Function copyDatabaseBranch

Rapfi/database/dbutils.cpp:62–101

}

void copyDatabaseBranch(DBStorage &dbSrc,
                        DBStorage &dbDst,
                        Board     &board,
                        Rule       rule,
                        int        threadId,
                        int        ply)
{
    // Find all potential children of this board position
    std::vector<Pos> toCopyPos;
    toCopyPos.reserve(board.movesLeft());
    FOR_EVERY_EMPTY_POS(&board, pos)
    {
        toCopyPos.push_back(pos);
    }

    // Do permutation based on thread id
    if (threadId > 0) {
        for (size_t i = 0; i < toCopyPos.size(); i += (threadId + 1) / 2) {
            size_t swapIndex = (i * (threadId + 1)) % toCopyPos.size();
            std::swap(toCopyPos[i], toCopyPos[swapIndex]);
        }
    }

    // Copy all children
    DBKey    key;
    DBRecord record, tempRecord;
    for (auto pos : toCopyPos) {
        board.move(rule, pos);

        key = constructDBKey(board, rule);

        if (dbSrc.get(key, record, RECORD_MASK_ALL)
            && !dbDst.get(key, tempRecord, RECORD_MASK_NONE)) {
            copyDatabaseBranch(dbSrc, dbDst, board, rule, threadId, ply + 1);
            dbDst.set(key, record, RECORD_MASK_ALL);
        }

        board.undo(rule);
    }
}

}  // namespace