inline bool StallAtNode(const DataFacadeT &facade,
const NodeID node,
const EdgeWeight weight,
QueryHeap &query_heap) const
{
for (auto edge : facade.GetAdjacentEdgeRange(node))
{
const auto &data = facade.GetEdgeData(edge);
const bool reverse_flag = ((!forward_direction) ? data.forward : data.backward);
if (reverse_flag)
{
const NodeID to = facade.GetTarget(edge);
const int edge_weight = data.weight;
BOOST_ASSERT_MSG(edge_weight > 0, "edge_weight invalid");
if (query_heap.WasInserted(to))
{
if (query_heap.GetKey(to) + edge_weight < weight)
{
return true;
}
}
}
}
return false;
}
inline void RelaxOutgoingEdges(const DataFacadeT &facade,
const NodeID node,
const EdgeWeight weight,
QueryHeap &query_heap) const
{
for (auto edge : facade.GetAdjacentEdgeRange(node))
{
const auto &data = facade.GetEdgeData(edge);
const bool direction_flag = (forward_direction ? data.forward : data.backward);
if (direction_flag)
{
const NodeID to = facade.GetTarget(edge);
const int edge_weight = data.weight;
BOOST_ASSERT_MSG(edge_weight > 0, "edge_weight invalid");
const int to_weight = weight + edge_weight;
// New Node discovered -> Add to Heap + Node Info Storage
if (!query_heap.WasInserted(to))
{
query_heap.Insert(to, to_weight, node);
}
// Found a shorter Path -> Update weight
else if (to_weight < query_heap.GetKey(to))
{
// new parent
query_heap.GetData(to).parent = node;
query_heap.DecreaseKey(to, to_weight);
}
}
}
}
void BackwardRoutingStep(const unsigned target_id,
QueryHeap &query_heap,
SearchSpaceWithBuckets &search_space_with_buckets) const
{
const NodeID node = query_heap.DeleteMin();
const int target_distance = query_heap.GetKey(node);
// store settled nodes in search space bucket
search_space_with_buckets[node].emplace_back(target_id, target_distance);
if (StallAtNode<false>(node, target_distance, query_heap))
{
return;
}
RelaxOutgoingEdges<false>(node, target_distance, query_heap);
}
void ForwardRoutingStep(const DataFacadeT &facade,
const unsigned row_idx,
const unsigned number_of_targets,
QueryHeap &query_heap,
const SearchSpaceWithBuckets &search_space_with_buckets,
std::vector<EdgeWeight> &result_table) const
{
const NodeID node = query_heap.DeleteMin();
const int source_weight = query_heap.GetKey(node);
// check if each encountered node has an entry
const auto bucket_iterator = search_space_with_buckets.find(node);
// iterate bucket if there exists one
if (bucket_iterator != search_space_with_buckets.end())
{
const std::vector<NodeBucket> &bucket_list = bucket_iterator->second;
for (const NodeBucket ¤t_bucket : bucket_list)
{
// get target id from bucket entry
const unsigned column_idx = current_bucket.target_id;
const int target_weight = current_bucket.weight;
auto ¤t_weight = result_table[row_idx * number_of_targets + column_idx];
// check if new weight is better
const EdgeWeight new_weight = source_weight + target_weight;
if (new_weight < 0)
{
const EdgeWeight loop_weight = super::GetLoopWeight(facade, node);
const int new_weight_with_loop = new_weight + loop_weight;
if (loop_weight != INVALID_EDGE_WEIGHT && new_weight_with_loop >= 0)
{
current_weight = std::min(current_weight, new_weight_with_loop);
}
}
else if (new_weight < current_weight)
{
result_table[row_idx * number_of_targets + column_idx] = new_weight;
}
}
}
if (StallAtNode<true>(facade, node, source_weight, query_heap))
{
return;
}
RelaxOutgoingEdges<true>(facade, node, source_weight, query_heap);
}
void BackwardRoutingStep(const DataFacadeT &facade,
const unsigned column_idx,
QueryHeap &query_heap,
SearchSpaceWithBuckets &search_space_with_buckets) const
{
const NodeID node = query_heap.DeleteMin();
const int target_weight = query_heap.GetKey(node);
// store settled nodes in search space bucket
search_space_with_buckets[node].emplace_back(column_idx, target_weight);
if (StallAtNode<false>(facade, node, target_weight, query_heap))
{
return;
}
RelaxOutgoingEdges<false>(facade, node, target_weight, query_heap);
}
void ForwardRoutingStep(const unsigned source_id,
const unsigned number_of_locations,
QueryHeap &query_heap,
const SearchSpaceWithBuckets &search_space_with_buckets,
std::shared_ptr<std::vector<EdgeWeight>> result_table) const
{
const NodeID node = query_heap.DeleteMin();
const int source_distance = query_heap.GetKey(node);
// check if each encountered node has an entry
const auto bucket_iterator = search_space_with_buckets.find(node);
// iterate bucket if there exists one
if (bucket_iterator != search_space_with_buckets.end())
{
const std::vector<NodeBucket> &bucket_list = bucket_iterator->second;
for (const NodeBucket ¤t_bucket : bucket_list)
{
// get target id from bucket entry
const unsigned target_id = current_bucket.target_id;
const int target_distance = current_bucket.distance;
const EdgeWeight current_distance =
(*result_table)[source_id * number_of_locations + target_id];
// check if new distance is better
const EdgeWeight new_distance = source_distance + target_distance;
if (new_distance >= 0 && new_distance < current_distance)
{
(*result_table)[source_id * number_of_locations + target_id] =
(source_distance + target_distance);
}
}
}
if (StallAtNode<true>(node, source_distance, query_heap))
{
return;
}
RelaxOutgoingEdges<true>(node, source_distance, query_heap);
}
