizes the benefit of the descendant cache and guarantees that
    // CTxMemPool::m_children will be updated, an assumption made in
    // UpdateForDescendants.
    for (const uint256 &hash : reverse_iterate(vHashesToUpdate)) {
        // calculate children from mapNextTx
        txiter it = mapTx.find(hash);
        if (it == mapTx.end()) {
            continue;
        }
        auto iter = mapNextTx.lower_bound(COutPoint(hash, 0));
        // First calculate the children, and update CTxMemPool::m_children to
        // include them, and update their CTxMemPoolEntry::m_parents to include this tx.
        // we cache the in-mempool children to avoid duplicate updates
        {
            WITH_FRESH_EPOCH(m_epoch);
            for (; iter != mapNextTx.end() && iter->first->hash == hash; ++iter) {
                const uint256 &childHash = iter->second->GetHash();
                txiter childIter = mapTx.find(childHash);
                assert(childIter != mapTx.end());
                // We can skip updating entries we've encountered before or that
                // are in the block (which are already accounted for).
                if (!visited(childIter) && !setAlreadyIncluded.count(childHash)) {
                    UpdateChild(it, childIter, true);
                    UpdateParent(childIter, it, true);
                }
            }
        } // release epoch guard for UpdateForDescendants
        UpdateForDescendants(it, mapMemPoolDescendantsToUpdate, setAlreadyIncluded, descendants_to_remove, ancestor_size_limit, ancestor_count_limit);
    }

    for (const auto& txid : descendants_to_remove) {
        // This txid may have been removed already in a prior call to removeRecursive.
        // Therefore we ensure it is not yet removed already.
        if (const std::optional<txiter> txiter = GetIter(txid)) {
            removeRecursive((*txiter)->GetTx(), MemPoolRemovalReason::SIZELIMIT);
        }
    }
}

bool CTxMemPool::CalculateAncestorsAndCheckLimits(size_t entry_size,
                                                  size_t entry_count,