Method ValidateAndProcessSingleHeader

src/headerssync.cpp:177–213

}

bool HeadersSyncState::ValidateAndProcessSingleHeader(const CBlockHeader& current)
{
    Assume(m_download_state == State::PRESYNC);
    if (m_download_state != State::PRESYNC) return false;

    int next_height = m_current_height + 1;

    // Verify that the difficulty isn't growing too fast; an adversary with
    // limited hashing capability has a greater chance of producing a high
    // work chain if they compress the work into as few blocks as possible,
    // so don't let anyone give a chain that would violate the difficulty
    // adjustment maximum.
    if (!PermittedDifficultyTransition(m_consensus_params, next_height,
                m_last_header_received.nBits, current.nBits)) {
        LogDebug(BCLog::NET, "Initial headers sync aborted with peer=%d: invalid difficulty transition at height=%i (presync phase)\n", m_id, next_height);
        return false;
    }

    if (next_height % m_params.commitment_period == m_commit_offset) {
        // Add a commitment.
        m_header_commitments.push_back(m_hasher(current.GetHash()) & 1);
        if (m_header_commitments.size() > m_max_commitments) {
            // The peer's chain is too long; give up.
            // It's possible the chain grew since we started the sync; so
            // potentially we could succeed in syncing the peer's chain if we
            // try again later.
            LogDebug(BCLog::NET, "Initial headers sync aborted with peer=%d: exceeded max commitments at height=%i (presync phase)\n", m_id, next_height);
            return false;
        }
    }

    m_current_chain_work += GetBlockProof(current);
    m_last_header_received = current;
    m_current_height = next_height;

    return true;
}

bool HeadersSyncState::ValidateAndStoreRedownloadedHeader(const CBlockHeader& header)
{