Open-Harbor/osrm-backend
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 3 Wiki Activity
279f8aabfb
osrm-backend/src/engine/routing_algorithms/alternative_path.cpp

771 lines
33 KiB
C++
Raw Blame History

#include "engine/routing_algorithms/alternative_path.hpp"
namespace osrm
{
namespace engine
{
namespace routing_algorithms
{
void AlternativeRouting::operator()(const std::shared_ptr<const datafacade::BaseDataFacade> facade,
const PhantomNodes &phantom_node_pair,
InternalRouteResult &raw_route_data)
{
std::vector<NodeID> alternative_path;
std::vector<NodeID> via_node_candidate_list;
std::vector<SearchSpaceEdge> forward_search_space;
std::vector<SearchSpaceEdge> reverse_search_space;
// Init queues, semi-expensive because access to TSS invokes a sys-call
engine_working_data.InitializeOrClearFirstThreadLocalStorage(facade->GetNumberOfNodes());
engine_working_data.InitializeOrClearSecondThreadLocalStorage(facade->GetNumberOfNodes());
engine_working_data.InitializeOrClearThirdThreadLocalStorage(facade->GetNumberOfNodes());
QueryHeap &forward_heap1 = *(engine_working_data.forward_heap_1);
QueryHeap &reverse_heap1 = *(engine_working_data.reverse_heap_1);
QueryHeap &forward_heap2 = *(engine_working_data.forward_heap_2);
QueryHeap &reverse_heap2 = *(engine_working_data.reverse_heap_2);
EdgeWeight upper_bound_to_shortest_path_weight = INVALID_EDGE_WEIGHT;
NodeID middle_node = SPECIAL_NODEID;
const EdgeWeight min_edge_offset =
std::min(phantom_node_pair.source_phantom.forward_segment_id.enabled
? -phantom_node_pair.source_phantom.GetForwardWeightPlusOffset()
: 0,
phantom_node_pair.source_phantom.reverse_segment_id.enabled
? -phantom_node_pair.source_phantom.GetReverseWeightPlusOffset()
: 0);
if (phantom_node_pair.source_phantom.forward_segment_id.enabled)
{
BOOST_ASSERT(phantom_node_pair.source_phantom.forward_segment_id.id != SPECIAL_SEGMENTID);
forward_heap1.Insert(phantom_node_pair.source_phantom.forward_segment_id.id,
-phantom_node_pair.source_phantom.GetForwardWeightPlusOffset(),
phantom_node_pair.source_phantom.forward_segment_id.id);
}
if (phantom_node_pair.source_phantom.reverse_segment_id.enabled)
{
BOOST_ASSERT(phantom_node_pair.source_phantom.reverse_segment_id.id != SPECIAL_SEGMENTID);
forward_heap1.Insert(phantom_node_pair.source_phantom.reverse_segment_id.id,
-phantom_node_pair.source_phantom.GetReverseWeightPlusOffset(),
phantom_node_pair.source_phantom.reverse_segment_id.id);
}
if (phantom_node_pair.target_phantom.forward_segment_id.enabled)
{
BOOST_ASSERT(phantom_node_pair.target_phantom.forward_segment_id.id != SPECIAL_SEGMENTID);
reverse_heap1.Insert(phantom_node_pair.target_phantom.forward_segment_id.id,
phantom_node_pair.target_phantom.GetForwardWeightPlusOffset(),
phantom_node_pair.target_phantom.forward_segment_id.id);
}
if (phantom_node_pair.target_phantom.reverse_segment_id.enabled)
{
BOOST_ASSERT(phantom_node_pair.target_phantom.reverse_segment_id.id != SPECIAL_SEGMENTID);
reverse_heap1.Insert(phantom_node_pair.target_phantom.reverse_segment_id.id,
phantom_node_pair.target_phantom.GetReverseWeightPlusOffset(),
phantom_node_pair.target_phantom.reverse_segment_id.id);
}
// search from s and t till new_min/(1+epsilon) > length_of_shortest_path
while (0 < (forward_heap1.Size() + reverse_heap1.Size()))
{
if (0 < forward_heap1.Size())
{
AlternativeRoutingStep<true>(facade,
forward_heap1,
reverse_heap1,
&middle_node,
&upper_bound_to_shortest_path_weight,
via_node_candidate_list,
forward_search_space,
min_edge_offset);
}
if (0 < reverse_heap1.Size())
{
AlternativeRoutingStep<false>(facade,
forward_heap1,
reverse_heap1,
&middle_node,
&upper_bound_to_shortest_path_weight,
via_node_candidate_list,
reverse_search_space,
min_edge_offset);
}
}
if (INVALID_EDGE_WEIGHT == upper_bound_to_shortest_path_weight)
{
return;
}
std::sort(begin(via_node_candidate_list), end(via_node_candidate_list));
auto unique_end = std::unique(begin(via_node_candidate_list), end(via_node_candidate_list));
via_node_candidate_list.resize(unique_end - begin(via_node_candidate_list));
std::vector<NodeID> packed_forward_path;
std::vector<NodeID> packed_reverse_path;
const bool path_is_a_loop =
upper_bound_to_shortest_path_weight !=
forward_heap1.GetKey(middle_node) + reverse_heap1.GetKey(middle_node);
if (path_is_a_loop)
{
// Self Loop
packed_forward_path.push_back(middle_node);
packed_forward_path.push_back(middle_node);
}
else
{
super::RetrievePackedPathFromSingleHeap(forward_heap1, middle_node, packed_forward_path);
super::RetrievePackedPathFromSingleHeap(reverse_heap1, middle_node, packed_reverse_path);
}
// this set is is used as an indicator if a node is on the shortest path
std::unordered_set<NodeID> nodes_in_path(packed_forward_path.size() +
packed_reverse_path.size());
nodes_in_path.insert(packed_forward_path.begin(), packed_forward_path.end());
nodes_in_path.insert(middle_node);
nodes_in_path.insert(packed_reverse_path.begin(), packed_reverse_path.end());
std::unordered_map<NodeID, int> approximated_forward_sharing;
std::unordered_map<NodeID, int> approximated_reverse_sharing;
// sweep over search space, compute forward sharing for each current edge (u,v)
for (const SearchSpaceEdge &current_edge : forward_search_space)
{
const NodeID u = current_edge.first;
const NodeID v = current_edge.second;
if (nodes_in_path.find(v) != nodes_in_path.end())
{
// current_edge is on shortest path => sharing(v):=queue.GetKey(v);
approximated_forward_sharing.emplace(v, forward_heap1.GetKey(v));
}
else
{
// current edge is not on shortest path. Check if we know a value for the other
// endpoint
const auto sharing_of_u_iterator = approximated_forward_sharing.find(u);
if (sharing_of_u_iterator != approximated_forward_sharing.end())
{
approximated_forward_sharing.emplace(v, sharing_of_u_iterator->second);
}
}
}
// sweep over search space, compute backward sharing
for (const SearchSpaceEdge &current_edge : reverse_search_space)
{
const NodeID u = current_edge.first;
const NodeID v = current_edge.second;
if (nodes_in_path.find(v) != nodes_in_path.end())
{
// current_edge is on shortest path => sharing(u):=queue.GetKey(u);
approximated_reverse_sharing.emplace(v, reverse_heap1.GetKey(v));
}
else
{
// current edge is not on shortest path. Check if we know a value for the other
// endpoint
const auto sharing_of_u_iterator = approximated_reverse_sharing.find(u);
if (sharing_of_u_iterator != approximated_reverse_sharing.end())
{
approximated_reverse_sharing.emplace(v, sharing_of_u_iterator->second);
}
}
}
// util::Log(logDEBUG) << "fwd_search_space size: " <<
// forward_search_space.size() << ", marked " << approximated_forward_sharing.size() << "
// nodes";
// util::Log(logDEBUG) << "rev_search_space size: " <<
// reverse_search_space.size() << ", marked " << approximated_reverse_sharing.size() << "
// nodes";
std::vector<NodeID> preselected_node_list;
for (const NodeID node : via_node_candidate_list)
{
if (node == middle_node)
continue;
const auto fwd_iterator = approximated_forward_sharing.find(node);
const int fwd_sharing =
(fwd_iterator != approximated_forward_sharing.end()) ? fwd_iterator->second : 0;
const auto rev_iterator = approximated_reverse_sharing.find(node);
const int rev_sharing =
(rev_iterator != approximated_reverse_sharing.end()) ? rev_iterator->second : 0;
const int approximated_sharing = fwd_sharing + rev_sharing;
const int approximated_length = forward_heap1.GetKey(node) + reverse_heap1.GetKey(node);
const bool length_passes =
(approximated_length < upper_bound_to_shortest_path_weight * (1 + VIAPATH_EPSILON));
const bool sharing_passes =
(approximated_sharing <= upper_bound_to_shortest_path_weight * VIAPATH_GAMMA);
const bool stretch_passes =
(approximated_length - approximated_sharing) <
((1. + VIAPATH_ALPHA) * (upper_bound_to_shortest_path_weight - approximated_sharing));
if (length_passes && sharing_passes && stretch_passes)
{
preselected_node_list.emplace_back(node);
}
}
std::vector<NodeID> &packed_shortest_path = packed_forward_path;
if (!path_is_a_loop)
{
std::reverse(packed_shortest_path.begin(), packed_shortest_path.end());
packed_shortest_path.emplace_back(middle_node);
packed_shortest_path.insert(
packed_shortest_path.end(), packed_reverse_path.begin(), packed_reverse_path.end());
}
std::vector<RankedCandidateNode> ranked_candidates_list;
// prioritizing via nodes for deep inspection
for (const NodeID node : preselected_node_list)
{
int length_of_via_path = 0, sharing_of_via_path = 0;
ComputeLengthAndSharingOfViaPath(facade,
node,
&length_of_via_path,
&sharing_of_via_path,
packed_shortest_path,
min_edge_offset);
const int maximum_allowed_sharing =
static_cast<int>(upper_bound_to_shortest_path_weight * VIAPATH_GAMMA);
if (sharing_of_via_path <= maximum_allowed_sharing &&
length_of_via_path <= upper_bound_to_shortest_path_weight * (1 + VIAPATH_EPSILON))
{
ranked_candidates_list.emplace_back(node, length_of_via_path, sharing_of_via_path);
}
}
std::sort(ranked_candidates_list.begin(), ranked_candidates_list.end());
NodeID selected_via_node = SPECIAL_NODEID;
int length_of_via_path = INVALID_EDGE_WEIGHT;
NodeID s_v_middle = SPECIAL_NODEID, v_t_middle = SPECIAL_NODEID;
for (const RankedCandidateNode &candidate : ranked_candidates_list)
{
if (ViaNodeCandidatePassesTTest(facade,
forward_heap1,
reverse_heap1,
forward_heap2,
reverse_heap2,
candidate,
upper_bound_to_shortest_path_weight,
&length_of_via_path,
&s_v_middle,
&v_t_middle,
min_edge_offset))
{
// select first admissable
selected_via_node = candidate.node;
break;
}
}
// Unpack shortest path and alternative, if they exist
if (INVALID_EDGE_WEIGHT != upper_bound_to_shortest_path_weight)
{
BOOST_ASSERT(!packed_shortest_path.empty());
raw_route_data.unpacked_path_segments.resize(1);
raw_route_data.source_traversed_in_reverse.push_back(
(packed_shortest_path.front() !=
phantom_node_pair.source_phantom.forward_segment_id.id));
raw_route_data.target_traversed_in_reverse.push_back((
packed_shortest_path.back() != phantom_node_pair.target_phantom.forward_segment_id.id));
super::UnpackPath(facade,
// -- packed input
packed_shortest_path.begin(),
packed_shortest_path.end(),
// -- start of route
phantom_node_pair,
// -- unpacked output
raw_route_data.unpacked_path_segments.front());
raw_route_data.shortest_path_length = upper_bound_to_shortest_path_weight;
}
if (SPECIAL_NODEID != selected_via_node)
{
std::vector<NodeID> packed_alternate_path;
// retrieve alternate path
RetrievePackedAlternatePath(forward_heap1,
reverse_heap1,
forward_heap2,
reverse_heap2,
s_v_middle,
v_t_middle,
packed_alternate_path);
raw_route_data.alt_source_traversed_in_reverse.push_back(
(packed_alternate_path.front() !=
phantom_node_pair.source_phantom.forward_segment_id.id));
raw_route_data.alt_target_traversed_in_reverse.push_back(
(packed_alternate_path.back() !=
phantom_node_pair.target_phantom.forward_segment_id.id));
// unpack the alternate path
super::UnpackPath(facade,
packed_alternate_path.begin(),
packed_alternate_path.end(),
phantom_node_pair,
raw_route_data.unpacked_alternative);
raw_route_data.alternative_path_length = length_of_via_path;
}
else
{
BOOST_ASSERT(raw_route_data.alternative_path_length == INVALID_EDGE_WEIGHT);
}
}
void AlternativeRouting::RetrievePackedAlternatePath(const QueryHeap &forward_heap1,
const QueryHeap &reverse_heap1,
const QueryHeap &forward_heap2,
const QueryHeap &reverse_heap2,
const NodeID s_v_middle,
const NodeID v_t_middle,
std::vector<NodeID> &packed_path) const
{
// fetch packed path [s,v)
std::vector<NodeID> packed_v_t_path;
super::RetrievePackedPathFromHeap(forward_heap1, reverse_heap2, s_v_middle, packed_path);
packed_path.pop_back(); // remove middle node. It's in both half-paths
// fetch patched path [v,t]
super::RetrievePackedPathFromHeap(forward_heap2, reverse_heap1, v_t_middle, packed_v_t_path);
packed_path.insert(packed_path.end(), packed_v_t_path.begin(), packed_v_t_path.end());
}
// TODO: reorder parameters
// compute and unpack <s,..,v> and <v,..,t> by exploring search spaces
// from v and intersecting against queues. only half-searches have to be
// done at this stage
void AlternativeRouting::ComputeLengthAndSharingOfViaPath(
const std::shared_ptr<const datafacade::BaseDataFacade> facade,
const NodeID via_node,
int *real_length_of_via_path,
int *sharing_of_via_path,
const std::vector<NodeID> &packed_shortest_path,
const EdgeWeight min_edge_offset)
{
engine_working_data.InitializeOrClearSecondThreadLocalStorage(facade->GetNumberOfNodes());
QueryHeap &existing_forward_heap = *engine_working_data.forward_heap_1;
QueryHeap &existing_reverse_heap = *engine_working_data.reverse_heap_1;
QueryHeap &new_forward_heap = *engine_working_data.forward_heap_2;
QueryHeap &new_reverse_heap = *engine_working_data.reverse_heap_2;
std::vector<NodeID> packed_s_v_path;
std::vector<NodeID> packed_v_t_path;
std::vector<NodeID> partially_unpacked_shortest_path;
std::vector<NodeID> partially_unpacked_via_path;
NodeID s_v_middle = SPECIAL_NODEID;
int upper_bound_s_v_path_length = INVALID_EDGE_WEIGHT;
new_reverse_heap.Insert(via_node, 0, via_node);
// compute path <s,..,v> by reusing forward search from s
const bool constexpr STALLING_ENABLED = true;
const bool constexpr DO_NOT_FORCE_LOOPS = false;
while (!new_reverse_heap.Empty())
{
super::RoutingStep(facade,
new_reverse_heap,
existing_forward_heap,
s_v_middle,
upper_bound_s_v_path_length,
min_edge_offset,
false,
STALLING_ENABLED,
DO_NOT_FORCE_LOOPS,
DO_NOT_FORCE_LOOPS);
}
// compute path <v,..,t> by reusing backward search from node t
NodeID v_t_middle = SPECIAL_NODEID;
int upper_bound_of_v_t_path_length = INVALID_EDGE_WEIGHT;
new_forward_heap.Insert(via_node, 0, via_node);
while (!new_forward_heap.Empty())
{
super::RoutingStep(facade,
new_forward_heap,
existing_reverse_heap,
v_t_middle,
upper_bound_of_v_t_path_length,
min_edge_offset,
true,
STALLING_ENABLED,
DO_NOT_FORCE_LOOPS,
DO_NOT_FORCE_LOOPS);
}
*real_length_of_via_path = upper_bound_s_v_path_length + upper_bound_of_v_t_path_length;
if (SPECIAL_NODEID == s_v_middle || SPECIAL_NODEID == v_t_middle)
{
return;
}
// retrieve packed paths
super::RetrievePackedPathFromHeap(
existing_forward_heap, new_reverse_heap, s_v_middle, packed_s_v_path);
super::RetrievePackedPathFromHeap(
new_forward_heap, existing_reverse_heap, v_t_middle, packed_v_t_path);
// partial unpacking, compute sharing
// First partially unpack s-->v until paths deviate, note length of common path.
const auto s_v_min_path_size =
std::min(packed_s_v_path.size(), packed_shortest_path.size()) - 1;
for (const auto current_node : util::irange<std::size_t>(0UL, s_v_min_path_size))
{
if (packed_s_v_path[current_node] == packed_shortest_path[current_node] &&
packed_s_v_path[current_node + 1] == packed_shortest_path[current_node + 1])
{
EdgeID edgeID = facade->FindEdgeInEitherDirection(packed_s_v_path[current_node],
packed_s_v_path[current_node + 1]);
*sharing_of_via_path += facade->GetEdgeData(edgeID).weight;
}
else
{
if (packed_s_v_path[current_node] == packed_shortest_path[current_node])
{
super::UnpackEdge(facade,
packed_s_v_path[current_node],
packed_s_v_path[current_node + 1],
partially_unpacked_via_path);
super::UnpackEdge(facade,
packed_shortest_path[current_node],
packed_shortest_path[current_node + 1],
partially_unpacked_shortest_path);
break;
}
}
}
// traverse partially unpacked edge and note common prefix
const int64_t packed_path_length =
static_cast<int64_t>(
std::min(partially_unpacked_via_path.size(), partially_unpacked_shortest_path.size())) -
1;
for (int64_t current_node = 0; (current_node < packed_path_length) &&
(partially_unpacked_via_path[current_node] ==
partially_unpacked_shortest_path[current_node] &&
partially_unpacked_via_path[current_node + 1] ==
partially_unpacked_shortest_path[current_node + 1]);
++current_node)
{
EdgeID selected_edge =
facade->FindEdgeInEitherDirection(partially_unpacked_via_path[current_node],
partially_unpacked_via_path[current_node + 1]);
*sharing_of_via_path += facade->GetEdgeData(selected_edge).weight;
}
// Second, partially unpack v-->t in reverse order until paths deviate and note lengths
int64_t via_path_index = static_cast<int64_t>(packed_v_t_path.size()) - 1;
int64_t shortest_path_index = static_cast<int64_t>(packed_shortest_path.size()) - 1;
for (; via_path_index > 0 && shortest_path_index > 0; --via_path_index, --shortest_path_index)
{
if (packed_v_t_path[via_path_index - 1] == packed_shortest_path[shortest_path_index - 1] &&
packed_v_t_path[via_path_index] == packed_shortest_path[shortest_path_index])
{
EdgeID edgeID = facade->FindEdgeInEitherDirection(packed_v_t_path[via_path_index - 1],
packed_v_t_path[via_path_index]);
*sharing_of_via_path += facade->GetEdgeData(edgeID).weight;
}
else
{
if (packed_v_t_path[via_path_index] == packed_shortest_path[shortest_path_index])
{
super::UnpackEdge(facade,
packed_v_t_path[via_path_index - 1],
packed_v_t_path[via_path_index],
partially_unpacked_via_path);
super::UnpackEdge(facade,
packed_shortest_path[shortest_path_index - 1],
packed_shortest_path[shortest_path_index],
partially_unpacked_shortest_path);
break;
}
}
}
via_path_index = static_cast<int64_t>(partially_unpacked_via_path.size()) - 1;
shortest_path_index = static_cast<int64_t>(partially_unpacked_shortest_path.size()) - 1;
for (; via_path_index > 0 && shortest_path_index > 0; --via_path_index, --shortest_path_index)
{
if (partially_unpacked_via_path[via_path_index - 1] ==
partially_unpacked_shortest_path[shortest_path_index - 1] &&
partially_unpacked_via_path[via_path_index] ==
partially_unpacked_shortest_path[shortest_path_index])
{
EdgeID edgeID =
facade->FindEdgeInEitherDirection(partially_unpacked_via_path[via_path_index - 1],
partially_unpacked_via_path[via_path_index]);
*sharing_of_via_path += facade->GetEdgeData(edgeID).weight;
}
else
{
break;
}
}
// finished partial unpacking spree! Amount of sharing is stored to appropriate pointer
// variable
}
// conduct T-Test
bool AlternativeRouting::ViaNodeCandidatePassesTTest(
const std::shared_ptr<const datafacade::BaseDataFacade> facade,
QueryHeap &existing_forward_heap,
QueryHeap &existing_reverse_heap,
QueryHeap &new_forward_heap,
QueryHeap &new_reverse_heap,
const RankedCandidateNode &candidate,
const int length_of_shortest_path,
int *length_of_via_path,
NodeID *s_v_middle,
NodeID *v_t_middle,
const EdgeWeight min_edge_offset) const
{
new_forward_heap.Clear();
new_reverse_heap.Clear();
std::vector<NodeID> packed_s_v_path;
std::vector<NodeID> packed_v_t_path;
*s_v_middle = SPECIAL_NODEID;
int upper_bound_s_v_path_length = INVALID_EDGE_WEIGHT;
// compute path <s,..,v> by reusing forward search from s
new_reverse_heap.Insert(candidate.node, 0, candidate.node);
const bool constexpr STALLING_ENABLED = true;
const bool constexpr DO_NOT_FORCE_LOOPS = false;
while (new_reverse_heap.Size() > 0)
{
super::RoutingStep(facade,
new_reverse_heap,
existing_forward_heap,
*s_v_middle,
upper_bound_s_v_path_length,
min_edge_offset,
false,
STALLING_ENABLED,
DO_NOT_FORCE_LOOPS,
DO_NOT_FORCE_LOOPS);
}
if (INVALID_EDGE_WEIGHT == upper_bound_s_v_path_length)
{
return false;
}
// compute path <v,..,t> by reusing backward search from t
*v_t_middle = SPECIAL_NODEID;
int upper_bound_of_v_t_path_length = INVALID_EDGE_WEIGHT;
new_forward_heap.Insert(candidate.node, 0, candidate.node);
while (new_forward_heap.Size() > 0)
{
super::RoutingStep(facade,
new_forward_heap,
existing_reverse_heap,
*v_t_middle,
upper_bound_of_v_t_path_length,
min_edge_offset,
true,
STALLING_ENABLED,
DO_NOT_FORCE_LOOPS,
DO_NOT_FORCE_LOOPS);
}
if (INVALID_EDGE_WEIGHT == upper_bound_of_v_t_path_length)
{
return false;
}
*length_of_via_path = upper_bound_s_v_path_length + upper_bound_of_v_t_path_length;
// retrieve packed paths
super::RetrievePackedPathFromHeap(
existing_forward_heap, new_reverse_heap, *s_v_middle, packed_s_v_path);
super::RetrievePackedPathFromHeap(
new_forward_heap, existing_reverse_heap, *v_t_middle, packed_v_t_path);
NodeID s_P = *s_v_middle, t_P = *v_t_middle;
if (SPECIAL_NODEID == s_P)
{
return false;
}
if (SPECIAL_NODEID == t_P)
{
return false;
}
const int T_threshold = static_cast<int>(VIAPATH_EPSILON * length_of_shortest_path);
EdgeWeight unpacked_until_weight = 0;
std::stack<SearchSpaceEdge> unpack_stack;
// Traverse path s-->v
for (std::size_t i = packed_s_v_path.size() - 1; (i > 0) && unpack_stack.empty(); --i)
{
const EdgeID current_edge_id =
facade->FindEdgeInEitherDirection(packed_s_v_path[i - 1], packed_s_v_path[i]);
const EdgeWeight length_of_current_edge = facade->GetEdgeData(current_edge_id).weight;
if ((length_of_current_edge + unpacked_until_weight) >= T_threshold)
{
unpack_stack.emplace(packed_s_v_path[i - 1], packed_s_v_path[i]);
}
else
{
unpacked_until_weight += length_of_current_edge;
s_P = packed_s_v_path[i - 1];
}
}
while (!unpack_stack.empty())
{
const SearchSpaceEdge via_path_edge = unpack_stack.top();
unpack_stack.pop();
EdgeID edge_in_via_path_id =
facade->FindEdgeInEitherDirection(via_path_edge.first, via_path_edge.second);
if (SPECIAL_EDGEID == edge_in_via_path_id)
{
return false;
}
const EdgeData &current_edge_data = facade->GetEdgeData(edge_in_via_path_id);
const bool current_edge_is_shortcut = current_edge_data.shortcut;
if (current_edge_is_shortcut)
{
const NodeID via_path_middle_node_id = current_edge_data.id;
const EdgeID second_segment_edge_id =
facade->FindEdgeInEitherDirection(via_path_middle_node_id, via_path_edge.second);
const int second_segment_length = facade->GetEdgeData(second_segment_edge_id).weight;
// attention: !unpacking in reverse!
// Check if second segment is the one to go over treshold? if yes add second segment
// to stack, else push first segment to stack and add weight of second one.
if (unpacked_until_weight + second_segment_length >= T_threshold)
{
unpack_stack.emplace(via_path_middle_node_id, via_path_edge.second);
}
else
{
unpacked_until_weight += second_segment_length;
unpack_stack.emplace(via_path_edge.first, via_path_middle_node_id);
}
}
else
{
// edge is not a shortcut, set the start node for T-Test to end of edge.
unpacked_until_weight += current_edge_data.weight;
s_P = via_path_edge.first;
}
}
EdgeWeight t_test_path_length = unpacked_until_weight;
unpacked_until_weight = 0;
// Traverse path s-->v
BOOST_ASSERT(!packed_v_t_path.empty());
for (unsigned i = 0, packed_path_length = static_cast<unsigned>(packed_v_t_path.size() - 1);
(i < packed_path_length) && unpack_stack.empty();
++i)
{
const EdgeID edgeID =
facade->FindEdgeInEitherDirection(packed_v_t_path[i], packed_v_t_path[i + 1]);
int length_of_current_edge = facade->GetEdgeData(edgeID).weight;
if (length_of_current_edge + unpacked_until_weight >= T_threshold)
{
unpack_stack.emplace(packed_v_t_path[i], packed_v_t_path[i + 1]);
}
else
{
unpacked_until_weight += length_of_current_edge;
t_P = packed_v_t_path[i + 1];
}
}
while (!unpack_stack.empty())
{
const SearchSpaceEdge via_path_edge = unpack_stack.top();
unpack_stack.pop();
EdgeID edge_in_via_path_id =
facade->FindEdgeInEitherDirection(via_path_edge.first, via_path_edge.second);
if (SPECIAL_EDGEID == edge_in_via_path_id)
{
return false;
}
const EdgeData &current_edge_data = facade->GetEdgeData(edge_in_via_path_id);
const bool IsViaEdgeShortCut = current_edge_data.shortcut;
if (IsViaEdgeShortCut)
{
const NodeID middleOfViaPath = current_edge_data.id;
EdgeID edgeIDOfFirstSegment =
facade->FindEdgeInEitherDirection(via_path_edge.first, middleOfViaPath);
int lengthOfFirstSegment = facade->GetEdgeData(edgeIDOfFirstSegment).weight;
// Check if first segment is the one to go over treshold? if yes first segment to
// stack, else push second segment to stack and add weight of first one.
if (unpacked_until_weight + lengthOfFirstSegment >= T_threshold)
{
unpack_stack.emplace(via_path_edge.first, middleOfViaPath);
}
else
{
unpacked_until_weight += lengthOfFirstSegment;
unpack_stack.emplace(middleOfViaPath, via_path_edge.second);
}
}
else
{
// edge is not a shortcut, set the start node for T-Test to end of edge.
unpacked_until_weight += current_edge_data.weight;
t_P = via_path_edge.second;
}
}
t_test_path_length += unpacked_until_weight;
// Run actual T-Test query and compare if weight equal.
engine_working_data.InitializeOrClearThirdThreadLocalStorage(facade->GetNumberOfNodes());
QueryHeap &forward_heap3 = *engine_working_data.forward_heap_3;
QueryHeap &reverse_heap3 = *engine_working_data.reverse_heap_3;
EdgeWeight upper_bound = INVALID_EDGE_WEIGHT;
NodeID middle = SPECIAL_NODEID;
forward_heap3.Insert(s_P, 0, s_P);
reverse_heap3.Insert(t_P, 0, t_P);
// exploration from s and t until deletemin/(1+epsilon) > _lengt_oO_sShortest_path
while ((forward_heap3.Size() + reverse_heap3.Size()) > 0)
{
if (!forward_heap3.Empty())
{
super::RoutingStep(facade,
forward_heap3,
reverse_heap3,
middle,
upper_bound,
min_edge_offset,
true,
STALLING_ENABLED,
DO_NOT_FORCE_LOOPS,
DO_NOT_FORCE_LOOPS);
}
if (!reverse_heap3.Empty())
{
super::RoutingStep(facade,
reverse_heap3,
forward_heap3,
middle,
upper_bound,
min_edge_offset,
false,
STALLING_ENABLED,
DO_NOT_FORCE_LOOPS,
DO_NOT_FORCE_LOOPS);
}
}
return (upper_bound <= t_test_path_length);
}
} // namespace routing_algorithms
} // namespace engine
} // namespace osrm}
Reference in New Issue View Git Blame Copy Permalink