Function buildTreeOffset

src/Processors/QueryPlan/QueryPlan.cpp:541–583

};

static void buildTreeOffset(
    const std::deque<ExplainPlan::Frame> & frames,
    const ExplainPlan::Frame & current,
    IQueryPlanStep::FormatSettings & settings_format,
    const std::string & parent_tree_prefix = "",
    bool is_last_child_plan = true)
{
    if (frames.empty())
        throw Exception(ErrorCodes::LOGICAL_ERROR, "Frames stack for building tree offset cannot be empty");

    settings_format.header_prefix = parent_tree_prefix;
    settings_format.detail_prefix = parent_tree_prefix;

    bool has_children = !current.node->children.empty() || !current.node->step->getChildPlans().empty();

    if (frames.size() == 1)
    {
        if (!parent_tree_prefix.empty())
        {
            settings_format.header_prefix += is_last_child_plan ? "└──" : "├──";
            settings_format.detail_prefix += is_last_child_plan ? "   " : "│  ";
        }
        settings_format.detail_prefix += has_children ? "│  " : "   ";
        return;
    }

    if (!parent_tree_prefix.empty())
    {
        settings_format.header_prefix += is_last_child_plan ? "   " : "│  ";
        settings_format.detail_prefix += is_last_child_plan ? "   " : "│  ";
    }

    for (size_t i = 0; i < frames.size() - 2; ++i)
    {
        const auto & segment = frames[i + 1].is_last_child ? "   " : "│  ";
        settings_format.header_prefix += segment;
        settings_format.detail_prefix += segment;
    }

    settings_format.header_prefix += current.is_last_child ? "└──" : "├──";
    settings_format.detail_prefix += current.is_last_child ? "   " : "│  ";
    settings_format.detail_prefix += has_children ? "│  " : "   ";
}

static void buildIndentOffset(const std::deque<ExplainPlan::Frame> & frames, IQueryPlanStep::FormatSettings & settings_format, size_t indent_offset)
{