Method TryDownloadingHistoricalBlocks

src/net_processing.cpp:1456–1483

}

void PeerManagerImpl::TryDownloadingHistoricalBlocks(const Peer& peer, unsigned int count, std::vector<const CBlockIndex*>& vBlocks, const CBlockIndex *from_tip, const CBlockIndex* target_block)
{
    Assert(from_tip);
    Assert(target_block);

    if (vBlocks.size() >= count) {
        return;
    }

    vBlocks.reserve(count);
    CNodeState *state = Assert(State(peer.m_id));

    if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->GetAncestor(target_block->nHeight) != target_block) {
        // This peer can't provide us the complete series of blocks leading up to the
        // assumeutxo snapshot base.
        //
        // Presumably this peer's chain has less work than our ActiveChain()'s tip, or else we
        // will eventually crash when we try to reorg to it. Let other logic
        // deal with whether we disconnect this peer.
        //
        // TODO at some point in the future, we might choose to request what blocks
        // this peer does have from the historical chain, despite it not having a
        // complete history beneath the snapshot base.
        return;
    }

    FindNextBlocks(vBlocks, peer, state, from_tip, count, std::min<int>(from_tip->nHeight + BLOCK_DOWNLOAD_WINDOW, target_block->nHeight));
}

void PeerManagerImpl::FindNextBlocks(std::vector<const CBlockIndex*>& vBlocks, const Peer& peer, CNodeState *state, const CBlockIndex *pindexWalk, unsigned int count, int nWindowEnd, const CChain* activeChain, NodeId* nodeStaller)
{