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fix: avoid stack overflow in traverse

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This commit is contained in:
Barend Gehrels
2025-08-01 18:48:59 +02:00
parent 69df6f89ed
commit 0a8c111d57
1 changed files with 63 additions and 47 deletions
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110
include/boost/geometry/algorithms/detail/overlay/graph/traverse_graph.hpp
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@@ -178,73 +178,89 @@ struct traverse_graph
bool continue_traverse(Ring& ring,
signed_size_type component_id,
signed_size_type start_node_id,
signed_size_type current_node_id)
signed_size_type target_node_id)
{
auto const current_turn_indices = get_turn_indices_by_node_id(m_turns, m_clusters,
current_node_id, allow_closed);
signed_size_type current_node_id = target_node_id;
// Any valid node should always deliver at least one turn
BOOST_ASSERT(! current_turn_indices.empty());
std::size_t iteration_count = 0;
auto const next_target_nodes = get_target_nodes<target_operation>(m_turns, m_clusters,
current_turn_indices, component_id);
if (next_target_nodes.empty())
// Keep traversing until it finds the start (successful finish), or it is stuck,
// or it find an already visited node during traversal.
// The iteration count is a defensive check to prevent endless loops and not iterate
// more than times there are turns (this should not happen).
while (iteration_count < m_turns.size())
{
auto const current_turn_indices = get_turn_indices_by_node_id(m_turns, m_clusters,
current_node_id, allow_closed);
// Any valid node should always deliver at least one turn
BOOST_ASSERT(! current_turn_indices.empty());
auto const next_target_nodes = get_target_nodes<target_operation>(m_turns, m_clusters,
current_turn_indices, component_id);
if (next_target_nodes.empty())
{
#if defined(BOOST_GEOMETRY_DEBUG_TRAVERSE_GRAPH)
std::cout << "Stuck, start: " << start_node_id
<< " stuck: " << current_node_id
<< " (no targets) " << std::endl;
std::cout << "Stuck, start: " << start_node_id
<< " stuck: " << current_node_id
<< " (no targets) " << std::endl;
#endif
return false;
}
return false;
}
auto const tois = get_tois<target_operation>(m_turns, m_clusters,
current_node_id, next_target_nodes);
auto const tois = get_tois<target_operation>(m_turns, m_clusters,
current_node_id, next_target_nodes);
if (tois.empty())
{
return false;
}
if (tois.empty())
{
return false;
}
auto const& turn_point = m_turns[*current_turn_indices.begin()].point;
auto const& turn_point = m_turns[*current_turn_indices.begin()].point;
auto toi = *tois.begin();
auto toi = *tois.begin();
if (tois.size() > 1)
{
// Select the best target edge, using the last point of the ring and the turn point
// for side calculations (if any).
toi = m_edge_selector.select_target_edge(tois, ring.back(), turn_point);
}
if (tois.size() > 1)
{
// Select the best target edge, using the last point of the ring and the turn point
// for side calculations (if any).
toi = m_edge_selector.select_target_edge(tois, ring.back(), turn_point);
}
if (m_visited_tois.count(toi) > 0 || m_finished_tois.count(toi) > 0)
{
if (m_visited_tois.count(toi) > 0 || m_finished_tois.count(toi) > 0)
{
#if defined(BOOST_GEOMETRY_DEBUG_TRAVERSE_GRAPH)
std::cout << "ALREADY visited, turn " << toi
<< " in {" << current_node_id
<< " -> size " << next_target_nodes.size() << "}" << std::endl;
std::cout << "ALREADY visited, turn " << toi
<< " in {" << current_node_id
<< " -> size " << next_target_nodes.size() << "}" << std::endl;
#endif
return false;
}
return false;
}
detail::overlay::append_no_collinear(ring, turn_point, m_strategy);
detail::overlay::append_no_collinear(ring, turn_point, m_strategy);
set_visited(toi);
use_vertices(ring, toi);
set_visited(toi);
use_vertices(ring, toi);
auto const& selected_op = m_turns[toi.turn_index].operations[toi.operation_index];
auto const next_target_node_id = get_node_id(m_turns,
selected_op.enriched.travels_to_ip_index);
if (next_target_node_id == start_node_id)
{
auto const& selected_op = m_turns[toi.turn_index].operations[toi.operation_index];
auto const next_target_node_id = get_node_id(m_turns,
selected_op.enriched.travels_to_ip_index);
if (next_target_node_id == start_node_id)
{
#if defined(BOOST_GEOMETRY_DEBUG_TRAVERSE_GRAPH)
std::cout << "Finished at: " << next_target_node_id << std::endl;
std::cout << "Finished at: " << next_target_node_id << std::endl;
#endif
return true;
}
return true;
}
return continue_traverse(ring, component_id, start_node_id, next_target_node_id);
current_node_id = next_target_node_id;
++iteration_count;
}
#if defined(BOOST_GEOMETRY_DEBUG_TRAVERSE_GRAPH)
std::cout << "Cancelled at: " << iteration_count << std::endl;
#endif
return false;
}
template <typename Rings>